From ml_news at posteo.de  Sun Dec  1 03:29:47 2019
From: ml_news at posteo.de (Manfred Lotz)
Date: Sun, 1 Dec 2019 09:29:47 +0100
Subject: "Don't install on the system Python"
References: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
Message-ID: <20191201092947.556bceab@arcor.com>

On Sat, 30 Nov 2019 20:42:21 -0800 (PST)
John Ladasky <john_ladasky at sbcglobal.net> wrote:

> Long-time Ubuntu user here.
> 
> For years, I've read warnings about not installing one's personal
> stack of Python modules on top of the system Python.  It is possible
> to corrupt the OS, or so I've gathered.
> 

This is nonsense as you presumably have no permission to change
anything Python related in /usr.

The only possiblity I can imagine is that you somehow screw up your
personal Python related setting in your home directory tree. But I have
never (in the short period of time I've been using Python) encountered
anything like this.


-- 
Manfred


From cs at cskk.id.au  Sun Dec  1 03:41:37 2019
From: cs at cskk.id.au (Cameron Simpson)
Date: Sun, 1 Dec 2019 19:41:37 +1100
Subject: "Don't install on the system Python"
In-Reply-To: <20191201092947.556bceab@arcor.com>
References: <20191201092947.556bceab@arcor.com>
Message-ID: <20191201084137.GA84892@cskk.homeip.net>

On 01Dec2019 09:29, Manfred Lotz <ml_news at posteo.de> wrote:
>On Sat, 30 Nov 2019 20:42:21 -0800 (PST)
>John Ladasky <john_ladasky at sbcglobal.net> wrote:
>> For years, I've read warnings about not installing one's personal
>> stack of Python modules on top of the system Python.  It is possible
>> to corrupt the OS, or so I've gathered.
>
>This is nonsense as you presumably have no permission to change
>anything Python related in /usr.
>
>The only possiblity I can imagine is that you somehow screw up your
>personal Python related setting in your home directory tree. But I have
>never (in the short period of time I've been using Python) encountered
>anything like this.

What is to be avoided: Some people run pip as root and install in the 
vendor/supplier controlled space.  This can lead to various problems, as 
it can conflict with or simply vary the system installed packages.

Provided the OP is using pip in its (modern default) "install in my home 
directory" mode, they should be fine.

Cheers,
Cameron Simpson <cs at cskk.id.au>

From __peter__ at web.de  Sun Dec  1 04:26:58 2019
From: __peter__ at web.de (Peter Otten)
Date: Sun, 01 Dec 2019 10:26:58 +0100
Subject: ModuleNotFoundError with click module
References: <32cc3ffc-bb43-284f-dfd8-7451ba100ec7@akwebsoft.com>
Message-ID: <qs0114$bnl$1@blaine.gmane.org>

Tim Johnson wrote:

> Using linux ubuntu 16.04 with bash shell.
> Am retired python programmer, but not terribly current.
> I have moderate bash experience.
> 
> When trying to install pgadmin4 via apt I get the following error
> traceback when pgadmin4 is invoked:
> 
> Traceback (most recent call last):
>  File "setup.py", line 17, in <module>
>  from pgadmin.model import db, User, Version, ServerGroup, Server, \
>  File "/usr/share/pgadmin4/web/pgadmin/__init__.py", line 19, in <module>
>  from flask import Flask, abort, request, current_app, session, url_for
>  File "/usr/local/lib/python3.7/site-packages/flask/__init__.py", line
> 21, in <module>
>  from .app import Flask
>  File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 34,
> in <module>
>  from . import cli
> File "/usr/local/lib/python3.7/site-packages/flask/cli.py", line 25, in
> <module>
> import click
> ModuleNotFoundError: No module named 'click'
> 
> 
> If I invoke python3 (/usr/local/bin/python3), version 3.7.2 and invoke
>  >>> import click
> click is imported successfully.
> 
> In this invocation, sys.path is:
> ['', '/usr/local/lib/python37.zip', '/usr/local/lib/python3.7',
> '/usr/local/lib/python3.7/lib-dynload',
> '/home/tim/.local/lib/python3.7/site-packages',
> '/usr/local/lib/python3.7/site-packages']
> 
> $PYTHONPATH is empty when the bash shell is invoked
> 
> $PATH as follows:
> 
/home/tim/bin:/home/tim/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
> 
> click.py can be found at
> /usr/local/lib/python3.7/site-packages/pipenv/patched/piptools/
> in turn click.py imports click, presumably as the package,
> which appears to be at
> /usr/local/lib/python3.7/site-packages/pipenv/vendor/click
> 
> Any number of settings of PYTHONPATH to the various paths above has
> failed to resolve the ModuleNotFoundError
> Same issues with attempting install from a virtual environment.
> 
> Any help will be appreciated.
> thanks
> tim
> 

I'm too lazy to look into the details of your paths -- I'd just make sure 
that click is installed with the same interpreter and user as pgadmin4, e. 
g. globally

$ sudo /usr/local/bin/python3 -m pip install click
$ sudo /usr/local/bin/python3 path/to/setup.py install  # or whatever it 
takes to install pgadmin4

or (better) in a virtual environment

$ /usr/local/bin/python3 -m venv whatever
$ cd whatever
$ . bin/activate
$ pip install click
$ python path/to/setup.py



From john_ladasky at sbcglobal.net  Sun Dec  1 04:33:50 2019
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Sun, 1 Dec 2019 01:33:50 -0800 (PST)
Subject: "Don't install on the system Python"
In-Reply-To: <mailman.266.1575190048.25794.python-list@python.org>
References: <20191201092947.556bceab@arcor.com>
 <20191201084137.GA84892@cskk.homeip.net>
 <mailman.266.1575190048.25794.python-list@python.org>
Message-ID: <cb7fe294-8f77-40d7-9cea-d73215cb58b2@googlegroups.com>

On Sunday, December 1, 2019 at 12:47:43 AM UTC-8, Cameron Simpson wrote:
> On 01Dec2019 09:29, Manfred Lotz <... at posteo.de> wrote:
> >On Sat, 30 Nov 2019 20:42:21 -0800 (PST)
> >John Ladasky <... at sbcglobal.net> wrote:
> >> For years, I've read warnings about not installing one's personal
> >> stack of Python modules on top of the system Python.  It is possible
> >> to corrupt the OS, or so I've gathered.
> >
> >This is nonsense as you presumably have no permission to change
> >anything Python related in /usr.
> >
> >The only possiblity I can imagine is that you somehow screw up your
> >personal Python related setting in your home directory tree. But I have
> >never (in the short period of time I've been using Python) encountered
> >anything like this.
> 
> What is to be avoided: Some people run pip as root and install in the 
> vendor/supplier controlled space.  This can lead to various problems, as 
> it can conflict with or simply vary the system installed packages.
> 
> Provided the OP is using pip in its (modern default) "install in my home 
> directory" mode, they should be fine.
> 
> Cheers,
> Cameron Simpson <... at cskk.id.au>

The only thing I must install with pip is tensorflow-gpu.  For everything else, I make use of the Ubuntu repositories.  The Synaptic package manager installs packages (including Python modules) for all user accounts at the same time, which I like.

When I installed tensorflow-gpu using pip, I was in fact frustrated because I couldn't figure out how to deploy it across multiple user accounts at one time.  I ended up installing it three times, once in each account.  You're suggesting that's actually preferred, at least when pip is performing the installation.  OK, I will endure the repetition.

From musbur at posteo.org  Sun Dec  1 06:24:11 2019
From: musbur at posteo.org (musbur at posteo.org)
Date: Sun, 1 Dec 2019 12:24:11 +0100
Subject: "Don't install on the system Python"
In-Reply-To: <cb7fe294-8f77-40d7-9cea-d73215cb58b2@googlegroups.com>
References: <20191201092947.556bceab@arcor.com>
 <20191201084137.GA84892@cskk.homeip.net>
 <mailman.266.1575190048.25794.python-list@python.org>
 <cb7fe294-8f77-40d7-9cea-d73215cb58b2@googlegroups.com>
Message-ID: <20191201122411.3d01a97c@nxp10225>

On Sun, 1 Dec 2019 01:33:50 -0800 (PST)
John Ladasky <john_ladasky at sbcglobal.net> wrote:

> The only thing I must install with pip is tensorflow-gpu.  For
> everything else, I make use of the Ubuntu repositories.  The Synaptic
> package manager installs packages (including Python modules) for all
> user accounts at the same time, which I like.
> 
> When I installed tensorflow-gpu using pip, I was in fact frustrated
> because I couldn't figure out how to deploy it across multiple user
> accounts at one time.  I ended up installing it three times, once in
> each account.  You're suggesting that's actually preferred, at least
> when pip is performing the installation.  OK, I will endure the
> repetition.

You can set up a system-wide virtualenv (for instance
in /usr/local/lib/myenv) and use pip install as root to set up
everything into that. All the normal users have to do then is
prepend /usr/local/lib/myenv/bin to their PATH. After that, you have a
system-wide consistent distribution of all your needed Python packages.
You can then uninstall all python packages provided by the Linux
distro which you don't need.

At the moment it seems as if all you need to install locally with pip
is tensorflow-gpu. This will change once some future version of
tensorflow-gpu depends on newer versions of the system-provided
packges. When that happens, pip will pull all those packages into the
user's local venv, and it will have to do that individually for each
user.

BTW, it took me a long time to embrace Python's "virtualenv" concept
because I had a hard time figuring out what it was and how it worked.
Turns out that there is no magic involved, and that "virtual
environment" is a misnomer. It is simply a full Python environment in a
separate location on your system. Nothing virtual about it.

From chema at rinzewind.org  Sun Dec  1 09:39:56 2019
From: chema at rinzewind.org (=?iso-8859-1?Q?Jos=E9_Mar=EDa?= Mateos)
Date: Sun, 1 Dec 2019 09:39:56 -0500
Subject: Pickle caching objects?
In-Reply-To: <CAPTjJmp99sfRd-_OdDOZVqcnXSYMwt0onmp3scJG1r1Z0NOyQw@mail.gmail.com>
References: <20191130220545.GA12875@equipaje>
 <CAPTjJmp99sfRd-_OdDOZVqcnXSYMwt0onmp3scJG1r1Z0NOyQw@mail.gmail.com>
Message-ID: <20191201143956.GB3751@equipaje>

On Sun, Dec 01, 2019 at 12:26:15PM +1100, Chris Angelico wrote:
>I can't answer your question authoritatively, but I can suggest a
>place to look. Python's memory allocator doesn't always return memory
>to the system when the objects are freed up, for various reasons
>including the way that memory pages get allocated from. But it
>internally knows which parts are in use and which parts aren't. You're
>seeing the RSS go down slightly at some points, which would be the
>times when entire pages can be released; but other than that, what
>you'll end up with is a sort of high-water-mark with lots of unused
>space inside it.
>
>So what you're seeing isn't actual objects being cached, but just
>memory ready to be populated with future objects.

Thank you and Richard for your responses, this makes perfect sense now.

Cheers,

-- 
Jos? Mar?a (Chema) Mateos || https://rinzewind.org/

From torriem at gmail.com  Sun Dec  1 10:41:01 2019
From: torriem at gmail.com (Michael Torrie)
Date: Sun, 1 Dec 2019 08:41:01 -0700
Subject: "Don't install on the system Python"
In-Reply-To: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
References: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
Message-ID: <6519290e-942a-340d-1eac-ee9f5a2c858f@gmail.com>

On 11/30/19 9:42 PM, John Ladasky wrote:
> Can anyone provide concrete examples of problems arising from
> installing modules on top of the system Python?  Am I courting
> disaster?

No you aren't.  I've also never had any problems. I've installed many
things into my root system Python installation with pip including PyQt5.
 It's just easier for me to have them in the system installation.  I'm
on a CentOS 7 box, which depends on Python 2 for a lot of system
functions. I've moved to Python 3 now, so I mess with the system Python
less and less.  I understand that I probably should be using a
virtualenv and pip installing into that, but I'm just too lazy.

A couple of years ago I even managed to upgrade the system Python from
2.6 to 2.7 without any issues. I ended up making an RPM that neatly
upgraded the system one.  I also have upgraded the gtk2 bindings and the
GTK2 library itself (again building RPMs), and everything worked fine,
even the graphical centos utilities.

The only problems I've ever heard of come from trying to manually remove
stuff from Python that the system depended on.  I've never heard of any
problems installing additional modules.  90% of the time the module you
need will be in the repositories, so no worries there at all. And not
much to worry about for the rest.

From tim at akwebsoft.com  Sun Dec  1 11:27:26 2019
From: tim at akwebsoft.com (Tim Johnson)
Date: Sun, 1 Dec 2019 07:27:26 -0900
Subject: ModuleNotFoundError with click module
In-Reply-To: <qs0114$bnl$1@blaine.gmane.org>
References: <32cc3ffc-bb43-284f-dfd8-7451ba100ec7@akwebsoft.com>
 <qs0114$bnl$1@blaine.gmane.org>
Message-ID: <a0c12917-a0fc-b6ee-e201-d121d8468861@akwebsoft.com>


On 12/1/19 12:26 AM, Peter Otten wrote:
> Tim Johnson wrote:
>
>> Using linux ubuntu 16.04 with bash shell.
>> Am retired python programmer, but not terribly current.
>> I have moderate bash experience.
>>
>> When trying to install pgadmin4 via apt I get the following error
>> traceback when pgadmin4 is invoked:
>>
>> Traceback (most recent call last):
snipped ...
>> File "/usr/local/lib/python3.7/site-packages/flask/cli.py", line 25, in
>> <module>
>> import click
>> ModuleNotFoundError: No module named 'click'
>>
>>
>> If I invoke python3 (/usr/local/bin/python3), version 3.7.2 and invoke
>>   >>> import click
>> click is imported successfully.
> ...
> I'm too lazy to look into the details of your paths -- I'd just make sure
> that click is installed with the same interpreter and user as pgadmin4, e.
> g. globally
>
> $ sudo /usr/local/bin/python3 -m pip install click
> $ sudo /usr/local/bin/python3 path/to/setup.py install  # or whatever it
> takes to install pgadmin4
Like I said, I'm not current. Yikes. Now I have 
/usr/local/lib/python3.7/site-packages/clic-0.1.3.dist-info/

After I have my coffee I will attempt to proceed from there with 
whatever it takes to finalize

thanks

-- 
Tim
tj49.com


From rmlibre at riseup.net  Sun Dec  1 13:10:20 2019
From: rmlibre at riseup.net (rmlibre at riseup.net)
Date: Sun, 01 Dec 2019 10:10:20 -0800
Subject: tab replace to space 4 (rmlibre)
In-Reply-To: <mailman.32.1575133202.25946.python-list@python.org>
References: <mailman.32.1575133202.25946.python-list@python.org>
Message-ID: <761066994586319cea87cbd542adeeec@riseup.net>

> Its just that I've just began to touch tkinter, and would like to know of
> bug-related pitfalls before I waste energy on trying to figure out what I
> did wrong. :-\

One thing which is not obvious or easy to debug: Text widgets have some
kind of 
inefficiency related to really long lines that don't have line breaks.
The 
result is that your cpu will be completely gobbled up if you have a
sufficiently
long line. I haven't run any tests to get an accurate view of what the
breaking 
point is. But one the cores in my cpu was hold up at 100% when
displaying 
many many thousands of characters without line breaks. After lots of
debugging
and optimization finding, I just happened to google for "cpu load issue
with" 
each of the widgets I was using and discovered that this indeed was the
cause
of the cpu load. Swapping in line breaks at regular, known intervals
quickly
fixed this.

tl;dr
Google for "issue with tkinter <widget>" for the widgets you'll be
using, or 
"<issue> with tkinter" if you're experiencing a particular issue and are
not 
sure if it could be caused for some reason by tkinter.


From Richard at Damon-Family.org  Sun Dec  1 13:35:31 2019
From: Richard at Damon-Family.org (Richard Damon)
Date: Sun, 1 Dec 2019 13:35:31 -0500
Subject: "Don't install on the system Python"
In-Reply-To: <6519290e-942a-340d-1eac-ee9f5a2c858f@gmail.com>
References: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
 <6519290e-942a-340d-1eac-ee9f5a2c858f@gmail.com>
Message-ID: <7fa2eec8-b5f7-45bf-79d0-4c4cb624e1a9@Damon-Family.org>

On 12/1/19 10:41 AM, Michael Torrie wrote:
> On 11/30/19 9:42 PM, John Ladasky wrote:
>> Can anyone provide concrete examples of problems arising from
>> installing modules on top of the system Python?  Am I courting
>> disaster?
> No you aren't.  I've also never had any problems. I've installed many
> things into my root system Python installation with pip including PyQt5.
>  It's just easier for me to have them in the system installation.  I'm
> on a CentOS 7 box, which depends on Python 2 for a lot of system
> functions. I've moved to Python 3 now, so I mess with the system Python
> less and less.  I understand that I probably should be using a
> virtualenv and pip installing into that, but I'm just too lazy.
>
> A couple of years ago I even managed to upgrade the system Python from
> 2.6 to 2.7 without any issues. I ended up making an RPM that neatly
> upgraded the system one.  I also have upgraded the gtk2 bindings and the
> GTK2 library itself (again building RPMs), and everything worked fine,
> even the graphical centos utilities.
>
> The only problems I've ever heard of come from trying to manually remove
> stuff from Python that the system depended on.  I've never heard of any
> problems installing additional modules.  90% of the time the module you
> need will be in the repositories, so no worries there at all. And not
> much to worry about for the rest.

My guess is that the issue is with some more complicated/esoteric
packages. Especially if there are ones that don't maintain strict
backwards compatibility, so that some packages using them have a maximum
usable version as well as a minimum usable version. This can lead to
troubles as some packages become incompatible because one needs a
version greater than x, while another needs a version less than x.

-- 
Richard Damon


From rosuav at gmail.com  Sun Dec  1 13:44:10 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 2 Dec 2019 05:44:10 +1100
Subject: "Don't install on the system Python"
In-Reply-To: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
References: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
Message-ID: <CAPTjJmq+ss3gY1u8FrwCSYOG3LzUgT5K-oS0aKsycPXVj6TJSQ@mail.gmail.com>

On Sun, Dec 1, 2019 at 3:46 PM John Ladasky <john_ladasky at sbcglobal.net> wrote:
>
> Long-time Ubuntu user here.
>
> For years, I've read warnings about not installing one's personal stack of Python modules on top of the system Python.  It is possible to corrupt the OS, or so I've gathered.
>
> Can anyone provide concrete examples of problems arising from installing modules on top of the system Python?  Am I courting disaster?
>

I'm going to start by separating out two concepts that are often, but
not always, the same.

The "system Python" is the one that the OS depends on. On my Debian
Stretch, that's /usr/bin/python3 (symlink to /usr/bin/python3.5). On
older systems, that might be a Python 2.7 (or worse). This is the
installation of Python that is managed by your OS package manager, and
- more importantly - is the one that any OS-provided scripts will
depend on.

The "default Python" is the one you get when you type "python3" at the
shell. Often this is the same as the system Python, but there's no
requirement for this to be the case. On many of my systems, I compile
and install a new build of Python periodically (usually from the
master branch, so it's a pre-alpha), and I'm happy for that to take
over the name "python3". Currently, on my main system (the
aforementioned Debian Stretch), that's /usr/local/bin/python3 (a
symlink to /usr/local/bin/python3.9).

Since the system Python is managed by your OS package manager, you
need to be careful about using pip to install packages into it. For
instance, if I were to "/usr/bin/python3 -m pip install psycopg2", it
would potentially conflict with "sudo apt install python3-psycopg2".
You MAY be safe using pip to install something that isn't available in
your package manager, but it's possible to run into dependency
versioning conflicts. Be careful.

But installing into your default Python, if it's not the system
Python, is absolutely safe. Or rather, if it breaks anything, then
it's not your fault - it's the fault of something depending on the
system Python but not using an absolute shebang :)

ChrisA

From tim at akwebsoft.com  Sun Dec  1 19:41:28 2019
From: tim at akwebsoft.com (Tim Johnson)
Date: Sun, 1 Dec 2019 15:41:28 -0900
Subject: ModuleNotFoundError with click module
In-Reply-To: <qs0114$bnl$1@blaine.gmane.org>
References: <32cc3ffc-bb43-284f-dfd8-7451ba100ec7@akwebsoft.com>
 <qs0114$bnl$1@blaine.gmane.org>
Message-ID: <49e16310-3ef8-acf2-9583-6843a81f1bd6@akwebsoft.com>


On 12/1/19 12:26 AM, Peter Otten wrote:
> Tim Johnson wrote:
>
>> Using linux ubuntu 16.04 with bash shell.
>> Am retired python programmer, but not terribly current.
>> I have moderate bash experience.
>>
>> When trying to install pgadmin4 via apt I get the following error
>> traceback when pgadmin4 is invoked:
>>
>> Traceback (most recent call last):
>>   File "setup.py", line 17, in <module>
>>   from pgadmin.model import db, User, Version, ServerGroup, Server, \
>>   File "/usr/share/pgadmin4/web/pgadmin/__init__.py", line 19, in <module>
>>   from flask import Flask, abort, request, current_app, session, url_for
>>   File "/usr/local/lib/python3.7/site-packages/flask/__init__.py", line
>> 21, in <module>
>>   from .app import Flask
>>   File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 34,
>> in <module>
>>   from . import cli
>> File "/usr/local/lib/python3.7/site-packages/flask/cli.py", line 25, in
>> <module>
>> import click
>> ModuleNotFoundError: No module named 'click'
>>
>>
>> If I invoke python3 (/usr/local/bin/python3), version 3.7.2 and invoke
>>   >>> import click
>> click is imported successfully.
>>
>> In this invocation, sys.path is:
>> ['', '/usr/local/lib/python37.zip', '/usr/local/lib/python3.7',
>> '/usr/local/lib/python3.7/lib-dynload',
>> '/home/tim/.local/lib/python3.7/site-packages',
>> '/usr/local/lib/python3.7/site-packages']
>>
>> $PYTHONPATH is empty when the bash shell is invoked
>>
>> $PATH as follows:
>>
> /home/tim/bin:/home/tim/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
>> click.py can be found at
>> /usr/local/lib/python3.7/site-packages/pipenv/patched/piptools/
>> in turn click.py imports click, presumably as the package,
>> which appears to be at
>> /usr/local/lib/python3.7/site-packages/pipenv/vendor/click
>>
>> Any number of settings of PYTHONPATH to the various paths above has
>> failed to resolve the ModuleNotFoundError
>> Same issues with attempting install from a virtual environment.
>>
>> Any help will be appreciated.
>> thanks
>> tim
>>
> I'm too lazy to look into the details of your paths -- I'd just make sure
> that click is installed with the same interpreter and user as pgadmin4, e.
> g. globally
>
> $ sudo /usr/local/bin/python3 -m pip install click
> $ sudo /usr/local/bin/python3 path/to/setup.py install  # or whatever it
> takes to install pgadmin4

OK. Now I have

/usr/local/lib/python3.7/site-packages/Click-7.0.dist-info/

which holds the following files:

INSTALLER? LICENSE.txt? METADATA? RECORD? top_level.txt? WHEEL

I haven't a clue as to how to proceed! Never seen this before ...

Furthermore, google is offering me nothing conclusive.

Where to go from here!


-- 
Tim
tj49.com


From tim at akwebsoft.com  Sun Dec  1 20:19:45 2019
From: tim at akwebsoft.com (Tim Johnson)
Date: Sun, 1 Dec 2019 16:19:45 -0900
Subject: ModuleNotFoundError with click module
In-Reply-To: <49e16310-3ef8-acf2-9583-6843a81f1bd6@akwebsoft.com>
References: <32cc3ffc-bb43-284f-dfd8-7451ba100ec7@akwebsoft.com>
 <qs0114$bnl$1@blaine.gmane.org>
 <49e16310-3ef8-acf2-9583-6843a81f1bd6@akwebsoft.com>
Message-ID: <510be00b-d87c-8054-cb5d-efb9179bd43b@akwebsoft.com>


On 12/1/19 3:41 PM, Tim Johnson wrote:
>
> On 12/1/19 12:26 AM, Peter Otten wrote:
>> Tim Johnson wrote:
>>
>>> Using linux ubuntu 16.04 with bash shell.
>>> Am retired python programmer, but not terribly current.
>>> I have moderate bash experience.
>>>
>>> When trying to install pgadmin4 via apt I get the following error
>>> traceback when pgadmin4 is invoked:
>>>
>>> Traceback (most recent call last):
>>> ? File "setup.py", line 17, in <module>
>>> ? from pgadmin.model import db, User, Version, ServerGroup, Server, \
>>> ? File "/usr/share/pgadmin4/web/pgadmin/__init__.py", line 19, in 
>>> <module>
>>> ? from flask import Flask, abort, request, current_app, session, 
>>> url_for
>>> ? File "/usr/local/lib/python3.7/site-packages/flask/__init__.py", line
>>> 21, in <module>
>>> ? from .app import Flask
>>> ? File "/usr/local/lib/python3.7/site-packages/flask/app.py", line 34,
>>> in <module>
>>> ? from . import cli
>>> File "/usr/local/lib/python3.7/site-packages/flask/cli.py", line 25, in
>>> <module>
>>> import click
>>> ModuleNotFoundError: No module named 'click'
>>>
>>>
>>> If I invoke python3 (/usr/local/bin/python3), version 3.7.2 and invoke
>>> ? >>> import click
>>> click is imported successfully.
>>>
>>> In this invocation, sys.path is:
>>> ['', '/usr/local/lib/python37.zip', '/usr/local/lib/python3.7',
>>> '/usr/local/lib/python3.7/lib-dynload',
>>> '/home/tim/.local/lib/python3.7/site-packages',
>>> '/usr/local/lib/python3.7/site-packages']
>>>
>>> $PYTHONPATH is empty when the bash shell is invoked
>>>
>>> $PATH as follows:
>>>
>> /home/tim/bin:/home/tim/.local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin 
>>
>>> click.py can be found at
>>> /usr/local/lib/python3.7/site-packages/pipenv/patched/piptools/
>>> in turn click.py imports click, presumably as the package,
>>> which appears to be at
>>> /usr/local/lib/python3.7/site-packages/pipenv/vendor/click
>>>
>>> Any number of settings of PYTHONPATH to the various paths above has
>>> failed to resolve the ModuleNotFoundError
>>> Same issues with attempting install from a virtual environment.
>>>
>>> Any help will be appreciated.
>>> thanks
>>> tim
>>>
>> I'm too lazy to look into the details of your paths -- I'd just make 
>> sure
>> that click is installed with the same interpreter and user as 
>> pgadmin4, e.
>> g. globally
>>
>> $ sudo /usr/local/bin/python3 -m pip install click
>> $ sudo /usr/local/bin/python3 path/to/setup.py install? # or whatever it
>> takes to install pgadmin4
>
> OK. Now I have
>
> /usr/local/lib/python3.7/site-packages/Click-7.0.dist-info/
>
> which holds the following files:
>
> INSTALLER? LICENSE.txt? METADATA? RECORD? top_level.txt? WHEEL
>
> I haven't a clue as to how to proceed! Never seen this before ...
>
> Furthermore, google is offering me nothing conclusive.
>
> Where to go from here!

P.S. It looks like that directory is sort of a stub; regardless of my 
take on it I am no longer having the ModuleNotFoundError.

Peter has a been a great help. Couldn't have done it without him.

cheers

-- 
Tim
tj49.com


From python.list at tim.thechases.com  Sun Dec  1 21:50:16 2019
From: python.list at tim.thechases.com (Tim Chase)
Date: Sun, 1 Dec 2019 20:50:16 -0600
Subject: increasing the page size of a dbm store?
In-Reply-To: <0EAFC9E0-02D2-4745-99B7-654B7A445EDD@barrys-emacs.org>
References: <20191126192432.535ee241@bigbox.attlocal.net>
 <0EAFC9E0-02D2-4745-99B7-654B7A445EDD@barrys-emacs.org>
Message-ID: <20191201205016.577673f9@bigbox.attlocal.net>

> Maybe port to SQLite? I would not choose dbm these days.

After sparring with it a while, I tweaked the existing job so that it
chunked things into dbm-appropriate sizes to limp through; for the
subsequent job (where I would have used dbm again) I went ahead and
switched to sqlite and had no further issues.

I'm not sure if it's worth mentioning the issue in the docs for the
dbm module so others don't bump against it.  I'm not sure if the
limit is on sum(size(key) for key in db) or the number of keys total.
Just not the sort of thing I'd want someone to be depending on,
unaware of the potential pitfalls.

Thanks,

-tkc




From niktnobodynikt at gmail.com  Mon Dec  2 02:52:44 2019
From: niktnobodynikt at gmail.com (niktnobodynikt at gmail.com)
Date: Sun, 1 Dec 2019 23:52:44 -0800 (PST)
Subject: "Don't install on the system Python"
In-Reply-To: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
References: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
Message-ID: <f68f1d0a-0120-4afa-9e6f-8a1192dcb166@googlegroups.com>

W dniu niedziela, 1 grudnia 2019 05:42:35 UTC+1 u?ytkownik John Ladasky napisa?:

> For years, I've read warnings about not installing one's personal stack of Python modules on top of the system Python.  It is possible to corrupt the OS, or so I've gathered.
> 
> Well, I've never heeded this advice, and so far nothing bad has happened to me.  I don't like Anaconda, or virtual environments in general.  I don't like heavyweight IDE's.  I like to be able to type "python3" at the command prompt and be sure what I'll be getting.  I have multiple user accounts on a system that I manage, and I want every user account to have access to the same modules.
> 
> Maybe the modules that I require are safe to install on the system Python, I'm not sure.  My must-haves are mostly scientific computing and data management modules: Numpy, Scipy, Scikit-learn, Matplotlib, Pandas, Biopython, and Tensorflow.  I also use PyQt5 from time to time.
> 
> Can anyone provide concrete examples of problems arising from installing modules on top of the system Python?  Am I courting disaster?


I did not heard of such problems. But I have another warning. Ubuntu 18.4 uses Python 3.6. Do not try to install 3.7 or 3.8 as systemwide python3 version. It breaks some programs including standard terminal.

From rosuav at gmail.com  Mon Dec  2 03:15:58 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 2 Dec 2019 19:15:58 +1100
Subject: "Don't install on the system Python"
In-Reply-To: <f68f1d0a-0120-4afa-9e6f-8a1192dcb166@googlegroups.com>
References: <0a065288-f851-4afc-9104-f5b5ca5188f9@googlegroups.com>
 <f68f1d0a-0120-4afa-9e6f-8a1192dcb166@googlegroups.com>
Message-ID: <CAPTjJmqTWd9h6pYN=KctBt-=6Y2RrvA1UxaDSdEfXRvpmPw5Pg@mail.gmail.com>

On Mon, Dec 2, 2019 at 6:56 PM <niktnobodynikt at gmail.com> wrote:
>
> W dniu niedziela, 1 grudnia 2019 05:42:35 UTC+1 u?ytkownik John Ladasky napisa?:
>
> > For years, I've read warnings about not installing one's personal stack of Python modules on top of the system Python.  It is possible to corrupt the OS, or so I've gathered.
> >
> > Well, I've never heeded this advice, and so far nothing bad has happened to me.  I don't like Anaconda, or virtual environments in general.  I don't like heavyweight IDE's.  I like to be able to type "python3" at the command prompt and be sure what I'll be getting.  I have multiple user accounts on a system that I manage, and I want every user account to have access to the same modules.
> >
> > Maybe the modules that I require are safe to install on the system Python, I'm not sure.  My must-haves are mostly scientific computing and data management modules: Numpy, Scipy, Scikit-learn, Matplotlib, Pandas, Biopython, and Tensorflow.  I also use PyQt5 from time to time.
> >
> > Can anyone provide concrete examples of problems arising from installing modules on top of the system Python?  Am I courting disaster?
>
>
> I did not heard of such problems. But I have another warning. Ubuntu 18.4 uses Python 3.6. Do not try to install 3.7 or 3.8 as systemwide python3 version. It breaks some programs including standard terminal.
>

And that's where the distinction between "system Python" and "default
Python" comes in. You are absolutely right that you shouldn't replace
the *system* Python. However, changing what the command "python3" runs
is safe.

ChrisA

From __peter__ at web.de  Mon Dec  2 03:46:37 2019
From: __peter__ at web.de (Peter Otten)
Date: Mon, 02 Dec 2019 09:46:37 +0100
Subject: ModuleNotFoundError with click module
References: <32cc3ffc-bb43-284f-dfd8-7451ba100ec7@akwebsoft.com>
 <qs0114$bnl$1@blaine.gmane.org>
 <49e16310-3ef8-acf2-9583-6843a81f1bd6@akwebsoft.com>
 <510be00b-d87c-8054-cb5d-efb9179bd43b@akwebsoft.com>
Message-ID: <qs2j1d$5e6g$1@blaine.gmane.org>

Tim Johnson wrote:

>> OK. Now I have
>>
>> /usr/local/lib/python3.7/site-packages/Click-7.0.dist-info/
>>
>> which holds the following files:
>>
>> INSTALLER  LICENSE.txt  METADATA  RECORD  top_level.txt  WHEEL
>>
>> I haven't a clue as to how to proceed! Never seen this before ...

Just leave it alone ;)

>> Furthermore, google is offering me nothing conclusive.
>>
>> Where to go from here!
> 
> P.S. It looks like that directory is sort of a stub; regardless of my
> take on it I am no longer having the ModuleNotFoundError.

Once you can import it you can find the actual module or package with

$ /usr/bin/python3.7 -c 'import click; print(click.__file__)'

In this case it's a package, so you'll probably see (something like)

/usr/local/lib/python3.7/site-packages/click/__init__.py

rather than

/usr/local/lib/python3.7/site-packages/click.py
/usr/local/lib/python3.7/site-packages/


From soyeomul at doraji.xyz  Mon Dec  2 03:58:42 2019
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Mon, 02 Dec 2019 17:58:42 +0900
Subject: tab replace to space 4
References: <yw87a8i0vu.fsf@delta.birch.chromebook>
 <DqxEF.113374$1S4.110719@fx10.am4>
Message-ID: <yw874ci91cvu.fsf@delta.birch.chromebook>

Hi, Gilmeh^^^

> We are Python people, aren't we?

Looks good, i did copy it [1], and thanks^^^

[1] https://gitlab.com/soyeomul/test/blob/master/untabify.py

Sincerely,

-- 
^????? _????_ ?????_^))//

From aishan0403 at gmail.com  Mon Dec  2 10:40:41 2019
From: aishan0403 at gmail.com (A S)
Date: Mon, 2 Dec 2019 07:40:41 -0800 (PST)
Subject: Extract sentences in nested parentheses using Python
Message-ID: <7a365fa0-e721-4a95-8c30-d3661301a7b2@googlegroups.com>

I am trying to extract all strings in nested parentheses (along with the parentheses itself) in my .txt file. Please see the sample .txt file that I have used in this example here: (https://drive.google.com/open?id=1UKc0ZgY9Fsz5O1rSeBCLqt5dwZkMaQgr).

I have tried and done up three different codes but none of them seems to be able to extract all the nested parentheses. They can only extract a portion of the nested parentheses. Any advice on what I've done wrong could really help!

Here are the three codes I have done so far:

1st attempt:

import re
from os.path import join

def balanced_braces(args):
    parts = []
    for arg in args:
        if '(' not in arg:
            continue
        chars = []
        n = 0
        for c in arg:
            if c == '(':
                if n > 0:
                    chars.append(c)
                n += 1
            elif c == ')':
                n -= 1
                if n > 0:
                    chars.append(c)
                elif n == 0:
                    parts.append(''.join(chars).lstrip().rstrip())
                    chars = []
            elif n > 0:
                chars.append(c)
    return parts

with open('lan sample text file.txt','r') as fd:
    #for words in fd.readlines():       
    t1 = balanced_braces(fd);
    print(t1)


Output:

['"xE\'", PUT(xx.xxxx.),"\'"', '"TRUuuuth"', "xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv.", '"xE\'", PUT(xx.xxxx.),"\'"', '"CUuuiiiiuth"', "xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv."]



2nd attempt:

from pyparsing import nestedExpr

matchedParens = nestedExpr('(',')')
with open('lan sample text file.txt','r') as fd:
    for words in fd.readlines():
        for e in matchedParens.searchString(words):
            print(e)


Output:

[['"xE\'"', ',', 'PUT', ['xx.xxxx.'], ',', '"\'"']]
[['"TRUuuuth"']]
[['xxx', ['xx_ix', 'as', 'format', "'xxxx-xx'"], 'gff', '&jfjfsj_jfjfj.']]
[['xxx', ['xx_ix', 'as', 'format', "'xxxx-xx'"], 'lec', '&jgjsd_vnv.']]
[['"xE\'"', ',', 'PUT', ['xx.xxxx.'], ',', '"\'"']]
[['"CUuuiiiiuth"']]
[['xxx', ['xx_ix', 'as', 'format', "'xxxx-xx'"], 'gff', '&jfjfsj_jfjfj.']]
[['xxx', ['xx_ix', 'as', 'format', "'xxxx-xx'"], 'lec', '&jgjsd_vnv.']]



3rd attempt:

def parse_segments(source, recurse=False):

    unmatched_count = 0
    start_pos = 0
    opened = False
    open_pos = 0
    cur_pos = 0

    finished = []
    segments = []

    for character in source:
        #scan for mismatched parenthesis:
        if character == '(':
            unmatched_count += 1
            if not opened:
                open_pos = cur_pos
            opened = True

        if character == ')':
            unmatched_count -= 1

        if opened and unmatched_count == 0:
            segment = source[open_pos:cur_pos+1]
            segments.append(segment)
            clean = source[start_pos:open_pos]
            if clean:
                finished.append(clean)
            opened = False
            start_pos = cur_pos+1

        cur_pos += 1

   # assert unmatched_count == 0

    if start_pos != cur_pos:
        #get anything that was left over here
        finished.append(source[start_pos:cur_pos])

    #now check on recursion:
    for item in segments:
        #get rid of bounding parentheses:
        pruned = item[1:-1]
        if recurse:
            results = parse_tags(pruned, recurse)
            finished.expand(results)
        else:
            finished.append(pruned)

    return finished

with open('lan sample text file.txt','r') as fd:
    for words in fd.readlines():
        t = parse_segments(words)
        print(t)


Output:

['kkkkk;\n']
['\n']
['  select xx', ' jdfjhf:jhfjj from xxxx_x_xx_L ;\n', '"xE\'", PUT(xx.xxxx.),"\'"']
['quit; \n']
['\n']
['/* 1.xxxxx FROM xxxx_x_Ex_x */ \n']
['proc sql; ', ';\n', '"TRUuuuth"']
['hhhjhfjs as fdsjfsj:\n']
['select * from djfkjd to jfkjs\n']
['(\n']
['SELECT abc AS abc1, abc_2_ AS efg, abc_fg, fkdkfj_vv, jjsflkl_ff, fjkdsf_jfkj\n']
['\tFROM &xxx..xxx_xxx_xxE\n']
["where ((xxx(xx_ix as format 'xxxx-xx') gff &jfjfsj_jfjfj.) and \n"]
['      ', ')\n', "xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv."]
[' );\n']
['\n']
['\n']
['jjjjjj;\n']
['\n']
['  select xx', ' jdfjhf:jhfjj from xxxx_x_xx_L ;\n', '"xE\'", PUT(xx.xxxx.),"\'"']
['quit; \n']
['\n']
['/* 1.xxxxx FROM xxxx_x_Ex_x */ \n']
['proc sql; ', ';\n', '"CUuuiiiiuth"']
['hhhjhfjs as fdsjfsj:\n']
['select * from djfkjd to jfkjs\n']
['(SELECT abc AS abc1, abc_2_ AS efg, abc_fg, fkdkfj_vv, jjsflkl_ff, fjkdsf_jfkj\n']
['\tFROM &xxx..xxx_xxx_xxE\n']
["where ((xxx(xx_ix as format 'xxxx-xx') gff &jfjfsj_jfjfj.) and \n"]
['      ', ')\n', "xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv."]
[' );']




My intended Output that I am unable to get should look something like this:


("xE'", PUT(xx.xxxx.),"'")
("TRUuuuth")
(
SELECT abc AS abc1, abc_2_ AS efg, abc_fg, fkdkfj_vv, jjsflkl_ff, fjkdsf_jfkj
    FROM &xxx..xxx_xxx_xxE
where ((xxx(xx_ix as format 'xxxx-xx') gff &jfjfsj_jfjfj.) and
      (xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv.))
 )
("xE'", PUT(xx.xxxx.),"'")
("CUuuiiiiuth")
(SELECT abc AS abc1, abc_2_ AS efg, abc_fg, fkdkfj_vv, jjsflkl_ff, fjkdsf_jfkj
    FROM &xxx..xxx_xxx_xxE
where ((xxx(xx_ix as format 'xxxx-xx') gff &jfjfsj_jfjfj.) and
      (xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv.))(( ))
 )

From __peter__ at web.de  Mon Dec  2 12:00:50 2019
From: __peter__ at web.de (Peter Otten)
Date: Mon, 02 Dec 2019 18:00:50 +0100
Subject: Extract sentences in nested parentheses using Python
References: <7a365fa0-e721-4a95-8c30-d3661301a7b2@googlegroups.com>
Message-ID: <qs3g03$57h2$1@blaine.gmane.org>

A S wrote:

I think I've seen this question before ;)

> I am trying to extract all strings in nested parentheses (along with the
> parentheses itself) in my .txt file. Please see the sample .txt file that
> I have used in this example here:
> (https://drive.google.com/open?id=1UKc0ZgY9Fsz5O1rSeBCLqt5dwZkMaQgr).
> 
> I have tried and done up three different codes but none of them seems to
> be able to extract all the nested parentheses. They can only extract a
> portion of the nested parentheses. Any advice on what I've done wrong
> could really help!
> 
> Here are the three codes I have done so far:
> 
> 1st attempt:
> 
> import re
> from os.path import join
> 
> def balanced_braces(args):
>     parts = []
>     for arg in args:
>         if '(' not in arg:
>             continue

There could still be a ")" that you miss

>         chars = []
>         n = 0
>         for c in arg:
>             if c == '(':
>                 if n > 0:
>                     chars.append(c)
>                 n += 1
>             elif c == ')':
>                 n -= 1
>                 if n > 0:
>                     chars.append(c)
>                 elif n == 0:
>                     parts.append(''.join(chars).lstrip().rstrip())
>                     chars = []
>             elif n > 0:
>                 chars.append(c)
>     return parts

It's probably easier to understand and implement when you process the 
complete text at once. Then arbitrary splits don't get in the way of your 
quest for ( and ). You just have to remember the position of the first 
opening ( and number of opening parens that have to be closed before you 
take the complete expression:

level:  00011112222100
text:   abc(def(gh))ij
   when we are here^
    we need^

A tentative implementation:

$ cat parse.py
import re

NOT_SET = object()

def scan(text):
    level = 0
    start = NOT_SET
    for m in re.compile("[()]").finditer(text):
        if m.group() == ")":
            level -= 1
            if level < 0:
                raise ValueError("underflow: more closing than opening 
parens")
            if level == 0:
                # outermost closing parenthesis:
                # deliver enclosed string including parens.
                yield text[start:m.end()]
                start = NOT_SET
        elif m.group() == "(":
            if level == 0:
                # outermost opening parenthesis: remember position.
                assert start is NOT_SET
                start = m.start()
            level += 1
        else:
            assert False
    if level > 0:
        raise ValueError("unclosed parens remain")


if __name__ == "__main__":
    with open("lan sample text file.txt") as instream:
        text = instream.read()
    for chunk in scan(text):
        print(chunk)
$ python3 parse.py
("xE'", PUT(xx.xxxx.),"'")
("TRUuuuth")



From Chris.Clark at actian.com  Mon Dec  2 12:26:00 2019
From: Chris.Clark at actian.com (Chris Clark)
Date: Mon, 2 Dec 2019 17:26:00 +0000
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and 2.7
Message-ID: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>

Test case:

               import array
               array.array('L', [0])
# x.itemsize == 8  rather than 4

This works fine (returns 4) under Windows Python 3.7.3 64-bit build.

Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
It impacts all uses types of array (e.g. reading from byte strings).

The struct module is a little different:

import struct
x = struct.pack('L', 0)
# len(x) ===8 rather than 4

This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.

Wanted to post here for comments before opening a bug at https://bugs.python.org/

Is anyone seeing this under Debian/Ubuntu?


Chris


From Richard at Damon-family.org  Mon Dec  2 12:47:06 2019
From: Richard at Damon-family.org (Richard Damon)
Date: Mon, 2 Dec 2019 12:47:06 -0500
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
Message-ID: <0BD00D4B-5445-46F8-BDE8-168939332F63@Damon-family.org>


On Dec 2, 2019, at 12:32 PM, Chris Clark <Chris.Clark at actian.com> wrote:
> 
> ?Test case:
> 
>               import array
>               array.array('L', [0])
> # x.itemsize == 8  rather than 4
> 
> This works fine (returns 4) under Windows Python 3.7.3 64-bit build.
> 
> Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
> It impacts all uses types of array (e.g. reading from byte strings).
> 
> The struct module is a little different:
> 
> import struct
> x = struct.pack('L', 0)
> # len(x) ===8 rather than 4
> 
> This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.
> 
> Wanted to post here for comments before opening a bug at https://bugs.python.org/
> 
> Is anyone seeing this under Debian/Ubuntu?
> 
> 
> Chris
> 

Documentation that I see says *Minimum* size is 4, nothing says that it will be 4
I wouldn?t be surprized if ?I? gave you a size of 4 on that platform (and maybe even on many 32 bit platforms too)

From rgaddi at highlandtechnology.invalid  Mon Dec  2 12:55:16 2019
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Mon, 2 Dec 2019 09:55:16 -0800
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <mailman.281.1575307698.25794.python-list@python.org>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
Message-ID: <qs3j66$vjf$1@dont-email.me>

On 12/2/19 9:26 AM, Chris Clark wrote:
> Test case:
> 
>                 import array
>                 array.array('L', [0])
> # x.itemsize == 8  rather than 4
> 
> This works fine (returns 4) under Windows Python 3.7.3 64-bit build.
> 
> Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
> It impacts all uses types of array (e.g. reading from byte strings).
> 
> The struct module is a little different:
> 
> import struct
> x = struct.pack('L', 0)
> # len(x) ===8 rather than 4
> 
> This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.
> 
> Wanted to post here for comments before opening a bug at https://bugs.python.org/
> 
> Is anyone seeing this under Debian/Ubuntu?
> 
> 
> Chris
> 

I'd say not a bug, at least in array.  Reading that array documentation you 
linked, 4 is explicitly the MINIMUM size in bytes, not the guaranteed size.

The struct situation is, as you said, a bit different.  I believe that with the 
default native alignment @, you're seeing 4-byte data padded to an 8-byte 
alignment, not 8-byte data.  That does seem to go against what the struct 
documentation says, "Padding is only automatically added between successive 
structure members. No padding is added at the beginning or the end of the 
encoded struct."

= alignment is documented as having the platform native byte-order, but the size 
and alignment is standardized as having no padding, which is exactly the 
behavior you seem to want.  The documentation is a bit obtuse and scattered, but 
no more than any other.

From tim at akwebsoft.com  Mon Dec  2 14:48:39 2019
From: tim at akwebsoft.com (Tim Johnson)
Date: Mon, 2 Dec 2019 10:48:39 -0900
Subject: ModuleNotFoundError with click module
In-Reply-To: <qs2j1d$5e6g$1@blaine.gmane.org>
References: <32cc3ffc-bb43-284f-dfd8-7451ba100ec7@akwebsoft.com>
 <qs0114$bnl$1@blaine.gmane.org>
 <49e16310-3ef8-acf2-9583-6843a81f1bd6@akwebsoft.com>
 <510be00b-d87c-8054-cb5d-efb9179bd43b@akwebsoft.com>
 <qs2j1d$5e6g$1@blaine.gmane.org>
Message-ID: <f318bff8-590b-b2e2-ef85-33aeef688716@akwebsoft.com>


On 12/1/19 11:46 PM, Peter Otten wrote:
> Tim Johnson wrote:
>
>>> OK. Now I have
>>>
>>> /usr/local/lib/python3.7/site-packages/Click-7.0.dist-info/
>>>
>>> which holds the following files:
>>>
>>> INSTALLER  LICENSE.txt  METADATA  RECORD  top_level.txt  WHEEL
>>>
>>> I haven't a clue as to how to proceed! Never seen this before ...
> Just leave it alone ;)
>
>>> Furthermore, google is offering me nothing conclusive.
>>>
>>> Where to go from here!
>> P.S. It looks like that directory is sort of a stub; regardless of my
>> take on it I am no longer having the ModuleNotFoundError.
> Once you can import it you can find the actual module or package with
>
> $ /usr/bin/python3.7 -c 'import click; print(click.__file__)'
>
> In this case it's a package, so you'll probably see (something like)
>
> /usr/local/lib/python3.7/site-packages/click/__init__.py
>
> rather than
>
> /usr/local/lib/python3.7/site-packages/click.py
> /usr/local/lib/python3.7/site-packages/

Good Explanation. Thanks again Peter. <wink> new since python 1.5 </wink>

-- 
Tim
tj49.com


From barry at barrys-emacs.org  Mon Dec  2 16:25:05 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Mon, 2 Dec 2019 21:25:05 +0000
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <qs3j66$vjf$1@dont-email.me>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
Message-ID: <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>



> On 2 Dec 2019, at 17:55, Rob Gaddi <rgaddi at highlandtechnology.invalid> wrote:
> 
> On 12/2/19 9:26 AM, Chris Clark wrote:
>> Test case:
>>                import array
>>                array.array('L', [0])
>> # x.itemsize == 8  rather than 4
>> This works fine (returns 4) under Windows Python 3.7.3 64-bit build.
>> Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
>> It impacts all uses types of array (e.g. reading from byte strings).
>> The struct module is a little different:
>> import struct
>> x = struct.pack('L', 0)
>> # len(x) ===8 rather than 4
>> This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.
>> Wanted to post here for comments before opening a bug at https://bugs.python.org/
>> Is anyone seeing this under Debian/Ubuntu?
>> Chris
> 
> I'd say not a bug, at least in array.  Reading that array documentation you linked, 4 is explicitly the MINIMUM size in bytes, not the guaranteed size.

I'm wondering how useful it is that for array you can read from a file but have no ideas how many bytes each item needs.
If I have a file with int32_t  in it I cannot from the docs know how to read that file into an array.

> 
> The struct situation is, as you said, a bit different.  I believe that with the default native alignment @, you're seeing 4-byte data padded to an 8-byte alignment, not 8-byte data.  That does seem to go against what the struct documentation says, "Padding is only automatically added between successive structure members. No padding is added at the beginning or the end of the encoded struct."

The 'L' in struct is documented for 3.7 to use 4 bytes, but in fact uses 8, on fedora 31. Doc bug?

>>> x=struct.pack('L',0x102030405)
>>> x
b'\x05\x04\x03\x02\x01\x00\x00\x00'

Given I have exact control with b, h, i, and q but L is not fixed in size I'm not sure how it can be used with certainty across OS and versions.

Barry


> 
> = alignment is documented as having the platform native byte-order, but the size and alignment is standardized as having no padding, which is exactly the behavior you seem to want. The documentation is a bit obtuse and scattered, but no more than any other.
> -- 
> https://mail.python.org/mailman/listinfo/python-list <https://mail.python.org/mailman/listinfo/python-list>

From post at tinita.de  Mon Dec  2 17:04:21 2019
From: post at tinita.de (=?ISO-8859-15?Q?Tina_M=FCller?=)
Date: Mon, 2 Dec 2019 23:04:21 +0100 (CET)
Subject: [ANN] PyYAML-5.2: YAML parser and emitter for Python
Message-ID: <alpine.DEB.2.00.1912022303000.13570@perl-community.de>

=======================
Announcing PyYAML-5.2
=======================

A new release of PyYAML is now available:
https://pypi.org/project/PyYAML/

This fixes some incompatibilities introduced in version 5.1 and also removes
another possibility of loading arbitrary code.

Changes
=======

* Repair incompatibilities introduced with 5.1. The default Loader was changed,
   but several methods like add_constructor still used the old default
   https://github.com/yaml/pyyaml/pull/279 -- A more flexible fix for custom tag constructors
   https://github.com/yaml/pyyaml/pull/287 -- Change default loader for yaml.add_constructor
   https://github.com/yaml/pyyaml/pull/305 -- Change default loader for add_implicit_resolver, add_path_resolver
* Make FullLoader safer by removing python/object/apply from the default FullLoader
   https://github.com/yaml/pyyaml/pull/347 -- Move constructor for object/apply to UnsafeConstructor
* Fix bug introduced in 5.1 where quoting went wrong on systems with sys.maxunicode <= 0xffff
   https://github.com/yaml/pyyaml/pull/276 -- Fix logic for quoting special characters
* Other PRs:
   https://github.com/yaml/pyyaml/pull/280 -- Update CHANGES for 5.1

Resources
=========

PyYAML IRC Channel: #pyyaml on irc.freenode.net
PyYAML homepage: https://github.com/yaml/pyyaml
PyYAML documentation: http://pyyaml.org/wiki/PyYAMLDocumentation
Source and binary installers: https://pypi.org/project/PyYAML/
GitHub repository: https://github.com/yaml/pyyaml/
Bug tracking: https://github.com/yaml/pyyaml/issues

YAML homepage: http://yaml.org/
YAML-core mailing list: http://lists.sourceforge.net/lists/listinfo/yaml-core


About PyYAML
============

YAML is a data serialization format designed for human readability and
interaction with scripting languages. PyYAML is a YAML parser and emitter for
Python.

PyYAML features a complete YAML 1.1 parser, Unicode support, pickle support,
capable extension API, and sensible error messages. PyYAML supports standard
YAML tags and provides Python-specific tags that allow to represent an
arbitrary Python object.

PyYAML is applicable for a broad range of tasks from complex configuration
files to object serialization and persistence.


Example
=======

>>> import yaml

>>> yaml.full_load("""
... name: PyYAML
... description: YAML parser and emitter for Python
... homepage: https://github.com/yaml/pyyaml
... keywords: [YAML, serialization, configuration, persistence, pickle]
... """)
{'keywords': ['YAML', 'serialization', 'configuration', 'persistence',
'pickle'], 'homepage': 'https://github.com/yaml/pyyaml', 'description':
'YAML parser and emitter for Python', 'name': 'PyYAML'}

>>> print(yaml.dump(_))
name: PyYAML
homepage: https://github.com/yaml/pyyaml
description: YAML parser and emitter for Python
keywords: [YAML, serialization, configuration, persistence, pickle]


Maintainers
===========

The following people are currently responsible for maintaining PyYAML:

* Ingy d?t Net
* Tina Mueller
* Matt Davis

and many thanks to all who have contribributed!
See: https://github.com/yaml/pyyaml/pulls


Copyright
=========

Copyright (c) 2017-2019 Ingy d?t Net <ingy at ingy.net>
Copyright (c) 2006-2016 Kirill Simonov <xi at resolvent.net>

The PyYAML module was written by Kirill Simonov <xi at resolvent.net>.
It is currently maintained by the YAML and Python communities.

PyYAML is released under the MIT license.
See the file LICENSE for more details.

From PythonList at DancesWithMice.info  Mon Dec  2 17:22:19 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 3 Dec 2019 11:22:19 +1300
Subject: Extract sentences in nested parentheses using Python
In-Reply-To: <qs3g03$57h2$1@blaine.gmane.org>
References: <7a365fa0-e721-4a95-8c30-d3661301a7b2@googlegroups.com>
 <qs3g03$57h2$1@blaine.gmane.org>
Message-ID: <1d689634-c3db-dd3f-c432-111604d5a784@DancesWithMice.info>

On 3/12/19 6:00 AM, Peter Otten wrote:
> A S wrote:
> I think I've seen this question before ;)

In addition to 'other reasons' for @Peter's comment, it is a common 
ComSc worked-problem or assignment. (in which case, we'd appreciate 
being told that you/OP is asking for help with "homework")


>> I am trying to extract all strings in nested parentheses (along with the
>> parentheses itself) in my .txt file. Please see the sample .txt file that
>> I have used in this example here:
>> (https://drive.google.com/open?id=1UKc0ZgY9Fsz5O1rSeBCLqt5dwZkMaQgr).
>>
>> I have tried and done up three different codes but none of them seems to
>> be able to extract all the nested parentheses. They can only extract a
>> portion of the nested parentheses. Any advice on what I've done wrong
>> could really help!

One approach is to research in the hope that there are already existing 
tools or techniques which may help/save you from 'reinventing the wheel' 
- when you think about it, a re-statement of open-source objectives.

How does the Python interpreter break-down Python (text) code into its 
constituent parts ("tokens") *including* parentheses? Such are made 
available in (perhaps) a lesser-known corner of the PSL (Python Standard 
Library). Might you be able to use one such tool?

The ComSc technique which sprang to mind involves "stacks" (a LIFO data 
structure) and "RPN" (Reverse Polish Notation). Whereas we like people 
to take their turn when it comes to limited resources, eg to form a 
"queue" to purchase/pay for goods at the local store, which is "FIFO" 
(first-in, first-out); a "stack"/LIFO (last-in, first-out) can be 
problematic to put into practical application. There are plenty of 
Python implementations or you can 'roll your own' with a list. Again, 
I'd likely employ a "deque" from the PSL's Collections library (although 
as a "stack" rather than as a "double-ended queue"), because the 
optimisation comes "free". (to my laziness, but after some kind soul 
sweated-bullets to make it fast (in both senses) for 'the rest of us'!)


> It's probably easier to understand and implement when you process the
> complete text at once. Then arbitrary splits don't get in the way of your
> quest for ( and ). You just have to remember the position of the first
> opening ( and number of opening parens that have to be closed before you
> take the complete expression:

+1
but as a 'silver surfer', I don't like to be asked to "remember" anything!


> level:  00011112222100
>      we need^


Consider:
original_text (the contents of the .txt file - add buffering if volumes 
are huge)
current_text (the characters we have processed/"recognised" so-far)
stack (what an original name for such a data-structure! Which will 
contain each of the partial parenthetical expressions found - but yet to 
be proven/made complete)

set current_text to NULSTRING
for each current_character in original_text:
	if current_character is LEFT_PARENTHESIS:
		push current_text to stack
		set current_text to LEFT_PARENTHESIS
	concatenate current_character with current_text
	if current_character is RIGHT_PARENTHESIS:
		# current_text is a parenthetical expression
		# do with it what you will
		pop the stack
		set current_text to the ex-stack string \
			concat current_text's p-expn

Once working: cover 'special cases' (after above loop), eg original_text 
which doesn't begin and/or end with parentheses; and error cases, eg 
pop-ping a NULSTRING, or thinking things are finished but the stack is 
not yet empty - likely events from unbalanced parentheses!

original text = "abc(def(gh))ij"

event 1: in-turn, concatenate characters "abc" as current_text
event 2: locate (first) left-parenthesis, push current_text to stack(&)
event 3: concatenate "(def"
event 4: push, likewise
event 5: concatenate "(gh"
event 6: locate (first) right-parenthesis (matches to left-parenthesis 
begining the current_string!)
result?: ?print current_text?
event 7: pop stack and redefine current_text as "(def(gh)"
event 8: repeat, per event 6
event 9: current_text will now become "(def(gh))"
event 10: (special case) run-out of input at "(def(gh)ij"
event 11: (special case) pop (!any) stack and report "abc(def(gh)"


NB not sure of need for a "level" number; but if required, you can infer 
that at any time, from the depth/len() of the stack!

NBB being a simple-boy, my preference is for a 'single layer' of code, 
cf @Peter's generator. Regardless the processes are "tokenisation" and 
"recognition".

At the back of my mind, was the notion that you may (eventually) be 
required to work with more than parentheses, eg pair-wise 
square-brackets and/or quotation-marks. In which case, you will need to 
also 'push' the token and check for token-pairs when 'pop-ping', as well 
as (perhaps) recognising lists of tokens to tokenise instead of the two 
parenthesis characters alone. In which case, I'd take a serious look at 
the Python Language Services rather than taking a 'roll your own' approach!

Contrarily, if this spec is 'it', then you might consider optimising the 
search processes which 'trigger' the two stack operations, by re-working 
the for-loop and utilising string.find() - prioritising whichever 
parenthesis is left-most/comes-first - assuming LtR text. (apologies if 
you have already tried this in one of your previous approaches) 
Unfortunately, such likely results in 'layers' of code, and a generator 
might well become the tool-of-choice (I say this before @Peter comes 
back and (quite deservedly) flays me alive!).


WebRefs:
Python Language Services: https://docs.python.org/3/library/language.html
collections ? Container datatypes: 
https://docs.python.org/3/library/collections.html

See also your ComSc text/reference materials.
-- 
Regards =dn

From christian at python.org  Mon Dec  2 17:37:45 2019
From: christian at python.org (Christian Heimes)
Date: Mon, 2 Dec 2019 23:37:45 +0100
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
 <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
Message-ID: <94e9ab79-12dd-e891-be80-7df913d5fdf4@python.org>

On 02/12/2019 22.25, Barry Scott wrote:
> 
> 
>> On 2 Dec 2019, at 17:55, Rob Gaddi <rgaddi at highlandtechnology.invalid> wrote:
>>
>> On 12/2/19 9:26 AM, Chris Clark wrote:
>>> Test case:
>>>                import array
>>>                array.array('L', [0])
>>> # x.itemsize == 8  rather than 4
>>> This works fine (returns 4) under Windows Python 3.7.3 64-bit build.
>>> Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
>>> It impacts all uses types of array (e.g. reading from byte strings).
>>> The struct module is a little different:
>>> import struct
>>> x = struct.pack('L', 0)
>>> # len(x) ===8 rather than 4
>>> This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.
>>> Wanted to post here for comments before opening a bug at https://bugs.python.org/
>>> Is anyone seeing this under Debian/Ubuntu?
>>> Chris
>>
>> I'd say not a bug, at least in array.  Reading that array documentation you linked, 4 is explicitly the MINIMUM size in bytes, not the guaranteed size.
> 
> I'm wondering how useful it is that for array you can read from a file but have no ideas how many bytes each item needs.
> If I have a file with int32_t  in it I cannot from the docs know how to read that file into an array.
> 
>>
>> The struct situation is, as you said, a bit different.  I believe that with the default native alignment @, you're seeing 4-byte data padded to an 8-byte alignment, not 8-byte data.  That does seem to go against what the struct documentation says, "Padding is only automatically added between successive structure members. No padding is added at the beginning or the end of the encoded struct."
> 
> The 'L' in struct is documented for 3.7 to use 4 bytes, but in fact uses 8, on fedora 31. Doc bug?

The documentation of the struct and array module carefully speak of
"minimum size in bytes", "standard size" and "native size". It's easy to
miss that it doesn't state just "size" for a reason.

A long is not int32_t. The actual size of long and unsigned long depend
on the ABI of your platform. The standard defined a long as *at least* 4
bytes. On Windows it's always a 32 bit data type. On POSIX sizeof(long)
is usually the same as the size of a pointer, 4 bytes on 32 bit
platforms and 8 bytes on 64 bit platforms.

https://en.wikipedia.org/wiki/Integer_(computer_science)#Long_integer

I agree that the behavior is confusing, even for C programmers. Please
feel free to open a ticket and request an improvement of the documentation.

Christian

From torriem at gmail.com  Mon Dec  2 18:49:17 2019
From: torriem at gmail.com (Michael Torrie)
Date: Mon, 2 Dec 2019 16:49:17 -0700
Subject: increasing the page size of a dbm store?
In-Reply-To: <20191201205016.577673f9@bigbox.attlocal.net>
References: <20191126192432.535ee241@bigbox.attlocal.net>
 <0EAFC9E0-02D2-4745-99B7-654B7A445EDD@barrys-emacs.org>
 <20191201205016.577673f9@bigbox.attlocal.net>
Message-ID: <4dd1ac29-8803-a1bd-3158-0cd90f392c48@gmail.com>

On 12/1/19 7:50 PM, Tim Chase wrote:
> After sparring with it a while, I tweaked the existing job so that it
> chunked things into dbm-appropriate sizes to limp through; for the
> subsequent job (where I would have used dbm again) I went ahead and
> switched to sqlite and had no further issues.

How did you replace a key/value store with a relational database?  Is a
SQLite database fast enough at this sort of thing that it wasn't really
designed for?

From Richard at Damon-Family.org  Mon Dec  2 20:50:16 2019
From: Richard at Damon-Family.org (Richard Damon)
Date: Mon, 2 Dec 2019 20:50:16 -0500
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
 <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
Message-ID: <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>

On 12/2/19 4:25 PM, Barry Scott wrote:
>
>> On 2 Dec 2019, at 17:55, Rob Gaddi <rgaddi at highlandtechnology.invalid> wrote:
>>
>> On 12/2/19 9:26 AM, Chris Clark wrote:
>>> Test case:
>>>                import array
>>>                array.array('L', [0])
>>> # x.itemsize == 8  rather than 4
>>> This works fine (returns 4) under Windows Python 3.7.3 64-bit build.
>>> Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
>>> It impacts all uses types of array (e.g. reading from byte strings).
>>> The struct module is a little different:
>>> import struct
>>> x = struct.pack('L', 0)
>>> # len(x) ===8 rather than 4
>>> This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.
>>> Wanted to post here for comments before opening a bug at https://bugs.python.org/
>>> Is anyone seeing this under Debian/Ubuntu?
>>> Chris
>> I'd say not a bug, at least in array.  Reading that array documentation you linked, 4 is explicitly the MINIMUM size in bytes, not the guaranteed size.
> I'm wondering how useful it is that for array you can read from a file but have no ideas how many bytes each item needs.
> If I have a file with int32_t  in it I cannot from the docs know how to read that file into an array.
>
>> The struct situation is, as you said, a bit different.  I believe that with the default native alignment @, you're seeing 4-byte data padded to an 8-byte alignment, not 8-byte data.  That does seem to go against what the struct documentation says, "Padding is only automatically added between successive structure members. No padding is added at the beginning or the end of the encoded struct."
> The 'L' in struct is documented for 3.7 to use 4 bytes, but in fact uses 8, on fedora 31. Doc bug?
>
>>>> x=struct.pack('L',0x102030405)
>>>> x
> b'\x05\x04\x03\x02\x01\x00\x00\x00'
>
> Given I have exact control with b, h, i, and q but L is not fixed in size I'm not sure how it can be used with certainty across OS and versions.
>
> Barry
>
Actually, you DON'T have exact control with those sizes, it just happens
that all the platforms you are using happen to have the same size for
those types. Welcome to the ambiguity in the C type system, the basic
types are NOT fixed in size. L means 'Long' and as Christian said, that
is 8 byte long on Linux-64 bit. 'L' is exactly the right type for
interfacing with a routine defined as taking a long. The issue is that
you don't know what type a int32_t will be (it might be int, or it might
be long, and long might not be 32 bits, it will be at least 32 bits).

Perhaps array could be extended so that it took '4' for a 4 byte integer
and '8' for an 8 byte integer (maybe 'U4' and 'U8' for unsigned). Might
as well also allow 1 and 2 for completeness for char and short (but
those are currently consistent).

-- 
Richard Damon


From maisarah at avlinfotech.net  Mon Dec  2 21:29:11 2019
From: maisarah at avlinfotech.net (Maisarah)
Date: Tue, 03 Dec 2019 10:29:11 +0800
Subject: Python Error Still Occured  on sklearn
In-Reply-To: <16ec5f25a9c.f89474fd188788.8117256455982324362@avlinfotech.net>
References: <16ec5f25a9c.f89474fd188788.8117256455982324362@avlinfotech.net>
Message-ID: <16ec99711a1.129d57e36335551.7298109250136335338@avlinfotech.net>

Thank you.





Maisarah Binti Mohd Yusak


Certified CPRE-FL & CTFL

Software Tester, IT Team.



AVL Infotech (Malaysia) Sdn. Bhd.



?



L2-I-3, Enterprise - 4 , Technology Park Malaysia,
Bukit Jalil, Kuala Lumpur, Malaysia -57000
Mobile: +6016 507 3051
Mail:?mailto:maisarah at avlinfotech.net

LinkedIn: https://my.linkedin.com/in/maimoyu

Web:?http://www.avlinfotech.net/










---- On Mon, 02 Dec 2019 17:30:24 +0800 Maisarah <maisarah at avlinfotech.net> wrote ----


Dear Admin,



I have install and upgrade Cython as well.?

I have modified and repaired and even update the library but error is still occurred:



C:\Windows\system32>pip install -U scikit-learn 

Collecting scikit-learn

? Using cached https://files.pythonhosted.org/packages/1e/ce/9d8c88e68af0a5b5c5d78d8d2b7bcadfd45e1d6afc863ccb9aee30765b06/scikit-learn-0.21.3.tar.gz

Requirement already satisfied, skipping upgrade: numpy>=1.11.0 in c:\users\user\appdata\local\programs\python\python38\lib\site-packages (from scikit-learn) (1.17.4)

Requirement already satisfied, skipping upgrade: scipy>=0.17.0 in c:\users\user\appdata\local\programs\python\python38\lib\site-packages (from scikit-learn) (1.3.3)

Requirement already satisfied, skipping upgrade: joblib>=0.11 in c:\users\user\appdata\local\programs\python\python38\lib\site-packages (from scikit-learn) (0.14.0)

Installing collected packages: scikit-learn

??? Running setup.py install for scikit-learn ... error

??? ERROR: Command errored out with exit status 1:

???? command: 'c:\users\user\appdata\local\programs\python\python38\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-caioz9bv\\scikit-learn\\setup.py'"'"'; __file__='"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-caioz9bv\\scikit-learn\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\user\AppData\Local\Temp\pip-record-o9y5q4bk\install-record.txt' --single-version-externally-managed --compile

???????? cwd: C:\Users\user\AppData\Local\Temp\pip-install-caioz9bv\scikit-learn\

??? Complete output (44 lines):

??? Partial import of sklearn during the build process.

??? No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils

??? Traceback (most recent call last):

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 489, in _find_latest_available_vc_ver

??????? return self.find_available_vc_vers()[-1]

??? IndexError: list index out of range



??? During handling of the above exception, another exception occurred:



??? Traceback (most recent call last):

????? File "<string>", line 1, in <module>

????? File "C:\Users\user\AppData\Local\Temp\pip-install-caioz9bv\scikit-learn\setup.py", line 290, in <module>

??????? setup_package()

????? File "C:\Users\user\AppData\Local\Temp\pip-install-caioz9bv\scikit-learn\setup.py", line 286, in setup_package

??????? setup(**metadata)

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\core.py", line 137, in setup

??????? config = configuration()

????? File "C:\Users\user\AppData\Local\Temp\pip-install-caioz9bv\scikit-learn\setup.py", line 174, in configuration

??????? config.add_subpackage('sklearn')

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\misc_util.py", line 1033, in add_subpackage

??????? config_list = self.get_subpackage(subpackage_name, subpackage_path,

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\misc_util.py", line 999, in get_subpackage

??????? config = self._get_configuration_from_setup_py(

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\misc_util.py", line 941, in _get_configuration_from_setup_py

??????? config = setup_module.configuration(*args)

????? File "sklearn\setup.py", line 76, in configuration

??????? maybe_cythonize_extensions(top_path, config)

????? File "C:\Users\user\AppData\Local\Temp\pip-install-caioz9bv\scikit-learn\sklearn\_build_utils\__init__.py", line 42, in maybe_cythonize_extensions

??????? with_openmp = check_openmp_support()

????? File "C:\Users\user\AppData\Local\Temp\pip-install-caioz9bv\scikit-learn\sklearn\_build_utils\openmp_helpers.py", line 83, in check_openmp_support

??????? ccompiler.compile(['test_openmp.c'], output_dir='objects',

????? File "c:\users\user\appdata\local\programs\python\python38\lib\distutils\_msvccompiler.py", line 360, in compile

??????? self.initialize()

????? File "c:\users\user\appdata\local\programs\python\python38\lib\distutils\_msvccompiler.py", line 253, in initialize

??????? vc_env = _get_vc_env(plat_spec)

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 185, in msvc14_get_vc_env

??????? return EnvironmentInfo(plat_spec, vc_min_ver=14.0).return_env()

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 843, in __init__

??????? self.si = SystemInfo(self.ri, vc_ver)

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 485, in __init__

??????? self.vc_ver = vc_ver or self._find_latest_available_vc_ver()

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 492, in _find_latest_available_vc_ver

??????? raise distutils.errors.DistutilsPlatformError(err)

??? distutils.errors.DistutilsPlatformError: Microsoft Visual C++ 14.0 is required. Get it with "Microsoft Visual C++ Build Tools": https://visualstudio.microsoft.com/downloads/

??? ----------------------------------------

ERROR: Command errored out with exit status 1: 'c:\users\user\appdata\local\programs\python\python38\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-caioz9bv\\scikit-learn\\setup.py'"'"'; __file__='"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-caioz9bv\\scikit-learn\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\user\AppData\Local\Temp\pip-record-o9y5q4bk\install-record.txt' --single-version-externally-managed --compile Check the logs for full command output.



C:\Windows\system32>pip install --upgrade -U scikit-learn

Collecting scikit-learn

? Using cached https://files.pythonhosted.org/packages/1e/ce/9d8c88e68af0a5b5c5d78d8d2b7bcadfd45e1d6afc863ccb9aee30765b06/scikit-learn-0.21.3.tar.gz

Requirement already satisfied, skipping upgrade: numpy>=1.11.0 in c:\users\user\appdata\local\programs\python\python38\lib\site-packages (from scikit-learn) (1.17.4)

Requirement already satisfied, skipping upgrade: scipy>=0.17.0 in c:\users\user\appdata\local\programs\python\python38\lib\site-packages (from scikit-learn) (1.3.3)

Requirement already satisfied, skipping upgrade: joblib>=0.11 in c:\users\user\appdata\local\programs\python\python38\lib\site-packages (from scikit-learn) (0.14.0)

Installing collected packages: scikit-learn

??? Running setup.py install for scikit-learn ... error

??? ERROR: Command errored out with exit status 1:

???? command: 'c:\users\user\appdata\local\programs\python\python38\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-48dlq_5d\\scikit-learn\\setup.py'"'"'; __file__='"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-48dlq_5d\\scikit-learn\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\user\AppData\Local\Temp\pip-record-arwze1t4\install-record.txt' --single-version-externally-managed --compile

???????? cwd: C:\Users\user\AppData\Local\Temp\pip-install-48dlq_5d\scikit-learn\

??? Complete output (44 lines):

??? Partial import of sklearn during the build process.

??? No module named 'numpy.distutils._msvccompiler' in numpy.distutils; trying from distutils

??? Traceback (most recent call last):

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 489, in _find_latest_available_vc_ver

??????? return self.find_available_vc_vers()[-1]

??? IndexError: list index out of range



??? During handling of the above exception, another exception occurred:



??? Traceback (most recent call last):

????? File "<string>", line 1, in <module>

????? File "C:\Users\user\AppData\Local\Temp\pip-install-48dlq_5d\scikit-learn\setup.py", line 290, in <module>

??????? setup_package()

????? File "C:\Users\user\AppData\Local\Temp\pip-install-48dlq_5d\scikit-learn\setup.py", line 286, in setup_package

??????? setup(**metadata)

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\core.py", line 137, in setup

??????? config = configuration()

????? File "C:\Users\user\AppData\Local\Temp\pip-install-48dlq_5d\scikit-learn\setup.py", line 174, in configuration

??????? config.add_subpackage('sklearn')

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\misc_util.py", line 1033, in add_subpackage

??????? config_list = self.get_subpackage(subpackage_name, subpackage_path,

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\misc_util.py", line 999, in get_subpackage

??????? config = self._get_configuration_from_setup_py(

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\numpy\distutils\misc_util.py", line 941, in _get_configuration_from_setup_py

??????? config = setup_module.configuration(*args)

????? File "sklearn\setup.py", line 76, in configuration

??????? maybe_cythonize_extensions(top_path, config)

????? File "C:\Users\user\AppData\Local\Temp\pip-install-48dlq_5d\scikit-learn\sklearn\_build_utils\__init__.py", line 42, in maybe_cythonize_extensions

??????? with_openmp = check_openmp_support()

????? File "C:\Users\user\AppData\Local\Temp\pip-install-48dlq_5d\scikit-learn\sklearn\_build_utils\openmp_helpers.py", line 83, in check_openmp_support

??????? ccompiler.compile(['test_openmp.c'], output_dir='objects',

????? File "c:\users\user\appdata\local\programs\python\python38\lib\distutils\_msvccompiler.py", line 360, in compile

??????? self.initialize()

????? File "c:\users\user\appdata\local\programs\python\python38\lib\distutils\_msvccompiler.py", line 253, in initialize

??????? vc_env = _get_vc_env(plat_spec)

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 185, in msvc14_get_vc_env

??????? return EnvironmentInfo(plat_spec, vc_min_ver=14.0).return_env()

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 843, in __init__

??????? self.si = SystemInfo(self.ri, vc_ver)

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 485, in __init__

??????? self.vc_ver = vc_ver or self._find_latest_available_vc_ver()

????? File "c:\users\user\appdata\local\programs\python\python38\lib\site-packages\setuptools\msvc.py", line 492, in _find_latest_available_vc_ver

??????? raise distutils.errors.DistutilsPlatformError(err)

??? distutils.errors.DistutilsPlatformError: Microsoft Visual C++ 14.0 is required. Get it with "Microsoft Visual C++ Build Tools": https://visualstudio.microsoft.com/downloads/

??? ----------------------------------------

ERROR: Command errored out with exit status 1: 'c:\users\user\appdata\local\programs\python\python38\python.exe' -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-48dlq_5d\\scikit-learn\\setup.py'"'"'; __file__='"'"'C:\\Users\\user\\AppData\\Local\\Temp\\pip-install-48dlq_5d\\scikit-learn\\setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' install --record 'C:\Users\user\AppData\Local\Temp\pip-record-arwze1t4\install-record.txt' --single-version-externally-managed --compile Check the logs for full command output.



C:\Windows\system32>







Kindly advice in English language, please.



Thank you.





Maisarah Binti Mohd Yusak


Certified CPRE-FL & CTFL

Software Tester, IT Team.



AVL Infotech (Malaysia) Sdn. Bhd.



?



L2-I-3, Enterprise - 4 , Technology Park Malaysia,
Bukit Jalil, Kuala Lumpur, Malaysia -57000
Mobile: +6016 507 3051
Mail:?mailto:maisarah at avlinfotech.net

LinkedIn: https://my.linkedin.com/in/maimoyu

Web:?http://www.avlinfotech.net/

From veek at dont-use-this.com  Tue Dec  3 04:19:28 2019
From: veek at dont-use-this.com (Veek M)
Date: Tue, 3 Dec 2019 09:19:28 -0000 (UTC)
Subject: Extending property using a Subclass - single method - why Super(Baz, 
 Baz).name.__set__ ?
Message-ID: <qs59b0$fmo$1@dont-email.me>

class Foo(object):
    @property
    def name(self):
        if hasattr(self, '_name'):
            print('Foo name', self._name)
            return self._name
        else: 
            return 'default'

    @name.setter
    def name(self, value):
        print('Foo', self)
        self._name = value
        print(self._name)
        
    @name.deleter
    def name(self):
        print('del')
        self._name = None
    
    print('Foo', name)

class Baz(Foo):
    @property
    def name(self):
        print('Baz wrapper around getter')
        return super().name
        
    @Foo.name.setter
    def name(self, value):
        print('Baz wrapper around setter')
        print(self)
        print(super(Baz,Baz).name, value)
        return super(Baz, Baz).name.__set__(self, value)
    
b = Baz()
print('print', b.name)
b.name = 'v'
print(b.name)

Why do we user super(Baz, Baz) - are we setting a class variable called 
Baz.name which would trigger Baz._name = value?

We are essentially doing:
Foo.name.__set__(Baz, value) ?

How come 'self' is not used.. like in the traditional property way where 
we pass an instance reference instead of a class?

From __peter__ at web.de  Tue Dec  3 06:16:12 2019
From: __peter__ at web.de (Peter Otten)
Date: Tue, 03 Dec 2019 12:16:12 +0100
Subject: Extending property using a Subclass - single method - why
 Super(Baz, Baz).name.__set__ ?
References: <qs59b0$fmo$1@dont-email.me>
Message-ID: <qs5g5t$40hs$1@blaine.gmane.org>

Veek M wrote:

> class Foo(object):
>     @property
>     def name(self):
>         if hasattr(self, '_name'):
>             print('Foo name', self._name)
>             return self._name
>         else:
>             return 'default'
> 
>     @name.setter
>     def name(self, value):
>         print('Foo', self)
>         self._name = value
>         print(self._name)
>         
>     @name.deleter
>     def name(self):
>         print('del')
>         self._name = None
>     
>     print('Foo', name)
> 
> class Baz(Foo):
>     @property
>     def name(self):
>         print('Baz wrapper around getter')
>         return super().name
>         
>     @Foo.name.setter

This looks like a bug as the read-only property defined above is overwritten 
by a copy of the name poperty of the base class (with an updated setter).

>     def name(self, value):
>         print('Baz wrapper around setter')
>         print(self)
>         print(super(Baz,Baz).name, value)
>         return super(Baz, Baz).name.__set__(self, value)

When you want to invoke a method of the base class property you have to look 
up that property in the base class. This is what super(Baz, Baz).name does.

super().name

for read access is an exception. The __get__() method is invoked implicitly 
which is probably also the reason why you cannot write 
super().name.somepropertymethod(...) for anything else.


>     
> b = Baz()
> print('print', b.name)
> b.name = 'v'
> print(b.name)
> 
> Why do we user super(Baz, Baz) - are we setting a class variable called
> Baz.name which would trigger Baz._name = value?
> 
> We are essentially doing:
> Foo.name.__set__(Baz, value) ?
> 
> How come 'self' is not used.. like in the traditional property way where
> we pass an instance reference instead of a class?



From veek at dont-use-this.com  Tue Dec  3 08:36:55 2019
From: veek at dont-use-this.com (Veek M)
Date: Tue, 3 Dec 2019 13:36:55 -0000 (UTC)
Subject: Extending property using a Subclass - single method - why
 Super(Baz, Baz).name.__set__ ?
References: <qs59b0$fmo$1@dont-email.me> <qs5g5t$40hs$1@blaine.gmane.org>
 <mailman.292.1575371781.25794.python-list@python.org>
Message-ID: <qs5odn$uut$1@dont-email.me>

you've misunderstood my question, let me try again:

So this is a simple descriptor class and as you can see, dunder-set needs 
3 args: the descriptor CONTAINER/Bar-instance is the first arg, then a 
reference to the using instance/Foo-instance

class Bar(object):
    
    def __set__(self, instance, value):
        #b-instance of Bar, f-instance of Foo, value
        print(self, instance, value)
        
        
class Foo(object):
    b = Bar()
    
f = Foo()
print(f)
f.b = 10

1. Now when we create/use @property..
what is the first and second argument to dunder-set

(my guess is, the @property is the first arg and the second arg is 'Foo' 
IF you do

class Foo(object):
   @property
   def whatever..

Am I right? Is there a way to check?


2. The Class Bar/descriptor acts a wrapper/protector for some sekret _var 
and therefore it gets all the data needed to make a judgement call.. that 
is, it's own name/instance-ref and the using class/instance-name-ref

Note that he's receiving instance-references

therefore when I start sub-classing a property why does he then switch to 
class-references/class-variables

From aishan0403 at gmail.com  Tue Dec  3 08:41:18 2019
From: aishan0403 at gmail.com (A S)
Date: Tue, 3 Dec 2019 05:41:18 -0800 (PST)
Subject: Extract sentences in nested parentheses using Python
In-Reply-To: <mailman.280.1575306068.25794.python-list@python.org>
References: <7a365fa0-e721-4a95-8c30-d3661301a7b2@googlegroups.com>
 <qs3g03$57h2$1@blaine.gmane.org>
 <mailman.280.1575306068.25794.python-list@python.org>
Message-ID: <f6af05a2-86ee-411b-949d-2e1aa24bc4c0@googlegroups.com>

On Tuesday, 3 December 2019 01:01:25 UTC+8, Peter Otten  wrote:
> A S wrote:
> 
> I think I've seen this question before ;)
> 
> > I am trying to extract all strings in nested parentheses (along with the
> > parentheses itself) in my .txt file. Please see the sample .txt file that
> > I have used in this example here:
> > (https://drive.google.com/open?id=1UKc0ZgY9Fsz5O1rSeBCLqt5dwZkMaQgr).
> > 
> > I have tried and done up three different codes but none of them seems to
> > be able to extract all the nested parentheses. They can only extract a
> > portion of the nested parentheses. Any advice on what I've done wrong
> > could really help!
> > 
> > Here are the three codes I have done so far:
> > 
> > 1st attempt:
> > 
> > import re
> > from os.path import join
> > 
> > def balanced_braces(args):
> >     parts = []
> >     for arg in args:
> >         if '(' not in arg:
> >             continue
> 
> There could still be a ")" that you miss
> 
> >         chars = []
> >         n = 0
> >         for c in arg:
> >             if c == '(':
> >                 if n > 0:
> >                     chars.append(c)
> >                 n += 1
> >             elif c == ')':
> >                 n -= 1
> >                 if n > 0:
> >                     chars.append(c)
> >                 elif n == 0:
> >                     parts.append(''.join(chars).lstrip().rstrip())
> >                     chars = []
> >             elif n > 0:
> >                 chars.append(c)
> >     return parts
> 
> It's probably easier to understand and implement when you process the 
> complete text at once. Then arbitrary splits don't get in the way of your 
> quest for ( and ). You just have to remember the position of the first 
> opening ( and number of opening parens that have to be closed before you 
> take the complete expression:
> 
> level:  00011112222100
> text:   abc(def(gh))ij
>    when we are here^
>     we need^
> 
> A tentative implementation:
> 
> $ cat parse.py
> import re
> 
> NOT_SET = object()
> 
> def scan(text):
>     level = 0
>     start = NOT_SET
>     for m in re.compile("[()]").finditer(text):
>         if m.group() == ")":
>             level -= 1
>             if level < 0:
>                 raise ValueError("underflow: more closing than opening 
> parens")
>             if level == 0:
>                 # outermost closing parenthesis:
>                 # deliver enclosed string including parens.
>                 yield text[start:m.end()]
>                 start = NOT_SET
>         elif m.group() == "(":
>             if level == 0:
>                 # outermost opening parenthesis: remember position.
>                 assert start is NOT_SET
>                 start = m.start()
>             level += 1
>         else:
>             assert False
>     if level > 0:
>         raise ValueError("unclosed parens remain")
> 
> 
> if __name__ == "__main__":
>     with open("lan sample text file.txt") as instream:
>         text = instream.read()
>     for chunk in scan(text):
>         print(chunk)
> $ python3 parse.py
> ("xE'", PUT(xx.xxxx.),"'")
> ("TRUuuuth")

Hello Peter! I tried this on my actual working files and it returned this error: "unclosed parens remain". In this case, how can I continue to parse through my text files by only extracting those with balanced parentheses and ignore those that are incomplete?

From __peter__ at web.de  Tue Dec  3 10:47:49 2019
From: __peter__ at web.de (Peter Otten)
Date: Tue, 03 Dec 2019 16:47:49 +0100
Subject: Extract sentences in nested parentheses using Python
References: <7a365fa0-e721-4a95-8c30-d3661301a7b2@googlegroups.com>
 <qs3g03$57h2$1@blaine.gmane.org>
 <mailman.280.1575306068.25794.python-list@python.org>
 <f6af05a2-86ee-411b-949d-2e1aa24bc4c0@googlegroups.com>
Message-ID: <qs6036$804m$1@blaine.gmane.org>

A S wrote:

> On Tuesday, 3 December 2019 01:01:25 UTC+8, Peter Otten  wrote:
>> A S wrote:
>> 
>> I think I've seen this question before ;)
>> 
>> > I am trying to extract all strings in nested parentheses (along with
>> > the parentheses itself) in my .txt file. Please see the sample .txt
>> > file that I have used in this example here:
>> > (https://drive.google.com/open?id=1UKc0ZgY9Fsz5O1rSeBCLqt5dwZkMaQgr).
>> > 
>> > I have tried and done up three different codes but none of them seems
>> > to be able to extract all the nested parentheses. They can only extract
>> > a portion of the nested parentheses. Any advice on what I've done wrong
>> > could really help!
>> > 
>> > Here are the three codes I have done so far:
>> > 
>> > 1st attempt:
>> > 
>> > import re
>> > from os.path import join
>> > 
>> > def balanced_braces(args):
>> >     parts = []
>> >     for arg in args:
>> >         if '(' not in arg:
>> >             continue
>> 
>> There could still be a ")" that you miss
>> 
>> >         chars = []
>> >         n = 0
>> >         for c in arg:
>> >             if c == '(':
>> >                 if n > 0:
>> >                     chars.append(c)
>> >                 n += 1
>> >             elif c == ')':
>> >                 n -= 1
>> >                 if n > 0:
>> >                     chars.append(c)
>> >                 elif n == 0:
>> >                     parts.append(''.join(chars).lstrip().rstrip())
>> >                     chars = []
>> >             elif n > 0:
>> >                 chars.append(c)
>> >     return parts
>> 
>> It's probably easier to understand and implement when you process the
>> complete text at once. Then arbitrary splits don't get in the way of your
>> quest for ( and ). You just have to remember the position of the first
>> opening ( and number of opening parens that have to be closed before you
>> take the complete expression:
>> 
>> level:  00011112222100
>> text:   abc(def(gh))ij
>>    when we are here^
>>     we need^
>> 
>> A tentative implementation:
>> 
>> $ cat parse.py
>> import re
>> 
>> NOT_SET = object()
>> 
>> def scan(text):
>>     level = 0
>>     start = NOT_SET
>>     for m in re.compile("[()]").finditer(text):
>>         if m.group() == ")":
>>             level -= 1
>>             if level < 0:
>>                 raise ValueError("underflow: more closing than opening
>> parens")
>>             if level == 0:
>>                 # outermost closing parenthesis:
>>                 # deliver enclosed string including parens.
>>                 yield text[start:m.end()]
>>                 start = NOT_SET
>>         elif m.group() == "(":
>>             if level == 0:
>>                 # outermost opening parenthesis: remember position.
>>                 assert start is NOT_SET
>>                 start = m.start()
>>             level += 1
>>         else:
>>             assert False
>>     if level > 0:
>>         raise ValueError("unclosed parens remain")
>> 
>> 
>> if __name__ == "__main__":
>>     with open("lan sample text file.txt") as instream:
>>         text = instream.read()
>>     for chunk in scan(text):
>>         print(chunk)
>> $ python3 parse.py
>> ("xE'", PUT(xx.xxxx.),"'")
>> ("TRUuuuth")
> 
> Hello Peter! I tried this on my actual working files and it returned this
> error: "unclosed parens remain". In this case, how can I continue to parse
> through my text files by only extracting those with balanced parentheses
> and ignore those that are incomplete?

filenames = ...
for filename in filenames:
    with open(filename) as instream:
        text = instream.read()
        try:
            chunks = list(scan(text))
        except ValueError as err:
            print(f"{err} in file {filename!r}", file=sys.stderr)
        else:
           for chunk in chunks:
               print(chunk)



From geremy85 at gmail.com  Mon Dec  2 23:58:11 2019
From: geremy85 at gmail.com (geremy85 at gmail.com)
Date: Mon, 2 Dec 2019 20:58:11 -0800 (PST)
Subject: lxml question -- creating an etree.Element attribute with ':' in
 the name
In-Reply-To: <mailman.129.1379531615.18130.python-list@python.org>
References: <F1EF559F-76E7-42F4-AC96-5EC0E8B6DBA1@panix.com>
 <mailman.129.1379531615.18130.python-list@python.org>
Message-ID: <0fc93031-c19f-47ea-9539-c4d94e12314a@googlegroups.com>

Theanks a lot

From Karsten.Hilbert at gmx.net  Tue Dec  3 11:00:45 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Tue, 3 Dec 2019 17:00:45 +0100
Subject: lxml question -- creating an etree.Element attribute with ':' in
 the name
In-Reply-To: <0fc93031-c19f-47ea-9539-c4d94e12314a@googlegroups.com>
References: <F1EF559F-76E7-42F4-AC96-5EC0E8B6DBA1@panix.com>
 <mailman.129.1379531615.18130.python-list@python.org>
 <0fc93031-c19f-47ea-9539-c4d94e12314a@googlegroups.com>
Message-ID: <20191203160044.GB1277@hermes.hilbert.loc>

On Mon, Dec 02, 2019 at 08:58:11PM -0800, geremy85 at gmail.com wrote:
> Date: Mon, 2 Dec 2019 20:58:11 -0800 (PST)
> From: geremy85 at gmail.com
> To: python-list at python.org
> Subject: Re: lxml question -- creating an etree.Element attribute with ':'
>  in the name
> User-Agent: G2/1.0
>
> Theanks a lot
> --
> https://mail.python.org/mailman/listinfo/python-list

you are welcoem

--
GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B

From __peter__ at web.de  Tue Dec  3 11:24:17 2019
From: __peter__ at web.de (Peter Otten)
Date: Tue, 03 Dec 2019 17:24:17 +0100
Subject: Extending property using a Subclass - single method - why
 Super(Baz, Baz).name.__set__ ?
References: <qs59b0$fmo$1@dont-email.me> <qs5g5t$40hs$1@blaine.gmane.org>
 <mailman.292.1575371781.25794.python-list@python.org>
 <qs5odn$uut$1@dont-email.me>
Message-ID: <qs627h$4at4$1@blaine.gmane.org>

Veek M wrote:

> you've misunderstood my question

There were a lot of foobars bazzing in my head, but at least I tried ;)

> , let me try again:
> 
> So this is a simple descriptor class and as you can see, dunder-set needs
> 3 args: the descriptor CONTAINER/Bar-instance is the first arg, then a
> reference to the using instance/Foo-instance
> 
> class Bar(object):
>     
>     def __set__(self, instance, value):
>         #b-instance of Bar, f-instance of Foo, value
>         print(self, instance, value)
>         
>         
> class Foo(object):
>     b = Bar()
>     
> f = Foo()
> print(f)
> f.b = 10
> 
> 1. Now when we create/use @property..
> what is the first and second argument to dunder-set
> 
> (my guess is, the @property is the first arg and the second arg is 'Foo'
> IF you do
> 
> class Foo(object):
>    @property
>    def whatever..
> 
> Am I right? Is there a way to check?

@foo
def bar(...):
...

is an alternative way to writing

def bar(...):
...
bar = foo(bar)

so you can just add conforming __init__() and __get__() methods to your Bar 
descriptor and see for yourself:

>> class Bar:
...     def __init__(self, fget): pass
...     def __set__(*args): print(args)
...     def __get__(*args): pass
... 
>>> class Foo:
...     @Bar
...     def whatever(self): pass
... 
>>> foo = Foo()
>>> foo.whatever = 42
(<__main__.Bar object at 0x7f92b55d70b8>, <__main__.Foo object at 
0x7f92b55d70f0>, 42)

> 2. The Class Bar/descriptor acts a wrapper/protector for some sekret _var
> and therefore it gets all the data needed to make a judgement call.. that
> is, it's own name/instance-ref and the using class/instance-name-ref
> 
> Note that he's receiving instance-references
> 
> therefore when I start sub-classing a property why does he then switch to
> class-references/class-variables

If you were subclassing a property you'd do

class my_property(property):
   # tinker with __get/set/whatnot__

When you want to wrap a property defined in a superclass the property 
instance is not part of the class hierarchy that you are interested in. 
Instead of calling super() it has to figure out the base class of its "host" 
class manually.

If you want overridable properties you can devise a way to look up the 
method:

>>> class Foo:
...     @property
...     def name(self): return self.get_name()
...     @name.setter
...     def name(self, value): self.set_name(value)
...     def set_name(self, value): self._name = value
...     def get_name(self): return self._name
... 
>>> class Bar(Foo):
...     def set_name(self, value):
...         print("setting")
...         super().set_name(value)
...     def get_name(self):
...         print("getting")
...         return super().get_name()
... 
>>> foo = Foo()
>>> foo.name = "bar"
>>> foo.name
'bar'
>>> bar = Bar()
>>> bar.name = "baz"
setting
>>> bar.name
getting
'baz'



From python.list at tim.thechases.com  Tue Dec  3 11:23:08 2019
From: python.list at tim.thechases.com (Tim Chase)
Date: Tue, 3 Dec 2019 10:23:08 -0600
Subject: increasing the page size of a dbm store?
In-Reply-To: <4dd1ac29-8803-a1bd-3158-0cd90f392c48@gmail.com>
References: <20191126192432.535ee241@bigbox.attlocal.net>
 <0EAFC9E0-02D2-4745-99B7-654B7A445EDD@barrys-emacs.org>
 <20191201205016.577673f9@bigbox.attlocal.net>
 <4dd1ac29-8803-a1bd-3158-0cd90f392c48@gmail.com>
Message-ID: <20191203102308.1c0911c8@bigbox.attlocal.net>

On 2019-12-02 16:49, Michael Torrie wrote:
> On 12/1/19 7:50 PM, Tim Chase wrote:
> > After sparring with it a while, I tweaked the existing job so
> > that it chunked things into dbm-appropriate sizes to limp
> > through; for the subsequent job (where I would have used dbm
> > again) I went ahead and switched to sqlite and had no further
> > issues.  
> 
> How did you replace a key/value store with a relational database?
> Is a SQLite database fast enough at this sort of thing that it
> wasn't really designed for?

It was certainly slower, though it wasn't so bad once I had proper
indexing and submitted queries that pulled back multiple results in
one query.

But even with the slightly slower run-time aspects, it was still
faster than starting a job (expecting it to run to completion
overnight), having it crash, manually deleting my cache, and manually
resuming from where it left off, all multiple times.

And all said, since it was network I/O bound, once I had the
populated cache (resulting cache.db file was about 1TB...thank
goodness for transparent compression with ZFS), turnarounds took more
like 30min rather than 3 days.  More the "go work on something else
and come back" than the "let it run overnight".

-tkc



From rgaddi at highlandtechnology.invalid  Tue Dec  3 13:01:22 2019
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Tue, 3 Dec 2019 10:01:22 -0800
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <mailman.290.1575337820.25794.python-list@python.org>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
 <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
 <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>
 <mailman.290.1575337820.25794.python-list@python.org>
Message-ID: <qs67ti$4h9$1@dont-email.me>

On 12/2/19 5:50 PM, Richard Damon wrote:

> 
> Perhaps array could be extended so that it took '4' for a 4 byte integer
> and '8' for an 8 byte integer (maybe 'U4' and 'U8' for unsigned). Might
> as well also allow 1 and 2 for completeness for char and short (but
> those are currently consistent).
> 

I will note that numpy arrays give exactly this level of control, as do ctypes 
arrays.  The standard array library might just be the wrong tool for the job of 
reading binary data.

From Chris.Clark at actian.com  Wed Dec  4 00:15:05 2019
From: Chris.Clark at actian.com (Chris Clark)
Date: Wed, 4 Dec 2019 05:15:05 +0000
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
 <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
 <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>
Message-ID: <CY4PR06MB234329EF5FB97642D2CBEFA39F5D0@CY4PR06MB2343.namprd06.prod.outlook.com>

Thanks for all the replies (and apologies for top posting, I have a brain dead email client ?).

I think the consensus from the various threads is that the docs are either lacking or misleading.

I mentioned that this impacts bytes and the problem there is more telling as it hard fails (this is how I first discovered this was an issue):

    >>> array.array('L', b'\0\0\0\0')
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    ValueError: string length not a multiple of item size

I don't believe the documentation is accurate by using the word "minimum". Minimum would suggest that it would accept a 4-byte value as a minimum and on 64-bit it does *not*, it hard fails. If it were to document that, "the sizes are native integer types for the platform, the table documents some typical but *not* guaranteed sizes", that would be more clear.

For struct - I think the '<' and '=' non-padding docs could benefit from some explanation.. I'm not sure what yet ?

I saw a few suggestions on alternatives for size specifications, I'm definitely in favor of that (right now I'm probing I and L to determine size before using them for real). I don?t think U prefix would work as array really only accepts a single specifier. If array was to be updated to use multiple character specifiers I would recommend matching the struct specifier (which it is close to at the moment) format.

For my uses case I'm seriously thinking about not using array moving forward and only using struct. I briefly wondered about ctypes (it has nice names, e.g. c_int64 that are unambiguous) but then I remembered it is not available in Jython).

With the benefit of hindsight it would have been better if array (and struct) used stdint.h types, those types and lengths are explicitly documented.

Regarding Barry's comment, yep size consistency with array is a pain - what I implemented as workaround is below (and likely to be my solution going forward):

    x = array.array('L', [0])
    if x.itemsize == 4:
        FMT_ARRAY_4BYTE = 'L'
        FMT_STRUCT_4BYTE = '<L'
    else:
        x = array.array('I', [0])
        if x.itemsize == 4:
            FMT_ARRAY_4BYTE = 'I'
            FMT_STRUCT_4BYTE = '<L'
    del(x)

and then use the constants in array/struct calls where (binary) file IO is happening.

Any other thoughts before I open doc bugs/PRs?

Thanks!

Chris

-----Original Message-----
From: Richard Damon <Richard at Damon-Family.org> 
Sent: Monday, December 2, 2019 5:50 PM
To: python-list at python.org
Subject: Re: array and struct 64-bit Linux change in behavior Python 3.7 and 2.7

On 12/2/19 4:25 PM, Barry Scott wrote:
>
>> On 2 Dec 2019, at 17:55, Rob Gaddi <rgaddi at highlandtechnology.invalid> wrote:
>>
>> On 12/2/19 9:26 AM, Chris Clark wrote:
>>> Test case:
>>>                import array
>>>                array.array('L', [0]) # x.itemsize == 8  rather than 
>>> 4 This works fine (returns 4) under Windows Python 3.7.3 64-bit 
>>> build.
>>> Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
>>> It impacts all uses types of array (e.g. reading from byte strings).
>>> The struct module is a little different:
>>> import struct
>>> x = struct.pack('L', 0)
>>> # len(x) ===8 rather than 4
>>> This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.
>>> Wanted to post here for comments before opening a bug at 
>>> https://bugs.python.org/ 
>>> Is anyone seeing this under Debian/Ubuntu?
>>> Chris
>> I'd say not a bug, at least in array.  Reading that array documentation you linked, 4 is explicitly the MINIMUM size in bytes, not the guaranteed size.
> I'm wondering how useful it is that for array you can read from a file but have no ideas how many bytes each item needs.
> If I have a file with int32_t  in it I cannot from the docs know how to read that file into an array.
>
>> The struct situation is, as you said, a bit different.  I believe that with the default native alignment @, you're seeing 4-byte data padded to an 8-byte alignment, not 8-byte data.  That does seem to go against what the struct documentation says, "Padding is only automatically added between successive structure members. No padding is added at the beginning or the end of the encoded struct."
> The 'L' in struct is documented for 3.7 to use 4 bytes, but in fact uses 8, on fedora 31. Doc bug?
>
>>>> x=struct.pack('L',0x102030405)
>>>> x
> b'\x05\x04\x03\x02\x01\x00\x00\x00'
>
> Given I have exact control with b, h, i, and q but L is not fixed in size I'm not sure how it can be used with certainty across OS and versions.
>
> Barry
>
Actually, you DON'T have exact control with those sizes, it just happens that all the platforms you are using happen to have the same size for those types. Welcome to the ambiguity in the C type system, the basic types are NOT fixed in size. L means 'Long' and as Christian said, that is 8 byte long on Linux-64 bit. 'L' is exactly the right type for interfacing with a routine defined as taking a long. The issue is that you don't know what type a int32_t will be (it might be int, or it might be long, and long might not be 32 bits, it will be at least 32 bits).

Perhaps array could be extended so that it took '4' for a 4 byte integer and '8' for an 8 byte integer (maybe 'U4' and 'U8' for unsigned). Might as well also allow 1 and 2 for completeness for char and short (but those are currently consistent).

--
Richard Damon



From rosuav at gmail.com  Wed Dec  4 00:48:42 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 4 Dec 2019 16:48:42 +1100
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <CY4PR06MB234329EF5FB97642D2CBEFA39F5D0@CY4PR06MB2343.namprd06.prod.outlook.com>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
 <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
 <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>
 <CY4PR06MB234329EF5FB97642D2CBEFA39F5D0@CY4PR06MB2343.namprd06.prod.outlook.com>
Message-ID: <CAPTjJmrg=1Ueh+As95OY7hxgMGi4FzWdGN1x5YasS6ve5j1L8w@mail.gmail.com>

On Wed, Dec 4, 2019 at 4:16 PM Chris Clark <Chris.Clark at actian.com> wrote:
> I think the consensus from the various threads is that the docs are either lacking or misleading.
>
> I mentioned that this impacts bytes and the problem there is more telling as it hard fails (this is how I first discovered this was an issue):
>
>     >>> array.array('L', b'\0\0\0\0')
>     Traceback (most recent call last):
>       File "<stdin>", line 1, in <module>
>     ValueError: string length not a multiple of item size
>
> I don't believe the documentation is accurate by using the word "minimum". Minimum would suggest that it would accept a 4-byte value as a minimum and on 64-bit it does *not*, it hard fails. If it were to document that, "the sizes are native integer types for the platform, the table documents some typical but *not* guaranteed sizes", that would be more clear.
>

I think array.array() is possibly the wrong tool for this job. If you
have a collection of bytes from some well-defined source (eg you're
parsing a file in a known format), struct is better suited to it,
because it's easy to define both the size and byte order.

> For my uses case I'm seriously thinking about not using array moving forward and only using struct. I briefly wondered about ctypes (it has nice names, e.g. c_int64 that are unambiguous) but then I remembered it is not available in Jython).
>

I wouldn't bother with ctypes for this type of job.

> Regarding Barry's comment, yep size consistency with array is a pain - what I implemented as workaround is below (and likely to be my solution going forward):
>
>     x = array.array('L', [0])
>     if x.itemsize == 4:
>         FMT_ARRAY_4BYTE = 'L'
>         FMT_STRUCT_4BYTE = '<L'
>     else:
>         x = array.array('I', [0])
>         if x.itemsize == 4:
>             FMT_ARRAY_4BYTE = 'I'
>             FMT_STRUCT_4BYTE = '<L'
>     del(x)
>
> and then use the constants in array/struct calls where (binary) file IO is happening.

Yep, looks like struct is the way to go here. (Especially since you
don't have a final 'else'.)

ChrisA

From p4j at j4d.net  Wed Dec  4 08:21:46 2019
From: p4j at j4d.net (Pankaj Jangid)
Date: Wed, 04 Dec 2019 18:51:46 +0530
Subject: Developers are advised to purge these malicious packages
Message-ID: <m2wobcusyd.fsf@j4d.net>


```
The Python security team removed two trojanized Python libraries from
PyPI (Python Package Index) that were caught stealing SSH and GPG keys
from the projects of infected developers.

The first is "python3-dateutil," which imitated the popular "dateutil"
library. The second is "jeIlyfish" (the first L is an I), which mimicked
the "jellyfish" library.
```

https://www.zdnet.com/article/two-malicious-python-libraries-removed-from-pypi/

Regards,
-- 
Pankaj Jangid



From ast at invalid  Wed Dec  4 10:18:04 2019
From: ast at invalid (ast)
Date: Wed, 4 Dec 2019 16:18:04 +0100
Subject: threading
Message-ID: <5de7ce2e$0$3871$426a74cc@news.free.fr>

Hi

An operation like x+=1 on a global variable x is not thread safe because 
there can be a thread switch between reading and writing to x.
The correct way is to use a lock

lock = threading.Lock

with lock:
     x+=1

I tried to write a program without the lock which should fail.
Here it is:

import threading

x = 0

def test():
     global x
     for i in range(100):
         x+=1

threadings = []

for i in range(100):
     t = threading.Thread(target=test)
     threadings.append(t)
     t.start()

for t in threadings:
     t.join()

print(x)

10000

The result is always correct: 10000
Why ?

Secondly, how the switch between threads is done by the processor ? Is 
there a hardware interrupt coming from a timer ?

From David.Raymond at tomtom.com  Wed Dec  4 10:47:57 2019
From: David.Raymond at tomtom.com (David Raymond)
Date: Wed, 4 Dec 2019 15:47:57 +0000
Subject: threading
In-Reply-To: <5de7ce2e$0$3871$426a74cc@news.free.fr>
References: <5de7ce2e$0$3871$426a74cc@news.free.fr>
Message-ID: <VI1PR07MB60298023CCE044C52897BE33875D0@VI1PR07MB6029.eurprd07.prod.outlook.com>

100 increments happen very fast, and means each thread will probably complete before the main thread has even started the next one. Bump that up to 1_000_000 or so and you'll probably trigger it.

I did a test with a print(x) at the start of test() to see what the number was when each thread kicked off, and the very first thread had got it up to 655,562 by the time the second thread had started and gotten to that print statement.


-----Original Message-----
From: Python-list <python-list-bounces+david.raymond=tomtom.com at python.org> On Behalf Of ast
Sent: Wednesday, December 4, 2019 10:18 AM
To: python-list at python.org
Subject: threading

Hi

An operation like x+=1 on a global variable x is not thread safe because 
there can be a thread switch between reading and writing to x.
The correct way is to use a lock

lock = threading.Lock

with lock:
     x+=1

I tried to write a program without the lock which should fail.
Here it is:

import threading

x = 0

def test():
     global x
     for i in range(100):
         x+=1

threadings = []

for i in range(100):
     t = threading.Thread(target=test)
     threadings.append(t)
     t.start()

for t in threadings:
     t.join()

print(x)

10000

The result is always correct: 10000
Why ?

Secondly, how the switch between threads is done by the processor ? Is 
there a hardware interrupt coming from a timer ?
-- 
https://mail.python.org/mailman/listinfo/python-list

From david at lowryduda.com  Wed Dec  4 12:59:57 2019
From: david at lowryduda.com (David Lowry-Duda)
Date: Wed, 4 Dec 2019 12:59:57 -0500
Subject: Developers are advised to purge these malicious packages
In-Reply-To: <mailman.18.1575478803.4247.python-list@python.org>
References: <mailman.18.1575478803.4247.python-list@python.org>
Message-ID: <20191204175957.GA24123@mail.lowryduda.com>

I notice that "python3-dateutil" is in over 4000 github repositories 
[1]. That sounds like a disaster.

[1]: https://github.com/search?q=python3-dateutil&type=Code

- DLD

--
David Lowry-Duda <david at lowryduda.com> <davidlowryduda.com>

From christian at python.org  Wed Dec  4 13:17:58 2019
From: christian at python.org (Christian Heimes)
Date: Wed, 4 Dec 2019 19:17:58 +0100
Subject: Developers are advised to purge these malicious packages
In-Reply-To: <20191204175957.GA24123@mail.lowryduda.com>
References: <mailman.18.1575478803.4247.python-list@python.org>
 <20191204175957.GA24123@mail.lowryduda.com>
Message-ID: <qs8t8m$cdn$1@blaine.gmane.org>

On 04/12/2019 18.59, David Lowry-Duda wrote:
> I notice that "python3-dateutil" is in over 4000 github repositories 
> [1]. That sounds like a disaster.
> 
> [1]: https://github.com/search?q=python3-dateutil&type=Code

At least the first pages are packaging files for Debian, Fedora, and
other Linux distributions. Downstream distributions provide a Python
package under multiple names. For example the Fedora's build spec [1]
creates python2-dateutil and python3-dateutil packages from the
python-dateutil upstream project.

Attackers abuse the fact and try to typo-squat packages in hope that
somebody uses the Linux distribution package name "python3-dateutil"
instead of the upstream name "python-dateutil" in requirements.txt

Christian

[1]
https://src.fedoraproject.org/rpms/python-dateutil/blob/master/f/python-dateutil.spec


From rob at despammer.com  Wed Dec  4 15:25:33 2019
From: rob at despammer.com (RobH)
Date: Wed, 4 Dec 2019 20:25:33 +0000
Subject: ImportError: No module named Adafruit_SSD1306
Message-ID: <h4qj1uFq6imU1@mid.individual.net>

I am trying to do this project on a pi zero:

http://frederickvandenbosch.be/?p=1365

I copied the code to the pi zero Download folder and when I run it I get 
the above error at line 4
Import Adafruit_SSD1306

I am using python version 2.7.16, if that makes any difference
I have the same module as the authors' link goes to :

Monochrome 1.3" 128x64 OLED graphic display - STEMMA QT / Qwiic

Have I missed something.

From torriem at gmail.com  Wed Dec  4 17:34:50 2019
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 4 Dec 2019 15:34:50 -0700
Subject: Developers are advised to purge these malicious packages
In-Reply-To: <20191204175957.GA24123@mail.lowryduda.com>
References: <mailman.18.1575478803.4247.python-list@python.org>
 <20191204175957.GA24123@mail.lowryduda.com>
Message-ID: <32dc24a3-1c25-4497-7bdb-428c7a516f2b@gmail.com>

On 12/4/19 10:59 AM, David Lowry-Duda wrote:
> I notice that "python3-dateutil" is in over 4000 github repositories 
> [1]. That sounds like a disaster.
> 
> [1]: https://github.com/search?q=python3-dateutil&type=Code

It's clearly not, as Christian has already said. In fact it would be
very difficult to determine from a github search whether this bad
package was actually deployed anywhere. Since it presents a fake
"dateutil" module, imports would look the same and proper as using the
correct one.  The only way this package comes into play is if someone
pip installed it, or had an install script that installed it, or if it
were bundled in the source tree.

So this is very bad indeed, but not as bad as you suggest. We're not
nearly as much at risk as node.js npm users are yet.

From best_lay at yahoo.com  Wed Dec  4 17:33:45 2019
From: best_lay at yahoo.com (Wildman)
Date: Wed, 04 Dec 2019 16:33:45 -0600
Subject: ImportError: No module named Adafruit_SSD1306
References: <h4qj1uFq6imU1@mid.individual.net>
Message-ID: <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>

On Wed, 04 Dec 2019 20:25:33 +0000, RobH wrote:

> I am trying to do this project on a pi zero:
> 
> http://frederickvandenbosch.be/?p=1365
> 
> I copied the code to the pi zero Download folder and when I run it I get 
> the above error at line 4
> Import Adafruit_SSD1306
> 
> I am using python version 2.7.16, if that makes any difference
> I have the same module as the authors' link goes to :
> 
> Monochrome 1.3" 128x64 OLED graphic display - STEMMA QT / Qwiic
> 
> Have I missed something.

The error indicates that Adafruit_SSD1306 in not installed.

https://github.com/adafruit/Adafruit_Python_SSD1306

-- 
<Wildman> GNU/Linux user #557453
The cow died so I don't need your bull!

From rob at despammer.com  Wed Dec  4 18:06:44 2019
From: rob at despammer.com (RobH)
Date: Wed, 4 Dec 2019 23:06:44 +0000
Subject: ImportError: No module named Adafruit_SSD1306
In-Reply-To: <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
Message-ID: <h4qsg6Fs2htU1@mid.individual.net>

On 04/12/2019 22:33, Wildman wrote:
> On Wed, 04 Dec 2019 20:25:33 +0000, RobH wrote:
> 
>> I am trying to do this project on a pi zero:
>>
>> http://frederickvandenbosch.be/?p=1365
>>
>> I copied the code to the pi zero Download folder and when I run it I get
>> the above error at line 4
>> Import Adafruit_SSD1306
>>
>> I am using python version 2.7.16, if that makes any difference
>> I have the same module as the authors' link goes to :
>>
>> Monochrome 1.3" 128x64 OLED graphic display - STEMMA QT / Qwiic
>>
>> Have I missed something.
> 
> The error indicates that Adafruit_SSD1306 in not installed.
> 
> https://github.com/adafruit/Adafruit_Python_SSD1306
> 

I have the library in the same Downloads folder, but I don't know how to 
actually install it as it doesn't have an .sh file included

From python at python.invalid  Wed Dec  4 18:15:28 2019
From: python at python.invalid (Python)
Date: Thu, 5 Dec 2019 00:15:28 +0100
Subject: ImportError: No module named Adafruit_SSD1306
In-Reply-To: <h4qsg6Fs2htU1@mid.individual.net>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net>
Message-ID: <5de83dea$0$31397$426a74cc@news.free.fr>

Le 05/12/2019 ? 00:06, RobH a ?crit?:
> On 04/12/2019 22:33, Wildman wrote:
>> On Wed, 04 Dec 2019 20:25:33 +0000, RobH wrote:
>>
>>> I am trying to do this project on a pi zero:
>>>
>>> http://frederickvandenbosch.be/?p=1365
>>>
>>> I copied the code to the pi zero Download folder and when I run it I get
>>> the above error at line 4
>>> Import Adafruit_SSD1306
>>>
>>> I am using python version 2.7.16, if that makes any difference
>>> I have the same module as the authors' link goes to :
>>>
>>> Monochrome 1.3" 128x64 OLED graphic display - STEMMA QT / Qwiic
>>>
>>> Have I missed something.
>>
>> The error indicates that Adafruit_SSD1306 in not installed.
>>
>> https://github.com/adafruit/Adafruit_Python_SSD1306
>>
> 
> I have the library in the same Downloads folder, but I don't know how to 
> actually install it as it doesn't have an .sh file included

What cannot you understand in the Installing section of README.md?

   sudo python -m pip install --upgrade pip setuptools wheel
   sudo pip install Adafruit-SSD1306

   Or alternatively:

   sudo python -m pip install --upgrade pip setuptools wheel
   git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
   cd Adafruit_Python_SSD1306
   sudo python setup.py install

even WORSE, what cannot you undertand at the top of same file?

   This library has been deprecated! We are leaving this up for
   historical and research purposes but archiving the repository.



From pahome.chen at mirlab.org  Wed Dec  4 22:28:51 2019
From: pahome.chen at mirlab.org (lampahome)
Date: Thu, 5 Dec 2019 11:28:51 +0800
Subject: What does the blue color section in background mean?
Message-ID: <CAB3eZfsPwe-rkmSa=w+S9WAvbQGxOd2XuzS6oy6h-AK483abBQ@mail.gmail.com>

I tried to plot graph about a time-series with library statsmodel.

I decide to plot autocorrelation function, but I don't know the blue
section in the example graph mean...

Can anyone tell me?

The plot_acf example link:
https://www.statsmodels.org/dev/generated/statsmodels.graphics.tsaplots.plot_acf.html#statsmodels.graphics.tsaplots.plot_acf


The  graph in example:
https://www.statsmodels.org/dev/plots/graphics_tsa_plot_acf.png

 thx

From p4j at j4d.net  Thu Dec  5 04:32:47 2019
From: p4j at j4d.net (Pankaj Jangid)
Date: Thu, 05 Dec 2019 15:02:47 +0530
Subject: Developers are advised to purge these malicious packages
References: <mailman.18.1575478803.4247.python-list@python.org>
 <20191204175957.GA24123@mail.lowryduda.com>
 <qs8t8m$cdn$1@blaine.gmane.org>
 <mailman.302.1575483490.25794.python-list@python.org>
Message-ID: <m2k17b2k3k.fsf@j4d.net>

Christian Heimes <christian at python.org> writes:
> On 04/12/2019 18.59, David Lowry-Duda wrote:
>> I notice that "python3-dateutil" is in over 4000 github repositories 
>> [1]. That sounds like a disaster.
>> 
>> [1]: https://github.com/search?q=python3-dateutil&type=Code
>
> At least the first pages are packaging files for Debian, Fedora, and
> other Linux distributions. Downstream distributions provide a Python
> package under multiple names. For example the Fedora's build spec [1]
> creates python2-dateutil and python3-dateutil packages from the
> python-dateutil upstream project.
>
> Attackers abuse the fact and try to typo-squat packages in hope that
> somebody uses the Linux distribution package name "python3-dateutil"
> instead of the upstream name "python-dateutil" in requirements.txt
>
Nice explanation. Thanks.

From barry at barrys-emacs.org  Thu Dec  5 04:27:43 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Thu, 5 Dec 2019 09:27:43 +0000
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
 <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
 <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>
Message-ID: <8C71B143-C11A-4A1F-901E-6CEFF6D73814@barrys-emacs.org>



> On 3 Dec 2019, at 01:50, Richard Damon <Richard at Damon-Family.org> wrote:
> 
> On 12/2/19 4:25 PM, Barry Scott wrote:
>> 
>>> On 2 Dec 2019, at 17:55, Rob Gaddi <rgaddi at highlandtechnology.invalid> wrote:
>>> 
>>> On 12/2/19 9:26 AM, Chris Clark wrote:
>>>> Test case:
>>>>               import array
>>>>               array.array('L', [0])
>>>> # x.itemsize == 8  rather than 4
>>>> This works fine (returns 4) under Windows Python 3.7.3 64-bit build.
>>>> Under Ubuntu; Python 2.7.15rc1, 3.6.5, 3.70b3 64-bit this returns 8. Documentation at https://docs.python.org/3/library/array.html explicitly states 'L' is for size 4.
>>>> It impacts all uses types of array (e.g. reading from byte strings).
>>>> The struct module is a little different:
>>>> import struct
>>>> x = struct.pack('L', 0)
>>>> # len(x) ===8 rather than 4
>>>> This can be worked around by using '=L' - which is not well documented - so this maybe a doc issue.
>>>> Wanted to post here for comments before opening a bug at https://bugs.python.org/
>>>> Is anyone seeing this under Debian/Ubuntu?
>>>> Chris
>>> I'd say not a bug, at least in array.  Reading that array documentation you linked, 4 is explicitly the MINIMUM size in bytes, not the guaranteed size.
>> I'm wondering how useful it is that for array you can read from a file but have no ideas how many bytes each item needs.
>> If I have a file with int32_t  in it I cannot from the docs know how to read that file into an array.
>> 
>>> The struct situation is, as you said, a bit different.  I believe that with the default native alignment @, you're seeing 4-byte data padded to an 8-byte alignment, not 8-byte data.  That does seem to go against what the struct documentation says, "Padding is only automatically added between successive structure members. No padding is added at the beginning or the end of the encoded struct."
>> The 'L' in struct is documented for 3.7 to use 4 bytes, but in fact uses 8, on fedora 31. Doc bug?
>> 
>>>>> x=struct.pack('L',0x102030405)
>>>>> x
>> b'\x05\x04\x03\x02\x01\x00\x00\x00'
>> 
>> Given I have exact control with b, h, i, and q but L is not fixed in size I'm not sure how it can be used with certainty across OS and versions.
>> 
>> Barry
>> 
> Actually, you DON'T have exact control with those sizes, it just happens
> that all the platforms you are using happen to have the same size for
> those types.

According to the docs for struct (python 2.7 and python 3.8) I do have exact control for the types I listed.
Or did I miss a caveat on that page?

The docs for array indeed show that you have no exact control and that is what I'm commenting on.
As other have observed that makes array the wrong tool to read data of a fixed format.

> Welcome to the ambiguity in the C type system, the basic
> types are NOT fixed in size.

Of course that is why int32_t etc where added to the C standards.

> L means 'Long' and as Christian said, that
> is 8 byte long on Linux-64 bit. 'L' is exactly the right type for
> interfacing with a routine defined as taking a long. The issue is that
> you don't know what type a int32_t will be (it might be int, or it might
> be long, and long might not be 32 bits, it will be at least 32 bits).
> 
> Perhaps array could be extended so that it took '4' for a 4 byte integer
> and '8' for an 8 byte integer (maybe 'U4' and 'U8' for unsigned). Might
> as well also allow 1 and 2 for completeness for char and short (but
> those are currently consistent).

Personally I have never thought to use array.

I have user struct and ctypes extensively and they give me the
documented control I need to work with data structures and APIs.

Barry

> 
> -- 
> Richard Damon
> 
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From rob at despammer.com  Thu Dec  5 05:07:28 2019
From: rob at despammer.com (RobH)
Date: Thu, 5 Dec 2019 10:07:28 +0000
Subject: ImportError: No module named Adafruit_SSD1306
In-Reply-To: <5de83dea$0$31397$426a74cc@news.free.fr>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
Message-ID: <h4s371F50c5U1@mid.individual.net>

On 04/12/2019 23:15, Python wrote:
> Le 05/12/2019 ? 00:06, RobH a ?crit?:
>> On 04/12/2019 22:33, Wildman wrote:
>>> On Wed, 04 Dec 2019 20:25:33 +0000, RobH wrote:
>>>
>>>> I am trying to do this project on a pi zero:
>>>>
>>>> http://frederickvandenbosch.be/?p=1365
>>>>
>>>> I copied the code to the pi zero Download folder and when I run it I 
>>>> get
>>>> the above error at line 4
>>>> Import Adafruit_SSD1306
>>>>
>>>> I am using python version 2.7.16, if that makes any difference
>>>> I have the same module as the authors' link goes to :
>>>>
>>>> Monochrome 1.3" 128x64 OLED graphic display - STEMMA QT / Qwiic
>>>>
>>>> Have I missed something.
>>>
>>> The error indicates that Adafruit_SSD1306 in not installed.
>>>
>>> https://github.com/adafruit/Adafruit_Python_SSD1306
>>>
>>
>> I have the library in the same Downloads folder, but I don't know how 
>> to actually install it as it doesn't have an .sh file included
> 
> What cannot you understand in the Installing section of README.md?
> 
>  ? sudo python -m pip install --upgrade pip setuptools wheel
>  ? sudo pip install Adafruit-SSD1306
> 
>  ? Or alternatively:
> 
>  ? sudo python -m pip install --upgrade pip setuptools wheel
>  ? git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
>  ? cd Adafruit_Python_SSD1306
>  ? sudo python setup.py install
> 
> even WORSE, what cannot you undertand at the top of same file?
> 
>  ? This library has been deprecated! We are leaving this up for
>  ? historical and research purposes but archiving the repository.
> 
> 

I was looking at the wrong file previously, and got mixed up, doh!
I have installed the Adafruit_Python_SSD1306 library now.

(There is no mention that I can see about installing other libraries etc 
to get the project to work, by the author)

I had to make some changes in the authors file here:

import time
import Adafruit_SSD1306
import RPi.GPIO as GPIO <<<<here
from PIL import Image   <<<<here
from PIL import ImageFont <<<<here
from PIL import ImageDraw <<<<here
import os

Due to
import ImageFont
ImportError: No module named ImageFont

etc

Now I get these errors:

pi at raspberrypi:~/Downloads $ python Internet.py
Traceback (most recent call last):
   File "Internet.py", line 164, in <module>
     disp.begin()
   File "build/bdist.linux-armv6l/egg/Adafruit_SSD1306/SSD1306.py", line 
148, in begin
   File "build/bdist.linux-armv6l/egg/Adafruit_SSD1306/SSD1306.py", line 
247, in _initialize
   File "build/bdist.linux-armv6l/egg/Adafruit_SSD1306/SSD1306.py", line 
129, in command
   File "build/bdist.linux-armv6l/egg/Adafruit_GPIO/I2C.py", line 116, 
in write8
   File "build/bdist.linux-armv6l/egg/Adafruit_PureIO/smbus.py", line 
268, in write_byte_data
IOError: [Errno 121] Remote I/O error.

Maybe I have created these errors unknowingly by the said changes I made.

Thanks

From python at mrabarnett.plus.com  Thu Dec  5 09:17:07 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 5 Dec 2019 14:17:07 +0000
Subject: What does the blue color section in background mean?
In-Reply-To: <CAB3eZfsPwe-rkmSa=w+S9WAvbQGxOd2XuzS6oy6h-AK483abBQ@mail.gmail.com>
References: <CAB3eZfsPwe-rkmSa=w+S9WAvbQGxOd2XuzS6oy6h-AK483abBQ@mail.gmail.com>
Message-ID: <5982de96-8609-eee2-9b94-cbbd8dabb874@mrabarnett.plus.com>

On 2019-12-05 03:28, lampahome wrote:
> I tried to plot graph about a time-series with library statsmodel.
> 
> I decide to plot autocorrelation function, but I don't know the blue
> section in the example graph mean...
> 
> Can anyone tell me?
> 
> The plot_acf example link:
> https://www.statsmodels.org/dev/generated/statsmodels.graphics.tsaplots.plot_acf.html#statsmodels.graphics.tsaplots.plot_acf
> 
> 
> The  graph in example:
> https://www.statsmodels.org/dev/plots/graphics_tsa_plot_acf.png
> 
I think that's the confidence interval.

Here's another example that shows the same kind of thing:

https://machinelearningmastery.com/gentle-introduction-autocorrelation-partial-autocorrelation/

From aishan0403 at gmail.com  Thu Dec  5 10:31:54 2019
From: aishan0403 at gmail.com (A S)
Date: Thu, 5 Dec 2019 07:31:54 -0800 (PST)
Subject: Extract sentences in nested parentheses using Python
In-Reply-To: <mailman.293.1575388083.25794.python-list@python.org>
References: <7a365fa0-e721-4a95-8c30-d3661301a7b2@googlegroups.com>
 <qs3g03$57h2$1@blaine.gmane.org>
 <mailman.280.1575306068.25794.python-list@python.org>
 <f6af05a2-86ee-411b-949d-2e1aa24bc4c0@googlegroups.com>
 <qs6036$804m$1@blaine.gmane.org>
 <mailman.293.1575388083.25794.python-list@python.org>
Message-ID: <dc0b0d02-0e6f-4ce5-b2fb-1906cf50c6a7@googlegroups.com>

On Tuesday, 3 December 2019 23:48:21 UTC+8, Peter Otten  wrote:
> A S wrote:
> 
> > On Tuesday, 3 December 2019 01:01:25 UTC+8, Peter Otten  wrote:
> >> A S wrote:
> >> 
> >> I think I've seen this question before ;)
> >> 
> >> > I am trying to extract all strings in nested parentheses (along with
> >> > the parentheses itself) in my .txt file. Please see the sample .txt
> >> > file that I have used in this example here:
> >> > (https://drive.google.com/open?id=1UKc0ZgY9Fsz5O1rSeBCLqt5dwZkMaQgr).
> >> > 
> >> > I have tried and done up three different codes but none of them seems
> >> > to be able to extract all the nested parentheses. They can only extract
> >> > a portion of the nested parentheses. Any advice on what I've done wrong
> >> > could really help!
> >> > 
> >> > Here are the three codes I have done so far:
> >> > 
> >> > 1st attempt:
> >> > 
> >> > import re
> >> > from os.path import join
> >> > 
> >> > def balanced_braces(args):
> >> >     parts = []
> >> >     for arg in args:
> >> >         if '(' not in arg:
> >> >             continue
> >> 
> >> There could still be a ")" that you miss
> >> 
> >> >         chars = []
> >> >         n = 0
> >> >         for c in arg:
> >> >             if c == '(':
> >> >                 if n > 0:
> >> >                     chars.append(c)
> >> >                 n += 1
> >> >             elif c == ')':
> >> >                 n -= 1
> >> >                 if n > 0:
> >> >                     chars.append(c)
> >> >                 elif n == 0:
> >> >                     parts.append(''.join(chars).lstrip().rstrip())
> >> >                     chars = []
> >> >             elif n > 0:
> >> >                 chars.append(c)
> >> >     return parts
> >> 
> >> It's probably easier to understand and implement when you process the
> >> complete text at once. Then arbitrary splits don't get in the way of your
> >> quest for ( and ). You just have to remember the position of the first
> >> opening ( and number of opening parens that have to be closed before you
> >> take the complete expression:
> >> 
> >> level:  00011112222100
> >> text:   abc(def(gh))ij
> >>    when we are here^
> >>     we need^
> >> 
> >> A tentative implementation:
> >> 
> >> $ cat parse.py
> >> import re
> >> 
> >> NOT_SET = object()
> >> 
> >> def scan(text):
> >>     level = 0
> >>     start = NOT_SET
> >>     for m in re.compile("[()]").finditer(text):
> >>         if m.group() == ")":
> >>             level -= 1
> >>             if level < 0:
> >>                 raise ValueError("underflow: more closing than opening
> >> parens")
> >>             if level == 0:
> >>                 # outermost closing parenthesis:
> >>                 # deliver enclosed string including parens.
> >>                 yield text[start:m.end()]
> >>                 start = NOT_SET
> >>         elif m.group() == "(":
> >>             if level == 0:
> >>                 # outermost opening parenthesis: remember position.
> >>                 assert start is NOT_SET
> >>                 start = m.start()
> >>             level += 1
> >>         else:
> >>             assert False
> >>     if level > 0:
> >>         raise ValueError("unclosed parens remain")
> >> 
> >> 
> >> if __name__ == "__main__":
> >>     with open("lan sample text file.txt") as instream:
> >>         text = instream.read()
> >>     for chunk in scan(text):
> >>         print(chunk)
> >> $ python3 parse.py
> >> ("xE'", PUT(xx.xxxx.),"'")
> >> ("TRUuuuth")
> > 
> > Hello Peter! I tried this on my actual working files and it returned this
> > error: "unclosed parens remain". In this case, how can I continue to parse
> > through my text files by only extracting those with balanced parentheses
> > and ignore those that are incomplete?
> 
> filenames = ...
> for filename in filenames:
>     with open(filename) as instream:
>         text = instream.read()
>         try:
>             chunks = list(scan(text))
>         except ValueError as err:
>             print(f"{err} in file {filename!r}", file=sys.stderr)
>         else:
>            for chunk in chunks:
>                print(chunk)

hey Peter, it works! Thank you :)

From aishan0403 at gmail.com  Thu Dec  5 10:33:41 2019
From: aishan0403 at gmail.com (A S)
Date: Thu, 5 Dec 2019 07:33:41 -0800 (PST)
Subject: Extract sentences in nested parentheses using Python
In-Reply-To: <mailman.287.1575325361.25794.python-list@python.org>
References: <7a365fa0-e721-4a95-8c30-d3661301a7b2@googlegroups.com>
 <qs3g03$57h2$1@blaine.gmane.org>
 <1d689634-c3db-dd3f-c432-111604d5a784@DancesWithMice.info>
 <mailman.287.1575325361.25794.python-list@python.org>
Message-ID: <9ea51f20-4ed7-4eaa-9042-8aa9d4d2eb6a@googlegroups.com>

On Tuesday, 3 December 2019 06:22:52 UTC+8, DL Neil  wrote:
> On 3/12/19 6:00 AM, Peter Otten wrote:
> > A S wrote:
> > I think I've seen this question before ;)
> 
> In addition to 'other reasons' for @Peter's comment, it is a common 
> ComSc worked-problem or assignment. (in which case, we'd appreciate 
> being told that you/OP is asking for help with "homework")
> 
> 
> >> I am trying to extract all strings in nested parentheses (along with the
> >> parentheses itself) in my .txt file. Please see the sample .txt file that
> >> I have used in this example here:
> >> (https://drive.google.com/open?id=1UKc0ZgY9Fsz5O1rSeBCLqt5dwZkMaQgr).
> >>
> >> I have tried and done up three different codes but none of them seems to
> >> be able to extract all the nested parentheses. They can only extract a
> >> portion of the nested parentheses. Any advice on what I've done wrong
> >> could really help!
> 
> One approach is to research in the hope that there are already existing 
> tools or techniques which may help/save you from 'reinventing the wheel' 
> - when you think about it, a re-statement of open-source objectives.
> 
> How does the Python interpreter break-down Python (text) code into its 
> constituent parts ("tokens") *including* parentheses? Such are made 
> available in (perhaps) a lesser-known corner of the PSL (Python Standard 
> Library). Might you be able to use one such tool?
> 
> The ComSc technique which sprang to mind involves "stacks" (a LIFO data 
> structure) and "RPN" (Reverse Polish Notation). Whereas we like people 
> to take their turn when it comes to limited resources, eg to form a 
> "queue" to purchase/pay for goods at the local store, which is "FIFO" 
> (first-in, first-out); a "stack"/LIFO (last-in, first-out) can be 
> problematic to put into practical application. There are plenty of 
> Python implementations or you can 'roll your own' with a list. Again, 
> I'd likely employ a "deque" from the PSL's Collections library (although 
> as a "stack" rather than as a "double-ended queue"), because the 
> optimisation comes "free". (to my laziness, but after some kind soul 
> sweated-bullets to make it fast (in both senses) for 'the rest of us'!)
> 
> 
> > It's probably easier to understand and implement when you process the
> > complete text at once. Then arbitrary splits don't get in the way of your
> > quest for ( and ). You just have to remember the position of the first
> > opening ( and number of opening parens that have to be closed before you
> > take the complete expression:
> 
> +1
> but as a 'silver surfer', I don't like to be asked to "remember" anything!
> 
> 
> > level:  00011112222100
> >      we need^
> 
> 
> Consider:
> original_text (the contents of the .txt file - add buffering if volumes 
> are huge)
> current_text (the characters we have processed/"recognised" so-far)
> stack (what an original name for such a data-structure! Which will 
> contain each of the partial parenthetical expressions found - but yet to 
> be proven/made complete)
> 
> set current_text to NULSTRING
> for each current_character in original_text:
> 	if current_character is LEFT_PARENTHESIS:
> 		push current_text to stack
> 		set current_text to LEFT_PARENTHESIS
> 	concatenate current_character with current_text
> 	if current_character is RIGHT_PARENTHESIS:
> 		# current_text is a parenthetical expression
> 		# do with it what you will
> 		pop the stack
> 		set current_text to the ex-stack string \
> 			concat current_text's p-expn
> 
> Once working: cover 'special cases' (after above loop), eg original_text 
> which doesn't begin and/or end with parentheses; and error cases, eg 
> pop-ping a NULSTRING, or thinking things are finished but the stack is 
> not yet empty - likely events from unbalanced parentheses!
> 
> original text = "abc(def(gh))ij"
> 
> event 1: in-turn, concatenate characters "abc" as current_text
> event 2: locate (first) left-parenthesis, push current_text to stack(&)
> event 3: concatenate "(def"
> event 4: push, likewise
> event 5: concatenate "(gh"
> event 6: locate (first) right-parenthesis (matches to left-parenthesis 
> begining the current_string!)
> result?: ?print current_text?
> event 7: pop stack and redefine current_text as "(def(gh)"
> event 8: repeat, per event 6
> event 9: current_text will now become "(def(gh))"
> event 10: (special case) run-out of input at "(def(gh)ij"
> event 11: (special case) pop (!any) stack and report "abc(def(gh)"
> 
> 
> NB not sure of need for a "level" number; but if required, you can infer 
> that at any time, from the depth/len() of the stack!
> 
> NBB being a simple-boy, my preference is for a 'single layer' of code, 
> cf @Peter's generator. Regardless the processes are "tokenisation" and 
> "recognition".
> 
> At the back of my mind, was the notion that you may (eventually) be 
> required to work with more than parentheses, eg pair-wise 
> square-brackets and/or quotation-marks. In which case, you will need to 
> also 'push' the token and check for token-pairs when 'pop-ping', as well 
> as (perhaps) recognising lists of tokens to tokenise instead of the two 
> parenthesis characters alone. In which case, I'd take a serious look at 
> the Python Language Services rather than taking a 'roll your own' approach!
> 
> Contrarily, if this spec is 'it', then you might consider optimising the 
> search processes which 'trigger' the two stack operations, by re-working 
> the for-loop and utilising string.find() - prioritising whichever 
> parenthesis is left-most/comes-first - assuming LtR text. (apologies if 
> you have already tried this in one of your previous approaches) 
> Unfortunately, such likely results in 'layers' of code, and a generator 
> might well become the tool-of-choice (I say this before @Peter comes 
> back and (quite deservedly) flays me alive!).
> 
> 
> WebRefs:
> Python Language Services: https://docs.python.org/3/library/language.html
> collections ? Container datatypes: 
> https://docs.python.org/3/library/collections.html
> 
> See also your ComSc text/reference materials.
> -- 
> Regards =dn

Hey DL Neil, this is rather sophisticated for me as I am still learning the basics of Python...But I truly appreciate your help and effort! I did try to read through what you said, but some parts I could not register!

From rob at despammer.com  Thu Dec  5 13:49:40 2019
From: rob at despammer.com (RobH)
Date: Thu, 5 Dec 2019 18:49:40 +0000
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <h4s371F50c5U1@mid.individual.net>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net>
Message-ID: <h4t1q6FbaknU1@mid.individual.net>

On 05/12/2019 10:07, RobH wrote:
> On 04/12/2019 23:15, Python wrote:
>> Le 05/12/2019 ? 00:06, RobH a ?crit?:
>>> On 04/12/2019 22:33, Wildman wrote:
>>>> On Wed, 04 Dec 2019 20:25:33 +0000, RobH wrote:
>>>>
>>>>> I am trying to do this project on a pi zero:
>>>>>
>>>>> http://frederickvandenbosch.be/?p=1365
>>>>>
>>>>> I copied the code to the pi zero Download folder and when I run it 
>>>>> I get
>>>>> the above error at line 4
>>>>> Import Adafruit_SSD1306
>>>>>
>>>>> I am using python version 2.7.16, if that makes any difference
>>>>> I have the same module as the authors' link goes to :
>>>>>
>>>>> Monochrome 1.3" 128x64 OLED graphic display - STEMMA QT / Qwiic
>>>>>
>>>>> Have I missed something.
>>>>
>>>> The error indicates that Adafruit_SSD1306 in not installed.
>>>>
>>>> https://github.com/adafruit/Adafruit_Python_SSD1306
>>>>
>>>
>>> I have the library in the same Downloads folder, but I don't know how 
>>> to actually install it as it doesn't have an .sh file included
>>
>> What cannot you understand in the Installing section of README.md?
>>
>> ?? sudo python -m pip install --upgrade pip setuptools wheel
>> ?? sudo pip install Adafruit-SSD1306
>>
>> ?? Or alternatively:
>>
>> ?? sudo python -m pip install --upgrade pip setuptools wheel
>> ?? git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
>> ?? cd Adafruit_Python_SSD1306
>> ?? sudo python setup.py install
>>
>> even WORSE, what cannot you undertand at the top of same file?
>>
>> ?? This library has been deprecated! We are leaving this up for
>> ?? historical and research purposes but archiving the repository.
>>
>>
> 
> I was looking at the wrong file previously, and got mixed up, doh!
> I have installed the Adafruit_Python_SSD1306 library now.
> 
> (There is no mention that I can see about installing other libraries etc 
> to get the project to work, by the author)
> 

Update:
I did python3 Internet.py
and now only get this error:

pi at raspberrypi:~/Downloads $ python3 Internet.py
   File "Internet.py", line 24
     font = ImageFont.truetype( 'Minecraftia.ttf', 35)
                                                     ^
TabError: inconsistent use of tabs and spaces in indentation

I cannot see what is wrong, as the text is all lined up with that above 
and below:

def display_time():
         # Collect current time and date
         if(time_format):
                 current_time = time.strftime("%I:%M")
         else:
                 current_time = time.strftime("%H:%M")

         current_date = time.strftime("%d/%m/%Y")

         # Clear image buffer by drawing a black filled box
         draw.rectangle((0,0,width,height), outline=0, fill=0)

         # Set font type and size
         font = ImageFont.truetype ('Minecraftia.ttf', 35) << error here

         # Position time
         x_pos = (disp.width/2)-(string_width(font,current_time)/2)
         y_pos = 2 + (disp.height-4-8)/2 - (35/2)


Thanks

From python at mrabarnett.plus.com  Thu Dec  5 14:28:43 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 5 Dec 2019 19:28:43 +0000
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <h4t1q6FbaknU1@mid.individual.net>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net> <h4t1q6FbaknU1@mid.individual.net>
Message-ID: <e1db29a6-550e-554a-bd0f-ee824e071895@mrabarnett.plus.com>

On 2019-12-05 18:49, RobH wrote:
> On 05/12/2019 10:07, RobH wrote:
>> On 04/12/2019 23:15, Python wrote:
>>> Le 05/12/2019 ? 00:06, RobH a ?crit?:
>>>> On 04/12/2019 22:33, Wildman wrote:
>>>>> On Wed, 04 Dec 2019 20:25:33 +0000, RobH wrote:
>>>>>
>>>>>> I am trying to do this project on a pi zero:
>>>>>>
>>>>>> http://frederickvandenbosch.be/?p=1365
>>>>>>
>>>>>> I copied the code to the pi zero Download folder and when I run it 
>>>>>> I get
>>>>>> the above error at line 4
>>>>>> Import Adafruit_SSD1306
>>>>>>
>>>>>> I am using python version 2.7.16, if that makes any difference
>>>>>> I have the same module as the authors' link goes to :
>>>>>>
>>>>>> Monochrome 1.3" 128x64 OLED graphic display - STEMMA QT / Qwiic
>>>>>>
>>>>>> Have I missed something.
>>>>>
>>>>> The error indicates that Adafruit_SSD1306 in not installed.
>>>>>
>>>>> https://github.com/adafruit/Adafruit_Python_SSD1306
>>>>>
>>>>
>>>> I have the library in the same Downloads folder, but I don't know how 
>>>> to actually install it as it doesn't have an .sh file included
>>>
>>> What cannot you understand in the Installing section of README.md?
>>>
>>> ?? sudo python -m pip install --upgrade pip setuptools wheel
>>> ?? sudo pip install Adafruit-SSD1306
>>>
>>> ?? Or alternatively:
>>>
>>> ?? sudo python -m pip install --upgrade pip setuptools wheel
>>> ?? git clone https://github.com/adafruit/Adafruit_Python_SSD1306.git
>>> ?? cd Adafruit_Python_SSD1306
>>> ?? sudo python setup.py install
>>>
>>> even WORSE, what cannot you undertand at the top of same file?
>>>
>>> ?? This library has been deprecated! We are leaving this up for
>>> ?? historical and research purposes but archiving the repository.
>>>
>>>
>> 
>> I was looking at the wrong file previously, and got mixed up, doh!
>> I have installed the Adafruit_Python_SSD1306 library now.
>> 
>> (There is no mention that I can see about installing other libraries etc 
>> to get the project to work, by the author)
>> 
> 
> Update:
> I did python3 Internet.py
> and now only get this error:
> 
> pi at raspberrypi:~/Downloads $ python3 Internet.py
>     File "Internet.py", line 24
>       font = ImageFont.truetype( 'Minecraftia.ttf', 35)
>                                                       ^
> TabError: inconsistent use of tabs and spaces in indentation
> 
> I cannot see what is wrong, as the text is all lined up with that above
> and below:
> 
Are you sure that the indentation is the same? Do all of the lines use 
all spaces or all tabs or indentation? Just because they look lined-up 
doesn't mean that they're doing it with the sequence of characters.

> def display_time():
>           # Collect current time and date
>           if(time_format):
>                   current_time = time.strftime("%I:%M")
>           else:
>                   current_time = time.strftime("%H:%M")
> 
>           current_date = time.strftime("%d/%m/%Y")
> 
>           # Clear image buffer by drawing a black filled box
>           draw.rectangle((0,0,width,height), outline=0, fill=0)
> 
>           # Set font type and size
>           font = ImageFont.truetype ('Minecraftia.ttf', 35) << error here
> 
>           # Position time
>           x_pos = (disp.width/2)-(string_width(font,current_time)/2)
>           y_pos = 2 + (disp.height-4-8)/2 - (35/2)
> 
> 

From rhodri at kynesim.co.uk  Thu Dec  5 14:30:31 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 5 Dec 2019 19:30:31 +0000
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <h4t1q6FbaknU1@mid.individual.net>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net> <h4t1q6FbaknU1@mid.individual.net>
Message-ID: <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>

On 05/12/2019 18:49, RobH wrote:
> Update:
> I did python3 Internet.py
> and now only get this error:
> 
> pi at raspberrypi:~/Downloads $ python3 Internet.py
>  ? File "Internet.py", line 24
>  ??? font = ImageFont.truetype( 'Minecraftia.ttf', 35)
>  ??????????????????????????????????????????????????? ^
> TabError: inconsistent use of tabs and spaces in indentation
> 
> I cannot see what is wrong, as the text is all lined up with that above 
> and below:

The problem will be that you have a mix of tabs and spaces in your 
indentation.  This causes problems because some people don't think that 
the One True Tab Width is 8 characters ;-) so to them the indentation 
looks ragged.  Worse, when they mix tabs and spaces, code that looks to 
be at the same indentation level to them looks different to the 
interpreter.  The decision was taken a while ago that Python should put 
its foot down about this, and demand that we use either all tabs or all 
spaces for our indentation.  That's what you've fallen foul off; there 
must be a mix of tabs and spaces in that line!

-- 
Rhodri James *-* Kynesim Ltd

From rhodri at kynesim.co.uk  Thu Dec  5 14:40:16 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 5 Dec 2019 19:40:16 +0000
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net> <h4t1q6FbaknU1@mid.individual.net>
 <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
Message-ID: <6d5f872f-5f96-8b00-d6a9-ffab3d177de7@kynesim.co.uk>

On 05/12/2019 19:30, Rhodri James wrote:
> On 05/12/2019 18:49, RobH wrote:
>> Update:
>> I did python3 Internet.py
>> and now only get this error:
>>
>> pi at raspberrypi:~/Downloads $ python3 Internet.py
>> ?? File "Internet.py", line 24
>> ???? font = ImageFont.truetype( 'Minecraftia.ttf', 35)
>> ???????????????????????????????????????????????????? ^
>> TabError: inconsistent use of tabs and spaces in indentation
>>
>> I cannot see what is wrong, as the text is all lined up with that 
>> above and below:
> 
> The problem will be that you have a mix of tabs and spaces in your 
> indentation.? This causes problems because some people don't think that 
> the One True Tab Width is 8 characters ;-) so to them the indentation 
> looks ragged.? Worse, when they mix tabs and spaces, code that looks to 
> be at the same indentation level to them looks different to the 
> interpreter.? The decision was taken a while ago that Python should put 
> its foot down about this, and demand that we use either all tabs or all 
> spaces for our indentation.? That's what you've fallen foul off; there 
> must be a mix of tabs and spaces in that line!

Or more likely you've used tabs on that line and spaces elsewhere, or 
vice versa.  I should have remember to say that, sorry.

-- 
Rhodri James *-* Kynesim Ltd

From rob at despammer.com  Thu Dec  5 15:28:52 2019
From: rob at despammer.com (RobH)
Date: Thu, 5 Dec 2019 20:28:52 +0000
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <mailman.311.1575574822.25794.python-list@python.org>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net> <h4t1q6FbaknU1@mid.individual.net>
 <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
 <6d5f872f-5f96-8b00-d6a9-ffab3d177de7@kynesim.co.uk>
 <mailman.311.1575574822.25794.python-list@python.org>
Message-ID: <h4t7k6FchdpU1@mid.individual.net>

On 05/12/2019 19:40, Rhodri James wrote:
> On 05/12/2019 19:30, Rhodri James wrote:
>> On 05/12/2019 18:49, RobH wrote:
>>> Update:
>>> I did python3 Internet.py
>>> and now only get this error:
>>>
>>> pi at raspberrypi:~/Downloads $ python3 Internet.py
>>> ?? File "Internet.py", line 24
>>> ???? font = ImageFont.truetype( 'Minecraftia.ttf', 35)
>>> ???????????????????????????????????????????????????? ^
>>> TabError: inconsistent use of tabs and spaces in indentation
>>>
>>> I cannot see what is wrong, as the text is all lined up with that 
>>> above and below:
>>
>> The problem will be that you have a mix of tabs and spaces in your 
>> indentation.? This causes problems because some people don't think 
>> that the One True Tab Width is 8 characters ;-) so to them the 
>> indentation looks ragged.? Worse, when they mix tabs and spaces, code 
>> that looks to be at the same indentation level to them looks different 
>> to the interpreter.? The decision was taken a while ago that Python 
>> should put its foot down about this, and demand that we use either all 
>> tabs or all spaces for our indentation.? That's what you've fallen 
>> foul off; there must be a mix of tabs and spaces in that line!
> 
> Or more likely you've used tabs on that line and spaces elsewhere, or 
> vice versa.? I should have remember to say that, sorry.
> 

Ok thanks for the explanation there, and I have placed the cursor at the 
beginning of the first indented line. Moving down 1 line at a time , 
each line is at the same position upto line 157 in the authors code .
Then it is closer in to the edge upto line 190, where it goes back out 
again.

What is my best course of action here now.


From joel.goldstick at gmail.com  Thu Dec  5 15:39:45 2019
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Thu, 5 Dec 2019 15:39:45 -0500
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <h4t7k6FchdpU1@mid.individual.net>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net> <h4t1q6FbaknU1@mid.individual.net>
 <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
 <6d5f872f-5f96-8b00-d6a9-ffab3d177de7@kynesim.co.uk>
 <mailman.311.1575574822.25794.python-list@python.org>
 <h4t7k6FchdpU1@mid.individual.net>
Message-ID: <CAPM-O+wQgU_zYbiHZ+jfMmW9SucnP0k+x4zkVw=6aUYc6bV-fQ@mail.gmail.com>

On Thu, Dec 5, 2019 at 3:31 PM RobH <rob at despammer.com> wrote:
>
> On 05/12/2019 19:40, Rhodri James wrote:
> > On 05/12/2019 19:30, Rhodri James wrote:
> >> On 05/12/2019 18:49, RobH wrote:
> >>> Update:
> >>> I did python3 Internet.py
> >>> and now only get this error:
> >>>
> >>> pi at raspberrypi:~/Downloads $ python3 Internet.py
> >>>    File "Internet.py", line 24
> >>>      font = ImageFont.truetype( 'Minecraftia.ttf', 35)
> >>>                                                      ^
> >>> TabError: inconsistent use of tabs and spaces in indentation
> >>>
> >>> I cannot see what is wrong, as the text is all lined up with that
> >>> above and below:
> >>
> >> The problem will be that you have a mix of tabs and spaces in your
> >> indentation.  This causes problems because some people don't think
> >> that the One True Tab Width is 8 characters ;-) so to them the
> >> indentation looks ragged.  Worse, when they mix tabs and spaces, code
> >> that looks to be at the same indentation level to them looks different
> >> to the interpreter.  The decision was taken a while ago that Python
> >> should put its foot down about this, and demand that we use either all
> >> tabs or all spaces for our indentation.  That's what you've fallen
> >> foul off; there must be a mix of tabs and spaces in that line!
> >
> > Or more likely you've used tabs on that line and spaces elsewhere, or
> > vice versa.  I should have remember to say that, sorry.
> >
>
> Ok thanks for the explanation there, and I have placed the cursor at the
> beginning of the first indented line. Moving down 1 line at a time ,
> each line is at the same position upto line 157 in the authors code .
> Then it is closer in to the edge upto line 190, where it goes back out
> again.
>
> What is my best course of action here now.
>
> --
> https://mail.python.org/mailman/listinfo/python-list

google or duckduckgo or whatever your text editor and tabs to spaces..
there is probably an easy way to convert the file

-- 
Joel Goldstick
http://joelgoldstick.com/blog
http://cc-baseballstats.info/stats/birthdays

From python at mrabarnett.plus.com  Thu Dec  5 15:55:42 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 5 Dec 2019 20:55:42 +0000
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <CAPM-O+wQgU_zYbiHZ+jfMmW9SucnP0k+x4zkVw=6aUYc6bV-fQ@mail.gmail.com>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net> <h4t1q6FbaknU1@mid.individual.net>
 <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
 <6d5f872f-5f96-8b00-d6a9-ffab3d177de7@kynesim.co.uk>
 <mailman.311.1575574822.25794.python-list@python.org>
 <h4t7k6FchdpU1@mid.individual.net>
 <CAPM-O+wQgU_zYbiHZ+jfMmW9SucnP0k+x4zkVw=6aUYc6bV-fQ@mail.gmail.com>
Message-ID: <c7d8916f-f0ba-1534-9a4a-b2d263a0ea65@mrabarnett.plus.com>

On 2019-12-05 20:39, Joel Goldstick wrote:
> On Thu, Dec 5, 2019 at 3:31 PM RobH <rob at despammer.com> wrote:
>>
>> On 05/12/2019 19:40, Rhodri James wrote:
>> > On 05/12/2019 19:30, Rhodri James wrote:
>> >> On 05/12/2019 18:49, RobH wrote:
>> >>> Update:
>> >>> I did python3 Internet.py
>> >>> and now only get this error:
>> >>>
>> >>> pi at raspberrypi:~/Downloads $ python3 Internet.py
>> >>>    File "Internet.py", line 24
>> >>>      font = ImageFont.truetype( 'Minecraftia.ttf', 35)
>> >>>                                                      ^
>> >>> TabError: inconsistent use of tabs and spaces in indentation
>> >>>
>> >>> I cannot see what is wrong, as the text is all lined up with that
>> >>> above and below:
>> >>
>> >> The problem will be that you have a mix of tabs and spaces in your
>> >> indentation.  This causes problems because some people don't think
>> >> that the One True Tab Width is 8 characters ;-) so to them the
>> >> indentation looks ragged.  Worse, when they mix tabs and spaces, code
>> >> that looks to be at the same indentation level to them looks different
>> >> to the interpreter.  The decision was taken a while ago that Python
>> >> should put its foot down about this, and demand that we use either all
>> >> tabs or all spaces for our indentation.  That's what you've fallen
>> >> foul off; there must be a mix of tabs and spaces in that line!
>> >
>> > Or more likely you've used tabs on that line and spaces elsewhere, or
>> > vice versa.  I should have remember to say that, sorry.
>> >
>>
>> Ok thanks for the explanation there, and I have placed the cursor at the
>> beginning of the first indented line. Moving down 1 line at a time ,
>> each line is at the same position upto line 157 in the authors code .
>> Then it is closer in to the edge upto line 190, where it goes back out
>> again.
>>
>> What is my best course of action here now.
>>
> google or duckduckgo or whatever your text editor and tabs to spaces..
> there is probably an easy way to convert the file
> 
Or expand the tabs using Python: at the Python prompt, read it in, use 
the expandtabs method of str, write it back out.

From tjreedy at udel.edu  Thu Dec  5 18:11:30 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Thu, 5 Dec 2019 18:11:30 -0500
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <c7d8916f-f0ba-1534-9a4a-b2d263a0ea65@mrabarnett.plus.com>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net> <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net> <h4t1q6FbaknU1@mid.individual.net>
 <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
 <6d5f872f-5f96-8b00-d6a9-ffab3d177de7@kynesim.co.uk>
 <mailman.311.1575574822.25794.python-list@python.org>
 <h4t7k6FchdpU1@mid.individual.net>
 <CAPM-O+wQgU_zYbiHZ+jfMmW9SucnP0k+x4zkVw=6aUYc6bV-fQ@mail.gmail.com>
 <c7d8916f-f0ba-1534-9a4a-b2d263a0ea65@mrabarnett.plus.com>
Message-ID: <qsc2r2$7b2i$1@blaine.gmane.org>

On 12/5/2019 3:55 PM, MRAB wrote:

>>> Ok thanks for the explanation there, and I have placed the cursor at the
>>> beginning of the first indented line. Moving down 1 line at a time ,
>>> each line is at the same position upto line 157 in the authors code .
>>> Then it is closer in to the edge upto line 190, where it goes back out
>>> again.
>>>
>>> What is my best course of action here now.
>>>
>> google or duckduckgo or whatever your text editor and tabs to spaces..
>> there is probably an easy way to convert the file
>>
> Or expand the tabs using Python: at the Python prompt, read it in, use 
> the expandtabs method of str, write it back out.

IDLE's Format menu has an option to do this in memory, so you can check 
before writing back to disk.

-- 
Terry Jan Reedy


From skip.montanaro at gmail.com  Fri Dec  6 10:55:20 2019
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 6 Dec 2019 09:55:20 -0600
Subject: IPC10 archive anywhere?
Message-ID: <CANc-5Uxm37p6d7ySj10V4fydwc8vMn2tTsuO+6xQpmNSjSBipg@mail.gmail.com>

I've poked around a bit and have been unable to come up with an
archive of the papers delivered at IPC10 (2001, I believe - pre-PyCon
days). Might anyone have a link?

Thanks,

Skip

From skip.montanaro at gmail.com  Fri Dec  6 11:08:39 2019
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Fri, 6 Dec 2019 10:08:39 -0600
Subject: IPC10 archive anywhere?
In-Reply-To: <CANc-5Uxm37p6d7ySj10V4fydwc8vMn2tTsuO+6xQpmNSjSBipg@mail.gmail.com>
References: <CANc-5Uxm37p6d7ySj10V4fydwc8vMn2tTsuO+6xQpmNSjSBipg@mail.gmail.com>
Message-ID: <CANc-5Uwi9vNC_BjHQahr7usKYGr7BYnGYoC0wQq5w4vp3vdqFw@mail.gmail.com>

> I've poked around a bit and have been unable to come up with an
> archive of the papers delivered at IPC10 (2001, I believe - pre-PyCon
> days). Might anyone have a link?

Found it a few minutes later:

https://legacy.python.org/workshops/

Skip

From arj.python at gmail.com  Fri Dec  6 12:49:20 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Fri, 6 Dec 2019 21:49:20 +0400
Subject: Zipapp can't find sqlite db
Message-ID: <CADrxXXmMCGoJbZ3TT1Ch30EFNgMNVVFSn0g_PEB3m4V1TYCAQg@mail.gmail.com>

Greetings,

I'm using zipapp to include a gui + db

__main__.py
dbs/
    file.db

When packaging, the db is there. When querying through sqlalchemy, it says
can't open db file. Help appreciated!

Yours,

Abdur-Rahmaan Janhangeer
pythonmembers.club <http://www.pythonmembers.club/> | github
<https://github.com/Abdur-rahmaanJ>
Mauritius

From bob at mellowood.ca  Fri Dec  6 13:17:48 2019
From: bob at mellowood.ca (Bob van der Poel)
Date: Fri, 6 Dec 2019 11:17:48 -0700
Subject: Unicode filenames
Message-ID: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>

I have some files which came off the net with, I'm assuming, unicode
characters in the names. I have a very short program which takes the
filename and puts into an emacs buffer, and then lets me add information to
that new file (it's a poor man's DB).

Next, I can look up text in the file and open the saved filename.
Everything works great until I hit those darn unicode filenames.

Just to confuse me even more, the error seems to be coming from a bit of
tkinter code:
 if sresults.has_key(textAtCursor):
        bookname = os.path.expanduser(sresults[textAtCursor].strip())

which generates

  UnicodeWarning: Unicode equal comparison failed to convert both arguments
to Unicode - interpreting them as being unequal  if
sresults.has_key(textAtCursor):

I really don't understand the business about "both arguments". Not sure how
to proceed here. Hoping for a guideline!

Thanks.


-- 

**** Listen to my FREE CD at http://www.mellowood.ca/music/cedars ****
Bob van der Poel ** Wynndel, British Columbia, CANADA **
EMAIL: bob at mellowood.ca
WWW:   http://www.mellowood.ca

From PythonList at danceswithmice.info  Fri Dec  6 14:40:47 2019
From: PythonList at danceswithmice.info (DL Neil)
Date: Sat, 7 Dec 2019 08:40:47 +1300
Subject: Unicode filenames
In-Reply-To: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
Message-ID: <2bb4a9d3-4941-1ab5-5acc-acbde6b57e34@DancesWithMice.info>

On 7/12/19 7:17 AM, Bob van der Poel wrote:
> I have some files which came off the net with, I'm assuming, unicode
> characters in the names. I have a very short program which takes the
> filename and puts into an emacs buffer, and then lets me add information to
> that new file (it's a poor man's DB).
> 
> Next, I can look up text in the file and open the saved filename.
> Everything works great until I hit those darn unicode filenames.
> 
> Just to confuse me even more, the error seems to be coming from a bit of
> tkinter code:
>   if sresults.has_key(textAtCursor):
>          bookname = os.path.expanduser(sresults[textAtCursor].strip())
> 
> which generates
> 
>    UnicodeWarning: Unicode equal comparison failed to convert both arguments
> to Unicode - interpreting them as being unequal  if
> sresults.has_key(textAtCursor):
> 
> I really don't understand the business about "both arguments". Not sure how
> to proceed here. Hoping for a guideline!


(I'm guessing that) the "both arguments" relates to expanduser() because 
this is the first time that the fileNM has been identified to Python as 
anything more than a string of characters.

[a fileNM will be a string of characters, but a string of characters is 
not necessarily a (legal) fileNM!]

Further suggesting, that if you are using Python3 (cf 2), your analysis 
may be the wrong-way-around. Python3 treats strings as Unicode. However, 
there is, and certainly in the past, was, no requirement for OpSys and 
IOCS to encode in Unicode.

The problem (for me) came from MSFT's (for example) many variations of 
ISO-8859-n and that there are no clues as to which of these was used in 
naming the file, and thus many possibly 'translations' into Unicode.

You can start to address the issue by using Python's bytes (instead of 
strings), however that cold reality still intrudes.

Do you know the provenance of these files, eg they are in French and 
from an MS-Win machine? If so, you may be able to use decode() and 
encode(), but...

Still looking for trouble? Knowing a fileNM was in Spanish/Portuguese I 
was able to take the fileNM's individual Unicode characters/surrogates 
and subtract an applicable constant, so that accented letters fell 
'back' into the correct Unicode range. (this is extremely risky, and 
could quite easily make matters worse/more confusing).

I warn you that pursuing this matter involves disappearing down into a 
very deep 'rabbit hole', but YMMV!

WebRefs:
https://docs.python.org/3/howto/unicode.html
https://www.dictionary.com/e/slang/rabbit-hole/
-- 
Regards =dn

From ijbrewster at alaska.edu  Fri Dec  6 15:58:36 2019
From: ijbrewster at alaska.edu (Israel Brewster)
Date: Fri, 6 Dec 2019 11:58:36 -0900
Subject: Make warning an exception?
Message-ID: <1EED26AD-2A95-42B0-8D31-58D9854D185B@alaska.edu>

I was running some code and I saw this pop up in the console:

2019-12-06 11:53:54.087 Python[85524:39651849] WARNING: nextEventMatchingMask should only be called from the Main Thread! This will throw an exception in the future.

The only problem is, I have no idea what is generating that warning - I never call nextEventMatchingMask directly, so it must be getting called from one of the libraries I?m calling. Is there some way I can force python to throw an exception now, so my debugger can catch it and let me know where in my code the originating call is? I?ve tried stepping through the obvious options, with no luck so far.

---
Israel Brewster
Software Engineer
Alaska Volcano Observatory 
Geophysical Institute - UAF 
2156 Koyukuk Drive 
Fairbanks AK 99775-7320
Work: 907-474-5172
cell:  907-328-9145


From rgaddi at highlandtechnology.invalid  Fri Dec  6 16:11:27 2019
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Fri, 6 Dec 2019 13:11:27 -0800
Subject: Make warning an exception?
In-Reply-To: <mailman.320.1575665922.25794.python-list@python.org>
References: <1EED26AD-2A95-42B0-8D31-58D9854D185B@alaska.edu>
 <mailman.320.1575665922.25794.python-list@python.org>
Message-ID: <qseg61$slh$1@dont-email.me>

On 12/6/19 12:58 PM, Israel Brewster wrote:
> I was running some code and I saw this pop up in the console:
> 
> 2019-12-06 11:53:54.087 Python[85524:39651849] WARNING: nextEventMatchingMask should only be called from the Main Thread! This will throw an exception in the future.
> 
> The only problem is, I have no idea what is generating that warning - I never call nextEventMatchingMask directly, so it must be getting called from one of the libraries I?m calling. Is there some way I can force python to throw an exception now, so my debugger can catch it and let me know where in my code the originating call is? I?ve tried stepping through the obvious options, with no luck so far.
> 
> ---
> Israel Brewster
> Software Engineer
> Alaska Volcano Observatory
> Geophysical Institute - UAF
> 2156 Koyukuk Drive
> Fairbanks AK 99775-7320
> Work: 907-474-5172
> cell:  907-328-9145
> 

You need to set the warning filter to "error", which you can do either with 
warnings.simplefilter at the start of your program or by setting the 
PYTHONWARNINGS environment variable.

https://docs.python.org/3/library/warnings.html#the-warnings-filter

This the same project you're having PySide/threading problems on?

From PythonList at danceswithmice.info  Fri Dec  6 16:16:13 2019
From: PythonList at danceswithmice.info (DL Neil)
Date: Sat, 7 Dec 2019 10:16:13 +1300
Subject: Make warning an exception?
In-Reply-To: <1EED26AD-2A95-42B0-8D31-58D9854D185B@alaska.edu>
References: <1EED26AD-2A95-42B0-8D31-58D9854D185B@alaska.edu>
Message-ID: <9a617d11-acc1-f810-2c7c-72d7b8b067b6@DancesWithMice.info>

On 7/12/19 9:58 AM, Israel Brewster wrote:
> I was running some code and I saw this pop up in the console:
> 
> 2019-12-06 11:53:54.087 Python[85524:39651849] WARNING: nextEventMatchingMask should only be called from the Main Thread! This will throw an exception in the future.
> 
> The only problem is, I have no idea what is generating that warning - I never call nextEventMatchingMask directly, so it must be getting called from one of the libraries I?m calling. Is there some way I can force python to throw an exception now, so my debugger can catch it and let me know where in my code the originating call is? I?ve tried stepping through the obvious options, with no luck so far.


We are able to "filter" errors, including turning warnings into 
full-bore errors. Of possible use: 
https://docs.python.org/3/library/warnings.html

-- 
Regards =dn

From tjreedy at udel.edu  Fri Dec  6 18:20:26 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 6 Dec 2019 18:20:26 -0500
Subject: Unicode filenames
In-Reply-To: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
Message-ID: <qsennr$5ebk$1@blaine.gmane.org>

On 12/6/2019 1:17 PM, Bob van der Poel wrote:
> I have some files which came off the net with, I'm assuming, unicode
> characters in the names. I have a very short program which takes the
> filename and puts into an emacs buffer, and then lets me add information to
> that new file (it's a poor man's DB).
> 
> Next, I can look up text in the file and open the saved filename.
> Everything works great until I hit those darn unicode filenames.
> 
> Just to confuse me even more, the error seems to be coming from a bit of
> tkinter code:
>   if sresults.has_key(textAtCursor):
>          bookname = os.path.expanduser(sresults[textAtCursor].strip())

'textAtCursor' does not appear in any 3.9 tkinter/*.py file

> which generates
> 
>    UnicodeWarning: Unicode equal comparison failed to convert both arguments
> to Unicode - interpreting them as being unequal  if
> sresults.has_key(textAtCursor):
> 
> I really don't understand the business about "both arguments".

'sresults.has_key(textAtCursor)' will see if the hash value of 
textAtCursor matches the hash value of any key and then compare the 
strings.  'failed to convert' suggests to me that you are running 2.x 
and that one of the strings is bytes and the other unicode.


  Not sure how
> to proceed here. Hoping for a guideline!
> 
> Thanks.
> 
> 


-- 
Terry Jan Reedy


From spayth77 at gmail.com  Fri Dec  6 18:53:11 2019
From: spayth77 at gmail.com (Sam Paython)
Date: Fri, 6 Dec 2019 15:53:11 -0800 (PST)
Subject: Error getting data from website
Message-ID: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>

Hi all,

This is the code I am writing:

import requests
from bs4 import BeautifulSoup


request = requests.get("https://www.amazon.ca/dp/B07RZFQ6HC")
content = request.content
soup = BeautifulSoup(content, "html.parser")
element = soup.find("span",{"id":"priceblock_dealprice"})
print(element.text.strip())


and this is the error I am getting: 

C:\Users\Sam\PycharmProjects\untitled2\venv\Scripts\python.exe C:/Users/Sam/PycharmProjects/untitled2/src/app.py
Traceback (most recent call last):
  File "C:/Users/Sam/PycharmProjects/untitled2/src/app.py", line 9, in <module>
    print(element.text.strip())
AttributeError: 'NoneType' object has no attribute 'text'

Could someone please help?

From PythonList at DancesWithMice.info  Fri Dec  6 19:31:05 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 7 Dec 2019 13:31:05 +1300
Subject: Error getting data from website
In-Reply-To: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
References: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
Message-ID: <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>

On 7/12/19 12:53 PM, Sam Paython wrote:
> This is the code I am writing:
> import requests
> from bs4 import BeautifulSoup
> request = requests.get("https://www.amazon.ca/dp/B07RZFQ6HC")
> content = request.content
> soup = BeautifulSoup(content, "html.parser")
> element = soup.find("span",{"id":"priceblock_dealprice"})
> print(element.text.strip())
> 
> and this is the error I am getting:
> C:\Users\Sam\PycharmProjects\untitled2\venv\Scripts\python.exe C:/Users/Sam/PycharmProjects/untitled2/src/app.py
> Traceback (most recent call last):
>    File "C:/Users/Sam/PycharmProjects/untitled2/src/app.py", line 9, in <module>
>      print(element.text.strip())
> AttributeError: 'NoneType' object has no attribute 'text'
> 
> Could someone please help?


The err.msg/stack-trace is your friend! The comment about "NoneType" 
means 'there's nothing there' (roughly!) to print().

The question then becomes: "why?" or "why not?"...

With a short piece of code like this, and (I am assuming) trying-out a 
library for the first time, may I recommend that you use the Python 
REPL, because it allows you to 'see' what's going-on behind the 
scenes/underneath the hood - and ultimately, reveals the problem.

 From a Python terminal (cmd is appropriate to your PC's OpSys):

[dn at JrBrown ~]$ python3
Python 3.7.4 (default, Jul  9 2019, 16:48:28)
[GCC 8.3.1 20190223 (Red Hat 8.3.1-2)] on linux
Type "help", "copyright", "credits" or "license" for more information.
 >>> import requests
 >>> from bs4 import BeautifulSoup
 >>> request = requests.get("https://www.amazon.ca/dp/B07RZFQ6HC")
 >>> request		# notice how I'm asking to 'see' what happened
<Response [503]>
 >>> content = request.content
 >>> content		# there is no need to enclose in print()!
b'<!DOCTYPE html>\n<!--[if lt IE 7]> <html lang="en-us" class="a-no-js 
...many lines of HTML, excised in the interests of brevity...
\')[0].appendChild(elem);\n    }\n    </script>\n</body></html>\n'
 >>> soup = BeautifulSoup(content, "html.parser")
 >>> soup
<!DOCTYPE html>
...many more lines of HTML...
</body></html>

 >>> element = soup.find("span",{"id":"priceblock_dealprice"})
 >>> element
 >>>

The last entry is asking for the contents of "element" to be displayed - 
and they are, excepting that element contains nothing/None. Oops!


Working 'backwards' (and using 'simple' Python functions to prove that 
it is not our use of requests/BS4 that is at-fault):

 >>> soup.find( "price" )		# not found

 >>> content.find( b"price" )		# the b"" is necessary because
					# we are dealing with bytes
					# not a Unicode string
-1
 >>> 					#

Sadly, the -1 indicates that "price" was not found. Which is bound to be 
disappointing to you.


Yet all is not lost!

If you read the HTML data that the REPL has happily splattered all over 
your terminal's screen (scroll back) (NB "soup" is easier to read than 
is "content"!) you will observe that what you saw in your web-browser is 
not what Amazon served in response to the Python "requests.get()"!
--
Regards =dn

From torriem at gmail.com  Fri Dec  6 19:38:18 2019
From: torriem at gmail.com (Michael Torrie)
Date: Fri, 6 Dec 2019 17:38:18 -0700
Subject: Error getting data from website
In-Reply-To: <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>
References: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
 <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>
Message-ID: <c07092a5-4034-eb91-8cbb-c71b0739c586@gmail.com>

On 12/6/19 5:31 PM, DL Neil via Python-list wrote:
> If you read the HTML data that the REPL has happily splattered all over 
> your terminal's screen (scroll back) (NB "soup" is easier to read than 
> is "content"!) you will observe that what you saw in your web-browser is 
> not what Amazon served in response to the Python "requests.get()"!

Sadly it's likely that Amazon's page is largely built from javascript.
So scraping static html is probably not going to get you where you want
to go.  There are heavier tools, such as Selenium that uses a real
browser to grab a page, and the result of that you can parse and search
perhaps.

From rosuav at gmail.com  Fri Dec  6 19:51:58 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 7 Dec 2019 11:51:58 +1100
Subject: Error getting data from website
In-Reply-To: <c07092a5-4034-eb91-8cbb-c71b0739c586@gmail.com>
References: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
 <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>
 <c07092a5-4034-eb91-8cbb-c71b0739c586@gmail.com>
Message-ID: <CAPTjJmqRiUSCZR3ZyDmV4a-0_Bo837oW=b-R1t=ZJf56fbHgOA@mail.gmail.com>

On Sat, Dec 7, 2019 at 11:46 AM Michael Torrie <torriem at gmail.com> wrote:
>
> On 12/6/19 5:31 PM, DL Neil via Python-list wrote:
> > If you read the HTML data that the REPL has happily splattered all over
> > your terminal's screen (scroll back) (NB "soup" is easier to read than
> > is "content"!) you will observe that what you saw in your web-browser is
> > not what Amazon served in response to the Python "requests.get()"!
>
> Sadly it's likely that Amazon's page is largely built from javascript.
> So scraping static html is probably not going to get you where you want
> to go.  There are heavier tools, such as Selenium that uses a real
> browser to grab a page, and the result of that you can parse and search
> perhaps.

Or look for an API instead.

ChrisA

From PythonList at DancesWithMice.info  Fri Dec  6 21:19:25 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 7 Dec 2019 15:19:25 +1300
Subject: Error getting data from website
In-Reply-To: <CAPTjJmqRiUSCZR3ZyDmV4a-0_Bo837oW=b-R1t=ZJf56fbHgOA@mail.gmail.com>
References: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
 <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>
 <c07092a5-4034-eb91-8cbb-c71b0739c586@gmail.com>
 <CAPTjJmqRiUSCZR3ZyDmV4a-0_Bo837oW=b-R1t=ZJf56fbHgOA@mail.gmail.com>
Message-ID: <7c0b9da0-3da7-4e64-a6d7-76476566a67b@DancesWithMice.info>

On 7/12/19 1:51 PM, Chris Angelico wrote:
> On Sat, Dec 7, 2019 at 11:46 AM Michael Torrie <torriem at gmail.com> wrote:
>>
>> On 12/6/19 5:31 PM, DL Neil via Python-list wrote:
>>> If you read the HTML data that the REPL has happily splattered all over
>>> your terminal's screen (scroll back) (NB "soup" is easier to read than
>>> is "content"!) you will observe that what you saw in your web-browser is
>>> not what Amazon served in response to the Python "requests.get()"!
>>
>> Sadly it's likely that Amazon's page is largely built from javascript.
>> So scraping static html is probably not going to get you where you want
>> to go.  There are heavier tools, such as Selenium that uses a real
>> browser to grab a page, and the result of that you can parse and search
>> perhaps.
> 
> Or look for an API instead.


Both +1
However, Selenium is possibly less-manageable for a 'beginner'.
(NB my poorly-based assumption of OP)

Amazon's HTML-response actually says this/these, but I left it open as a 
(learning) exercise for the OP. They likely prefer the API approach, 
because it can be measured...

-- 
Regards =dn

From rosuav at gmail.com  Fri Dec  6 21:28:26 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 7 Dec 2019 13:28:26 +1100
Subject: Error getting data from website
In-Reply-To: <7c0b9da0-3da7-4e64-a6d7-76476566a67b@DancesWithMice.info>
References: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
 <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>
 <c07092a5-4034-eb91-8cbb-c71b0739c586@gmail.com>
 <CAPTjJmqRiUSCZR3ZyDmV4a-0_Bo837oW=b-R1t=ZJf56fbHgOA@mail.gmail.com>
 <7c0b9da0-3da7-4e64-a6d7-76476566a67b@DancesWithMice.info>
Message-ID: <CAPTjJmpshv7dUudrjFQ4wNtF4qon5ExUoDy1SqCdfyykjWUecg@mail.gmail.com>

On Sat, Dec 7, 2019 at 1:21 PM DL Neil via Python-list
<python-list at python.org> wrote:
>
> On 7/12/19 1:51 PM, Chris Angelico wrote:
> > On Sat, Dec 7, 2019 at 11:46 AM Michael Torrie <torriem at gmail.com> wrote:
> >>
> >> On 12/6/19 5:31 PM, DL Neil via Python-list wrote:
> >>> If you read the HTML data that the REPL has happily splattered all over
> >>> your terminal's screen (scroll back) (NB "soup" is easier to read than
> >>> is "content"!) you will observe that what you saw in your web-browser is
> >>> not what Amazon served in response to the Python "requests.get()"!
> >>
> >> Sadly it's likely that Amazon's page is largely built from javascript.
> >> So scraping static html is probably not going to get you where you want
> >> to go.  There are heavier tools, such as Selenium that uses a real
> >> browser to grab a page, and the result of that you can parse and search
> >> perhaps.
> >
> > Or look for an API instead.
>
>
> Both +1
> However, Selenium is possibly less-manageable for a 'beginner'.
> (NB my poorly-based assumption of OP)
>
> Amazon's HTML-response actually says this/these, but I left it open as a
> (learning) exercise for the OP. They likely prefer the API approach,
> because it can be measured...
>

Yes, and because it's way WAY easier to guarantee API stability than
Selenium-based page parseability.

But even when there's no *actual* API, you can sometimes delve into
the page and find the actual useful content, perhaps as a big blob of
JSON inside a <script> tag. There'll be no guarantees, of course (but
there aren't any with parsing the HTML either), but it'll be way
easier to parse.

ChrisA

From __peter__ at web.de  Sat Dec  7 04:10:56 2019
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Dec 2019 10:10:56 +0100
Subject: Unicode filenames
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
Message-ID: <qsfqb2$2tro$1@blaine.gmane.org>

Bob van der Poel wrote:

> I have some files which came off the net with, I'm assuming, unicode
> characters in the names. I have a very short program which takes the
> filename and puts into an emacs buffer, and then lets me add information
> to that new file (it's a poor man's DB).
> 
> Next, I can look up text in the file and open the saved filename.
> Everything works great until I hit those darn unicode filenames.
> 
> Just to confuse me even more, the error seems to be coming from a bit of
> tkinter code:
>  if sresults.has_key(textAtCursor):
>         bookname = os.path.expanduser(sresults[textAtCursor].strip())
> 
> which generates
> 
>   UnicodeWarning: Unicode equal comparison failed to convert both
>   arguments
> to Unicode - interpreting them as being unequal  if
> sresults.has_key(textAtCursor):
> 
> I really don't understand the business about "both arguments". Not sure
> how to proceed here. Hoping for a guideline!

I cannot provoke the error with dict.has_key() over here, only with direct 
comparisons:

>>> u"a" == u"?"
False
>>> u"a" == "?"
__main__:1: UnicodeWarning: Unicode equal comparison failed to convert both 
arguments to Unicode - interpreting them as being unequal
False

The problem is that you are mixing strings of type str and type unicode, and 
generally speaking the remedy is to use unicode throughout. In your case
this means opening files with io.open() or codecs.open() instead of the 
builtin, and invoking os.listdir() with a unicode argument.

I don't remember about Tkinter, I think it provides ascii-only strings as 
str and everything else as unicode. If that's correct you could play it safe 
with a conversion function:

def ensure_unicode(s):
    if isinstance(s, bytes):
        return s.decode("ascii")
    return s

Your other option is to live with the *warning* -- it's not an error, just a 
reminder that you have to rethink your types once you switch to Python 3.

You can also switch off the message with

python -W ignore::UnicodeWarning yourscript

or by setting the PYTHONWARNINGS environment variable.



From dieter at handshake.de  Sat Dec  7 05:07:07 2019
From: dieter at handshake.de (dieter)
Date: Sat, 07 Dec 2019 11:07:07 +0100
Subject: Zipapp can't find sqlite db
References: <CADrxXXmMCGoJbZ3TT1Ch30EFNgMNVVFSn0g_PEB3m4V1TYCAQg@mail.gmail.com>
Message-ID: <877e38e9f8.fsf@handshake.de>

Abdur-Rahmaan Janhangeer <arj.python at gmail.com> writes:
> I'm using zipapp to include a gui + db
>
> __main__.py
> dbs/
>     file.db
>
> When packaging, the db is there. When querying through sqlalchemy, it says
> can't open db file. Help appreciated!

I am unsure what you mean with "packaging". If you mean
"create a package for PyPI management", then data files
(unlike Python source code files) need special treatment.
In this case, read the documentation for your packageing tool.


From hjp-python at hjp.at  Sat Dec  7 05:16:26 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 7 Dec 2019 11:16:26 +0100
Subject: Vim settings for Python (was: tab replace to space 4)
In-Reply-To: <yw87a8i0vu.fsf@delta.birch.chromebook>
References: <yw87a8i0vu.fsf@delta.birch.chromebook>
Message-ID: <20191207101626.GA22981@hjp.at>

On 2019-11-29 13:46:38 +0900, ??? wrote:
> usally i write python code in gnu emacs on ubuntu 18.04 sometimes i
> re-edit the code vim in same machine so often when i do run the code in
> shell like as ./test.py i meet consol error -- which line wrong!
> 
> so i am considering how can i replace all tab to space 4 within python

As an aside, to prevent vim from inserting tabs in the first place, set
    expandtab
    sw=4
and maybe also
    ts=4
(The latter is very much a matter of taste. I don't unless I have to
edit code which already contains tabs intended to be at a certain width.)

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191207/dd151ba7/attachment.sig>

From countryone77 at gmail.com  Sat Dec  7 05:34:57 2019
From: countryone77 at gmail.com (Bev In TX)
Date: Sat, 7 Dec 2019 04:34:57 -0600
Subject: Vim settings for Python (was: tab replace to space 4)
In-Reply-To: <20191207101626.GA22981@hjp.at>
References: <yw87a8i0vu.fsf@delta.birch.chromebook>
 <20191207101626.GA22981@hjp.at>
Message-ID: <AF247D51-D197-4405-9A22-0F3AAE70E1C4@gmail.com>


> On Dec 7, 2019, at 4:16 AM, Peter J. Holzer <hjp-python at hjp.at> wrote:
> 
> As an aside, to prevent vim from inserting tabs in the first place, set
>    expandtab
>    sw=4
> and maybe also
>    ts=4
> (The latter is very much a matter of taste. I don't unless I have to
> edit code which already contains tabs intended to be at a certain width.)

I?m not the OP, but I do appreciate this info.  Thanks!
Bev in TX

From __peter__ at web.de  Sat Dec  7 05:53:59 2019
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Dec 2019 11:53:59 +0100
Subject: Error getting data from website
References: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
 <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>
 <c07092a5-4034-eb91-8cbb-c71b0739c586@gmail.com>
Message-ID: <qsg0c7$6ug1$1@blaine.gmane.org>

Michael Torrie wrote:

> On 12/6/19 5:31 PM, DL Neil via Python-list wrote:
>> If you read the HTML data that the REPL has happily splattered all over
>> your terminal's screen (scroll back) (NB "soup" is easier to read than
>> is "content"!) you will observe that what you saw in your web-browser is
>> not what Amazon served in response to the Python "requests.get()"!
> 
> Sadly it's likely that Amazon's page is largely built from javascript.

That's not the problem here. Quoting the html returned by

requests.get("https://www.amazon.ca/dp/B07RZFQ6HC")

"""
To discuss automated access to Amazon data please contact api-services-
support at amazon.com.
"""

If you retrieve the page manually:

$ wget "https://www.amazon.ca/dp/B07RZFQ6HC" -O tmp.gz
[...]
2019-12-07 11:47:03 (80,6 KB/s) - ?tmp.gz? gespeichert [115426]

$ gunzip tmp.gz
$ python3
[...]
Type "help", "copyright", "credits" or "license" for more information.
>>> from bs4 import BeautifulSoup
>>> soup = BeautifulSoup(open("tmp").read())
>>> soup.find("span", dict(id="priceblock_dealprice")
... )
<span class="a-size-medium a-color-price priceBlockDealPriceString" 
id="priceblock_dealprice">CDN$ 1,019.00</span>
>>> _.text
'CDN$\xa01,019.00'

> So scraping static html is probably not going to get you where you want
> to go.  

... because Amazon doesn' like what you do. You can cheat or play by their 
rules and use the API.

> There are heavier tools, such as Selenium that uses a real
> browser to grab a page, and the result of that you can parse and search
> perhaps.




From hjp-python at hjp.at  Sat Dec  7 06:21:16 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 7 Dec 2019 12:21:16 +0100
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <8C71B143-C11A-4A1F-901E-6CEFF6D73814@barrys-emacs.org>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
 <475624D9-15D8-4A82-A8B4-5A174BA87DCD@barrys-emacs.org>
 <2b3d0c1a-aab4-9084-1011-975f911352d8@Damon-Family.org>
 <8C71B143-C11A-4A1F-901E-6CEFF6D73814@barrys-emacs.org>
Message-ID: <20191207112116.GB22981@hjp.at>

On 2019-12-05 09:27:43 +0000, Barry Scott wrote:
> On 3 Dec 2019, at 01:50, Richard Damon <Richard at Damon-Family.org> wrote:
> > On 12/2/19 4:25 PM, Barry Scott wrote:
> >>>>> x=struct.pack('L',0x102030405)
> >>>>> x
> >> b'\x05\x04\x03\x02\x01\x00\x00\x00'
> >> 
> >> Given I have exact control with b, h, i, and q but L is not fixed
> >> in size I'm not sure how it can be used with certainty across OS
> >> and versions.
> >> 
> >> Barry
> >> 
> > Actually, you DON'T have exact control with those sizes, it just happens
> > that all the platforms you are using happen to have the same size for
> > those types.
> 
> According to the docs for struct (python 2.7 and python 3.8) I do have
> exact control for the types I listed.

You also have exact control over the size of the 'L' type.

But only if you use the prefixes with a standard size (see the table in
https://docs.python.org/3/library/struct.html#byte-order-size-and-alignment),
not with "@" (which is the default). 

This is also true for the other sizes. A platform where short is 32 bits
or int is 64 bits might exist (in fact I've used the former (not with
Python, though), and while I've never used the latter, I've certainly
heard of one machine where that was the case (the Cray was quite famous
in its time)).

When you are reading and writing files which "can be used with certainty
across OS and versions" you need to use one of the prefixes "<", ">" or
"!" anyway because you also want to control the byte order, not just the
size (although big-endian architectures may be history in a few years).

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191207/0a278c23/attachment.sig>

From hjp-python at hjp.at  Sat Dec  7 06:26:37 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 7 Dec 2019 12:26:37 +0100
Subject: array and struct 64-bit Linux change in behavior Python 3.7 and
 2.7
In-Reply-To: <qs3j66$vjf$1@dont-email.me>
References: <CY4PR06MB2343383AED5C1CD7CEE8BB8B9F430@CY4PR06MB2343.namprd06.prod.outlook.com>
 <mailman.281.1575307698.25794.python-list@python.org>
 <qs3j66$vjf$1@dont-email.me>
Message-ID: <20191207112637.GC22981@hjp.at>

On 2019-12-02 09:55:16 -0800, Rob Gaddi wrote:
> The struct situation is, as you said, a bit different.  I believe that with
> the default native alignment @, you're seeing 4-byte data padded to an
> 8-byte alignment, not 8-byte data.

Nope. That's really an 8 byte long:

    Python 3.7.3 (default, Apr  3 2019, 05:39:12)
    [GCC 8.3.0] on linux
    Type "help", "copyright", "credits" or "license" for more information.
    >>> import struct

    >>> struct.pack('L', 0x0807060504030201)
    b'\x01\x02\x03\x04\x05\x06\x07\x08'

All 8 bytes are serialized. Trying to serialize 9 bytes (actually only 68
non-zero bits) fails:

    >>> struct.pack('L', 0x090807060504030201)
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    struct.error: argument out of range

And when you use the "standard size", 8 bytes are also too much:

    >>> struct.pack('=L', 0x0807060504030201)
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    struct.error: 'L' format requires 0 <= number <= 4294967295

But 4 bytes are ok:
    >>> struct.pack('=L', 0x04030201)
    b'\x01\x02\x03\x04'


        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191207/366e0e41/attachment.sig>

From barry at barrys-emacs.org  Sat Dec  7 06:05:42 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Sat, 7 Dec 2019 11:05:42 +0000
Subject: Zipapp can't find sqlite db
In-Reply-To: <877e38e9f8.fsf@handshake.de>
References: <CADrxXXmMCGoJbZ3TT1Ch30EFNgMNVVFSn0g_PEB3m4V1TYCAQg@mail.gmail.com>
 <877e38e9f8.fsf@handshake.de>
Message-ID: <D8C36B09-B574-4F4B-83D2-25F887FD6CC0@barrys-emacs.org>



> On 7 Dec 2019, at 10:07, dieter <dieter at handshake.de> wrote:
> 
> Abdur-Rahmaan Janhangeer <arj.python at gmail.com> writes:
>> I'm using zipapp to include a gui + db
>> 
>> __main__.py
>> dbs/
>>    file.db
>> 
>> When packaging, the db is there. When querying through sqlalchemy, it says
>> can't open db file. Help appreciated!
> 
> I am unsure what you mean with "packaging". If you mean
> "create a package for PyPI management", then data files
> (unlike Python source code files) need special treatment.
> In this case, read the documentation for your packageing tool.


zipapp is part of the python standard library.

The docs only talk about packaging pure python code, not data files.

Barry


From barry at barrys-emacs.org  Sat Dec  7 06:00:27 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Sat, 7 Dec 2019 11:00:27 +0000
Subject: Unicode filenames
In-Reply-To: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
Message-ID: <270842FC-3C9D-4EE0-8426-CD28FBDC7F4C@barrys-emacs.org>



> On 6 Dec 2019, at 18:17, Bob van der Poel <bob at mellowood.ca> wrote:
> 
> I have some files which came off the net with, I'm assuming, unicode
> characters in the names. I have a very short program which takes the
> filename and puts into an emacs buffer, and then lets me add information to
> that new file (it's a poor man's DB).
> 
> Next, I can look up text in the file and open the saved filename.
> Everything works great until I hit those darn unicode filenames.

Yes the names you download are unicode.
All OS can save that filename to disk these days.
Can you see the file on disk with the name you expect?

What OS are you using? 

> 
> Just to confuse me even more, the error seems to be coming from a bit of
> tkinter code:
> if sresults.has_key(textAtCursor):
>        bookname = os.path.expanduser(sresults[textAtCursor].strip())
> 
> which generates
> 
>  UnicodeWarning: Unicode equal comparison failed to convert both arguments
> to Unicode - interpreting them as being unequal  if
> sresults.has_key(textAtCursor):

What version of python are you using? Peter only managed to get the error
with python 2. 

Do you get the error with python 3?

Barry


> I really don't understand the business about "both arguments". Not sure how
> to proceed here. Hoping for a guideline!
> 
> Thanks.
> 
> 
> -- 
> 
> **** Listen to my FREE CD at http://www.mellowood.ca/music/cedars ****
> Bob van der Poel ** Wynndel, British Columbia, CANADA **
> EMAIL: bob at mellowood.ca
> WWW:   http://www.mellowood.ca
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From ferzans97 at gmail.com  Sat Dec  7 07:18:23 2019
From: ferzans97 at gmail.com (ferzan saglam)
Date: Sat, 7 Dec 2019 04:18:23 -0800 (PST)
Subject: JavaScript Calculator Program
Message-ID: <d663cf89-4253-42f7-87f9-ee8668f3b208@googlegroups.com>

Hi People, I am working on a simple calculator which uses operands (+-*/).
The program allows me to choose an operand and enter the first two values, but when it gets to doing the maths, it gives me an error on 
"console.log ("The result is ", res);" under the + operand.
(error code reads: Println is not a function)

Any help will be much appreciated. 
Thanks in advance.

-----------------------------------------------------------

console.log ("1. Add numbers");	 	       	  	  	  	    	   	
console.log("2. Subtract numbers");	 	       	  	  	  	    	   	
console.log("3. Multiply numbers");	 	       	  	  	  	    	   	
console.log("4. Divide numbers");	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
console.log = prompt("What's your choice?");	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
var num1 = prompt("Enter the first number ");	 	       	  	  	  	    	   	
firstnumber = prompt;	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
var num2 = prompt("Enter the second number ");	 	       	  	  	  	    	   	
secondnumber = prompt;	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
var choice;	 	       	  	  	  	    	   	
var res;	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
if (choice == 1);	 	       	  	  	  	    	   	
    result = (num1 + num2);	 	       	  	  	  	    	   	
    console.log ("The result is ", res);	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
if (choice == 2);	 	       	  	  	  	    	   	
    result = (num1 - num2);	 	       	  	  	  	    	   	
    console.log ("The result is = ", res);	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
if (choice == 3);	 	       	  	  	  	    	   	
    result = (num1 * num2);	 	       	  	  	  	    	   	
    console.log ("The result is = ", res);	 	       	  	  	  	    	   	
	 	       	  	  	  	    	   	
if (choice == 4);	 	       	  	  	  	    	   	
    result = (num1 / num2);	 	       	  	  	  	    	   	
    console.log ("The result is = ", res);

-------------------------------------------------------------------

From rosuav at gmail.com  Sat Dec  7 07:24:14 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 7 Dec 2019 23:24:14 +1100
Subject: JavaScript Calculator Program
In-Reply-To: <d663cf89-4253-42f7-87f9-ee8668f3b208@googlegroups.com>
References: <d663cf89-4253-42f7-87f9-ee8668f3b208@googlegroups.com>
Message-ID: <CAPTjJmrbY5Ww6fA87XQGBK1+869ODigLNZLrDwszEy_nA1Rsqg@mail.gmail.com>

On Sat, Dec 7, 2019 at 11:21 PM ferzan saglam <ferzans97 at gmail.com> wrote:
>
> Hi People, I am working on a simple calculator which uses operands (+-*/).
> The program allows me to choose an operand and enter the first two values, but when it gets to doing the maths, it gives me an error on
> "console.log ("The result is ", res);" under the + operand.
> (error code reads: Println is not a function)
>
> Any help will be much appreciated.
> Thanks in advance.

Do your own homework.

You've just posted a JavaScript homework problem to a Python mailing
list. The only help I'm going to give you is to remind you to read
your error messages, because they are there to help you.

ChrisA

From hjp-python at hjp.at  Sat Dec  7 07:43:25 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 7 Dec 2019 13:43:25 +0100
Subject: ImportError: No module named Adafruit_SSD1306 Update
In-Reply-To: <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
References: <h4qj1uFq6imU1@mid.individual.net>
 <KqadnXalEMbUqXXAnZ2dnUU7-SGdnZ2d@giganews.com>
 <h4qsg6Fs2htU1@mid.individual.net>
 <5de83dea$0$31397$426a74cc@news.free.fr>
 <h4s371F50c5U1@mid.individual.net>
 <h4t1q6FbaknU1@mid.individual.net>
 <1c044f94-c429-b7d8-150c-7068148a841e@kynesim.co.uk>
Message-ID: <20191207124325.GD22981@hjp.at>

On 2019-12-05 19:30:31 +0000, Rhodri James wrote:
> On 05/12/2019 18:49, RobH wrote:
> > TabError: inconsistent use of tabs and spaces in indentation
> 
> The problem will be that you have a mix of tabs and spaces in your
> indentation.  This causes problems because some people don't think that the
> One True Tab Width is 8 characters ;-) so to them the indentation looks
> ragged.  Worse, when they mix tabs and spaces, code that looks to be at the
> same indentation level to them looks different to the interpreter.  The
> decision was taken a while ago that Python should put its foot down about
> this, and demand that we use either all tabs or all spaces for our
> indentation.

At least as of Python 3.7, this is not true: You can mix spaces and tabs
in the same line. The mix just has to be consistent between lines. So
for example:

  1 #!/usr/bin/python3
  2 
  3 def f(a, b, c):
  4     if a < b:
  5 ????????if b < c:
  6 ????????    print("x")
  7 ????????else:
  8 ????????    print("y")

(I have configured vim to display a tab as a right guillemet followed by
middle dots and simply pasted that into this message)

produces the error message:

      File "./indent3", line 5
        if b < c:
                ^
    TabError: inconsistent use of tabs and spaces in indentation

because depending on the tab width line 5 might be more or less indented
than line 4.

(I don't actually understand the rules here: I constructed a very
similar example before that the same python interpreter accepted.)

However, this works:

  1 #!/usr/bin/python3
  2
  3 def f(a, b, c):
  4     if a < b:
  5     ????if b < c:
  6     ????    print("x")
  7     ????else:
  8     ????    print("y")


I would recommend to avoid that and stick to either tabs or spaces
(personally, I prefer spaces). You might want to use an editor which
can display tabs specially (like vim).

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191207/dba77bed/attachment.sig>

From soyeomul at doraji.xyz  Sat Dec  7 08:18:35 2019
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Sat, 07 Dec 2019 22:18:35 +0900
Subject: Vim settings for Python
References: <yw87a8i0vu.fsf@delta.birch.chromebook>
 <20191207101626.GA22981@hjp.at>
 <mailman.330.1575714303.25794.python-list@python.org>
Message-ID: <yw87ur5evwvu.fsf@delta.birch.chromebook>

Hello Peter^^^

> As an aside, to prevent vim from inserting tabs in the first place, set
>     expandtab
>     sw=4
> and maybe also
>     ts=4
> (The latter is very much a matter of taste. I don't unless I have to
> edit code which already contains tabs intended to be at a certain width.)

Because sometimes, i use vim (Ubuntu 18.04 LTS), so very much thanks^^^

Sincerely,

-- 
^????? _????_ ?????_^))//

From rob at despammer.com  Sat Dec  7 10:43:27 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 15:43:27 +0000
Subject: IOError: cannot open resource
Message-ID: <h51vkvFc2s3U1@mid.individual.net>

When I run a python project with an oled display on a rasperry pi zero, 
it calls for the Minecraftia.ttf font. I have the said file in 
home/pi/.fonts/

I get this error:

pi at raspberrypi:~/Downloads $ python interdisplay.py
Traceback (most recent call last):
   File "interdisplay.py", line 220, in <module>
     display_time()
   File "interdisplay.py", line 26, in display_time
     font = ImageFont.truetype('home/pi/.fonts/Minecraftia.ttf', 35)
   File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 280, 
in truetype
     return FreeTypeFont(font, size, index, encoding, layout_engine)
   File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 145, 
in __init__
     layout_engine=layout_engine)
IOError: cannot open resource

PILLOW version forked from PIL 1.1.7

I have no idea to what to do about this.

Thanks

From __peter__ at web.de  Sat Dec  7 11:04:40 2019
From: __peter__ at web.de (Peter Otten)
Date: Sat, 07 Dec 2019 17:04:40 +0100
Subject: IOError: cannot open resource
References: <h51vkvFc2s3U1@mid.individual.net>
Message-ID: <qsgiio$4icb$1@blaine.gmane.org>

RobH wrote:

> When I run a python project with an oled display on a rasperry pi zero,
> it calls for the Minecraftia.ttf font. I have the said file in
> home/pi/.fonts/
> 
> I get this error:
> 
> pi at raspberrypi:~/Downloads $ python interdisplay.py
> Traceback (most recent call last):
>    File "interdisplay.py", line 220, in <module>
>      display_time()
>    File "interdisplay.py", line 26, in display_time
>      font = ImageFont.truetype('home/pi/.fonts/Minecraftia.ttf', 35)
>    File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 280,
> in truetype
>      return FreeTypeFont(font, size, index, encoding, layout_engine)
>    File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 145,
> in __init__
>      layout_engine=layout_engine)
> IOError: cannot open resource
> 
> PILLOW version forked from PIL 1.1.7
> 
> I have no idea to what to do about this.

You don't have the font "Minecraftia.ttf". You can either try to find and 
install it or replace it with another that you already have in the 
/home/pi/.fonts directory.

You may even lie about it, e. g. assuming there is a font called 
"NotoSerif-Regular.ttf"

$ cd /home/pi/.fonts
$ ln NotoSerif-Regular.ttf Minecraftia.ttf

should fix the error without making changes to the code.


From 2QdxY4RzWzUUiLuE at potatochowder.com  Sat Dec  7 11:00:33 2019
From: 2QdxY4RzWzUUiLuE at potatochowder.com (Dan Sommers)
Date: Sat, 7 Dec 2019 10:00:33 -0600
Subject: IOError: cannot open resource
In-Reply-To: <h51vkvFc2s3U1@mid.individual.net>
References: <h51vkvFc2s3U1@mid.individual.net>
Message-ID: <3ade3661-469f-bf28-fa62-c9de7cf71699@potatochowder.com>

On 12/7/19 9:43 AM, RobH wrote:
> When I run a python project with an oled display on a rasperry pi zero,
> it calls for the Minecraftia.ttf font. I have the said file in
> home/pi/.fonts/

Do you mean /home/pi/.fonts (with a leading slash, an absolute path
rather than a relative one)?

Dan

From torriem at gmail.com  Sat Dec  7 11:34:10 2019
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 7 Dec 2019 09:34:10 -0700
Subject: Error getting data from website
In-Reply-To: <qsg0c7$6ug1$1@blaine.gmane.org>
References: <789b0fa9-e2ef-4daa-9e85-d3c8b34223cd@googlegroups.com>
 <0dfb757a-0549-4c15-0e67-48511e10f671@DancesWithMice.info>
 <c07092a5-4034-eb91-8cbb-c71b0739c586@gmail.com>
 <qsg0c7$6ug1$1@blaine.gmane.org>
Message-ID: <23e51bbf-89f8-a79c-e752-57b9cbbdb7e6@gmail.com>

On 12/7/19 3:53 AM, Peter Otten wrote:
> 
> ... because Amazon doesn' like what you do. You can cheat or play by their 
> rules and use the API.

Yup and although I have no love for Amazon, I can understand why they
don't want bots on the site. Already they have enough trouble with bots
buying up merchandise that gets resold on the grey market later.  And
also fake reviews.

From rob at despammer.com  Sat Dec  7 11:37:49 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 16:37:49 +0000
Subject: IOError: cannot open resource
In-Reply-To: <mailman.339.1575734690.25794.python-list@python.org>
References: <h51vkvFc2s3U1@mid.individual.net> <qsgiio$4icb$1@blaine.gmane.org>
 <mailman.339.1575734690.25794.python-list@python.org>
Message-ID: <h522qtFcno4U1@mid.individual.net>

On 07/12/2019 16:04, Peter Otten wrote:
> RobH wrote:
> 
>> When I run a python project with an oled display on a rasperry pi zero,
>> it calls for the Minecraftia.ttf font. I have the said file in
>> home/pi/.fonts/
>>
>> I get this error:
>>
>> pi at raspberrypi:~/Downloads $ python interdisplay.py
>> Traceback (most recent call last):
>>     File "interdisplay.py", line 220, in <module>
>>       display_time()
>>     File "interdisplay.py", line 26, in display_time
>>       font = ImageFont.truetype('home/pi/.fonts/Minecraftia.ttf', 35)
>>     File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 280,
>> in truetype
>>       return FreeTypeFont(font, size, index, encoding, layout_engine)
>>     File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 145,
>> in __init__
>>       layout_engine=layout_engine)
>> IOError: cannot open resource
>>
>> PILLOW version forked from PIL 1.1.7
>>
>> I have no idea to what to do about this.
> 
> You don't have the font "Minecraftia.ttf". You can either try to find and
> install it or replace it with another that you already have in the
> /home/pi/.fonts directory.
> 
> You may even lie about it, e. g. assuming there is a font called
> "NotoSerif-Regular.ttf"
> 
> $ cd /home/pi/.fonts
> $ ln NotoSerif-Regular.ttf Minecraftia.ttf
> 
> should fix the error without making changes to the code.
> 

Thanks for that.
I actually replaced Minecraftia.ttf in the code for 
NotoSerif-Regular.ttf, after I put that font in the .font folder.
It now runs without the above errors.


From rob at despammer.com  Sat Dec  7 11:48:09 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 16:48:09 +0000
Subject: IOError: cannot open resource
In-Reply-To: <mailman.340.1575735967.25794.python-list@python.org>
References: <h51vkvFc2s3U1@mid.individual.net>
 <3ade3661-469f-bf28-fa62-c9de7cf71699@potatochowder.com>
 <mailman.340.1575735967.25794.python-list@python.org>
Message-ID: <h523e9FcrmhU1@mid.individual.net>

On 07/12/2019 16:00, Dan Sommers wrote:
> On 12/7/19 9:43 AM, RobH wrote:
>> When I run a python project with an oled display on a rasperry pi zero,
>> it calls for the Minecraftia.ttf font. I have the said file in
>> home/pi/.fonts/
> 
> Do you mean /home/pi/.fonts (with a leading slash, an absolute path
> rather than a relative one)?
> 
> Dan

Not sure how you mean, but it is just as I typed it, with a forward or 
leading slash.
I have it solved now, with a different font.

From bob at mellowood.ca  Sat Dec  7 11:50:05 2019
From: bob at mellowood.ca (Bob van der Poel)
Date: Sat, 7 Dec 2019 09:50:05 -0700
Subject: Unicode filenames
In-Reply-To: <270842FC-3C9D-4EE0-8426-CD28FBDC7F4C@barrys-emacs.org>
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
 <270842FC-3C9D-4EE0-8426-CD28FBDC7F4C@barrys-emacs.org>
Message-ID: <CA+HdcZjZ4+Pc_S5EK-_4YY=59sQaMhM+rS4kHop0GrCLYiSbGw@mail.gmail.com>

On Sat, Dec 7, 2019 at 4:00 AM Barry Scott <barry at barrys-emacs.org> wrote:

>
>
> > On 6 Dec 2019, at 18:17, Bob van der Poel <bob at mellowood.ca> wrote:
> >
> > I have some files which came off the net with, I'm assuming, unicode
> > characters in the names. I have a very short program which takes the
> > filename and puts into an emacs buffer, and then lets me add information
> to
> > that new file (it's a poor man's DB).
> >
> > Next, I can look up text in the file and open the saved filename.
> > Everything works great until I hit those darn unicode filenames.
>
> Yes the names you download are unicode.
> All OS can save that filename to disk these days.
> Can you see the file on disk with the name you expect?
>
> What OS are you using?
>
> >
> > Just to confuse me even more, the error seems to be coming from a bit of
> > tkinter code:
> > if sresults.has_key(textAtCursor):
> >        bookname = os.path.expanduser(sresults[textAtCursor].strip())
> >
> > which generates
> >
> >  UnicodeWarning: Unicode equal comparison failed to convert both
> arguments
> > to Unicode - interpreting them as being unequal  if
> > sresults.has_key(textAtCursor):
>
> What version of python are you using? Peter only managed to get the error
> with python 2.
>
> Do you get the error with python 3?
>
>
I'm running this program on Linux (Ubuntu 19.10) and Python2.

>
>
> > I really don't understand the business about "both arguments". Not sure
> how
> > to proceed here. Hoping for a guideline!
>
>
I've taking the coward's way out and renamed the 1/2 dozen files. Seems
that it is when I grab a filename from the DB it is in unicode and the the
textAtCursor() and then I am trying to open that file using a fork to a
pdf-display program. This is all Q&D stuff so I'm going to file it under
"mysteries of life" and live with it :)

Thanks all!

-- 

**** Listen to my FREE CD at http://www.mellowood.ca/music/cedars ****
Bob van der Poel ** Wynndel, British Columbia, CANADA **
EMAIL: bob at mellowood.ca
WWW:   http://www.mellowood.ca

From torriem at gmail.com  Sat Dec  7 11:58:30 2019
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 7 Dec 2019 09:58:30 -0700
Subject: IOError: cannot open resource
In-Reply-To: <h523e9FcrmhU1@mid.individual.net>
References: <h51vkvFc2s3U1@mid.individual.net>
 <3ade3661-469f-bf28-fa62-c9de7cf71699@potatochowder.com>
 <mailman.340.1575735967.25794.python-list@python.org>
 <h523e9FcrmhU1@mid.individual.net>
Message-ID: <ec9aac66-ca94-38e7-4765-f8e63dde8fe2@gmail.com>

On 12/7/19 9:48 AM, RobH wrote:
> On 07/12/2019 16:00, Dan Sommers wrote:
>> On 12/7/19 9:43 AM, RobH wrote:
>>> When I run a python project with an oled display on a rasperry pi zero,
>>> it calls for the Minecraftia.ttf font. I have the said file in
>>> home/pi/.fonts/
>>
>> Do you mean /home/pi/.fonts (with a leading slash, an absolute path
>> rather than a relative one)?
>>
>> Dan
> 
> Not sure how you mean, but it is just as I typed it, with a forward or 
> leading slash.
> I have it solved now, with a different font.

What he means is that according to the stack trace you were asking for:
       home/pi/.fonts/Minecraftia.ttf

instead of
       /home/pi/.fonts/Minecraftia.ttf

If you cut and paste the traceback then that is what happened.  Likely
when you tried a different font you added the missing / and all was well.


From rob at despammer.com  Sat Dec  7 12:29:45 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 17:29:45 +0000
Subject: IOError: cannot open resource
In-Reply-To: <mailman.343.1575737914.25794.python-list@python.org>
References: <h51vkvFc2s3U1@mid.individual.net>
 <3ade3661-469f-bf28-fa62-c9de7cf71699@potatochowder.com>
 <mailman.340.1575735967.25794.python-list@python.org>
 <h523e9FcrmhU1@mid.individual.net>
 <ec9aac66-ca94-38e7-4765-f8e63dde8fe2@gmail.com>
 <mailman.343.1575737914.25794.python-list@python.org>
Message-ID: <h525s9Fdb5cU1@mid.individual.net>

On 07/12/2019 16:58, Michael Torrie wrote:
> On 12/7/19 9:48 AM, RobH wrote:
>> On 07/12/2019 16:00, Dan Sommers wrote:
>>> On 12/7/19 9:43 AM, RobH wrote:
>>>> When I run a python project with an oled display on a rasperry pi zero,
>>>> it calls for the Minecraftia.ttf font. I have the said file in
>>>> home/pi/.fonts/
>>>
>>> Do you mean /home/pi/.fonts (with a leading slash, an absolute path
>>> rather than a relative one)?
>>>
>>> Dan
>>
>> Not sure how you mean, but it is just as I typed it, with a forward or
>> leading slash.
>> I have it solved now, with a different font.
> 
> What he means is that according to the stack trace you were asking for:
>         home/pi/.fonts/Minecraftia.ttf
> 
> instead of
>         /home/pi/.fonts/Minecraftia.ttf
> 
> If you cut and paste the traceback then that is what happened.  Likely
> when you tried a different font you added the missing / and all was well.
> 

Yes that is correct, my mistake.


From rob at despammer.com  Sat Dec  7 12:48:00 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 17:48:00 +0000
Subject: stuck on time
Message-ID: <h526ugFdie9U1@mid.individual.net>

I am trying to do this project on a pi zero:

http://frederickvandenbosch.be/?p=1365

After overcoming a few errors, I now have the display working and the 
start of the code showing on the display, that being the time.

It doesn't move on to the next part of the code ie, no rectangle drawn
def display_time():
	# Collect current time and date
	if(time_format):
		current_time = time.strftime("%I:%M")<<< stays at this line
	else:
		current_time = time.strftime("%H:%M")
		
	current_date = time.strftime("%d/%m/%Y")

	# Clear image buffer by drawing a black filled box
	draw.rectangle((0,0,width,height), outline=0, fill=0

In the original code you can see that the author used the 
Minecraftia.ttf font, but I had to download the Minecraftia-Regular.ttf 
font. The link the author gave took me to that.

The Minecraft-Regular.ttf font produced errors when the code was run, 
saying at the end of the error that it cannot open resource.

I then used the NotoSerif-Regular.ttf font which let the code start 
without error, but as above it is stuck at the time.

From Karsten.Hilbert at gmx.net  Sat Dec  7 12:54:18 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Sat, 7 Dec 2019 18:54:18 +0100
Subject: stuck on time
In-Reply-To: <h526ugFdie9U1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
Message-ID: <20191207175418.GD1626@hermes.hilbert.loc>

On Sat, Dec 07, 2019 at 05:48:00PM +0000, RobH wrote:

What happens if your run this line:

> 		current_time = time.strftime("%I:%M")<<< stays at this line

in an interactive Python interpreter ?

(after you define "time" appropriately)

Karsten
--
GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B

From david at lowryduda.com  Sat Dec  7 13:20:20 2019
From: david at lowryduda.com (David Lowry-Duda)
Date: Sat, 7 Dec 2019 13:20:20 -0500
Subject: Developers are advised to purge these malicious packages
In-Reply-To: <qs8t8m$cdn$1@blaine.gmane.org>
References: <mailman.18.1575478803.4247.python-list@python.org>
 <20191204175957.GA24123@mail.lowryduda.com>
 <qs8t8m$cdn$1@blaine.gmane.org>
Message-ID: <20191207182020.GA23146@mail.lowryduda.com>

On Wed, Dec 04, 2019 at 07:17:58PM +0100, Christian Heimes wrote:
> 
> At least the first pages are packaging files for Debian, Fedora, and
> other Linux distributions. Downstream distributions provide a Python
>
> <snip>
> 
> Attackers abuse the fact and try to typo-squat packages in hope that
> somebody uses the Linux distribution package name "python3-dateutil"
> instead of the upstream name "python-dateutil" in requirements.txt

Yes, I understand. Thank you.

- DLD

From phd at phdru.name  Sat Dec  7 13:10:56 2019
From: phd at phdru.name (Oleg Broytman)
Date: Sat, 7 Dec 2019 19:10:56 +0100
Subject: SQLObject 3.8.0
Message-ID: <20191207181056.c2ir7c37fzea6dur@phdru.name>

Hello!

I'm pleased to announce version 3.8.0, the first stable release of branch
3.8 of SQLObject.


What's new in SQLObject
=======================

Features
--------

* Add driver ``supersqlite``. Not all tests are passing
  so the driver isn't added to the list of default drivers.

Minor features
--------------

* Improve sqlrepr'ing ``ALL/ANY/SOME()``: always put the expression
  at the right side of the comparison operation.

Bug fixes
---------

* Fixed a bug in cascade deletion/nullification.

* Fixed a bug in ``PostgresConnection.columnsFromSchema``:
  PostgreSQL 12 removed outdated catalog attribute
  ``pg_catalog.pg_attrdef.adsrc``.

* Fixed a bug working with microseconds in Time columns.

CI
--

* Run tests with Python 3.8 at Travis CI.

Contributors for this release are Andrew Trusty, Marco Sirabella and darix.

For a more complete list, please see the news:
http://sqlobject.org/News.html


What is SQLObject
=================

SQLObject is an object-relational mapper.  Your database tables are described
as classes, and rows are instances of those classes.  SQLObject is meant to be
easy to use and quick to get started with.

SQLObject supports a number of backends: MySQL, PostgreSQL, SQLite,
Firebird, Sybase, MSSQL and MaxDB (also known as SAPDB).

Python 2.7 or 3.4+ is required.


Where is SQLObject
==================

Site:
http://sqlobject.org

Development:
http://sqlobject.org/devel/

Mailing list:
https://lists.sourceforge.net/mailman/listinfo/sqlobject-discuss

Download:
https://pypi.org/project/SQLObject/3.8.0

News and changes:
http://sqlobject.org/News.html

StackOverflow:
https://stackoverflow.com/questions/tagged/sqlobject


Example
=======

Create a simple class that wraps a table::

  >>> from sqlobject import *
  >>>
  >>> sqlhub.processConnection = connectionForURI('sqlite:/:memory:')
  >>>
  >>> class Person(SQLObject):
  ...     fname = StringCol()
  ...     mi = StringCol(length=1, default=None)
  ...     lname = StringCol()
  ...
  >>> Person.createTable()

Use the object::

  >>> p = Person(fname="John", lname="Doe")
  >>> p
  <Person 1 fname='John' mi=None lname='Doe'>
  >>> p.fname
  'John'
  >>> p.mi = 'Q'
  >>> p2 = Person.get(1)
  >>> p2
  <Person 1 fname='John' mi='Q' lname='Doe'>
  >>> p is p2
  True

Queries::

  >>> p3 = Person.selectBy(lname="Doe")[0]
  >>> p3
  <Person 1 fname='John' mi='Q' lname='Doe'>
  >>> pc = Person.select(Person.q.lname=="Doe").count()
  >>> pc
  1

Oleg.
-- 
    Oleg Broytman            https://phdru.name/            phd at phdru.name
           Programmers don't die, they just GOSUB without RETURN.

From rob at despammer.com  Sat Dec  7 13:56:17 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 18:56:17 +0000
Subject: stuck on time
In-Reply-To: <mailman.344.1575741260.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
Message-ID: <h52auhFecpmU1@mid.individual.net>

On 07/12/2019 17:54, Karsten Hilbert wrote:
> On Sat, Dec 07, 2019 at 05:48:00PM +0000, RobH wrote:
> 
> What happens if your run this line:
> 
>> 		current_time = time.strftime("%I:%M")<<< stays at this line
> 
> in an interactive Python interpreter ?
> 
> (after you define "time" appropriately)
> 
> Karsten
> --
> GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B
> 

The python code is in a terminal window or shell, and when I run it only 
the time is displayed on an oled display, with no indication elsewhere 
of anything else. No errors of any description in the shell. It just 
appears as tho the code has stalled.

Could it be the actual font I am using which is causing the stalling.

From Karsten.Hilbert at gmx.net  Sat Dec  7 14:15:43 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Sat, 7 Dec 2019 20:15:43 +0100
Subject: stuck on time
In-Reply-To: <h52auhFecpmU1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net>
Message-ID: <20191207191543.GE1626@hermes.hilbert.loc>

On Sat, Dec 07, 2019 at 06:56:17PM +0000, RobH wrote:

> > What happens if your run this line:
> >
> > > 		current_time = time.strftime("%I:%M")<<< stays at this line
> >
> > in an interactive Python interpreter ?
> >
> > (after you define "time" appropriately)
>
> The python code is in a terminal window or shell, and when I run it only the
> time is displayed on an oled display, with no indication elsewhere of
> anything else. No errors of any description in the shell. It just appears as
> tho the code has stalled.
>
> Could it be the actual font I am using which is causing the stalling.

That does not sound likely because the line you are asserting
it is stuck on does not output anything so where should
whatever font get involved ?

So, what happens if *you* run the line in an *interactive interpreter* ?

Karsten
--
GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B

From PythonList at DancesWithMice.info  Sat Dec  7 14:47:13 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sun, 8 Dec 2019 08:47:13 +1300
Subject: Unicode filenames
In-Reply-To: <CA+HdcZjZ4+Pc_S5EK-_4YY=59sQaMhM+rS4kHop0GrCLYiSbGw@mail.gmail.com>
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
 <270842FC-3C9D-4EE0-8426-CD28FBDC7F4C@barrys-emacs.org>
 <CA+HdcZjZ4+Pc_S5EK-_4YY=59sQaMhM+rS4kHop0GrCLYiSbGw@mail.gmail.com>
Message-ID: <dbd0ebde-e5e4-6736-ead9-29e9375f998e@DancesWithMice.info>

On 8/12/19 5:50 AM, Bob van der Poel wrote:
> On Sat, Dec 7, 2019 at 4:00 AM Barry Scott <barry at barrys-emacs.org> wrote:
>>> On 6 Dec 2019, at 18:17, Bob van der Poel <bob at mellowood.ca> wrote:
>>>
>>> I have some files which came off the net with, I'm assuming, unicode
>>> characters in the names. I have a very short program which takes the
>>> filename and puts into an emacs buffer, and then lets me add information
>> to
>>> that new file (it's a poor man's DB).
>>>
>>> Next, I can look up text in the file and open the saved filename.
>>> Everything works great until I hit those darn unicode filenames.

...

>> Do you get the error with python 3?
> I'm running this program on Linux (Ubuntu 19.10) and Python2.

...

> I've taking the coward's way out and renamed the 1/2 dozen files. Seems
> that it is when I grab a filename from the DB it is in unicode and the the
> textAtCursor() and then I am trying to open that file using a fork to a
> pdf-display program. This is all Q&D stuff so I'm going to file it under
> "mysteries of life" and live with it :)


Fair enough, for such small number no other solution could be as 
efficient! My quick-and-dirty 'solution' would only work for (very few) 
'old data files' being recognised/name-updated using Python3.


Insert here: obligatory warning about the deprecation of Python2 at the 
end of this month/year...
-- 
Regards =dn

From bill at celestial.net  Sat Dec  7 14:59:31 2019
From: bill at celestial.net (Bill Campbell)
Date: Sat, 7 Dec 2019 11:59:31 -0800
Subject: Vim settings for Python (was: tab replace to space 4)
In-Reply-To: <20191207101626.GA22981@hjp.at>
References: <yw87a8i0vu.fsf@delta.birch.chromebook>
 <20191207101626.GA22981@hjp.at>
Message-ID: <20191207195931.GA9598@hazlitt.celestial.com>

On Sat, Dec 07, 2019, Peter J. Holzer wrote:

>As an aside, to prevent vim from inserting tabs in the first place, set
>    expandtab
>    sw=4
>and maybe also
>    ts=4

Inserting a comment in the file like this makes thing easy.

# vim: expandtab sw=4 ts=4 nows wm=0

Bill
-- 
INTERNET:   bill at celestial.com  Bill Campbell; Celestial Software LLC
URL: http://www2.celestial.com/ 6641 E. Mercer Way
Mobile:         (206) 947-5591  PO Box 820
Fax:            (206) 232-9186  Mercer Island, WA 98040-0820

Political language... is designed to make lies sound truthful and
murder respectable, and to give an appearance of solidity to pure
wind. -- George Orwell

From rob at despammer.com  Sat Dec  7 15:38:20 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 20:38:20 +0000
Subject: stuck on time
In-Reply-To: <mailman.347.1575746147.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
Message-ID: <h52gttFfjp4U1@mid.individual.net>

On 07/12/2019 19:15, Karsten Hilbert wrote:
> On Sat, Dec 07, 2019 at 06:56:17PM +0000, RobH wrote:
> 
>>> What happens if your run this line:
>>>
>>>> 		current_time = time.strftime("%I:%M")<<< stays at this line
>>>
>>> in an interactive Python interpreter ?
>>>
>>> (after you define "time" appropriately)
>>
>> The python code is in a terminal window or shell, and when I run it only the
>> time is displayed on an oled display, with no indication elsewhere of
>> anything else. No errors of any description in the shell. It just appears as
>> tho the code has stalled.
>>
>> Could it be the actual font I am using which is causing the stalling.
> 
> That does not sound likely because the line you are asserting
> it is stuck on does not output anything so where should
> whatever font get involved ?
> 
> So, what happens if *you* run the line in an *interactive interpreter* ?
> 
> Karsten
> --
> GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B
> 

I have tried the code in Thonny and ran it, but after about 5 minutes 
nothing happened and no errors at all.

Also just running the line in Thonny, nothing happened, no errors.

What program has or is an interactive interpreter, if it's not Thonny

From Karsten.Hilbert at gmx.net  Sat Dec  7 16:22:37 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Sat, 7 Dec 2019 22:22:37 +0100
Subject: stuck on time
In-Reply-To: <h52gttFfjp4U1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
Message-ID: <20191207212236.GF1626@hermes.hilbert.loc>

On Sat, Dec 07, 2019 at 08:38:20PM +0000, RobH wrote:

> I have tried the code in Thonny and ran it

Notice how I said "line", not "code".

If you hope to debug anything you need to be precise.

Karsten
--
GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B

From bob at mellowood.ca  Sat Dec  7 16:31:56 2019
From: bob at mellowood.ca (Bob van der Poel)
Date: Sat, 7 Dec 2019 14:31:56 -0700
Subject: Unicode filenames
In-Reply-To: <dbd0ebde-e5e4-6736-ead9-29e9375f998e@DancesWithMice.info>
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
 <270842FC-3C9D-4EE0-8426-CD28FBDC7F4C@barrys-emacs.org>
 <CA+HdcZjZ4+Pc_S5EK-_4YY=59sQaMhM+rS4kHop0GrCLYiSbGw@mail.gmail.com>
 <dbd0ebde-e5e4-6736-ead9-29e9375f998e@DancesWithMice.info>
Message-ID: <CA+HdcZjpJgNcLhNTw9M74Me8f+Mk=3WMv-tCDAC-jP6+J-HD9w@mail.gmail.com>

On Sat, Dec 7, 2019 at 12:47 PM DL Neil via Python-list <
python-list at python.org> wrote:

> On 8/12/19 5:50 AM, Bob van der Poel wrote:
> > On Sat, Dec 7, 2019 at 4:00 AM Barry Scott <barry at barrys-emacs.org>
> wrote:
> >>> On 6 Dec 2019, at 18:17, Bob van der Poel <bob at mellowood.ca> wrote:
> >>>
> >>> I have some files which came off the net with, I'm assuming, unicode
> >>> characters in the names. I have a very short program which takes the
> >>> filename and puts into an emacs buffer, and then lets me add
> information
> >> to
> >>> that new file (it's a poor man's DB).
> >>>
> >>> Next, I can look up text in the file and open the saved filename.
> >>> Everything works great until I hit those darn unicode filenames.
>
> ...
>
> >> Do you get the error with python 3?
> > I'm running this program on Linux (Ubuntu 19.10) and Python2.
>
> ...
>
> > I've taking the coward's way out and renamed the 1/2 dozen files. Seems
> > that it is when I grab a filename from the DB it is in unicode and the
> the
> > textAtCursor() and then I am trying to open that file using a fork to a
> > pdf-display program. This is all Q&D stuff so I'm going to file it under
> > "mysteries of life" and live with it :)
>
>
> Fair enough, for such small number no other solution could be as
> efficient! My quick-and-dirty 'solution' would only work for (very few)
> 'old data files' being recognised/name-updated using Python3.
>
>
> Insert here: obligatory warning about the deprecation of Python2 at the
> end of this month/year...
>
>
Yeah, heard all that before :) But, seriously, I wonder how many short
(less than 100 lines) programs there are out there written in py2 that will
not run in py3. Good thing py2 will still be available to be installed for
many, many years!


-- 

**** Listen to my FREE CD at http://www.mellowood.ca/music/cedars ****
Bob van der Poel ** Wynndel, British Columbia, CANADA **
EMAIL: bob at mellowood.ca
WWW:   http://www.mellowood.ca

From rosuav at gmail.com  Sat Dec  7 16:36:23 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 8 Dec 2019 08:36:23 +1100
Subject: Unicode filenames
In-Reply-To: <CA+HdcZjpJgNcLhNTw9M74Me8f+Mk=3WMv-tCDAC-jP6+J-HD9w@mail.gmail.com>
References: <CA+HdcZhJ3xDXx6vxBPNT1xBWozzvr3SdeF+Kr=Ufh=KP2zxseQ@mail.gmail.com>
 <270842FC-3C9D-4EE0-8426-CD28FBDC7F4C@barrys-emacs.org>
 <CA+HdcZjZ4+Pc_S5EK-_4YY=59sQaMhM+rS4kHop0GrCLYiSbGw@mail.gmail.com>
 <dbd0ebde-e5e4-6736-ead9-29e9375f998e@DancesWithMice.info>
 <CA+HdcZjpJgNcLhNTw9M74Me8f+Mk=3WMv-tCDAC-jP6+J-HD9w@mail.gmail.com>
Message-ID: <CAPTjJmpQwXfJRRbx+pSZaKm7ZkfJoKHBcQafMd2WOsbeUD+DTg@mail.gmail.com>

On Sun, Dec 8, 2019 at 8:33 AM Bob van der Poel <bob at mellowood.ca> wrote:
> Yeah, heard all that before :) But, seriously, I wonder how many short
> (less than 100 lines) programs there are out there written in py2 that will
> not run in py3. Good thing py2 will still be available to be installed for
> many, many years!

If they're that short and people are depending on them, it won't be
too much work to port them. And you gain a huge measure of
reliability: you no longer have to worry about "Unicode filenames" -
or, to be more precise, "non-ASCII filenames" - because everything
will just work.

ChrisA

From rob at despammer.com  Sat Dec  7 18:04:56 2019
From: rob at despammer.com (RobH)
Date: Sat, 7 Dec 2019 23:04:56 +0000
Subject: stuck on time
In-Reply-To: <mailman.351.1575753760.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
Message-ID: <h52pgoFh9c9U1@mid.individual.net>

On 07/12/2019 21:22, Karsten Hilbert wrote:
> On Sat, Dec 07, 2019 at 08:38:20PM +0000, RobH wrote:
> 
>> I have tried the code in Thonny and ran it
> 
> Notice how I said "line", not "code".
> 
> If you hope to debug anything you need to be precise.
> 
> Karsten
> --
> GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B
> 

Sorry, I should have said just the line, and it didn't return anything.
Is Thonny an interpreter then.

From python at python.invalid  Sat Dec  7 18:08:08 2019
From: python at python.invalid (Python)
Date: Sun, 8 Dec 2019 00:08:08 +0100
Subject: IOError: cannot open resource
In-Reply-To: <h522qtFcno4U1@mid.individual.net>
References: <h51vkvFc2s3U1@mid.individual.net> <qsgiio$4icb$1@blaine.gmane.org>
 <mailman.339.1575734690.25794.python-list@python.org>
 <h522qtFcno4U1@mid.individual.net>
Message-ID: <5dec3093$0$21591$426a74cc@news.free.fr>

RobH wrote:
> On 07/12/2019 16:04, Peter Otten wrote:
>> RobH wrote:
>>
>>> When I run a python project with an oled display on a rasperry pi zero,
>>> it calls for the Minecraftia.ttf font. I have the said file in
>>> home/pi/.fonts/
>>>
>>> I get this error:
>>>
>>> pi at raspberrypi:~/Downloads $ python interdisplay.py
>>> Traceback (most recent call last):
>>> ??? File "interdisplay.py", line 220, in <module>
>>> ????? display_time()
>>> ??? File "interdisplay.py", line 26, in display_time
>>> ????? font = ImageFont.truetype('home/pi/.fonts/Minecraftia.ttf', 35)
>>> ??? File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 280,
>>> in truetype
>>> ????? return FreeTypeFont(font, size, index, encoding, layout_engine)
>>> ??? File "/usr/lib/python2.7/dist-packages/PIL/ImageFont.py", line 145,
>>> in __init__
>>> ????? layout_engine=layout_engine)
>>> IOError: cannot open resource
>>>
>>> PILLOW version forked from PIL 1.1.7
>>>
>>> I have no idea to what to do about this.
>>
>> You don't have the font "Minecraftia.ttf". You can either try to find and
>> install it or replace it with another that you already have in the
>> /home/pi/.fonts directory.
>>
>> You may even lie about it, e. g. assuming there is a font called
>> "NotoSerif-Regular.ttf"
>>
>> $ cd /home/pi/.fonts
>> $ ln NotoSerif-Regular.ttf Minecraftia.ttf
>>
>> should fix the error without making changes to the code.
>>
> 
> Thanks for that.
> I actually replaced Minecraftia.ttf in the code for 
> NotoSerif-Regular.ttf, after I put that font in the .font folder.
> It now runs without the above errors.

You are a genious.




From tjreedy at udel.edu  Sat Dec  7 23:51:40 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 7 Dec 2019 23:51:40 -0500
Subject: stuck on time
In-Reply-To: <h52auhFecpmU1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net>
Message-ID: <qshvgs$7n4r$1@blaine.gmane.org>

On 12/7/2019 1:56 PM, RobH wrote:

>>> ??????? current_time = time.strftime("%I:%M")<<< stays at this line
>> in an interactive Python interpreter ?

In IDLE on Windows with 3.7 and 3.9, time.strftime runs fine.

 >>> import time
 >>> time.strftime("%I:%M")
'11:48'
 >>> current_time = time.strftime("%I:%M")
 >>> current_time
'11:48'

-- 
Terry Jan Reedy



From Karsten.Hilbert at gmx.net  Sun Dec  8 03:18:07 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Sun, 8 Dec 2019 09:18:07 +0100
Subject: Aw: Re: stuck on time
In-Reply-To: <h52pgoFh9c9U1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
 <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
Message-ID: <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>

> Sorry, I should have said just the line, and it didn't return anything.

OK, a bit strange, but then that might be due to Thonny.

> Is Thonny an interpreter then.

It sort of is, or at least it runs one. We'd like to take
that out of the equation. I meant to run *just* an interpreter, namely,
the interactive shell built into Python itself.

IOW, run just "python" (or python3) on a command line and a shell
should open in which you can run the line in question.

(remember to define "time" appropriately)

Karsten

From songbird at anthive.com  Sun Dec  8 03:30:00 2019
From: songbird at anthive.com (songbird)
Date: Sun, 8 Dec 2019 03:30:00 -0500
Subject: python 2 to 3 converter
Message-ID: <8toubg-08n.ln1@anthive.com>

  wouldn't it make more sense to just go back and fix the
converter program than to have to manually convert all this
python2 code?

  how many small test bits of code from PyPI could be
used as templates for patterns to search for that can then
be automatically converted and the test rerun?  thousands,
millions?  i bet it isn't a small amount of code that 
could be done and save everyone a large amount of time.

  having a large code repository would be useful for such
things, but also i think it would be a very good idea for
people who make changes to their code which obsolete
features or deprecations or whatever you want to call them
that they also need to formally describe the transformations
needed and supply a conversion script for the code so
that there would always be a potential path forwards where
some portion of the changes can be done automatically.

  the thing is that having such a large code repository
means you can also index it for code fragments and see 
which are the most frequently used and then focus on getting
those fixes back into the automatic translator program and
then keep iterating through as updates are applied and
automatic tests succeed.

  this would be a heck of a lot of fun.


  songbird

From PythonList at DancesWithMice.info  Sun Dec  8 03:41:31 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sun, 8 Dec 2019 21:41:31 +1300
Subject: Aw: Re: stuck on time
In-Reply-To: <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
Message-ID: <e50fb05f-e3ea-b0fa-3c2a-b741e13e6d3f@DancesWithMice.info>

On 8/12/19 9:18 PM, Karsten Hilbert wrote:
>> Sorry, I should have said just the line, and it didn't return anything.
> 
> OK, a bit strange, but then that might be due to Thonny.
> 
>> Is Thonny an interpreter then.
> 
> It sort of is, or at least it runs one. We'd like to take
> that out of the equation. I meant to run *just* an interpreter, namely,
> the interactive shell built into Python itself.
> 
> IOW, run just "python" (or python3) on a command line and a shell
> should open in which you can run the line in question.
> 
> (remember to define "time" appropriately)

 From response just posted to Python-Tutor list:

WebRefs:
https://pythonprogramminglanguage.com/repl/
https://codewith.mu/en/tutorials/1.0/repl

-- 
Regards =dn

From rob at despammer.com  Sun Dec  8 04:44:54 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 09:44:54 +0000
Subject: Aw: Re: stuck on time
In-Reply-To: <mailman.357.1575793090.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
Message-ID: <h53v0nFofdlU1@mid.individual.net>

On 08/12/2019 08:18, Karsten Hilbert wrote:
>> Sorry, I should have said just the line, and it didn't return anything.
> 
> OK, a bit strange, but then that might be due to Thonny.
> 
>> Is Thonny an interpreter then.
> 
> It sort of is, or at least it runs one. We'd like to take
> that out of the equation. I meant to run *just* an interpreter, namely,
> the interactive shell built into Python itself.
> 
> IOW, run just "python" (or python3) on a command line and a shell
> should open in which you can run the line in question.
> 
> (remember to define "time" appropriately)
> 
> Karsten
> 

In an interactive interpreter:

def print_time():
	  current_time = time.strftime("%I:%M")

returns nothing.

I don't know if that is the correct way as I am just using the code from 
the project I am trying to do

From rob at despammer.com  Sun Dec  8 04:51:01 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 09:51:01 +0000
Subject: stuck on time
In-Reply-To: <mailman.355.1575779856.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
 <lotoue5tbcojhvb23sk063fca23lr4eha0@4ax.com>
 <mailman.355.1575779856.25794.python-list@python.org>
Message-ID: <h53vc5Fohl3U1@mid.individual.net>

On 08/12/2019 04:37, Dennis Lee Bieber wrote:
> On Sat, 7 Dec 2019 20:38:20 +0000, RobH <rob at despammer.com> declaimed the
> following:
> 
> 
>>
>> What program has or is an interactive interpreter, if it's not Thonny
> 
> 	Thonny is an IDE... It might expose access to the Python interpreter
> (I've only loaded it once -- I tend to write my code using PythonWin [on
> Windows10] and FTP it to the target machine). However...
> 
> 	The basic interactive interpreter is reached by starting Python in a
> command shell with no source file specified, as in...
> 
> wulfraed at ElusiveUnicorn:~$ python3
> Python 3.7.3 (default, Apr  3 2019, 05:39:12)
> [GCC 8.3.0] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> print("This is the interactive interpreter state")
> This is the interactive interpreter state
>>>>
> 
> 
> 	It is difficult to offer aid when you fail to provide complete examples
> of the problem.
> 
>> def display_time():
>> 	# Collect current time and date
>> 	if(time_format):
>> 		current_time = time.strftime("%I:%M")<<< stays at this line
>> 	else:
>> 		current_time = time.strftime("%H:%M")
>> 		
>> 	current_date = time.strftime("%d/%m/%Y")
>>
>> 	# Clear image buffer by drawing a black filled box
>> 	draw.rectangle((0,0,width,height), outline=0, fill=0
> 
> 	Fails to provide anything usable: What is "time_format"? Where is it
> defined. Where/What are "width" and "height"? Also, that line is incomplete
> -- you should be getting a syntax error on "draw.rectangle" if that is all
> you really have.
> 
> 	Nothing in the provided snippet outputs anything to do with time/date.
> 
> 

I could not provide examples of the problem because there were none, as 
the display was showing just the current time and nothing else happened 
as I expected it to do according to the code.

The snippet of code you see is the code taken from the code of the said 
project I linked  to in my first post.

I only provided or posted it to show what should happen next after the 
time was displayed.




From rosuav at gmail.com  Sun Dec  8 05:27:06 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 8 Dec 2019 21:27:06 +1100
Subject: python 2 to 3 converter
In-Reply-To: <8toubg-08n.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com>
Message-ID: <CAPTjJmpSxeXNgoLsgf5A-fJY+SGiMdzyOH_BE6Nv=c=fJoA3yA@mail.gmail.com>

On Sun, Dec 8, 2019 at 7:36 PM songbird <songbird at anthive.com> wrote:
>   this would be a heck of a lot of fun.

Then go ahead and do it.

ChrisA

From Karsten.Hilbert at gmx.net  Sun Dec  8 05:39:17 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Sun, 8 Dec 2019 11:39:17 +0100
Subject: Aw: Re:  Re: stuck on time
In-Reply-To: <h53v0nFofdlU1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
 <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
Message-ID: <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>

> In an interactive interpreter:
>
> def print_time():
> 	  current_time = time.strftime("%I:%M")
>
> returns nothing.

That should be correct.

What happens if you then do

print_time()

inside the interpreter ?

Karsten

From rob at despammer.com  Sun Dec  8 07:10:57 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 12:10:57 +0000
Subject: Aw: Re: Re: stuck on time
In-Reply-To: <mailman.360.1575801559.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207175418.GD1626@hermes.hilbert.loc>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
Message-ID: <h547iiFq6o4U1@mid.individual.net>

On 08/12/2019 10:39, Karsten Hilbert wrote:
>> In an interactive interpreter:
>>
>> def print_time():
>> 	  current_time = time.strftime("%I:%M")
>>
>> returns nothing.
> 
> That should be correct.
> 
> What happens if you then do
> 
> print_time()
> 
> inside the interpreter ?
> 
> Karsten
> 
print_time()
on it's own returns NameError: name 'print_time' is not defined

def print_time();
	print_time()

returns nothing

From Karsten.Hilbert at gmx.net  Sun Dec  8 08:06:24 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Sun, 8 Dec 2019 14:06:24 +0100
Subject: Aw: Re:  Re: Re: stuck on time
In-Reply-To: <h547iiFq6o4U1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
 <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
Message-ID: <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>

> >> In an interactive interpreter:
> >>
> >> def print_time():
> >> 	  current_time = time.strftime("%I:%M")
> >
> > What happens if you then do
> >
> > print_time()
> >
>
> print_time()
> on it's own returns NameError: name 'print_time' is not defined

Notice the "then" above ?

More precisely: directly one after the other without leaving the interpreter ...

Karsten


From hjp-python at hjp.at  Sun Dec  8 08:19:23 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sun, 8 Dec 2019 14:19:23 +0100
Subject: Vim settings for Python (was: tab replace to space 4)
In-Reply-To: <20191207195931.GA9598@hazlitt.celestial.com>
References: <yw87a8i0vu.fsf@delta.birch.chromebook>
 <20191207101626.GA22981@hjp.at>
 <20191207195931.GA9598@hazlitt.celestial.com>
Message-ID: <20191208131923.GA20643@hjp.at>

On 2019-12-07 11:59:31 -0800, Bill Campbell wrote:
> On Sat, Dec 07, 2019, Peter J. Holzer wrote:
> >As an aside, to prevent vim from inserting tabs in the first place, set
> >    expandtab
> >    sw=4
> >and maybe also
> >    ts=4
> 
> Inserting a comment in the file like this makes thing easy.
> 
> # vim: expandtab sw=4 ts=4 nows wm=0

Yeah, I do that a lot.

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191208/848badbc/attachment.sig>

From rob at despammer.com  Sun Dec  8 09:04:24 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 14:04:24 +0000
Subject: Aw: Re: Re: Re: stuck on time
In-Reply-To: <mailman.361.1575810386.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
Message-ID: <h54e78FrhufU1@mid.individual.net>

On 08/12/2019 13:06, Karsten Hilbert wrote:
>>>> In an interactive interpreter:
>>>>
>>>> def print_time():
>>>> 	  current_time = time.strftime("%I:%M")
>>>
>>> What happens if you then do
>>>
>>> print_time()
>>>
>>
>> print_time()
>> on it's own returns NameError: name 'print_time' is not defined
> 
> Notice the "then" above ?
> 
> More precisely: directly one after the other without leaving the interpreter ...
> 
> Karsten
> 
I'm not sure what you mean.

Like this?
 >>>print_time()
Traceback (most recent call last)
File "stdin>", line 1, in <module>
File "stdin>", line 2, in print_time
File "stdin>", line 2, in print_time
File "stdin>", line 2, in print_time
[Previous line  repeated 996 more times]
RecursionError: maximum recursion depth excedded.

Running the code in a shell , it is displaying the time and now also the 
date .
Nothing else tho', as in no rectangle drawn

From Karsten.Hilbert at gmx.net  Sun Dec  8 09:26:30 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Sun, 8 Dec 2019 15:26:30 +0100
Subject: Aw: Re:  Re: Re: Re: stuck on time
In-Reply-To: <h54e78FrhufU1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
 <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
 <h54e78FrhufU1@mid.individual.net>
Message-ID: <trinity-6b176b19-e976-4a76-b3ba-038ad08b9cef-1575815190533@3c-app-gmx-bap32>

> Like this?
>  >>>print_time()
> Traceback (most recent call last)
> File "stdin>", line 1, in <module>
> File "stdin>", line 2, in print_time
> File "stdin>", line 2, in print_time
> File "stdin>", line 2, in print_time
> [Previous line  repeated 996 more times]
> RecursionError: maximum recursion depth excedded.

Sort of, yes, but since you meanwhile redeclared the function:

def print_time():
   print_time()

to be recursive and then you ran that recursive function
it recursed until it ran out of resources.

However,

> Running the code in a shell , it is displaying the time and now also the  date .

That would prove that the code itself is not
the reason why it hangs where you think it
hangs.

I suggest sprinkling print statements about the initial code
and see what it prints to the console to find out where
(and whether) it actually hangs.

Karsten

From python at python.invalid  Sun Dec  8 09:32:02 2019
From: python at python.invalid (Python)
Date: Sun, 8 Dec 2019 15:32:02 +0100
Subject: Aw: Re: Re: Re: stuck on time
In-Reply-To: <h54e78FrhufU1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
 <h54e78FrhufU1@mid.individual.net>
Message-ID: <5ded0918$0$4022$426a74cc@news.free.fr>

RobH wrote:
> On 08/12/2019 13:06, Karsten Hilbert wrote:
>>>>> In an interactive interpreter:
>>>>>
>>>>> def print_time():
>>>>> ????? current_time = time.strftime("%I:%M")
>>>>
>>>> What happens if you then do
>>>>
>>>> print_time()
>>>>
>>>
>>> print_time()
>>> on it's own returns NameError: name 'print_time' is not defined
>>
>> Notice the "then" above ?
>>
>> More precisely: directly one after the other without leaving the 
>> interpreter ...
>>
>> Karsten
>>
> I'm not sure what you mean.
> 
> Like this?
>  >>>print_time()
> Traceback (most recent call last)
> File "stdin>", line 1, in <module>
> File "stdin>", line 2, in print_time
> File "stdin>", line 2, in print_time
> File "stdin>", line 2, in print_time
> [Previous line? repeated 996 more times]
> RecursionError: maximum recursion depth excedded.
> 
> Running the code in a shell , it is displaying the time and now also the 
> date .
> Nothing else tho', as in no rectangle drawn

Well... Maybe it's time to admit, Rob, that programming is not
your thing.



From rosuav at gmail.com  Sun Dec  8 09:39:25 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 9 Dec 2019 01:39:25 +1100
Subject: Aw: Re: Re: Re: stuck on time
In-Reply-To: <5ded0918$0$4022$426a74cc@news.free.fr>
References: <h526ugFdie9U1@mid.individual.net>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
 <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
 <h54e78FrhufU1@mid.individual.net>
 <5ded0918$0$4022$426a74cc@news.free.fr>
Message-ID: <CAPTjJmo9nH-efHZ26+0PWBLfO-8z4qVHEtOuh1fowU8=DSymug@mail.gmail.com>

On Mon, Dec 9, 2019 at 1:36 AM Python <python at python.invalid> wrote:
>
> RobH wrote:
> > On 08/12/2019 13:06, Karsten Hilbert wrote:
> >>>>> In an interactive interpreter:
> >>>>>
> >>>>> def print_time():
> >>>>>       current_time = time.strftime("%I:%M")
> >>>>
> >>>> What happens if you then do
> >>>>
> >>>> print_time()
> >>>>
> >>>
> >>> print_time()
> >>> on it's own returns NameError: name 'print_time' is not defined
> >>
> >> Notice the "then" above ?
> >>
> >> More precisely: directly one after the other without leaving the
> >> interpreter ...
> >>
> >> Karsten
> >>
> > I'm not sure what you mean.
> >
> > Like this?
> >  >>>print_time()
> > Traceback (most recent call last)
> > File "stdin>", line 1, in <module>
> > File "stdin>", line 2, in print_time
> > File "stdin>", line 2, in print_time
> > File "stdin>", line 2, in print_time
> > [Previous line  repeated 996 more times]
> > RecursionError: maximum recursion depth excedded.
> >
> > Running the code in a shell , it is displaying the time and now also the
> > date .
> > Nothing else tho', as in no rectangle drawn
>
> Well... Maybe it's time to admit, Rob, that programming is not
> your thing.
>

That's rude and uncalled for, and since you're hiding behind
anonymity, you're painting your newsgroup server in a bad light (it's
proxad.net if anyone's curious).

Rob, I recommend working through a Python tutorial. There are some
subtleties to what you're doing that would best be discovered through
experimentation, and a good tutorial will help with that. Try this
one:

https://docs.python.org/3/tutorial/index.html

ChrisA

From rob at despammer.com  Sun Dec  8 09:52:04 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 14:52:04 +0000
Subject: Aw: Re: Re: Re: stuck on time
In-Reply-To: <mailman.364.1575815979.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
 <h54e78FrhufU1@mid.individual.net> <5ded0918$0$4022$426a74cc@news.free.fr>
 <CAPTjJmo9nH-efHZ26+0PWBLfO-8z4qVHEtOuh1fowU8=DSymug@mail.gmail.com>
 <mailman.364.1575815979.25794.python-list@python.org>
Message-ID: <h54h0kFs4ikU1@mid.individual.net>

On 08/12/2019 14:39, Chris Angelico wrote:
> On Mon, Dec 9, 2019 at 1:36 AM Python <python at python.invalid> wrote:
>>
>> RobH wrote:
>>> On 08/12/2019 13:06, Karsten Hilbert wrote:
>>>>>>> In an interactive interpreter:
>>>>>>>
>>>>>>> def print_time():
>>>>>>>        current_time = time.strftime("%I:%M")
>>>>>>
>>>>>> What happens if you then do
>>>>>>
>>>>>> print_time()
>>>>>>
>>>>>
>>>>> print_time()
>>>>> on it's own returns NameError: name 'print_time' is not defined
>>>>
>>>> Notice the "then" above ?
>>>>
>>>> More precisely: directly one after the other without leaving the
>>>> interpreter ...
>>>>
>>>> Karsten
>>>>
>>> I'm not sure what you mean.
>>>
>>> Like this?
>>>   >>>print_time()
>>> Traceback (most recent call last)
>>> File "stdin>", line 1, in <module>
>>> File "stdin>", line 2, in print_time
>>> File "stdin>", line 2, in print_time
>>> File "stdin>", line 2, in print_time
>>> [Previous line  repeated 996 more times]
>>> RecursionError: maximum recursion depth excedded.
>>>
>>> Running the code in a shell , it is displaying the time and now also the
>>> date .
>>> Nothing else tho', as in no rectangle drawn
>>
>> Well... Maybe it's time to admit, Rob, that programming is not
>> your thing.
>>
> 
> That's rude and uncalled for, and since you're hiding behind
> anonymity, you're painting your newsgroup server in a bad light (it's
> proxad.net if anyone's curious).
> 
> Rob, I recommend working through a Python tutorial. There are some
> subtleties to what you're doing that would best be discovered through
> experimentation, and a good tutorial will help with that. Try this
> one:
> 
> https://docs.python.org/3/tutorial/index.html
> 
> ChrisA
> 

Thanks, but I am only using the code which someone else has written, and 
apparently it works ok for them and others but not for me.

I only came here to find out why, and that is why I posted the link to 
the code, which I thought would be helpful to anyone who wishes to reply.

I know I am not a python programmer, although have done some VB 
programming years ago.


From rosuav at gmail.com  Sun Dec  8 10:19:47 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 9 Dec 2019 02:19:47 +1100
Subject: Aw: Re: Re: Re: stuck on time
In-Reply-To: <h54h0kFs4ikU1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net>
 <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
 <h54e78FrhufU1@mid.individual.net>
 <5ded0918$0$4022$426a74cc@news.free.fr>
 <CAPTjJmo9nH-efHZ26+0PWBLfO-8z4qVHEtOuh1fowU8=DSymug@mail.gmail.com>
 <mailman.364.1575815979.25794.python-list@python.org>
 <h54h0kFs4ikU1@mid.individual.net>
Message-ID: <CAPTjJmo2fQYw12kPKeE4N7tRG1NES3=9V_cLLxWGi7zVyY7Akg@mail.gmail.com>

On Mon, Dec 9, 2019 at 1:56 AM RobH <rob at despammer.com> wrote:
> Thanks, but I am only using the code which someone else has written, and
> apparently it works ok for them and others but not for me.
>
> I only came here to find out why, and that is why I posted the link to
> the code, which I thought would be helpful to anyone who wishes to reply.
>
> I know I am not a python programmer, although have done some VB
> programming years ago.

"Not a Python programmer" is something that can easily be changed :)
Python's an easy language to pick up, and since you have some
programming experience already, even easier. If you have half an hour
- maybe a whole hour to be on the safe side - just work your way
through the tutorial and get that "ah ha" moment as you figure out
what's actually happening here. You'll unlock a ton of coolness! :)

ChrisA

From rob at despammer.com  Sun Dec  8 10:32:22 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 15:32:22 +0000
Subject: Aw: Re: Re: Re: Re: stuck on time
In-Reply-To: <mailman.363.1575815195.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
 <h54e78FrhufU1@mid.individual.net>
 <trinity-6b176b19-e976-4a76-b3ba-038ad08b9cef-1575815190533@3c-app-gmx-bap32>
 <mailman.363.1575815195.25794.python-list@python.org>
Message-ID: <h54jc6FsjjlU1@mid.individual.net>

On 08/12/2019 14:26, Karsten Hilbert wrote:
>> Like this?
>>   >>>print_time()
>> Traceback (most recent call last)
>> File "stdin>", line 1, in <module>
>> File "stdin>", line 2, in print_time
>> File "stdin>", line 2, in print_time
>> File "stdin>", line 2, in print_time
>> [Previous line  repeated 996 more times]
>> RecursionError: maximum recursion depth excedded.
> 
> Sort of, yes, but since you meanwhile redeclared the function:
> 
> def print_time():
>     print_time()
> 
> to be recursive and then you ran that recursive function
> it recursed until it ran out of resources.
> 
> However,
> 
>> Running the code in a shell , it is displaying the time and now also the  date .
> 
> That would prove that the code itself is not
> the reason why it hangs where you think it
> hangs.
> 
> I suggest sprinkling print statements about the initial code
> and see what it prints to the console to find out where
> (and whether) it actually hangs.
> 
> Karsten
> 

Ok, when I do:
 >>>def print_time():
        print_time()

It hangs.

the code I linked to apparently works for the author and also for some 
others, but not for me. Admittedly they are using the Minecraftia.ttf 
font which gives me the IOError which posted about above this one.
I am presently using the NotoSerif-Regular.ttf font, and I only think 
that that is why nothing else happens.

Thanks

From duncan at invalid.invalid  Sun Dec  8 11:09:24 2019
From: duncan at invalid.invalid (duncan smith)
Date: Sun, 8 Dec 2019 16:09:24 +0000
Subject: stuck on time
In-Reply-To: <h526ugFdie9U1@mid.individual.net>
References: <h526ugFdie9U1@mid.individual.net>
Message-ID: <Ve9HF.209209$3u6.152527@fx34.iad>

On 07/12/2019 17:48, RobH wrote:
> I am trying to do this project on a pi zero:
> 
> http://frederickvandenbosch.be/?p=1365
> 
> After overcoming a few errors, I now have the display working and the
> start of the code showing on the display, that being the time.
> 
> It doesn't move on to the next part of the code ie, no rectangle drawn
> def display_time():
> ????# Collect current time and date
> ????if(time_format):
> ??????? current_time = time.strftime("%I:%M")<<< stays at this line
> ????else:
> ??????? current_time = time.strftime("%H:%M")
> ???????
> ????current_date = time.strftime("%d/%m/%Y")
> 
> ????# Clear image buffer by drawing a black filled box
> ????draw.rectangle((0,0,width,height), outline=0, fill=0
> 
> In the original code you can see that the author used the
> Minecraftia.ttf font, but I had to download the Minecraftia-Regular.ttf
> font. The link the author gave took me to that.
> 
> The Minecraft-Regular.ttf font produced errors when the code was run,
> saying at the end of the error that it cannot open resource.
> 
> I then used the NotoSerif-Regular.ttf font which let the code start
> without error, but as above it is stuck at the time.

One thing you certainly need to do is add a closing brace to the last line.

Duncan

From address at not.available  Sun Dec  8 11:29:20 2019
From: address at not.available (R.Wieser)
Date: Sun, 8 Dec 2019 17:29:20 +0100
Subject: Python3 - How do I import a class from another file
Message-ID: <qsj8da$ll8$1@gioia.aioe.org>

Hello all,

Using Python3 I would like to import a specific class from another file (in 
the same folder), and have trouble doing so.

"from file import function" works, but fails when I try to do the same with 
a class.

"import file
x = file.class"

works, but also executes commands that are in the root of the file. And 
ofcourse loads all of the file, not just the class that I'm after ...

In other words, what is the syntaxt I should use ?

Regards,
Rudy Wieser



From ethan at stoneleaf.us  Sun Dec  8 11:40:31 2019
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sun, 8 Dec 2019 08:40:31 -0800
Subject: Aw: Re: Re: Re: stuck on time
In-Reply-To: <5ded0918$0$4022$426a74cc@news.free.fr>
References: <h526ugFdie9U1@mid.individual.net>
 <mailman.344.1575741260.25794.python-list@python.org>
 <h52auhFecpmU1@mid.individual.net> <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <trinity-c0c397db-e78e-4a60-9743-5f3044a6609c-1575801557953@3c-app-gmx-bap32>
 <mailman.360.1575801559.25794.python-list@python.org>
 <h547iiFq6o4U1@mid.individual.net>
 <trinity-ba715d73-45bc-4526-a886-cfddee284f10-1575810384650@3c-app-gmx-bap32>
 <mailman.361.1575810386.25794.python-list@python.org>
 <h54e78FrhufU1@mid.individual.net> <5ded0918$0$4022$426a74cc@news.free.fr>
Message-ID: <68db7ea6-8824-2eaf-2800-1d2e662d5898@stoneleaf.us>

On 12/08/2019 06:32 AM, Python wrote:

> Well... Maybe it's time to admit, Rob, that programming is not
> your thing.

Rob, my apologies.  Whoever this person is, they are not "Python", and their behavior will not be tolerated.

"Python", if you don't want to help then remain silent.  If you don't want to be frustrated, stop reading the thread.
Rude behavior will not be tolerated.  Consider this your one warning.

--
~Ethan~
Python List Moderator

From rosuav at gmail.com  Sun Dec  8 11:41:30 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 9 Dec 2019 03:41:30 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsj8da$ll8$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
Message-ID: <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>

On Mon, Dec 9, 2019 at 3:31 AM R.Wieser <address at not.available> wrote:
>
> Hello all,
>
> Using Python3 I would like to import a specific class from another file (in
> the same folder), and have trouble doing so.
>
> "from file import function" works, but fails when I try to do the same with
> a class.
>
> "import file
> x = file.class"
>
> works, but also executes commands that are in the root of the file. And
> ofcourse loads all of the file, not just the class that I'm after ...
>
> In other words, what is the syntaxt I should use ?
>

Are you sure there's a difference between classes and functions here?
Try "from file import function" and see if it runs commands at the
root of the file.

ChrisA

From python at python.invalid  Sun Dec  8 11:45:36 2019
From: python at python.invalid (Python)
Date: Sun, 8 Dec 2019 17:45:36 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsj8da$ll8$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
Message-ID: <5ded2867$0$20334$426a34cc@news.free.fr>

R.Wieser wrote:
> Hello all,
> 
> Using Python3 I would like to import a specific class from another file (in
> the same folder), and have trouble doing so.
> 
> "from file import function" works, but fails when I try to do the same with
> a class.
> 
> "import file
> x = file.class"
> 
> works, but also executes commands that are in the root of the file. And
> ofcourse loads all of the file, not just the class that I'm after ...

from the_file import ClassName

should work. I guess that your class name is not "class" right?

Note that in all cases when you import a module (either by
import the_file or from the_file importe whatever) you actually
import ALL of it (even if you don't see ALL names your name
space). If you do not want part of a module to be executed when
it is imported (any ways) but only when the file is executed
as a script (i.e. python3 the_file.py or ./the_file.py) then
you can test the name __name__ : it is a string "__main__"
when it is executed and the module name when imported :

if __name__ == '__main__':
     # not run when imported
     print("Hello world!")


From __peter__ at web.de  Sun Dec  8 11:59:02 2019
From: __peter__ at web.de (Peter Otten)
Date: Sun, 08 Dec 2019 17:59:02 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
Message-ID: <qsja4n$4k5b$1@blaine.gmane.org>

R.Wieser wrote:

> Hello all,
> 
> Using Python3 I would like to import a specific class from another file
> (in the same folder), and have trouble doing so.
> 
> "from file import function" works, but fails when I try to do the same
> with a class.

Are you sure? It should behave the same for any name in the module.
 
> "import file
> x = file.class"
> 
> works, but also executes commands that are in the root of the file. And
> ofcourse loads all of the file, not just the class that I'm after ...
> 
> In other words, what is the syntaxt I should use ?

The body of a module that is imported is always executed -- that's how the 
classes and functions (and everything else) in the module are created.
It's all or nothing, you cannot cherry-pick specific classes or functions.

You can however protect part of the code with 
'if __name__ == "__main__": ...':


print("this will always be executed")
if __name__ == "__main__":
   print("this will only be executed when you run")
   print("the module directly as a script")



From songbird at anthive.com  Sun Dec  8 13:10:55 2019
From: songbird at anthive.com (songbird)
Date: Sun, 8 Dec 2019 13:10:55 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com>
 <CAPTjJmpSxeXNgoLsgf5A-fJY+SGiMdzyOH_BE6Nv=c=fJoA3yA@mail.gmail.com>
 <mailman.359.1575800839.25794.python-list@python.org>
Message-ID: <fuqvbg-a18.ln1@anthive.com>

Chris Angelico wrote:
> On Sun, Dec 8, 2019 at 7:36 PM songbird <songbird at anthive.com> wrote:
>>   this would be a heck of a lot of fun.
>
> Then go ahead and do it.

  i know you're just being flip here and that's fine
with me.  that said, i'd love to!  how big is PyPI? 
(huge)  will it fit on an SSD?  (no)  my local machine 
and pipeline isn't big enough to crunch it (too bad).
etc.

  i'm going to have fun here so you can ignore this if
you'd like.

  my name for the new archive is called OctoPyPIE.  :)

  uploads to OPPIE are parsed from the start to be python3
compatible only.  if it is not compatible then the code is
quarantined with a message which says "fix it and try 
again, we no longer accept incompatible code."

  the quarantined python2 code will be used for background
processing (to see what is most broken) but it is never
distributed further.  it is just indexed, dependencies 
checked, noting which ones are most frequently used and
that information kept to help focus the broader effort of
conversion.  i think we should call the quarantine area
ISENGUARD and the programs for chewing it up called ENT.  
code that eventually may get a fixer so that it could be 
promoted back to OPPIE without any manual intervention 
would be done by ELROND.  code which is impossible to ever 
be manually converted would be left and perhaps would 
eventually end up in MORDOR after being transported by 
the RINGWRAITH.

  dev null is of course MTDOOM.

  those who come to the table of OPPIE only eat the 
freshest pie.  HOBBITS like only the best.

  thus is finished the 2nd AGE.


  songbird

From address at not.available  Sun Dec  8 12:28:21 2019
From: address at not.available (R.Wieser)
Date: Sun, 8 Dec 2019 18:28:21 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
Message-ID: <qsjfeh$1nbf$1@gioia.aioe.org>

Chris,

> Are you sure there's a difference between classes and functions here?

Yes, quite sure.

If not my attempt to load a class he same way as a function would have 
worked.  Which it doesn't.

> Try "from file import function" and see if it runs commands at
> the root of the file.

What function ?   The imported file doesn't contain any.

Regards,
Rudy Wieser



From address at not.available  Sun Dec  8 13:18:05 2019
From: address at not.available (R.Wieser)
Date: Sun, 8 Dec 2019 19:18:05 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org> <qsja4n$4k5b$1@blaine.gmane.org>
 <mailman.369.1575824356.25794.python-list@python.org>
Message-ID: <qsjfeh$1nbf$2@gioia.aioe.org>

Peter,

>> "from file import function" works, but fails when I try to do the same
>> with a class.
>
> Are you sure? It should behave the same for any name in the module.

I am.

At least, that is what the error said: "cannot import 'classname' from 
'filename' "

But as it turns out the problem is not the importing, but that my importing 
of the class also caused my testcode (instanciating the class, calling it 
and deleting the instance afterwards) to run.

... in which I created an instance with the same name as the class. 
Changing the instances name made the error go away (probably something to do 
with the "del instance" in the testcode).

> It's all or nothing, you cannot cherry-pick specific classes or functions.

Shucks.

> You can however protect part of the code with
> 'if __name__ == "__main__": ...':

Thanks.  (Python" also mentioned the above two).

Regards,
Rudy Wieser



From address at not.available  Sun Dec  8 13:29:24 2019
From: address at not.available (R.Wieser)
Date: Sun, 8 Dec 2019 19:29:24 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
Message-ID: <qsjfeh$1nbf$3@gioia.aioe.org>

Python,

> from the_file import ClassName
>
> should work. I guess that your class name is not "class" right?

You guessed that right. :-)   Not a good idea to pick confusing names like
that, especially when you do something the first time.

> Note that in all cases when you import a module (either by import the_file
> or from the_file importe whatever) you actually import ALL of it

So much for my assumption only the class itself would be loaded - and a
wrench into my idea to have a number of classes in a "library" file.

And it turns out its also the cause of my problem: The displayed error told
me that it could not import the class from the file, but when I block-quoted
the testcode (instanciating the class, calling it and deleting the instance
afterwards) it all worked as it should.   No idea why though.

> if __name__ == '__main__':
>     # not run when imported
>     print("Hello world!")

Thanks for that.  It means I do not have to block-quote the testcode every
time - which I'm certain I will forget now-and-again ...

Update: While testing a bit more it turned out that, in the testcode, my 
creating an instance with the same name as the class is to blame (who again 
said that it isn't a good idea to use confusing names ?).  The moment I 
changed the name of the instance everything works as expected.

Question: what is, in python, the convention in naming classes ?   Pre- or 
postfix it with "class" ?  Something else ?

Regards,
Rudy Wieser




From rob at despammer.com  Sun Dec  8 13:47:21 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 18:47:21 +0000
Subject: Aw: Re: stuck on time
In-Reply-To: <mailman.368.1575823788.25794.python-list@python.org>
References: <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <qb9quehe4t1c54furmc8hjfd57ocsb8gpj@4ax.com>
 <mailman.368.1575823788.25794.python-list@python.org>
Message-ID: <h54uppFfr3U1@mid.individual.net>

On 08/12/2019 16:49, Dennis Lee Bieber wrote:
> On Sun, 8 Dec 2019 09:44:54 +0000, RobH <rob at despammer.com> declaimed the
> following:
> 
>> def print_time():
>> 	  current_time = time.strftime("%I:%M")
>>
>> returns nothing.
>>
> 	So what did you expect it to do?
> 
> 	All that does is define a function (binding the name "print_time" to a
> compiled function object), and that function itself returns nothing IF
> invoked (you haven't invoked it). (Presuming time has been imported, the
> function will bind the name "current_time" to a string representation of
> the current time... and then throws away "current_time" when the function
> falls off the end and returns to the caller.)
> 
>> I don't know if that is the correct way as I am just using the code from
>> the project I am trying to do
> 
> 	This is showing a severe lack of understanding in how Python itself
> operates, leading me to recommend rereading a Python tutorial book before
> attempting to hack into some one else's code.
> 
> 

Err, excuse me, I was not attempting to hack into someone else's code.
As the code is in the public domain, I wanted it to work as is, like it 
did for the author, without changing anything.

So why should I now start to learn how python works.

If the code doesn't work for me after a fair trial, I'll move on to 
something else.

From aloksingh0799 at gmail.com  Sun Dec  8 13:08:10 2019
From: aloksingh0799 at gmail.com (alok singh)
Date: Sun, 8 Dec 2019 23:38:10 +0530
Subject: Regarding problem in python 3.8.0 installation
In-Reply-To: <CAArzVw51e8n4PKRFZjgcH7-9JU6_TnnxyH6ijdtkVZHBW8p=0g@mail.gmail.com>
References: <CAArzVw51e8n4PKRFZjgcH7-9JU6_TnnxyH6ijdtkVZHBW8p=0g@mail.gmail.com>
Message-ID: <CAArzVw4r2rt3dkFEXSPMSprWvWwG7UDZCNmVGRdEgbWQg874fw@mail.gmail.com>

Sir,

My system is windows 7 SP1 32-bit . after installing python in my
system,when i try to launch it using command prompt then a message is
shown. I am attaching a screenshot of the following.
kindly look seriously into my problem and tell me the solution..

thank you

From address at not.available  Sun Dec  8 14:40:21 2019
From: address at not.available (R.Wieser)
Date: Sun, 8 Dec 2019 20:40:21 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <vhhqueh2a8mo4tplotg5ae5bc2ut70l7vm@4ax.com>
 <mailman.371.1575831345.25794.python-list@python.org>
Message-ID: <qsjjjh$b87$1@gioia.aioe.org>

Dennis,

> Common practice is that the class is capitalized. Instances
>are lowercase.

Thanks.

Regards,
Rudy Wieser



From tjreedy at udel.edu  Sun Dec  8 14:47:57 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Sun, 8 Dec 2019 14:47:57 -0500
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsjfeh$1nbf$3@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
Message-ID: <qsjk1d$13b9$1@blaine.gmane.org>

On 12/8/2019 1:29 PM, R.Wieser wrote:


> from the_file import ClassName

from somemod import name

has the same effect as

import somemod
name = somemod.name
del somemod

which is to import a particular 'name' linked to a particular python 
object into the namespace where the import is executed. 
sys.modules['somemod'] will become or continue to be the module 
resulting from executing the 'somemod' code.

>> Note that in all cases when you import a module (either by import the_file
>> or from the_file importe whatever) you actually import ALL of it

The entire module is executed the first time it is imported.

> So much for my assumption only the class itself would be loaded - and a
> wrench into my idea to have a number of classes in a "library" file.

Not really.  The resulting global objects do not normally take enough 
space to worry about on normal modern desktops.  It is normal for a 
module to only use a subset, possibly just one, of the objects in an 
imported module.  For instance, itertools has 18 public classes but 
almost no importer uses all of them.

>> if __name__ == '__main__':
>>      # not run when imported
>>      print("Hello world!")
> 
> Thanks for that.  It means I do not have to block-quote the testcode every
> time - which I'm certain I will forget now-and-again ...

Standard for in-file test is

def test(): <test code>

if __name__ == '__main__':
     test()

> Question: what is, in python, the convention in naming classes ?

The PEP 8 convention (except for basic builtin data structures like int, 
str, list, tuple, set, and dict) is TitleCase.  Follow or not as you wish.

> Pre- or postfix it with "class" ?

No


-- 
Terry Jan Reedy


From PythonList at DancesWithMice.info  Sun Dec  8 15:01:25 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 9 Dec 2019 09:01:25 +1300
Subject: Aw: Re: stuck on time
In-Reply-To: <h54uppFfr3U1@mid.individual.net>
References: <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <qb9quehe4t1c54furmc8hjfd57ocsb8gpj@4ax.com>
 <mailman.368.1575823788.25794.python-list@python.org>
 <h54uppFfr3U1@mid.individual.net>
Message-ID: <b14046c4-4a26-599e-0c82-f757fbd36752@DancesWithMice.info>

On 9/12/19 7:47 AM, RobH wrote:
> On 08/12/2019 16:49, Dennis Lee Bieber wrote:
>> On Sun, 8 Dec 2019 09:44:54 +0000, RobH <rob at despammer.com> declaimed the
>> following:
>>> def print_time():
>>> ????? current_time = time.strftime("%I:%M")
...

>>> I don't know if that is the correct way as I am just using the code from
>>> the project I am trying to do
>>
>> ????This is showing a severe lack of understanding in how Python itself
>> operates, leading me to recommend rereading a Python tutorial book before
>> attempting to hack into some one else's code.

+1
(in other words, agreement with others who have suggested that your 
knowledge of Python and/or programming, is insufficient to cope with the 
project you've set yourself)


> Err, excuse me, I was not attempting to hack into someone else's code.
> As the code is in the public domain, I wanted it to work as is, like it 
> did for the author, without changing anything.

Please don't be upset. There are multiple understandings of the words 
"hack" and "hacker". Whereas most 'computer people' take the word "hack" 
to mean exactly what you are doing (and "crack" to refer to illegal 
access or ill-intent); the sad state of journalism (and Hollywood) has 
resulted in a confusion of the two.

Within the Python community, the word "hack" is used freely and without 
rancour, and includes both the permitted use of someone else's code, as 
you describe; and improving said code, as per @wlfraed's detailed 
analysis of the code-base's short-comings, a few hours ago.


> So why should I now start to learn how python works.

Only you can answer this: is the effort required to bend the code to 
your will, worth the pleasure or utility the result will bring?

Alternatively, look at how much time *volunteers* have thought 
worth-while investing in helping you! (kudos @Karsten)


There is a safety issue here too. What if the original author had wicked 
intent, and the code actually performs to your disadvantage. How would 
you know? The only way is to inspect the code - reading it for example.


Following-on from the "hacking" comment, if the original author offered 
it to you/the world, and uploaded this code to some public repo(sitory), 
(s)he will also be happy for you/others to correct and improve.

Added to the observation that the code is missing parentheses, it would 
seem that (this version of) the code would never work. Now that you have 
discovered this, the conventions of "open source" are that you will 
propose, or better still, supply a fix...


> If the code doesn't work for me after a fair trial, I'll move on to 
> something else.

Frankly, given @wlfraed's extensive analysis of the code, I'd be 
wondering about its utility too - but again, your assessment is the only 
one that counts.

(If I am confusing two recent list-threads, I apologise)
If you are going to be experimenting with IoT and/or SBCs, the sad 
reality is that it is not an area which has had time to 'collect' a body 
of mature software. Accordingly, lots of the code made 'available' for 
use will be in a fairly rough (or "early") stage. Thus, the greater 
*your* skill-set, the more likely will be success - same as for any 
hobby/work-project! Also, IIRC you are also short-cutting by using a 
Pi-Zero (designed for application and roll-out) rather than a board 
designed for experimentation - but I'm guessing, so again, please don't 
take offense.
-- 
Regards =dn

From torriem at gmail.com  Sun Dec  8 15:34:52 2019
From: torriem at gmail.com (Michael Torrie)
Date: Sun, 8 Dec 2019 13:34:52 -0700
Subject: Aw: Re: stuck on time
In-Reply-To: <h54uppFfr3U1@mid.individual.net>
References: <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <qb9quehe4t1c54furmc8hjfd57ocsb8gpj@4ax.com>
 <mailman.368.1575823788.25794.python-list@python.org>
 <h54uppFfr3U1@mid.individual.net>
Message-ID: <03a58baa-848c-8b59-fad2-0c59fc39a398@gmail.com>

On 12/8/19 11:47 AM, RobH wrote:
> Err, excuse me, I was not attempting to hack into someone else's code.
> As the code is in the public domain, I wanted it to work as is, like it 
> did for the author, without changing anything.

No worries, you're totally fine.  The word "hack" means something
different.  To hack means to work on, learn, modify, etc.  It's a
positive word in this context.  I was hacking on python code myself
yesterday.

> So why should I now start to learn how python works.

Well if you learn how Python works, then a lot of what you are trying to
do will become easier and make more sense.  For example, knowing how
Python works will tell you why your print_time() function returns
nothing (hint, the code you posted does not show a "return" statement,
hence the function will not return anything).

> If the code doesn't work for me after a fair trial, I'll move on to 
> something else.

I can sense that you are frustrated, and I can also sense frustration on
the part of those trying to assist you. I hope you will give it a fair
trial as the entire endeavor, and Python in particular, can be really
fun once you grasp it!


From tjreedy at udel.edu  Sun Dec  8 15:43:42 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Sun, 8 Dec 2019 15:43:42 -0500
Subject: Regarding problem in python 3.8.0 installation
In-Reply-To: <CAArzVw4r2rt3dkFEXSPMSprWvWwG7UDZCNmVGRdEgbWQg874fw@mail.gmail.com>
References: <CAArzVw51e8n4PKRFZjgcH7-9JU6_TnnxyH6ijdtkVZHBW8p=0g@mail.gmail.com>
 <CAArzVw4r2rt3dkFEXSPMSprWvWwG7UDZCNmVGRdEgbWQg874fw@mail.gmail.com>
Message-ID: <qsjn9u$7joc$1@blaine.gmane.org>

On 12/8/2019 1:08 PM, alok singh wrote:

> My system is windows 7 SP1 32-bit . after installing python in my
> system,when i try to launch it using command prompt then a message is
> shown. I am attaching a screenshot of the following.

Screenshots are not allowed.  Copy and paste from CommandPrompt.


-- 
Terry Jan Reedy


From bob at bbhoyer.com  Sun Dec  8 14:13:26 2019
From: bob at bbhoyer.com (bob at bbhoyer.com)
Date: Sun, 08 Dec 2019 12:13:26 -0700
Subject: ModuleNotFoundError: No module named 'email.mime';
 'email' is not a package
Message-ID: <20191208121326.c4c393e9d43f0b3d3b467334468749bf.c744b2351a.wbe@email18.godaddy.com>

   Just registered?
   Thanks

     -------- Original Message --------
     Subject: ModuleNotFoundError: No module named 'email.mime'; 'email' is
     not a package
     From: <[1]bob at bbhoyer.com>
     Date: Sun, December 08, 2019 11:14 am
     To: [2]python-list at python.org

     Hello Python Team,?
     I am a beginner in Python, been working on class material from Mosh
     youtube 6 hrs., Mosh 12 hr paid course; Python Cash Course by Eric
     Matthes? ? most of the time everything works just fine or a little
     adjustment for updated versions.
     I am running Python 3.8.0?
     In example, Mosh 12 hr course, he did an exercise on sending email from
     within Python, so here is the code :
     from?email.mime.multipart?import?MIMEMultipart
     from?email.mime.text?import?MIMEText
     import?smtplib
     message?=?MIMEMultipart()
     message["from"]?=?"Bob?Hoyer?=?Python"
     message["to"]?=?"[3]bob at bbhoyer.com"
     message["subject"]?=?"This?is?a?test?using?Python"
     message.attach(MIMEText("Body"))
     #?godaddy?recommended?SMTP_SSL,?host?name?&?port?#
     with?smtplib.SMTP(host="smtpout.secureserver.net",?port=465)?as?smtp:
     ????smtp.ehlo()
     ????#?godaddy?recommended?removing?...
     ????#?smtp.starttls()
     ????smtp.login("[4]email at email.com",?"password")? #email login &
     password blanked out for this msg
     ????smtp.send_message(message)
     ????print("Sent?...")
     smtp.close()
     Here is the error message:?
     Traceback?(most?recent?call?last):
     ??File?"c:\Users\Owner\Desktop\HelloWorld\[5]email.py",?line?1,?in?<module>
     ????from?email.mime.multipart?import?MIMEMultipart
     ??File?"c:\Users\Owner\Desktop\HelloWorld\[6]email.py",?line?1,?in?<module>
     ????from?email.mime.multipart?import?MIMEMultipart
     ModuleNotFoundError:?No?module?named?'email.mime';?'email'?is?not?a?package
     I have spent some time trying to figure out resolve ...
     Can you help me with this pistol of a problem ??
     Bob Hoyer

References

   Visible links
   1. mailto:bob at bbhoyer.com
   2. mailto:python-list at python.org
   3. mailto:bob at bbhoyer.com
   4. mailto:email at email.com
   5. http://email.py/
   6. http://email.py/

From PythonList at DancesWithMice.info  Sun Dec  8 16:30:19 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 9 Dec 2019 10:30:19 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsjfeh$1nbf$3@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
Message-ID: <bd53a93d-d637-655e-f47b-14dfb63c8319@DancesWithMice.info>

On 9/12/19 7:29 AM, R.Wieser wrote:
...

>> Note that in all cases when you import a module (either by import the_file
>> or from the_file importe whatever) you actually import ALL of it
> 
> So much for my assumption only the class itself would be loaded - and a
> wrench into my idea to have a number of classes in a "library" file.

There are three separate ideas which may be confusing:
1 we can 'load' a single class from a module, and
2 we can have 'library files' ("modules") which contains more than one 
importable-object
3 when a module is imported, parts of it are/may be executed at import-time

...

> Update: While testing a bit more it turned out that, in the testcode, my
> creating an instance with the same name as the class is to blame (who again
> said that it isn't a good idea to use confusing names ?).  The moment I
> changed the name of the instance everything works as expected.

and then there are the concepts of "scope" and "namespace".


Some of this you will know. (Hopefully) some will be 'new':


import moduleNM

- imports the entire contents of the module and executes what can be. 
This means that functions and classes are defined, and any executable 
code in the 'mainline', eg print( "Hello World" ); will be run.
- from that time you may then refer to the objects detailed within the 
module, eg

	a = moduleNM.ClassA()

- note how the module has become part of the program, but occupies a 
separate "namespace"


from moduleNM import ClassA

- changes things so that you may now refer to ClassA without mention of 
the moduleNM, ie brings the name "ClassA" into the current namespace
- causes confusion if there is already a ClassA in the current namespace!


from moduleNM import ClassA as ClassA2

- also obviates the need to mention moduleNM/adds to the current namespace
- allows use of both ClassA-s - the 'local' ClassA as "ClassA", as well 
as providing an alias ("ClassA2") to the ClassA defined in moduleNM


import moduleNM as aliasNM; is also available!


WebRefs:
A comfortably readable expansion of the above: 
https://www.digitalocean.com/community/tutorials/how-to-import-modules-in-python-3
Python's view of (import-able) modules: 
https://docs.python.org/3/tutorial/modules.html
Other questions answered: 
https://docs.python.org/3/faq/programming.html?highlight=import, eg 
what-are-the-best-practices-for-using-import-in-a-module
The importlib library which under-pins "import": 
https://docs.python.org/3/reference/import.html
The full-fat range of import-possibilities: 
https://docs.python.org/3/library/modules.html--
Regards =dn

From greg.ewing at canterbury.ac.nz  Sun Dec  8 17:06:21 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 9 Dec 2019 11:06:21 +1300
Subject: Aw: Re: stuck on time
In-Reply-To: <h54uppFfr3U1@mid.individual.net>
References: <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <qb9quehe4t1c54furmc8hjfd57ocsb8gpj@4ax.com>
 <mailman.368.1575823788.25794.python-list@python.org>
 <h54uppFfr3U1@mid.individual.net>
Message-ID: <h55aevF2rhbU1@mid.individual.net>

On 9/12/19 7:47 am, RobH wrote:
> I wanted it to work as is, like it 
> did for the author, without changing anything.
> 
> So why should I now start to learn how python works.

There are many, many reasons a piece of code could work in one
environment but not another. Figuring out why requires actual
understanding, not just copy-pasting. Part of that involves
gaining at least a basic knowledge of the language you're using.

You can't expect folks here to do all your work for you. We're
trying to help, but we can't debug your code and/or system
remotely, because we don't know everything about it. We can
offer advice, but ultimately you're the one who has to work
it out.

If you don't think the project is worth that much effort,
that's up to you. But you asked for help, and we're doing our
best to give it.

-- 
Greg

From greg.ewing at canterbury.ac.nz  Sun Dec  8 17:12:08 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 9 Dec 2019 11:12:08 +1300
Subject: stuck on time
In-Reply-To: <mailman.370.1575830819.25794.python-list@python.org>
References: <h526ugFdie9U1@mid.individual.net>
 <mucque5cfd4lnk1u3alhjeoctqr9kvco66@4ax.com>
 <mailman.370.1575830819.25794.python-list@python.org>
Message-ID: <h55apqF2tniU1@mid.individual.net>

On 9/12/19 7:46 am, Dennis Lee Bieber wrote:
> 	Minecraftia appears to be a monospaced font meant to look like the
> character set of old 8-bit gaming systems from the 80s.

 From the name, it's probably mean to resemble the font in
Minecraft. As used in the game it's not actually monospaced, but
it is designed for very low resolution, so it's probably a
reasonable choice for use on a small display.

-- 
Greg

From greg.ewing at canterbury.ac.nz  Sun Dec  8 17:18:15 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 9 Dec 2019 11:18:15 +1300
Subject: python 2 to 3 converter
In-Reply-To: <8toubg-08n.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com>
Message-ID: <h55b5aF2vtcU1@mid.individual.net>

On 8/12/19 9:30 pm, songbird wrote:
>    wouldn't it make more sense to just go back and fix the
> converter program than to have to manually convert all this
> python2 code?

Anything that isn't already fixed by 2to3 is probably
somewhere between very difficult and impossible to fix
using an automated process. It sounds like an interesting
project, but be aware that it's probably an AI-complete
problem.

-- 
Greg

From python at mrabarnett.plus.com  Sun Dec  8 17:18:14 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 8 Dec 2019 22:18:14 +0000
Subject: ModuleNotFoundError: No module named 'email.mime'; 'email' is not
 a package
In-Reply-To: <20191208121326.c4c393e9d43f0b3d3b467334468749bf.c744b2351a.wbe@email18.godaddy.com>
References: <20191208121326.c4c393e9d43f0b3d3b467334468749bf.c744b2351a.wbe@email18.godaddy.com>
Message-ID: <2780c348-500a-8429-2b07-0f3dc78ec623@mrabarnett.plus.com>

On 2019-12-08 19:13, bob at bbhoyer.com wrote:
>     Just registered
>     Thanks
> 
>       -------- Original Message --------
>       Subject: ModuleNotFoundError: No module named 'email.mime'; 'email' is
>       not a package
>       From: <[1]bob at bbhoyer.com>
>       Date: Sun, December 08, 2019 11:14 am
>       To: [2]python-list at python.org
> 
>       Hello Python Team,
>       I am a beginner in Python, been working on class material from Mosh
>       youtube 6 hrs., Mosh 12 hr paid course; Python Cash Course by Eric
>       Matthes? ? most of the time everything works just fine or a little
>       adjustment for updated versions.
>       I am running Python 3.8.0
>       In example, Mosh 12 hr course, he did an exercise on sending email from
>       within Python, so here is the code :
>       from?email.mime.multipart?import?MIMEMultipart
>       from?email.mime.text?import?MIMEText
>       import?smtplib
>       message?=?MIMEMultipart()
>       message["from"]?=?"Bob?Hoyer?=?Python"
>       message["to"]?=?"[3]bob at bbhoyer.com"
>       message["subject"]?=?"This?is?a?test?using?Python"
>       message.attach(MIMEText("Body"))
>       #?godaddy?recommended?SMTP_SSL,?host?name?&?port?#
>       with?smtplib.SMTP(host="smtpout.secureserver.net",?port=465)?as?smtp:
>       ????smtp.ehlo()
>       ????#?godaddy?recommended?removing?...
>       ????#?smtp.starttls()
>       ????smtp.login("[4]email at email.com",?"password")? #email login &
>       password blanked out for this msg
>       ????smtp.send_message(message)
>       ????print("Sent?...")
>       smtp.close()
>       Here is the error message:
>       Traceback?(most?recent?call?last):
>       ??File?"c:\Users\Owner\Desktop\HelloWorld\[5]email.py",?line?1,?in?<module>
>       ????from?email.mime.multipart?import?MIMEMultipart
>       ??File?"c:\Users\Owner\Desktop\HelloWorld\[6]email.py",?line?1,?in?<module>
>       ????from?email.mime.multipart?import?MIMEMultipart
>       ModuleNotFoundError:?No?module?named?'email.mime';?'email'?is?not?a?package
>       I have spent some time trying to figure out resolve ...
>       Can you help me with this pistol of a problem ?
>       Bob Hoyer
> 
[snip]
I notice you have files called "[5]email.py" and "[6]email.py". Do you 
also have one called "email.py"?

If so, then what's happening is that Python is finding that one before 
the one in the stdlib.

From python at mrabarnett.plus.com  Sun Dec  8 17:27:22 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 8 Dec 2019 22:27:22 +0000
Subject: Aw: Re: stuck on time
In-Reply-To: <03a58baa-848c-8b59-fad2-0c59fc39a398@gmail.com>
References: <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <qb9quehe4t1c54furmc8hjfd57ocsb8gpj@4ax.com>
 <mailman.368.1575823788.25794.python-list@python.org>
 <h54uppFfr3U1@mid.individual.net>
 <03a58baa-848c-8b59-fad2-0c59fc39a398@gmail.com>
Message-ID: <46c3200b-6ad3-75c7-9689-114e9bae8c5c@mrabarnett.plus.com>

On 2019-12-08 20:34, Michael Torrie wrote:
> On 12/8/19 11:47 AM, RobH wrote:
>> Err, excuse me, I was not attempting to hack into someone else's code.
>> As the code is in the public domain, I wanted it to work as is, like it 
>> did for the author, without changing anything.
> 
> No worries, you're totally fine.  The word "hack" means something
> different.  To hack means to work on, learn, modify, etc.  It's a
> positive word in this context.  I was hacking on python code myself
> yesterday.
> 
The word for breaking into a system or program is/was "crack", like in 
"safe-cracking". In common parlance, however, people have picked up the 
word "hack" instead, which, as Michael says, means something else.

It's a lot like the misuse of the word "theory".

[snip]

From PythonList at DancesWithMice.info  Sun Dec  8 17:34:31 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 9 Dec 2019 11:34:31 +1300
Subject: ModuleNotFoundError: No module named 'email.mime'; 'email' is not
 a package
In-Reply-To: <20191208121326.c4c393e9d43f0b3d3b467334468749bf.c744b2351a.wbe@email18.godaddy.com>
References: <20191208121326.c4c393e9d43f0b3d3b467334468749bf.c744b2351a.wbe@email18.godaddy.com>
Message-ID: <ac3c780c-39b3-c43e-36d9-e6c0efbff5be@DancesWithMice.info>

On 9/12/19 8:13 AM, bob at bbhoyer.com wrote:
>     Just registered
>     Thanks

Hi @bob, welcome to the gang...


>       I am a beginner in Python, been working on class material from Mosh
...

>       from?email.mime.multipart?import?MIMEMultipart
...

>       Here is the error message:
>       Traceback?(most?recent?call?last):
>       ??File?"c:\Users\Owner\Desktop\HelloWorld\[5]email.py",?line?1,?in?<module>
>       ????from?email.mime.multipart?import?MIMEMultipart
>       ??File?"c:\Users\Owner\Desktop\HelloWorld\[6]email.py",?line?1,?in?<module>
>       ????from?email.mime.multipart?import?MIMEMultipart
>       ModuleNotFoundError:?No?module?named?'email.mime';?'email'?is?not?a?package
>       I have spent some time trying to figure out resolve ...
>       Can you help me with this pistol of a problem ?


("pistol"? ...he says, manfully-struggling with the temptation to 
suggest that you "make love not war"...)


Let's look at the information given (in the "stack trace":

<<<ModuleNotFoundError: No module named 'email.mime'; 'email' is not a 
package>>>

On line 1, the code requests that a module named/addressed as 
"email.mime.multipart" be located ("found"), and an object 
("MIMEMultipart") be imported (etc, etc).

So, when executing line 1, Python was unable to find the specified 
module (let's over-simplify and use the word: "file").


Libraries from the Python Standard Library are not included in the basic 
"python" download, and have to be added/separately downloaded, when 
needed. I suspect this is the problem (but may not be)!


Sadly, I am not a user of MS-Win, so am loath to try to help much more, 
for fear of leading you along the wrong track.  Herewith some self-study 
which should put your boots (back) on the ground...


WebRefs: installing packages
This is more readable: 
https://protechguides.com/how-to-install-python-library/
This is from 'the book of words': 
https://packaging.python.org/tutorials/installing-packages/

NB I understand that "pip" is installed on MS-Win as part of python, so 
you don't need to worry about that/can quickly check. If your course has 
not taken you through "virtual environments" then feel free to ignore 
such, for now.
-- 
Regards =dn

From PythonList at DancesWithMice.info  Sun Dec  8 17:35:59 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 9 Dec 2019 11:35:59 +1300
Subject: Aw: Re: stuck on time
In-Reply-To: <46c3200b-6ad3-75c7-9689-114e9bae8c5c@mrabarnett.plus.com>
References: <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <qb9quehe4t1c54furmc8hjfd57ocsb8gpj@4ax.com>
 <mailman.368.1575823788.25794.python-list@python.org>
 <h54uppFfr3U1@mid.individual.net>
 <03a58baa-848c-8b59-fad2-0c59fc39a398@gmail.com>
 <46c3200b-6ad3-75c7-9689-114e9bae8c5c@mrabarnett.plus.com>
Message-ID: <63ceaa47-cc35-cda2-6bc6-53858aab7fdc@DancesWithMice.info>

> It's a lot like the misuse of the word "theory".

You mean to say that in theory there is no difference between theory and 
practice, but in practice there is?

-- 
Regards =dn

From greg.ewing at canterbury.ac.nz  Sun Dec  8 17:52:05 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 9 Dec 2019 11:52:05 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsjfeh$1nbf$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
 <qsjfeh$1nbf$1@gioia.aioe.org>
Message-ID: <h55d4nF3d5fU1@mid.individual.net>

On 9/12/19 6:28 am, R.Wieser wrote:
> 
>> Are you sure there's a difference between classes and functions here?
> 
> Yes, quite sure.

And we're even more sure that there isn't. :-) Try it with
a test module containing a class definition, a function
definition and some top-level code that does something
noticeable. You'll find that *any* form of import executes
all the top-level code.

-- 
Greg


From rob at despammer.com  Sun Dec  8 18:10:49 2019
From: rob at despammer.com (RobH)
Date: Sun, 8 Dec 2019 23:10:49 +0000
Subject: Aw: Re: stuck on time
In-Reply-To: <h55aevF2rhbU1@mid.individual.net>
References: <h52auhFecpmU1@mid.individual.net>
 <20191207191543.GE1626@hermes.hilbert.loc>
 <mailman.347.1575746147.25794.python-list@python.org>
 <h52gttFfjp4U1@mid.individual.net> <20191207212236.GF1626@hermes.hilbert.loc>
 <mailman.351.1575753760.25794.python-list@python.org>
 <h52pgoFh9c9U1@mid.individual.net>
 <trinity-f80ad9df-6e1d-4a08-aa5e-e180388a3a4a-1575793087786@3c-app-gmx-bap32>
 <mailman.357.1575793090.25794.python-list@python.org>
 <h53v0nFofdlU1@mid.individual.net>
 <qb9quehe4t1c54furmc8hjfd57ocsb8gpj@4ax.com>
 <mailman.368.1575823788.25794.python-list@python.org>
 <h54uppFfr3U1@mid.individual.net> <h55aevF2rhbU1@mid.individual.net>
Message-ID: <h55e7pF3ht8U1@mid.individual.net>

On 08/12/2019 22:06, Greg Ewing wrote:
> On 9/12/19 7:47 am, RobH wrote:
>> I wanted it to work as is, like it did for the author, without 
>> changing anything.
>>
>> So why should I now start to learn how python works.
> 
> There are many, many reasons a piece of code could work in one
> environment but not another. Figuring out why requires actual
> understanding, not just copy-pasting. Part of that involves
> gaining at least a basic knowledge of the language you're using.
> 
> You can't expect folks here to do all your work for you. We're
> trying to help, but we can't debug your code and/or system
> remotely, because we don't know everything about it. We can
> offer advice, but ultimately you're the one who has to work
> it out.
> 
> If you don't think the project is worth that much effort,
> that's up to you. But you asked for help, and we're doing our
> best to give it.
> 

Yes, fair comment that, and I do appreciate the people who do try to help.

Thank you to those.

From jfong at ms4.hinet.net  Sun Dec  8 21:51:50 2019
From: jfong at ms4.hinet.net (jfong at ms4.hinet.net)
Date: Sun, 8 Dec 2019 18:51:50 -0800 (PST)
Subject: python 2 to 3 converter
In-Reply-To: <h55b5aF2vtcU1@mid.individual.net>
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
Message-ID: <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>

Greg Ewing? 2019?12?9???? UTC+8??6?18?32????
> On 8/12/19 9:30 pm, songbird wrote:
> >    wouldn't it make more sense to just go back and fix the
> > converter program than to have to manually convert all this
> > python2 code?
> 
> Anything that isn't already fixed by 2to3 is probably
> somewhere between very difficult and impossible to fix
> using an automated process. It sounds like an interesting
> project, but be aware that it's probably an AI-complete
> problem.
> 
> -- 
> Greg

Even string is hard to be handled by the AI:-)

Quoted from https://portingguide.readthedocs.io/en/latest/strings.html
" ... This means that you need to go through the entire codebase, and decide which value is what type. Unfortunately, this process generally cannot be automated."

--Jach

From veek at dont-use-this.com  Mon Dec  9 01:58:30 2019
From: veek at dont-use-this.com (Veek M)
Date: Mon, 9 Dec 2019 06:58:30 -0000 (UTC)
Subject: Decorator as a class and Descriptor __get__ working? - cookbook, 9.9, 
 pg 349
Message-ID: <qskram$4ah$1@dont-email.me>

I did not follow the grok bit..
He's creating a Descriptor within class 'Spam' by doing 
@Profiled 
def bar()
because Profiled replaces 'bar' with it's instance that contains __get__

which means I have to do s.grok = 20 to trigger it? Which would imply,
s.__get__(instance, instance, value) NOT whatever he's done..  ? How is 
he passing Spam to 'grok'? It should be (self=decorator-instance, Spam-
instance-s and value) being passed to __get__

(for those who don't have the book, he's switched to 'grok' instead of 
'bar')


>>> s = Spam()
>>> def grok(self, x):
...     pass
...
>>> grok.__get__(s, Spam)

class Spam:
    @Profiled
    def bar(self, x):
        print(self, x)

import types
from functools import wraps
class Profiled:
    def __init__(self, func):
        wraps(func)(self)
        self.ncalls = 0
  
    def __call__(self, *args, **kwargs):
        self.ncalls += 1
        return self.__wrapped__(*args, **kwargs)
    
    def __get__(self, instance, cls):
        if instance is None:
            return self
        else:
            return types.MethodType(self, instance)

From address at not.available  Mon Dec  9 02:36:15 2019
From: address at not.available (R.Wieser)
Date: Mon, 9 Dec 2019 08:36:15 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
Message-ID: <qskump$eo2$1@gioia.aioe.org>

Terry,

> Not really.  The resulting global objects do not normally take enough 
> space to worry about on normal modern desktops.

For some reason I still aim to keep my (running) programs as small as 
possible - even though the ammount of memory has grown more than a 
thousandfold since I started programming.  Old habits die hard.

> Standard for in-file test is
[snip]

Any reason to put the testcode in a procedure instead of just have it 
directly follow the "if __name__ == '__main__' " test ?

> The PEP 8 convention (except for basic builtin data structures like int, 
> str, list, tuple, set, and dict) is TitleCase.

Thanks.

> Follow or not as you wish.

:-) If I ever want/need to share my code with others (or post here as part 
of a question) it is a good idea to conform to certain standards to keep it 
easily readable.  It will take some getting acustomed to though, as every 
language seems to have its own way to do it  (I myself prefer single prefix 
chars to indicate the variables intended type).

Regards,
Rudy Wieser



From address at not.available  Mon Dec  9 02:55:55 2019
From: address at not.available (R.Wieser)
Date: Mon, 9 Dec 2019 08:55:55 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <bd53a93d-d637-655e-f47b-14dfb63c8319@DancesWithMice.info>
 <mailman.378.1575840631.25794.python-list@python.org>
Message-ID: <qskumq$eo2$2@gioia.aioe.org>

DL,

> Some of this you will know. (Hopefully) some will be 'new':

Some of it is known to me, and indeed I do hope that there will be new stuff 
in there too.  Its why I took up Python. :-)

Thanks for the explanation (including the aliassing I wasn't aware of) and 
the links.

Regards,
Rudy Wieser



From address at not.available  Mon Dec  9 03:15:10 2019
From: address at not.available (R.Wieser)
Date: Mon, 9 Dec 2019 09:15:10 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
 <qsjfeh$1nbf$1@gioia.aioe.org> <h55d4nF3d5fU1@mid.individual.net>
Message-ID: <qskvqt$kev$1@gioia.aioe.org>

Greg,

>>> Are you sure there's a difference between classes and functions here?
>>
>> Yes, quite sure.
>
> And we're even more sure that there isn't. :-)

As it turned out "we're" are right, and I was thrown off by the error 
message. :-p

The problem is that I had no idea why I got that (rather explicit) error 
message, and took it by its face-value - sending me of in the wrong 
direction.

The actual caise ?  I made a mistake by, in the testcode (which I had not 
blocked off) in the imported file creating an instance with the exact same 
name as the class.   The deleting of that instance at the end of the 
testcode somehow caused the class to disappear as well, resulting in the 
"can't find it" error.

To be honest, I was not aware/did not assume that I could delete a class 
definition that way (I even find it a bit weird, but as I'm a newbie in 
regard to Python that does not say much).

Bottom line: I was caught by my own choice to give the instance the exact 
same name as the class. :-\

>You'll find that *any* form of import executes all the top-level code.

Thats certainly something I did not expect.

Regards,
Rudy Wieser



From greg.ewing at canterbury.ac.nz  Mon Dec  9 05:04:34 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 9 Dec 2019 23:04:34 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qskvqt$kev$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
 <qsjfeh$1nbf$1@gioia.aioe.org> <h55d4nF3d5fU1@mid.individual.net>
 <qskvqt$kev$1@gioia.aioe.org>
Message-ID: <h56khkFb187U1@mid.individual.net>

On 9/12/19 9:15 pm, R.Wieser wrote:
> To be honest, I was not aware/did not assume that I could delete a class
> definition that way (I even find it a bit weird, but as I'm a newbie in
> regard to Python that does not say much).

Python is very dynamic. The class statement is actually an executable
statement that creates a class object and binds it to a name. There's
nothing stopping you from subsequently rebinding that name to some
other object, or deleting it altogether.

-- 
Greg

From tjreedy at udel.edu  Mon Dec  9 05:32:47 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 9 Dec 2019 05:32:47 -0500
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qskump$eo2$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org>
Message-ID: <qsl7sg$1db5$1@blaine.gmane.org>

On 12/9/2019 2:36 AM, R.Wieser wrote:
> Terry,
>> Standard for in-file test is
> [snip]
> 
> Any reason to put the testcode in a procedure instead of just have it
> directly follow the "if __name__ == '__main__' " test ?

One can, for instance, interactively do

 >>> import mod
 >>> mod.test()

and explore the contents of mod, perhaps depending on the result of test()

def test(): ... also marks the code as test code rather than, for 
instance, command-line or setup code.  Putting such alternative code in 
function 'main' has the same effect.

For instance, 3.x has idlelib.__main__, which has something like

from idlelib.pyshell import main
main()

so than one can run 3.x IDLE from a command line with 'python -m idlelib'.

-- 
Terry Jan Reedy


From address at not.available  Mon Dec  9 05:32:05 2019
From: address at not.available (R.Wieser)
Date: Mon, 9 Dec 2019 11:32:05 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
 <qsjfeh$1nbf$1@gioia.aioe.org> <h55d4nF3d5fU1@mid.individual.net>
 <qskvqt$kev$1@gioia.aioe.org> <5dee1725$0$31399$426a34cc@news.free.fr>
Message-ID: <qsl8ca$1tct$1@gioia.aioe.org>

Python,

> Child *depends* on Parent.

I'm sorry, but without any kind of underbuilding statements like that are of 
no value to me I'm afraid.

Also: if I can just copy-and-paste the class into the file which origionally 
included it and have the whole program run without a problem than that 
dependency upon its origional parent doesn't seem to mean all too much (if 
anything at all).

Regards,
Rudy Wieser



From address at not.available  Mon Dec  9 05:41:02 2019
From: address at not.available (R.Wieser)
Date: Mon, 9 Dec 2019 11:41:02 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
 <qsjfeh$1nbf$1@gioia.aioe.org> <h55d4nF3d5fU1@mid.individual.net>
 <qskvqt$kev$1@gioia.aioe.org> <h56khkFb187U1@mid.individual.net>
Message-ID: <qsl8ca$1tct$2@gioia.aioe.org>

Greg,

> There's nothing stopping you from subsequently rebinding that name to some 
> other object, or deleting it altogether.

Which is something I did not expect.  But running into is what makes doing 
something new interesting. :-)

And I just realized something else: I just assumed that the "del instance" 
command did something more than it should, but there is a good chance that 
the mere action of creating an instance with the same name as the class made 
the classname disappear from the internal availability list, and not return 
after the instance (and I assume its name too) got deleted.

Regards,
Rudy Wieser



From jezkator at gmail.com  Mon Dec  9 06:21:55 2019
From: jezkator at gmail.com (jezkator at gmail.com)
Date: Mon, 9 Dec 2019 03:21:55 -0800 (PST)
Subject: python 3 prefix to infix without too many parethesis
Message-ID: <94f6efbc-15b9-47bb-8be8-1a01c7108b78@googlegroups.com>

Hi, I have got a problem.
I wrote a code for prefix to infix. It works, but I need improve it
so on input there will be only necessary parentheses. Can u help me?
Here is the code:

import re
a = input()

class Calculator:

    def __init__ (self):
        self.stack = []

    def push (self, p):
        if p in ['+', '-', '*', '/', "**"]:
            op1 = self.stack.pop ()
            op2 = self.stack.pop ()
            self.stack.append ('(%s%s%s)' % (op1, p, op2))

            
            print("op1 =", op1)
            print("op2 =", op2)
            print("p=", p)
            print(self.stack)

        else:
            self.stack.append (p)


    def convert (self, l):
        l.reverse ()
        for e in l:
            self.push (e)
        return self.stack.pop ()

c = Calculator ()

print (c.convert (re.findall(r'\d+|\*\*|[-+*/]', a)))


input is like /-*+*++**85 27 39 87 65 65 37 63 91


From musbur at posteo.org  Mon Dec  9 06:27:01 2019
From: musbur at posteo.org (Musbur)
Date: Mon, 09 Dec 2019 12:27:01 +0100
Subject: More efficient/elegant branching
Message-ID: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>

Hello,

I have a function with a long if/elif chain that sets a couple of 
variables according to a bunch of test expressions, similar to function 
branch1() below. I never liked that approach much because it is clumsy 
and repetetive, and pylint thinks so as well. I've come up with two 
alternatives which I believe are less efficient due to the reasons given 
in the respective docstrings. Does anybody have a better idea?

def branch1(a, b, z):
     """Inelegant, unwieldy, and pylint complains
     about too many branches"""
     if a > 4 and b == 0:
         result = "first"
     elif len(z) < 2:
         result = "second"
     elif b + a == 10:
         result = "third"
     return result

def branch2(a, b, z):
     """Elegant but inefficient because all expressions
     are pre-computed althogh the first one is most likely
     to hit"""
     decision = [
         (a > 4 and b == 0, "first"),
         (len(z) < 2,       "second"),
         (b + a == 10,      "third")]
     for (test, result) in decision:
         if test: return result

def branch3(a, b, z):
     """Elegant but inefficient because expressions
     need to be parsed each time"""
     decision = [
         ("a > 4 and b == 0", "first"),
         ("len(z) < 2",       "second"),
         ("b + a == 10",      "third")]
     for (test, result) in decision:
         if eval(test): return result
(env) [dh at deham01in015:~/python/rscl_fdc/devel]$


From rosuav at gmail.com  Mon Dec  9 06:46:58 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 9 Dec 2019 22:46:58 +1100
Subject: More efficient/elegant branching
In-Reply-To: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
Message-ID: <CAPTjJmpEyKhCDjTKMGThmv1ZRKxB0E8T4mXzd0-DQde9njW5wQ@mail.gmail.com>

On Mon, Dec 9, 2019 at 10:36 PM Musbur <musbur at posteo.org> wrote:
>
> Hello,
>
> I have a function with a long if/elif chain that sets a couple of
> variables according to a bunch of test expressions, similar to function
> branch1() below. I never liked that approach much because it is clumsy
> and repetetive, and pylint thinks so as well. I've come up with two
> alternatives which I believe are less efficient due to the reasons given
> in the respective docstrings. Does anybody have a better idea?
>
> def branch1(a, b, z):
>      """Inelegant, unwieldy, and pylint complains
>      about too many branches"""
>      if a > 4 and b == 0:
>          result = "first"
>      elif len(z) < 2:
>          result = "second"
>      elif b + a == 10:
>          result = "third"
>      return result

If the branches are completely independent, there's not really a lot
you can do differently. I'd rewrite these as return statements rather
than assigning to a variable and returning it at the end (which also
allows you to make them 'if' rather than 'elif'), but that's a
marginal gain. This is the sort of thing that tends to fall into the
category of "inherent complexity" - the code is complex because the
problem it's solving is complex. Imagine trying to write a function
that tells you whether to hold or tap a button:

def button_action(color, word):
    if color == "blue" and word == "Abort":
        return "Hold"
    if battery_count() > 1 and word == "Detonate":
        return "Tap"
    if color == "white" and "CAR" in indicators:
        return "Hold"
    if battery_count() > 2 and "FRK" in indicators:
        return "Tap"
    if color == "yellow":
        return "Hold"
    if color == "red" and word == "Hold":
        return "Tap"
    return "Hold"

You might be able to simplify this very slightly, but the conditions
are sufficiently varied that you can't really gain much, and they are
strictly ordered. The code here has as much complexity as the problem
it's solving, so you may as well just silence your linter's warnings
and carry on.

And yes, this sort of thing happens ALL THE TIME in real-world code.

https://thedailywtf.com/articles/The-Mythical-Business-Layer

IMO your code's fine. :)

ChrisA

From __peter__ at web.de  Mon Dec  9 08:49:13 2019
From: __peter__ at web.de (Peter Otten)
Date: Mon, 09 Dec 2019 14:49:13 +0100
Subject: More efficient/elegant branching
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
Message-ID: <qsljcr$23m3$1@blaine.gmane.org>

Musbur wrote:

> Hello,
> 
> I have a function with a long if/elif chain that sets a couple of
> variables according to a bunch of test expressions, similar to function
> branch1() below. I never liked that approach much because it is clumsy
> and repetetive, and pylint thinks so as well. I've come up with two
> alternatives which I believe are less efficient due to the reasons given
> in the respective docstrings. Does anybody have a better idea?
> 
> def branch1(a, b, z):
>      """Inelegant, unwieldy, and pylint complains
>      about too many branches"""
>      if a > 4 and b == 0:
>          result = "first"
>      elif len(z) < 2:
>          result = "second"
>      elif b + a == 10:
>          result = "third"
>      return result

I agree with Chris that this is the way to go.
pylint be damned ;)

> 
> def branch2(a, b, z):
>      """Elegant but inefficient because all expressions
>      are pre-computed althogh the first one is most likely
>      to hit"""

Also, it doesn't work in the general case, like

decision = [
   (a == 0, "first"),
   (b/a > 1, "second"),
   ...

>      decision = [
>          (a > 4 and b == 0, "first"),
>          (len(z) < 2,       "second"),
>          (b + a == 10,      "third")]
>      for (test, result) in decision:
>          if test: return result
> 
> def branch3(a, b, z):
>      """Elegant but inefficient because expressions
>      need to be parsed each time"""
>      decision = [
>          ("a > 4 and b == 0", "first"),
>          ("len(z) < 2",       "second"),
>          ("b + a == 10",      "third")]
>      for (test, result) in decision:
>          if eval(test): return result

You can shave off most of the overhead by precompiling the expressions:

DECISIONS = [
        ("a > 4 and b == 0", "first"),
        ("len(z) < 2",       "second"),
        ("b + a == 10",      "third")
]

DECISIONS4 = [
    (compile(expr, "<nofile>", "eval"), result)
    for expr, result in DECISIONS
]

def branch4(a, b, z):
    for test, result in DECISIONS4:
        if eval(test):
            return result
    raise ValueError

Using lambdas instead of precompiled expressions is a tad faster:

DECISIONS5 = [
    (eval("lambda a, b, z: " + expr), result)
    for expr, result in DECISIONS
]

def branch5(a, b, z):
    for test, result in DECISIONS5:
        if test(a, b, z):
            return result
    raise ValueError

This is is a slippery slope as you might now consider building branch1() 
from the DECISIONS list...


From rhodri at kynesim.co.uk  Mon Dec  9 08:54:25 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Mon, 9 Dec 2019 13:54:25 +0000
Subject: Regarding problem in python 3.8.0 installation
In-Reply-To: <CAArzVw4r2rt3dkFEXSPMSprWvWwG7UDZCNmVGRdEgbWQg874fw@mail.gmail.com>
References: <CAArzVw51e8n4PKRFZjgcH7-9JU6_TnnxyH6ijdtkVZHBW8p=0g@mail.gmail.com>
 <CAArzVw4r2rt3dkFEXSPMSprWvWwG7UDZCNmVGRdEgbWQg874fw@mail.gmail.com>
Message-ID: <68a9388d-a132-dbea-fde1-889a8e029321@kynesim.co.uk>

On 08/12/2019 18:08, alok singh wrote:
> Sir,
> 
> My system is windows 7 SP1 32-bit . after installing python in my
> system,when i try to launch it using command prompt then a message is
> shown. I am attaching a screenshot of the following.
> kindly look seriously into my problem and tell me the solution..

I'm afraid this is a text-only mailing list, so your screenshot has been 
stripped off before any of us could see it.  Please could you copy and 
paste the text of the error message you receive.

-- 
Rhodri James *-* Kynesim Ltd

From python.list at tim.thechases.com  Mon Dec  9 08:33:40 2019
From: python.list at tim.thechases.com (Tim Chase)
Date: Mon, 9 Dec 2019 07:33:40 -0600
Subject: More efficient/elegant branching
In-Reply-To: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
Message-ID: <20191209073340.4062a56f@bigbox.attlocal.net>

On 2019-12-09 12:27, Musbur wrote:
> def branch1(a, b, z):
>      """Inelegant, unwieldy, and pylint complains
>      about too many branches"""
>      if a > 4 and b == 0:
>          result = "first"
>      elif len(z) < 2:
>          result = "second"
>      elif b + a == 10:
>          result = "third"
>      return result

Because of the diversity of test-types, I tend to agree with ChrisA
and be strongly tempted to ignore linting warning.  I have some ETL
code that has umpty-gazillion odd if-conditions like this and they
all update some global-to-the-if/local-to-the-loop state, and if I
split each out somehow, I'd either be passing an object around that I
mutate, or I would do a lot of copy-the-data-updating-one-field per
function.

Alternatively, ...

> def branch2(a, b, z):
>      """Elegant but inefficient because all expressions
>      are pre-computed althogh the first one is most likely
>      to hit"""
> def branch3(a, b, z):
>      """Elegant but inefficient because expressions
>      need to be parsed each time"""

If you really want to do lazy evaluation, you can create a
function for each, which might (or might not) make it easier to read:

  def something_descriptive(a, b, z):
    return a > 4 and b == 0

  def z_is_short(a, b, z):
    return len(z) < 2

  def proper_total(a, b, z)
     return b + a == 10

  def branch4(a, b, z):
    for test, result in [
        (something_descriptive, "first"),
        (z_is_short, "second"),
        (proper_total, "third"),
        ]:
      if test(a, b, z):
        return result
    return "some default"

or possibly

  def something_descriptive(a, b):
    return a > 4 and b == 0

  def z_is_short(z):
    return len(z) < 2

  def proper_total(a, b)
     return b + a == 10

  def branch5(a, b, z):
    for test, params, result in [
        (something_descriptive, (a, b), "first"),
        (z_is_short, (z,), "second"),
        (proper_total, (a, b), "third"),
        ]:
      if test(*params):
        return result
    return "some default"

I'm not sure either of those is necessarily *better*, but they're at
least options that you can try and see if it improves readability in
your particular case.

-tkc





From python at python.invalid  Mon Dec  9 04:44:20 2019
From: python at python.invalid (Python)
Date: Mon, 9 Dec 2019 10:44:20 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qskvqt$kev$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
 <qsjfeh$1nbf$1@gioia.aioe.org> <h55d4nF3d5fU1@mid.individual.net>
 <qskvqt$kev$1@gioia.aioe.org>
Message-ID: <5dee1725$0$31399$426a34cc@news.free.fr>

Le 09/12/2019 ? 09:15, R.Wieser a ?crit?:
...
>> You'll find that *any* form of import executes all the top-level code.
> 
> Thats certainly something I did not expect.

How could it be otherwise? Consider a module defining two
classes: Parent and Child, Child inheriting from Parent.

if you do "from the_module import Child", how could it
not execute the code defining Parent as well? Child
*depends* on Parent.



From songbird at anthive.com  Mon Dec  9 12:47:22 2019
From: songbird at anthive.com (songbird)
Date: Mon, 9 Dec 2019 12:47:22 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
Message-ID: <aud2cg-qd7.ln1@anthive.com>

Greg Ewing wrote:
> On 8/12/19 9:30 pm, songbird wrote:
>>    wouldn't it make more sense to just go back and fix the
>> converter program than to have to manually convert all this
>> python2 code?
>
> Anything that isn't already fixed by 2to3 is probably
> somewhere between very difficult and impossible to fix
> using an automated process. It sounds like an interesting
> project, but be aware that it's probably an AI-complete
> problem.

  if the program already exists and is working then that
implies a parser already exists for it.

  this is not a general AI or CS issue.


  songbird

From songbird at anthive.com  Mon Dec  9 12:55:11 2019
From: songbird at anthive.com (songbird)
Date: Mon, 9 Dec 2019 12:55:11 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
Message-ID: <vce2cg-qd7.ln1@anthive.com>

jfong at ms4.hinet.net wrote:
...
> Even string is hard to be handled by the AI:-)
>
> Quoted from https://portingguide.readthedocs.io/en/latest/strings.html
> " ... This means that you need to go through the entire codebase, and decide which value is what type. Unfortunately, this process generally cannot be automated."

  i don't agree.  if the language is already parsed then
you have the strings.  the contents of the strings will
have to be finite if they are fixed strings.  so to convert
a fixed string you can choose a type for the value and run
a test to see if it works.  if it does then you've picked 
the correct type, if it doesn't you pick the next type.
there are only a finite number of types.

  yes it is brute force but it would find something that
worked eventually if there was something to be found.

  for programs using indefinite strings via input you
can't predict what those would be doing, but then of
course you would be able to say the most general type could 
be tried first and then run tests to see if it worked.

  the overall patterns to try for a string could be 
driven by examining code which has already been converted
that contains similar patterns - eventually you would
have enough of an idea of which things to try first to
speed things up.

  yes, this is a generally hard issue if you are talking
random strings and not sure what is what, but in the
case of a computer language it is already specified and
parsers already exist.


  songbird

From rosuav at gmail.com  Mon Dec  9 13:19:46 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Dec 2019 05:19:46 +1100
Subject: python 2 to 3 converter
In-Reply-To: <vce2cg-qd7.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
Message-ID: <CAPTjJmpJgKuVkpWfWiRmtwCRef1JeRS_2g0U_HrP1+gs+PS4Hw@mail.gmail.com>

On Tue, Dec 10, 2019 at 5:05 AM songbird <songbird at anthive.com> wrote:
>
> jfong at ms4.hinet.net wrote:
> ...
> > Even string is hard to be handled by the AI:-)
> >
> > Quoted from https://portingguide.readthedocs.io/en/latest/strings.html
> > " ... This means that you need to go through the entire codebase, and decide which value is what type. Unfortunately, this process generally cannot be automated."
>
>   i don't agree.  if the language is already parsed then
> you have the strings.  the contents of the strings will
> have to be finite if they are fixed strings.  so to convert
> a fixed string you can choose a type for the value and run
> a test to see if it works.  if it does then you've picked
> the correct type, if it doesn't you pick the next type.
> there are only a finite number of types.
>

Here's an example piece of code.

sock = socket.socket(...)
name = input("Enter your username: ")
code = input("Enter the base64 code: ")
code = base64.b64decode(code)
sock.write("""GET /foo HTTP/1.0
Authentication: Demo %s/%s

""" % (name, code))
match = re.search(r"#[A-Za-z0-9]+#", sock.read())
if match: print("Response: " + match.group(0))

Your challenge: Figure out which of those strings should be a byte
string and which should be text. Or alternatively, prove that this is
a hard problem. There are only a finite number of types - two, to be
precise - so by your argument, this should be straightforward, right?

ChrisA

From rgaddi at highlandtechnology.invalid  Mon Dec  9 13:20:07 2019
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Mon, 9 Dec 2019 10:20:07 -0800
Subject: python 2 to 3 converter
In-Reply-To: <vce2cg-qd7.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
Message-ID: <qsm38p$q4k$1@dont-email.me>

On 12/9/19 9:55 AM, songbird wrote:
> jfong at ms4.hinet.net wrote:
> ...
>> Even string is hard to be handled by the AI:-)
>>
>> Quoted from https://portingguide.readthedocs.io/en/latest/strings.html
>> " ... This means that you need to go through the entire codebase, and decide which value is what type. Unfortunately, this process generally cannot be automated."
> 
>    i don't agree.  if the language is already parsed then
> you have the strings.  the contents of the strings will
> have to be finite if they are fixed strings.  so to convert
> a fixed string you can choose a type for the value and run
> a test to see if it works.  if it does then you've picked
> the correct type, if it doesn't you pick the next type.
> there are only a finite number of types.
> 

And how exactly do you propose to determine whether the constant I've enclosed 
in quotation marks in Python2 represents "text" or "binary data"?  Not all text 
is words; think of SQL queries.  And some words are binary data, think SCPI 
commands being sent to a serial port.


From address at not.available  Mon Dec  9 14:21:39 2019
From: address at not.available (R.Wieser)
Date: Mon, 9 Dec 2019 20:21:39 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <CAPTjJmo2DAX2V8SUTtocQZ_5a4LXuQUEiGG6d9M+jyWB6QCVSQ@mail.gmail.com>
 <mailman.367.1575823304.25794.python-list@python.org>
 <qsjfeh$1nbf$1@gioia.aioe.org> <h55d4nF3d5fU1@mid.individual.net>
 <qskvqt$kev$1@gioia.aioe.org> <h56khkFb187U1@mid.individual.net>
 <qsl8ca$1tct$2@gioia.aioe.org> <lo1tue1qg6eqf6kg1lnmvk1sc5oqp0fpd6@4ax.com>
 <mailman.391.1575913676.25794.python-list@python.org>
Message-ID: <qsm6se$od6$1@gioia.aioe.org>

Dennis,

> "del instance" only deletes the NAME.
[snip]

Yep, I already assumed that that would happen.  Just wanted to keep it 
simple.

> "instance" xyz does not shadow "class" xyz... instead, the name "xyz"
> only exists in the binding to the instance.

That is what I tried to say: the name-binding to the class is removed.

> However, that instance has a binding to the class object,

And than when the instance is deleted the binding to the class is lost, and 
as a result it is garbage-collected.  Right ?

Regards,
Rudy Wieser



From tjreedy at udel.edu  Mon Dec  9 14:40:42 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Mon, 9 Dec 2019 14:40:42 -0500
Subject: python 3 prefix to infix without too many parethesis
In-Reply-To: <94f6efbc-15b9-47bb-8be8-1a01c7108b78@googlegroups.com>
References: <94f6efbc-15b9-47bb-8be8-1a01c7108b78@googlegroups.com>
Message-ID: <qsm7vr$7enb$1@blaine.gmane.org>

On 12/9/2019 6:21 AM, jezkator at gmail.com wrote:
> Hi, I have got a problem.

Is this homework?

> I wrote a code for prefix to infix. It works, but I need improve it
> so on input there will be only necessary parentheses.

Define 'necessary'; give multiple input/output examples.
Put them in a test function.

> Here is the code:
> 
> import re
> a = input()
> 
> class Calculator:
> 
>      def __init__ (self):
>          self.stack = []
> 
>      def push (self, p):
>          if p in ['+', '-', '*', '/', "**"]:
>              op1 = self.stack.pop ()
>              op2 = self.stack.pop ()
>              self.stack.append ('(%s%s%s)' % (op1, p, op2))
> 
>              
>              print("op1 =", op1)
>              print("op2 =", op2)
>              print("p=", p)
>              print(self.stack)
> 
>          else:
>              self.stack.append (p)
> 
> 
>      def convert (self, l):
>          l.reverse ()
>          for e in l:
>              self.push (e)
>          return self.stack.pop ()
> 
> c = Calculator ()
> 
> print (c.convert (re.findall(r'\d+|\*\*|[-+*/]', a)))
> 
> 
> input is like /-*+*++**85 27 39 87 65 65 37 63 91

Since '*' and '**' are both allowed operators (see 'p in' above), spaces 
are needed between operators to disambiguate.  In any case, what output 
does your code produce now, and what do you want it to produce.

-- 
Terry Jan Reedy


From PythonList at DancesWithMice.info  Mon Dec  9 15:30:59 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 10 Dec 2019 09:30:59 +1300
Subject: python 3 prefix to infix without too many parethesis
In-Reply-To: <qsm7vr$7enb$1@blaine.gmane.org>
References: <94f6efbc-15b9-47bb-8be8-1a01c7108b78@googlegroups.com>
 <qsm7vr$7enb$1@blaine.gmane.org>
Message-ID: <a886c4e9-a653-0c79-deba-c8c6d9df8907@DancesWithMice.info>

On 10/12/19 8:40 AM, Terry Reedy wrote:
> On 12/9/2019 6:21 AM, jezkator at gmail.com wrote:
>> Hi, I have got a problem.
> 
> Is this homework?

Same question - that way we know that our task is to help you learn to 
code in Python, cf a problem with Python itself...

Similarly, you may like to  know that there is a separate Python-Tutor 
Discussion List.


>> I wrote a code for prefix to infix. It works, but I need improve it
>> so on input there will be only necessary parentheses.

The example code processes, like a calculator (um, yes, well...). What 
do you mean by "prefix to infix"?


> Define 'necessary'; give multiple input/output examples.
> Put them in a test function.

+1


>> Here is the code:

Question: with abbreviated variableNMs, eg "p", "a", even "op"; how 
easily will you comprehend the code in six month's time? How easy do you 
think it is for someone else to read the code now? NB the print 
functions are no help because the labels are equally-abbreviated, plus 
my aged-eyes start to strain when following lists of %s-es and regexps - 
mea culpa!


>> import re
>> a = input()
>>
>> class Calculator:
>>
>> ???? def __init__ (self):
>> ???????? self.stack = []
>>
>> ???? def push (self, p):
>> ???????? if p in ['+', '-', '*', '/', "**"]:
>> ???????????? op1 = self.stack.pop ()
>> ???????????? op2 = self.stack.pop ()
>> ???????????? self.stack.append ('(%s%s%s)' % (op1, p, op2))
>>
>> ???????????? print("op1 =", op1)
>> ???????????? print("op2 =", op2)
>> ???????????? print("p=", p)
>> ???????????? print(self.stack)
>>
>> ???????? else:
>> ???????????? self.stack.append (p)
>>
>>
>> ???? def convert (self, l):
>> ???????? l.reverse ()
>> ???????? for e in l:
>> ???????????? self.push (e)
>> ???????? return self.stack.pop ()
>>
>> c = Calculator ()
>>
>> print (c.convert (re.findall(r'\d+|\*\*|[-+*/]', a)))
>>
>>
>> input is like /-*+*++**85 27 39 87 65 65 37 63 91

ALWAYS, ALWAYS, ALWAYS, document a RegExp with a comment!!!

After 'translating' the abbreviations according to my recollection of 
this form of a frequently-used ComSc course problem, I was then 
surprised by the format of the input - using an infix calculator we 
enter a value, then an operator, and then another value, etc; and using 
a postfix calculator one usually inputs a couple of values and then an 
operator, another value, and then an operator, and so on - rather than 
receiving it all at once. Is this 'all at once' a feature of an infix 
calculator or am I missing/forgetting something?

For which I am obviously not the only one with a confused expression on 
my face...


> Since '*' and '**' are both allowed operators (see 'p in' above), spaces 
> are needed between operators to disambiguate.? In any case, what output 
> does your code produce now, and what do you want it to produce.

I hate RegExps because it is sooooo easy to write a wrong 'un. However, 
because the "\*\*" selection precedes the "[-+*/]", it appears (rheumy 
eyes allowing) to enact arithmetic priority correctly. However, as 
mentioned before, most of us will have created a serial and algorithmic 
approach to this problem, back-when; so it does seem a little strange.


OK, let's address your actual question: the parentheses!

How do you plan to make them work? As elsewhere: please provide example 
input and expected output, so that we can be sure of the code's 
objective. Multiple examples can only help, especially if there are 
exceptions and "edge-cases". Also, if your progress in Python is ready 
for it, we can talk PyTest (or equivalent), plus such a plan enables you 
to practice Test-Driven Development...


These problems stretch one's mental acuities. It would seem that I am 
not the only one looking forward to hearing back from you...
-- 
Regards =dn

From PythonList at DancesWithMice.info  Mon Dec  9 17:59:31 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 10 Dec 2019 11:59:31 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsl7sg$1db5$1@blaine.gmane.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
Message-ID: <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>

It might be becoming 'long', but this discussion contains much of profit 
to many people!


Us 'silver surfers' do need to periodically question those beliefs we 
hold as 'tenets' of ComSc. Amongst them is RAM (or "core"!) 
conservation. It remains a virtue somewhat, but at the same time, 
storage costs are considerably cheaper than they were four decades ago, 
whereas the relative-cost of your time (to think about such things) has 
increased!

That said, many of our more youthful (and in their own words "better in 
every way", harrumph!) colleagues should also review their own beliefs 
from time-to-time, eg working with IoT devices certainly requires a more 
conservative and considerate approach to resources!
(and in such applications, we tend to enjoy significant advantage 
because we've 'been there, done that'!)


Similarly, it is a serious fallacy to attempt to directly 'translate' a 
'command' from one language into an 'equivalent' in another/a new 
language. Whilst the syntax may appear similar, such superficiality 
doesn't allow for subtleties of meaning! In the same way, if you ask one 
person to translate the English word "preserve" into German, and then 
another person to translate that German word into English, what are the 
chances that the 'answer' will be "preserve"? Given that "preserve" 
could mean a jam/jelly/conserve (noun) or (verb) 'maintain the meaning', 
with a similar range of synonyms (etc) on the German side; the word 
"preserve" is unlikely to be preserved!
(with all due apologies for such terrible humor and word-play!)


On 9/12/19 11:32 PM, Terry Reedy wrote:
> On 12/9/2019 2:36 AM, R.Wieser wrote:
>> Terry,
>>> Standard for in-file test is
>> [snip]
>>
>> Any reason to put the testcode in a procedure instead of just have it
>> directly follow the "if __name__ == '__main__' " test ?
> 
> One can, for instance, interactively do
> 
>  >>> import mod
>  >>> mod.test()
...

I went through this cycle of thinking, first using if __name__... to 
'hide' testing, then adding test functions within the module, and now 
keep test code quite separate from 'the real thing'.

In fact, PyTest (for example) will auto-magically look for test-code in 
sub-directories of the project directory, eg "projectNM/tests". So, for 
every (Python) file in my projectDIR, you should be able to find at 
least one corresponding Python test-file in the tests sub-dir!

This fits with your philosophy of keeping (imported) modules small, 
perhaps to the point of separating each class into its own module - if 
'efficiency' is the goal, why would you want to include test-code within 
a 'production system'?


On which point, if we had a class Person(); and then decided that in 
certain cases we wanted specific methods that didn't apply to every 
(type of) Person, we would likely create a sub-class, eg class Man( 
Person ); - although some might dispute the accuracy of such an "is a" 
relationship...

That being the case, were you to put the Man class' code into (say) a 
module called "man.py" and Person()'s code into "person.py", then a 
point made earlier is that you can't merely import man.py;! You must 
also ensure that person.py is imported, somewhere along the line. Thus, 
because it names (and requires the logic of) the super-class, the 
sub-class cannot be imported 'alone'. (regardless of saving-space 
objectives, etc)


Expanding on 'names' and del(): the first point is that there is seldom 
much to be gained by using del(), ie becoming your own 'garbage 
collector'. That said, there are some very specific times when it 
becomes absolutely necessary (otherwise the Python 'gods' would not have 
given us the functionality!). Once again, RAM is (relatively) plentiful, 
and when you need to replicate many multiples of an object, it is likely 
within a loop and therefore the same instanceNM is being 're-used' and 
the garbage-collector takes care of 'recycling' the storage space 
auto-magically.


Regarding 'names', yes some languages are "strongly typed" and (mostly) 
for that reason include an indicator of "type" within the name. Python 
enables you to play fast-and-loose, eg

 >>> x = 1
 >>> x = "abc"
 >>> x = 2.3
 >>> x = [ 1, 2, 3 ]
 >>> x = ( 1, 2, 3 )
 >>> x = 1, 2, 3

constitutes a perfectly legal program (where "legal" != "useful").


There again, there are times when values are processed into a different 
data structure, eg we start with a list of values, but only want to use 
unique values/process each representative-member once.

A Python-list will handle the former (wow, that's a bit of 'rocket 
science'!?) whereas a Python-set will only contain unique values. So, 
rather than using a somewhat-bland varNM such as "letters", I would 
choose to be more explicit:

 >>> letters_list = [ "a", "b", "a", "c", "a", "d", "a" ]
 >>> len( letters_list )
7
 >>> letters_set = set( letters_list )
 >>> len( letters_set )
4
 >>> letters_set
{'b', 'a', 'd', 'c'}

There is no question whether "letters" is a list, or a set, (or ...), 
because of the explicit varNMs.

However, there are many people who dislike such an approach. Sadly, I'm 
not smart-enough to run with that crowd...


Remember that the naming conventions (mentioned elsewhere) also give you 
a hint as to type. Relevant here:

class Person(): ...	# Person is a classNM = title-case

class Man( Person ): ...	# as is Man

david = Man( etc )	# david is an instance and NOT a class (?classy)
rudy = Man( etc )	#rudy probably does have class, in this instance

del( david )	# is quite different to/separate from rudy
del( Person )	# and we know this is a class cf an instance

However, I'd question:

del( rudy )

because that might risk a tear in your space-time continuum... (!?)


-- 
Regards =dn

From songbird at anthive.com  Mon Dec  9 20:07:21 2019
From: songbird at anthive.com (songbird)
Date: Mon, 9 Dec 2019 20:07:21 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com> <qsm38p$q4k$1@dont-email.me>
Message-ID: <9n73cg-50n.ln1@anthive.com>

Rob Gaddi wrote:
...
> And how exactly do you propose to determine whether the constant I've enclosed 
> in quotation marks in Python2 represents "text" or "binary data"?  Not all text 
> is words; think of SQL queries.  And some words are binary data, think SCPI 
> commands being sent to a serial port.

  why not assume one, see if it works and then if it doesn't you
know it is the other?  if those are the only two choices then 
that speeds things up.


  songbird

From songbird at anthive.com  Mon Dec  9 20:05:11 2019
From: songbird at anthive.com (songbird)
Date: Mon, 9 Dec 2019 20:05:11 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
 <CAPTjJmpJgKuVkpWfWiRmtwCRef1JeRS_2g0U_HrP1+gs+PS4Hw@mail.gmail.com>
 <mailman.392.1575915601.25794.python-list@python.org>
Message-ID: <7j73cg-50n.ln1@anthive.com>

Chris Angelico wrote:
...
>
> Here's an example piece of code.
>
> sock = socket.socket(...)
> name = input("Enter your username: ")
> code = input("Enter the base64 code: ")
> code = base64.b64decode(code)
> sock.write("""GET /foo HTTP/1.0
> Authentication: Demo %s/%s
>
> """ % (name, code))
> match = re.search(r"#[A-Za-z0-9]+#", sock.read())
> if match: print("Response: " + match.group(0))
>
> Your challenge: Figure out which of those strings should be a byte
> string and which should be text. Or alternatively, prove that this is
> a hard problem. There are only a finite number of types - two, to be
> precise - so by your argument, this should be straightforward, right?

  this isn't a process of looking at isolated code.  this
is a process of looking at the code, but also the test cases
or working examples.  so the inputs are known and the code 
itself gives clues about what it is expecting.

  regular expressions can be matched in finite time as well
as a fixed length text of any type can be scanned as a match
or rejected.

  if you examined a thousand uses of match and found the
pattern used above and then examined what those programs did
with that match what would you select as the first type, the
one used the most first, if that doesn't work go with the 2nd,
etc.


  songbird

From info at tundraware.com  Mon Dec  9 19:52:11 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 9 Dec 2019 18:52:11 -0600
Subject: Randomizing Strings In A Microservices World
Message-ID: <rq63cg-3fp1.ln1@oceanview.tundraware.com>

I ran across a kind of fun problem today that I wanted to run past you Gentle Geniuses (tm):

- Imagine an environment in which there may be multiple instances of a given
  microservice written in Python.

- Each of these services needs to produce a string of ten digits guaranteed to be unique
  on a per service instance basis AND to not collide for - oh, let's say - forever :)s

Can anyone suggest a randomization method that might achieve this efficiently?

My first thought was to something like nanonseconds since the epoch plus something
unique about the service instance - like it's IP?  (This is in a K8s cluster) - to
see the randomization and essentially eliminate the string being repeated.

Ideas welcome ..

P.S. I do not want to resort to a number generation service that each instance asks
     for a new number.  The network and service call overhead militates against this
     in my application.


From rosuav at gmail.com  Mon Dec  9 20:13:22 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Dec 2019 12:13:22 +1100
Subject: python 2 to 3 converter
In-Reply-To: <9n73cg-50n.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
 <qsm38p$q4k$1@dont-email.me> <9n73cg-50n.ln1@anthive.com>
Message-ID: <CAPTjJmoTB_BDTOWv-tXNxMs-Jh6x6Ux9Mx2N-zV1+7OzS6GaSw@mail.gmail.com>

On Tue, Dec 10, 2019 at 12:11 PM songbird <songbird at anthive.com> wrote:
>
> Rob Gaddi wrote:
> ...
> > And how exactly do you propose to determine whether the constant I've enclosed
> > in quotation marks in Python2 represents "text" or "binary data"?  Not all text
> > is words; think of SQL queries.  And some words are binary data, think SCPI
> > commands being sent to a serial port.
>
>   why not assume one, see if it works and then if it doesn't you
> know it is the other?  if those are the only two choices then
> that speeds things up.
>

What if neither works, because there are assumptions that don't work?

I get the very strong impression that you've never tried this.

ChrisA

From rosuav at gmail.com  Mon Dec  9 20:24:51 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Dec 2019 12:24:51 +1100
Subject: python 2 to 3 converter
In-Reply-To: <7j73cg-50n.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
 <CAPTjJmpJgKuVkpWfWiRmtwCRef1JeRS_2g0U_HrP1+gs+PS4Hw@mail.gmail.com>
 <mailman.392.1575915601.25794.python-list@python.org>
 <7j73cg-50n.ln1@anthive.com>
Message-ID: <CAPTjJmphytnzZhNk9WnVhCMAn2Vgn3zdkPG0yHw+p+B7qu2sPA@mail.gmail.com>

On Tue, Dec 10, 2019 at 12:15 PM songbird <songbird at anthive.com> wrote:
>
> Chris Angelico wrote:
> ...
> >
> > Here's an example piece of code.
> >
> > sock = socket.socket(...)
> > name = input("Enter your username: ")
> > code = input("Enter the base64 code: ")
> > code = base64.b64decode(code)
> > sock.write("""GET /foo HTTP/1.0
> > Authentication: Demo %s/%s
> >
> > """ % (name, code))
> > match = re.search(r"#[A-Za-z0-9]+#", sock.read())
> > if match: print("Response: " + match.group(0))
> >
> > Your challenge: Figure out which of those strings should be a byte
> > string and which should be text. Or alternatively, prove that this is
> > a hard problem. There are only a finite number of types - two, to be
> > precise - so by your argument, this should be straightforward, right?
>
>   this isn't a process of looking at isolated code.  this
> is a process of looking at the code, but also the test cases
> or working examples.  so the inputs are known and the code
> itself gives clues about what it is expecting.

Okay. The test cases are also written in Python, and they use
unadorned string literals to provide mock values for input() and the
socket response. Now what?

What if the test cases are entirely ASCII characters?

What if the test cases are NOT entirely ASCII characters?

>   regular expressions can be matched in finite time as well
> as a fixed length text of any type can be scanned as a match
> or rejected.
>
>   if you examined a thousand uses of match and found the
> pattern used above and then examined what those programs did
> with that match what would you select as the first type, the
> one used the most first, if that doesn't work go with the 2nd,
> etc.
>

That's not really the point. Are your regular expressions working with
text or bytes? Does your socket return text or bytes?

I've deliberately chosen these examples because they are hard. And I
didn't even get into an extremely hard problem, with the inclusion of
text inside binary data inside of text inside of bytes. (It does
happen.)

These problems are fundamentally hard because there is insufficient
information in the source code alone to determine the programmer's
intent.

ChrisA

From PythonList at DancesWithMice.info  Mon Dec  9 20:32:49 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 10 Dec 2019 14:32:49 +1300
Subject: More efficient/elegant branching
In-Reply-To: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
Message-ID: <a892e74d-04c6-8bc0-15d9-0e537b26a955@DancesWithMice.info>

I agree with you, so I'm going to ignore def branch2(a, b, z): and def 
branch3(a, b, z) because they appear too contrived - and I guess that's 
fair, in that you've contrived to satisfy pylint.

Question: are there other people/factors who/which should be regarded as 
more important than the linter's opinion?

The usual dictionary-controlled construct I've seen (and used) involves 
using functions as the dict's values:

def branch1( *args): pass
...
alternative[ x ] = branch1

and thus:

alternative[ choice ]( *args )


On 10/12/19 12:27 AM, Musbur wrote:
> I have a function with a long if/elif chain that sets a couple of 
> variables according to a bunch of test expressions, similar to function 
> branch1() below. I never liked that approach much because it is clumsy 
> and repetetive, and pylint thinks so as well. I've come up with two 
> alternatives which I believe are less efficient due to the reasons given 
> in the respective docstrings. Does anybody have a better idea?
> 
> def branch1(a, b, z):
>  ??? """Inelegant, unwieldy, and pylint complains
>  ??? about too many branches"""
>  ??? if a > 4 and b == 0:
>  ??????? result = "first"
>  ??? elif len(z) < 2:
>  ??????? result = "second"
>  ??? elif b + a == 10:
>  ??????? result = "third"
>  ??? return result

Is it ironic that the language does not have a form of case/switch 
statement (despite many pleas and attempts to add it), yet the linter 
objects to an if-elif-else nesting???


One reason why this code looks a bit strange (and possibly why PyLint 
reacts?) is because it is trivial. When we look at the overall picture, 
the question becomes: what will the 'mainline' do with "result" (the 
returned value)? Immediately one suspects it will be fed into another 
decision, eg:

	if result == "first": # do the first-thing...
	if result == "second": # do the second-thing...

When found 'in real life', the above structure with such decisions is 
almost certainly followed by a second decision to select which 
'action(s)' will be carried-out. The original-code rarely stands-alone, 
because all we've achieved is a labelling of the circumstances according 
to the arguments provided.


Rather than using a variable for 'labelling', (all other things being 
equal) I'd prefer to go straight to a function which 'does the business' 
- and use the function's name as a documenting 'label'!


A quick reflection shows that I have vacillated between two approaches:

1 put the decision-making in the 'mainline' and call a variety of 
functions/methods to do 'the first thing' etc. ie more-or-less what you 
have here, except the cascade of decisions is not separated from 'what 
came before'.

def calculation( value, operator, operand):
	if operator == "+":
		add( value, operand)
	elif operator == "-":
		sub( value, operand)


2 arrange/call a series of functions each dealing with a single 
circumstance, eg (borrowing from @Chris) should I "tap"?. Thus each 
function will firstly check if the circumstances demand that action, ie 
the applicable one of the if-clauses above, and if they do, then 
implement that action: 'do the first thing' (etc).

value = handle_add( value, operator, operand )
value = handle_sub( value, operator, operand )

where:

def handle_add( value, operator, operand):
	if operator == "+":
		return value + operand
	return value

Ugh - the example is no less contrived and grossly artificial...


The second of those appears somewhat 'cleaner' - in that we have 'hidden 
away' all those pesky if-constructs; BUT it is NOT immediately obvious 
exactly how many of the series of functions will actually result in any 
'action' (if not, all of them). So, perhaps that raises the 
(earlier/elsewhere) question of whether the various action-functions are 
dependent or independent/exclusive of each other? It also requires 
carefully choosing descriptive function names!
-- 
Regards =dn

From akkana at shallowsky.com  Mon Dec  9 20:34:19 2019
From: akkana at shallowsky.com (Akkana Peck)
Date: Mon, 9 Dec 2019 18:34:19 -0700
Subject: Testing a TestPyPI package with dependencies
Message-ID: <20191210013419.GE2008@shallowsky.com>

I'm a novice packager, trying to test a package I built and
uploaded to TestPyPI. It has dependencies and I want to make
sure my setup.py works before uploading to the real PyPI.

https://packaging.python.org/guides/using-testpypi/
says that if a package has dependencies, to use this command to get
the package from TestPyPI while getting dependencies from PyPI:

pip install --index-url https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple your-package

That doesn't seem to work, though. It seems like it never checks
pypi.org and looks for everything in test.pypi.org. Here's what I'm
doing, starting from a new virtualenv:

......
    $ python3 -m venv /tmp/test3env

    $ source /tmp/test3env/bin/activate

    (test3env) $ pip install wheel
    Collecting wheel
      Using cached https://files.pythonhosted.org/packages/00/83/b4a77d044e78ad1a45610eb88f745be2fd2c6d658f9798a15e384b7d57c9/wheel-0.33.6-py2.py3-none-any.whl
    Installing collected packages: wheel
    Successfully installed wheel-0.33.6

    (test3env) $ pip install --index-url https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple pytopo==1.6.1
    Looking in indexes: https://test.pypi.org/simple/, https://pypi.org/simple
    Collecting pytopo
      Using cached https://test-files.pythonhosted.org/packages/1d/dd/f46722bed2296676053b333a97babf05cb31b20e4a621161d44399a3ed18/pytopo-1.6.1-py3-none-any.whl
    Collecting simplejson (from pytopo)
    Could not install packages due to an EnvironmentError: 404 Client Error: Not Found for url: https://test.pypi.org/simple/simplejson/
......

I can pip install simplejson without errors, so I know it's in PyPI.
(If I then try the install again, it fails on pycairo, same error.)

Am I misunderstanding that packaging.python.org guide, or making
some silly typo? Is there a trick it doesn't mention to getting pip
to use both PyPI and TestPyPI?

Thanks for any suggestions!

        ...Akkana

From timothy.c.delaney at gmail.com  Mon Dec  9 20:52:42 2019
From: timothy.c.delaney at gmail.com (Tim Delaney)
Date: Tue, 10 Dec 2019 12:52:42 +1100
Subject: Randomizing Strings In A Microservices World
In-Reply-To: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
Message-ID: <CAN8CLg=d9zan4fy1Dy02yoynmTSh4bkaQMPKxqOSt4XRHfLfjA@mail.gmail.com>

On Tue, 10 Dec 2019 at 12:12, Tim Daneliuk <info at tundraware.com> wrote:

> - Each of these services needs to produce a string of ten digits
> guaranteed to be unique
>   on a per service instance basis AND to not collide for - oh, let's say -
> forever :)s
>
> Can anyone suggest a randomization method that might achieve this
> efficiently?
>
> My first thought was to something like nanonseconds since the epoch plus
> something
> unique about the service instance - like it's IP?  (This is in a K8s
> cluster) - to
> see the randomization and essentially eliminate the string being repeated.
>

10 digits is only 999999999. That's not a very big number. Forget
nanoseconds since the epoch, that won't currently give you seconds since
the epoch - let alone combining with any other identifier.

$ date '+%s'
1575942612

Tim Delaney

From info at tundraware.com  Mon Dec  9 22:35:56 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 9 Dec 2019 21:35:56 -0600
Subject: Randomizing Strings In A Microservices World
In-Reply-To: <878snkdhcp.fsf@nightsong.com>
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
 <878snkdhcp.fsf@nightsong.com>
Message-ID: <sdg3cg-93s1.ln1@oceanview.tundraware.com>

On 12/9/19 8:50 PM, Paul Rubin wrote:
> Tim Daneliuk <info at tundraware.com> writes:
>> - Imagine an environment in which there may be multiple instances of a given
>>   microservice written in Python.
> 
> Decide the maximum number of microservice instances, say 1000.  Chop up
> the 10 digit range into 1000 pieces, so 0..999999, 1000000-1999999, etc.
> Give one range to each microservice instance.  Then have the
> microservices give out the numbers sequentially, but treating them as 10
> digit numbers and encrypting each one under a 10 digit pseudorandom
> permutation shared by all the instances.  Look up "format preserving
> encryption" for how to do this.
> 
> Obvious variants of the above are obvious, and maybe you need some way
> to hand around chunks of range if some instance gives out more than a
> million numbers.
> 


The problem here is that the services are ephemeral and the number of said
services is not fixed.


From info at tundraware.com  Mon Dec  9 22:38:43 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 9 Dec 2019 21:38:43 -0600
Subject: Randomizing Strings In A Microservices World
In-Reply-To: <mailman.404.1575946535.25794.python-list@python.org>
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
 <022uued8o9evis6rruhg4g99cslhh0do5f@4ax.com>
 <mailman.404.1575946535.25794.python-list@python.org>
Message-ID: <3jg3cg-93s1.ln1@oceanview.tundraware.com>

On 12/9/19 8:54 PM, Dennis Lee Bieber wrote:
> On Mon, 9 Dec 2019 18:52:11 -0600, Tim Daneliuk <info at tundraware.com>
> declaimed the following:
> 
>>
>> - Each of these services needs to produce a string of ten digits guaranteed to be unique
>>  on a per service instance basis AND to not collide for - oh, let's say - forever :)s
>>
>> Can anyone suggest a randomization method that might achieve this efficiently?
>>
>> My first thought was to something like nanonseconds since the epoch plus something
>> unique about the service instance - like it's IP?  (This is in a K8s cluster) - to
>> see the randomization and essentially eliminate the string being repeated.
>>
>> Ideas welcome ..
>>
> 
> 	Well, 10 digits is rather short, but studying
> https://en.wikipedia.org/wiki/Universally_unique_identifier might provide
> some ideas.
> 
> 

For a variety of reasons the length of this string cannot exceed 10 digits.  It is believed
that - in this application - the consumption of values will be sparse over time.  All
I really need is a high entropy way to select from among the billion possible values to
minimize the possibility of collisions (which require retry and time we don't want to burn).


From songbird at anthive.com  Tue Dec 10 00:32:32 2019
From: songbird at anthive.com (songbird)
Date: Tue, 10 Dec 2019 00:32:32 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com> <qsm38p$q4k$1@dont-email.me>
 <9n73cg-50n.ln1@anthive.com>
 <CAPTjJmoTB_BDTOWv-tXNxMs-Jh6x6Ux9Mx2N-zV1+7OzS6GaSw@mail.gmail.com>
 <mailman.399.1575940416.25794.python-list@python.org>
Message-ID: <g8n3cg-5kr.ln1@anthive.com>

Chris Angelico wrote:
...
> What if neither works, because there are assumptions that don't work?

  then you get stuck doing it by hand, but you would have
been stuck doing it before for sure by hand so if you can
write something which might get some of the easy cases
done then at least you're saving your efforts for the 
harder stuff.


> I get the very strong impression that you've never tried this.

  of course not!  i don't have that kind of pipeline
or machine power and i'm several years away from being 
where i'd like to be in terms of understanding the
language itself.  i hope to have the time over the 
next few years to learn enough but i don't know how 
that will go.

  i'm glad in looking around more the past few evenings
that the conversion effort is making progress and 
things are not as dire as some have made it out to be.
i just hope the lessons have been learned going 
forwards.


  songbird

From rosuav at gmail.com  Tue Dec 10 00:44:10 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Dec 2019 16:44:10 +1100
Subject: python 2 to 3 converter
In-Reply-To: <g8n3cg-5kr.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
 <qsm38p$q4k$1@dont-email.me> <9n73cg-50n.ln1@anthive.com>
 <CAPTjJmoTB_BDTOWv-tXNxMs-Jh6x6Ux9Mx2N-zV1+7OzS6GaSw@mail.gmail.com>
 <mailman.399.1575940416.25794.python-list@python.org>
 <g8n3cg-5kr.ln1@anthive.com>
Message-ID: <CAPTjJmpB5UO7YDEuUgpG7r9wNRmc-feC-T+ufLbUVvhBtTm4cA@mail.gmail.com>

On Tue, Dec 10, 2019 at 4:41 PM songbird <songbird at anthive.com> wrote:
>
> Chris Angelico wrote:
> ...
> > What if neither works, because there are assumptions that don't work?
>
>   then you get stuck doing it by hand, but you would have
> been stuck doing it before for sure by hand so if you can
> write something which might get some of the easy cases
> done then at least you're saving your efforts for the
> harder stuff.

The easy cases are easy for anything, and don't need AI.

> > I get the very strong impression that you've never tried this.
>
>   of course not!  i don't have that kind of pipeline
> or machine power and i'm several years away from being
> where i'd like to be in terms of understanding the
> language itself.  i hope to have the time over the
> next few years to learn enough but i don't know how
> that will go.
>
>   i'm glad in looking around more the past few evenings
> that the conversion effort is making progress and
> things are not as dire as some have made it out to be.
> i just hope the lessons have been learned going
> forwards.

Never even done it manually, I mean. It's very difficult to try to
design an AI to do something that you can't do yourself and don't even
understand the problem.

ChrisA

From address at not.available  Tue Dec 10 03:45:01 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 09:45:01 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
Message-ID: <qsnlut$1g3l$1@gioia.aioe.org>

DL,

> I went through this cycle of thinking, first using if __name__... to 
> 'hide' testing, then adding test functions within the module, and now keep 
> test code quite separate from 'the real thing'.

:-) The normal newbie progression, off of which I'm in phase #1.   Having a 
working program (riddeled with debugging output) is still (way) more 
important than having the best code I'm afraid.   But reading about how 
others handle it definitily makes it easier for me to progress.

> Expanding on 'names' and del(): the first point is that there is seldom 
> much to be gained by using del(), ie becoming your own 'garbage 
> collector'.

In my case deleting the instance was needed to release its hold on something 
that was taken when the instance was initialised (in my case a GPIO pin on a 
Raspberry Pi).   I did not even think of garbage collection.

> Python enables you to play fast-and-loose, eg

I know (similar to VBScript which uses Variants for everything).   Its all 
about wnat I /intend/ to have inside it, and the type prefix character 
keeping myself aware of where (not) to use the variable.  Also, silent type 
conversions can work against you.    I normally prefix an instanciated class 
(having methods) with an "o".

Than again, I normally camel-case my variable and function names (to make 
them stand out from the build-in commands), as I normally do not use editors 
with syntax highlighting.

> A Python-list will handle the former (wow, that's a bit of 'rocket 
> science'!?) whereas a Python-set will only contain unique values. So, 
> rather than using a somewhat-bland varNM such as "letters", I would choose 
> to be more explicit:

:-) Always start with a descriptive* name for the variable, regardless of if 
it is a compounded one or not.   As said, the type prefix is just a 
reminder.

*though not /too/ descriptive.   Languages which can easily have 
40-character names for variables, functions and such are simply the pits, 
especially when they start to differ only for a single/few character(s) 
somewhere in the middle. :-(

> rudy = Man( etc ) #rudy probably does have class, in this instance

You almost owed me a new keyboard there. :-p

Regards,
Rudy Wieser



From lukasz at langa.pl  Tue Dec 10 04:22:57 2019
From: lukasz at langa.pl (=?utf-8?Q?=C5=81ukasz_Langa?=)
Date: Tue, 10 Dec 2019 10:22:57 +0100
Subject: [RELEASE] Python 3.8.1rc1 is now available for testing
Message-ID: <F06150A9-BFEE-4BD5-AD35-E41CF47FF1CF@langa.pl>

Python 3.8.1rc1 is the release candidate of the first maintenance release of Python 3.8.

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. You can find Python 3.8.1rc1 here:

https://www.python.org/downloads/release/python-381rc1/ <https://www.python.org/downloads/release/python-381rc1/>
Assuming no critical problems are found prior to 2019-12-16, the scheduled release date for 3.8.1 as well as Ned Deily's birthday, no code changes are planned between this release candidate and the final release.

That being said, please keep in mind that this is a pre-release of 3.8.1 and as such its main purpose is testing.

See the ?What?s New in Python 3.8 <https://docs.python.org/3.8/whatsnew/3.8.html>? document for more information about features included in the 3.8 series. Detailed information about all changes made in 3.8.0 can be found in its change log.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.2 planned for February 2020.

We hope you enjoy Python 3.8!

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organization contributions to the Python Software Foundation.

https://www.python.org/psf/ <https://www.python.org/psf/>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Message signed with OpenPGP
URL: <http://mail.python.org/pipermail/python-list/attachments/20191210/756c830c/attachment.sig>

From greg.ewing at canterbury.ac.nz  Tue Dec 10 04:25:42 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Tue, 10 Dec 2019 22:25:42 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsnlut$1g3l$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
Message-ID: <h596koFrgm6U1@mid.individual.net>

On 10/12/19 9:45 pm, R.Wieser wrote:

> In my case deleting the instance was needed to release its hold on something
> that was taken when the instance was initialised (in my case a GPIO pin on a
> Raspberry Pi).   I did not even think of garbage collection.

In that case, it was only working by accident. You were unwittingly
relying on the garbage collector to immediately clean up the object
as soon as the last reference to it disappeared. That happens to be
true currently in CPython (which uses reference counting), but it's
not guaranteed by the language.

If your object has a method for explicitly making it release its
resources, it would be better to use that rather than rely on
the garbage collector.

> Than again, I normally camel-case my variable and function names (to make
> them stand out from the build-in commands), as I normally do not use editors
> with syntax highlighting.

Python differs from VBScript and other VB-family languages in that
names are case-sensitive. So it's common to use case to distinguish
between things such as a class and an instance.

-- 
Greg


From stephen_tucker at sil.org  Tue Dec 10 05:15:45 2019
From: stephen_tucker at sil.org (Stephen Tucker)
Date: Tue, 10 Dec 2019 10:15:45 +0000
Subject: The file method read does not "see" CR
Message-ID: <CAP=-cKWowYeb5S4W_Qa-tYqLQ5xf5T+pD5mOnESVSmUMP26D5Q@mail.gmail.com>

I am running Python 2.7.10 on a Windows 10 machine. I have written a Python
program that counts occurrences of bytes in a text file and have run it on
a small test file. This file has CR-LF sequences at the ends of its lines.
The Python program counted the LF bytes, but didn't count any CR bytes.
Given that the documentation for the read method claims that exactly size
bytes are read by each call to the method (in this case, size is 1) does
this behaviour constitute a bug?

Stephen Tucker.

From python at invalid  Tue Dec 10 05:33:56 2019
From: python at invalid (Python)
Date: Tue, 10 Dec 2019 11:33:56 +0100
Subject: More efficient/elegant branching
In-Reply-To: <mailman.385.1575891329.25794.python-list@python.org>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <mailman.385.1575891329.25794.python-list@python.org>
Message-ID: <5def749e$0$5887$426a74cc@news.free.fr>

Musbur wrote:
> Hello,
> 
> I have a function with a long if/elif chain that sets a couple of 
> variables according to a bunch of test expressions, similar to function 
> branch1() below. I never liked that approach much because it is clumsy 
> and repetetive, and pylint thinks so as well. I've come up with two 
> alternatives which I believe are less efficient due to the reasons given 
> in the respective docstrings. Does anybody have a better idea?

I tried a lot of times to write down a useful Switch module
without convincing myself. Recently here is what I ended up
with, what do you think ?

https://gitlab.com/snippets/1921123



From rosuav at gmail.com  Tue Dec 10 05:39:18 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Dec 2019 21:39:18 +1100
Subject: The file method read does not "see" CR
In-Reply-To: <CAP=-cKWowYeb5S4W_Qa-tYqLQ5xf5T+pD5mOnESVSmUMP26D5Q@mail.gmail.com>
References: <CAP=-cKWowYeb5S4W_Qa-tYqLQ5xf5T+pD5mOnESVSmUMP26D5Q@mail.gmail.com>
Message-ID: <CAPTjJmrpjkPfSWKW1_j2rMjob63tXhRjyEdOTeRAS1B_RvyrNw@mail.gmail.com>

On Tue, Dec 10, 2019 at 9:17 PM Stephen Tucker <stephen_tucker at sil.org> wrote:
>
> I am running Python 2.7.10 on a Windows 10 machine. I have written a Python
> program that counts occurrences of bytes in a text file and have run it on
> a small test file. This file has CR-LF sequences at the ends of its lines.
> The Python program counted the LF bytes, but didn't count any CR bytes.
> Given that the documentation for the read method claims that exactly size
> bytes are read by each call to the method (in this case, size is 1) does
> this behaviour constitute a bug?
>

Are you trying to treat the file as text, or bytes? Are you looking
for occurrences of bytes, or characters? Make a decision on that, then
code accordingly. If you want to look for bytes, then open the file in
binary mode and read it as bytes. If you want to look for characters,
then you probably shouldn't care about which sort of line ending it
is, but if you really do, then disable newline processing and examine
the end of each logical line.

The read call will return one character, if the file is in text mode.

ChrisA

From address at not.available  Tue Dec 10 05:47:01 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 11:47:01 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
Message-ID: <qsnt45$i6f$1@gioia.aioe.org>

Greg,

> In that case, it was only working by accident.

I don't think so.

Or you must be thinking that the __del__ method of an instance is only 
called by the garbage collector - which would be rather daft (just think of 
a file thats created when initialising an instance, but not closes until the 
garbage collector comes around to it.   Much luck with reopening the file). 
Removing an unused object from memory is a bit different than 
closing/"destroying" an instance.

> Python differs from VBScript and other VB-family languages in that
> names are case-sensitive.

I was aware of that.

> So it's common to use case to distinguish
> between things such as a class and an instance.

For some reason (the lacluster use of interpunction on tha intarwebz, or 
perhaps The Irritating Habit To Capitalise Every Word) I tend to largely 
ignore capitalisation.   Time will tell if I can cope with names that only 
differ by their capitalisation.   Most likely not.  Combine that with 
Pythons create-on-use behaviour and you have a recipe for disaster. :-|

Regards,
Rudy Wieser



From rosuav at gmail.com  Tue Dec 10 07:12:47 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Dec 2019 23:12:47 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsnt45$i6f$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
Message-ID: <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>

On Tue, Dec 10, 2019 at 9:51 PM R.Wieser <address at not.available> wrote:
>
> Greg,
>
> > In that case, it was only working by accident.
>
> I don't think so.
>
> Or you must be thinking that the __del__ method of an instance is only
> called by the garbage collector - which would be rather daft (just think of
> a file thats created when initialising an instance, but not closes until the
> garbage collector comes around to it.   Much luck with reopening the file).
> Removing an unused object from memory is a bit different than
> closing/"destroying" an instance.

Well, that's exactly what happens. Daft as it might seem, the __del__
method IS only called when an object is disposed of by the garbage
collector. CPython happens to use a refcounting garbage collector that
will usually dispose of things fairly promptly, but in the case of
cyclic references, that won't happen till the cycle detection GC goes
through.

Check out the 'with' statement. Also, when you scorn something without
knowing your facts, you tend to make yourself look like a fool :)

ChrisA

From musbur at posteo.org  Tue Dec 10 07:12:56 2019
From: musbur at posteo.org (Musbur)
Date: Tue, 10 Dec 2019 13:12:56 +0100
Subject: More efficient/elegant branching
In-Reply-To: <5def749e$0$5887$426a74cc@news.free.fr>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <mailman.385.1575891329.25794.python-list@python.org>
 <5def749e$0$5887$426a74cc@news.free.fr>
Message-ID: <a60e03b859b5f5054c0f1cfab8328e7e@posteo.de>

I like it! I think it's a cute exercise but it doesn't really solve any 
problem. The if/elif chain can accomplish the same thing (and much more) 
in the same line count for the price of being clunkier. **D


From address at not.available  Tue Dec 10 07:44:29 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 13:44:29 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
Message-ID: <qso3vr$1jk2$1@gioia.aioe.org>

Chris,

> Well, that's exactly what happens.

So, only the reference count gets lowered.  Yep, thats daft.

... unless you explain why it can only be done that way.

> Also, when you scorn something without knowing your facts,
> you tend to make yourself look like a fool :)

I tend to go with logic.   No logic => it most likely doesn't work that way.

Choosing to go with a delayed action like you say will, as I already 
explained, create problems later on (race conditions everywhere).  And as I 
do not think the designers of the language where that stupid I must 
therefore reject your claim to what you think happens.

But, as you mentioned, I do not know (all) the facts.  Please do present 
them.   Maybe there is a logic in there I do not yet see.

> Check out the 'with' statement.

I'm sorry, but nope.

Rule one: When debugging do *not* throw more stuff at a problem than what is 
neccessary to make it show its ugly head.
Rule two: When in doubt, see rule One. :-)

Regards,
Rudy Wieser



From rosuav at gmail.com  Tue Dec 10 07:53:00 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 10 Dec 2019 23:53:00 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qso3vr$1jk2$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
Message-ID: <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>

On Tue, Dec 10, 2019 at 11:46 PM R.Wieser <address at not.available> wrote:
>
> Chris,
>
> > Well, that's exactly what happens.
>
> So, only the reference count gets lowered.  Yep, thats daft.
>
> ... unless you explain why it can only be done that way.

Okay. What should happen when you do this?

x = 5
del x

Should the integer 5 be deleted?

> > Also, when you scorn something without knowing your facts,
> > you tend to make yourself look like a fool :)
>
> I tend to go with logic.   No logic => it most likely doesn't work that way.
>
> Choosing to go with a delayed action like you say will, as I already
> explained, create problems later on (race conditions everywhere).  And as I
> do not think the designers of the language where that stupid I must
> therefore reject your claim to what you think happens.
>
> But, as you mentioned, I do not know (all) the facts.  Please do present
> them.   Maybe there is a logic in there I do not yet see.
>
> > Check out the 'with' statement.
>
> I'm sorry, but nope.
>
> Rule one: When debugging do *not* throw more stuff at a problem than what is
> neccessary to make it show its ugly head.
> Rule two: When in doubt, see rule One. :-)

So the language designers couldn't possibly have been so stupid as to
do things this way, but you're going to ignore what they did? Cool.
Bye!

ChrisA

From horluchi420 at gmail.com  Mon Dec  9 23:11:56 2019
From: horluchi420 at gmail.com (Princess Oluchi)
Date: Mon, 9 Dec 2019 20:11:56 -0800
Subject: I downloaded the python application but my system is having issues
 with it. please, can you provide help?
Message-ID: <5def1b0d.1c69fb81.2d699.8203@mx.google.com>



Sent from Mail for Windows 10


From abhipatel274 at gmail.com  Mon Dec  9 23:31:41 2019
From: abhipatel274 at gmail.com (Abhi Patel)
Date: Tue, 10 Dec 2019 10:01:41 +0530
Subject: Installation Error (0xc000007b)
Message-ID: <CAH9pm4SEqb07VxU6=RNGZW5P4uFi0udbQd0p4qNunWgBov8bgw@mail.gmail.com>

i'm getting the error message while installing python in my dell laptop.
ERROR: the application was unable to start (0xc000007b). Close the
application
Please help

From tcoca at usc.edu  Tue Dec 10 02:25:07 2019
From: tcoca at usc.edu (Timothy Coca)
Date: Tue, 10 Dec 2019 02:25:07 -0500
Subject: Site Packages Folder Red on Clean Install
Message-ID: <CAGzSfRk_Wo5vEWhsgZ3HfMxucPsDcuEwO5FdF-aGGa4pzeQ91Q@mail.gmail.com>

Hello,

I have a new dell XPS, I freshly installed the latest version of
Pythong (3.8.0) and pycharm. Pycharm shows the site packages folder as red,
and I can not import and modules from inside of it. Pip install works to
install some programs like numpy, scipy, but would not install matplotlib
successfully.

Even though Pip installed numpy successfully to the Sitpackages folder, I
can not import or use it. Any advice?

Note: Upon purchase I did replace the hard drive and ram, and reinstall
windows. It all runs fine, but if you suspect that can be related please
let me know.

Any advice on how to resolve this would be appreciated. I've seen forum
posts where others had the same issue but no ressolutions.

I am trying installing a previous version of Python to see if it works.

Thanks,

Tim Coca

From dhaude at posteo.de  Tue Dec 10 07:07:05 2019
From: dhaude at posteo.de (Daniel Haude)
Date: Tue, 10 Dec 2019 13:07:05 +0100
Subject: More efficient/elegant branching
In-Reply-To: <a892e74d-04c6-8bc0-15d9-0e537b26a955@DancesWithMice.info>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <a892e74d-04c6-8bc0-15d9-0e537b26a955@DancesWithMice.info>
Message-ID: <cabcf64dbb845791154c694832c858d2@posteo.de>

Hello Neil,

thanks for the detailed answer.

> Question: are there other people/factors who/which should be regarded
> as more important than the linter's opinion?

Yes. Mine.

I was just puzzled at the linter's output (took me a while to figure out 
what it actually meant), and that got me started on the track if there 
was maybe a more Pythonic way of dealing with that decision chain.

> The usual dictionary-controlled construct I've seen (and used)
> involves using functions as the dict's values:
> [...]

Yeah, I do that a lot, too, but for that you need a meaningful "key" 
object. In the case at hand, I'm really using individually formulated 
conditions.

> Is it ironic that the language does not have a form of case/switch
> statement (despite many pleas and attempts to add it),

Wouldn't do me any good here because case/switch also compares a fiked 
key against a bunch of candidates, like a dict. Also, in terms of line 
count the if/elif chain isn't worse than a switch statement.

> yet the linter objects to an if-elif-else nesting???

Like I said, that's what got me started on this. And it's not even 
nested, it's purely linear.

> One reason why this code looks a bit strange (and possibly why PyLint
> reacts?) is because it is trivial. When we look at the overall
> picture, the question becomes: what will the 'mainline' do with
> "result" (the returned value)? Immediately one suspects it will be fed
> into another decision, eg:

No, the "result" is a text message that actually means something and is 
eventually output for human consumption.

The whole thing is rather academic. Also my efficiency argument doesn't 
hold water because this routine is executed just a few times per hour. I 
like the "condition table" approach for its lower line count but I'll 
stick with if/elif because it's more conventional and therefore easier 
to understand for the casual reader.


From python at python.invalid  Tue Dec 10 07:51:50 2019
From: python at python.invalid (Python)
Date: Tue, 10 Dec 2019 13:51:50 +0100
Subject: More efficient/elegant branching
In-Reply-To: <mailman.5.1575980003.11485.python-list@python.org>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <mailman.385.1575891329.25794.python-list@python.org>
 <5def749e$0$5887$426a74cc@news.free.fr>
 <a60e03b859b5f5054c0f1cfab8328e7e@posteo.de>
 <mailman.5.1575980003.11485.python-list@python.org>
Message-ID: <5def949a$0$20344$426a74cc@news.free.fr>

Musbur wrote:
> I like it! I think it's a cute exercise but it doesn't really solve any 
> problem. The if/elif chain can accomplish the same thing (and much more) 
> in the same line count for the price of being clunkier. **D

Yep! This is why I wrote half a dozen of switch implementation but never
actually used any of them in a real project :-)

If we had macros it may be another story, but we don't, and we won't (or
will we ?)




From python at python.invalid  Tue Dec 10 07:54:44 2019
From: python at python.invalid (Python)
Date: Tue, 10 Dec 2019 13:54:44 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qso3vr$1jk2$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
Message-ID: <5def9548$0$10400$426a74cc@news.free.fr>

R.Wieser wrote:
> Chris,
...
> 
> But, as you mentioned, I do not know (all) the facts.  Please do present
> them.   Maybe there is a logic in there I do not yet see.

We may, but then you wrote:

>> Check out the 'with' statement.
> 
> I'm sorry, but nope.
> 
> Rule one: When debugging do *not* throw more stuff at a problem than what is
> neccessary to make it show its ugly head.
> Rule two: When in doubt, see rule One. :-)

which contradicts your previous statement.

"with" is "more stuff" it is the right way to deal with disposable
ressource in the first place. In the documentation it is used from
the very first example of, say, open().



From rosuav at gmail.com  Tue Dec 10 08:43:23 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 00:43:23 +1100
Subject: More efficient/elegant branching
In-Reply-To: <cabcf64dbb845791154c694832c858d2@posteo.de>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <a892e74d-04c6-8bc0-15d9-0e537b26a955@DancesWithMice.info>
 <cabcf64dbb845791154c694832c858d2@posteo.de>
Message-ID: <CAPTjJmrdY3cKANt9r6c+V_EtS8kehD75-bA1X=hGrveoMrnvEw@mail.gmail.com>

On Wed, Dec 11, 2019 at 12:26 AM Daniel Haude <dhaude at posteo.de> wrote:
> The whole thing is rather academic. Also my efficiency argument doesn't
> hold water because this routine is executed just a few times per hour. I
> like the "condition table" approach for its lower line count but I'll
> stick with if/elif because it's more conventional and therefore easier
> to understand for the casual reader.

Agreed. It is a fault with the linter, and nothing more.

ChrisA

From rhodri at kynesim.co.uk  Tue Dec 10 09:18:10 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 10 Dec 2019 14:18:10 +0000
Subject: Randomizing Strings In A Microservices World
In-Reply-To: <sdg3cg-93s1.ln1@oceanview.tundraware.com>
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
 <878snkdhcp.fsf@nightsong.com> <sdg3cg-93s1.ln1@oceanview.tundraware.com>
Message-ID: <f7ed610a-ad93-eb27-e86e-f1040f2007c5@kynesim.co.uk>

On 10/12/2019 03:35, Tim Daneliuk wrote:
> On 12/9/19 8:50 PM, Paul Rubin wrote:
>> Tim Daneliuk <info at tundraware.com> writes:
>>> - Imagine an environment in which there may be multiple instances of a given
>>>    microservice written in Python.
>>
>> Decide the maximum number of microservice instances, say 1000.  Chop up
>> the 10 digit range into 1000 pieces, so 0..999999, 1000000-1999999, etc.
>> Give one range to each microservice instance.  Then have the
>> microservices give out the numbers sequentially, but treating them as 10
>> digit numbers and encrypting each one under a 10 digit pseudorandom
>> permutation shared by all the instances.  Look up "format preserving
>> encryption" for how to do this.
>>
>> Obvious variants of the above are obvious, and maybe you need some way
>> to hand around chunks of range if some instance gives out more than a
>> million numbers.
>>
> 
> 
> The problem here is that the services are ephemeral and the number of said
> services is not fixed.

Hm.  Normally I'd mash together the MAC address of the interface and the 
process ID of the service (or whatever individual identifier 
microservices have -- indeed, whatever microservices *are* :-), but ten 
digits is a bit few for that.  So you want some variant of Paul's approach.

* I assume there are a number of machines providing these services. 
Give them unique numbers -- I'm guessing three digits should be enough 
for that, but you know your own setup better.  How you assign those 
numbers is up to you; a config file in /etc, a Windows registry key, or 
some broadcast protocol that the machines use to dynamically configure 
themselves are all options that spring to mind.

* On each machine, something must spin up services when they are needed. 
  That something will be in a position to assign a unique number (within 
an individual machine) to each service.  So do that, using whatever 
digits you have left after the unique machine number.

* Mash these two numbers into a single ten digit identifier.

-- 
Rhodri James *-* Kynesim Ltd

From __peter__ at web.de  Tue Dec 10 09:47:49 2019
From: __peter__ at web.de (Peter Otten)
Date: Tue, 10 Dec 2019 15:47:49 +0100
Subject: Randomizing Strings In A Microservices World
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
Message-ID: <qsob6m$4347$1@blaine.gmane.org>

Tim Daneliuk wrote:

> I ran across a kind of fun problem today that I wanted to run past you
> Gentle Geniuses (tm):
> 
> - Imagine an environment in which there may be multiple instances of a
> given
>   microservice written in Python.
> 
> - Each of these services needs to produce a string of ten digits
> guaranteed to be unique
>   on a per service instance basis AND to not collide for - oh, let's say -
>   forever :)s
> 
> Can anyone suggest a randomization method that might achieve this
> efficiently?
> 
> My first thought was to something like nanonseconds since the epoch plus
> something
> unique about the service instance - like it's IP?  (This is in a K8s
> cluster) - to see the randomization and essentially eliminate the string
> being repeated.
> 
> Ideas welcome ..
> 
> P.S. I do not want to resort to a number generation service that each
> instance asks
>      for a new number.  The network and service call overhead militates
>      against this in my application.

Hand out a range of numbers when the service is started. Once that range is 
used up the service can terminate itself.


From musbur at posteo.org  Tue Dec 10 09:49:16 2019
From: musbur at posteo.org (Musbur)
Date: Tue, 10 Dec 2019 15:49:16 +0100
Subject: More efficient/elegant branching
Message-ID: <7e0f98ceaf19fb551c24e1cdab5e0654@posteo.de>

Hello Neil,

thanks for the detailed answer.

> Question: are there other people/factors who/which should be regarded
> as more important than the linter's opinion?

Yes. Mine.

I was just puzzled at the linter's output (took me a while to figure out 
what it actually meant), and that got me started on the track if there 
was maybe a more Pythonic way of dealing with that decision chain.

> The usual dictionary-controlled construct I've seen (and used)
> involves using functions as the dict's values:
> [...]

Yeah, I do that a lot, too, but for that you need a meaningful "key" 
object. In the case at hand, I'm really using individually formulated 
conditions.

> Is it ironic that the language does not have a form of case/switch
> statement (despite many pleas and attempts to add it),

Wouldn't do me any good here because case/switch also compares a fiked 
key against a bunch of candidates, like a dict. Also, in terms of line 
count the if/elif chain isn't worse than a switch statement.

> yet the linter objects to an if-elif-else nesting???

Like I said, that's what got me started on this. And it's not even 
nested, it's purely linear.

> One reason why this code looks a bit strange (and possibly why PyLint
> reacts?) is because it is trivial. When we look at the overall
> picture, the question becomes: what will the 'mainline' do with
> "result" (the returned value)? Immediately one suspects it will be fed
> into another decision, eg:

No, the "result" is a text message that actually means something and is 
eventually output for human consumption.

The whole thing is rather academic. Also my efficiency argument doesn't 
hold water because this routine is executed just a few times per hour. I 
like the "condition table" approach for its lower line count but I'll 
stick with if/elif because it's more conventional and therefore easier 
to understand for the casual reader.

From antoon.pardon at vub.be  Tue Dec 10 09:50:24 2019
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 10 Dec 2019 15:50:24 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qso3vr$1jk2$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
Message-ID: <8dba129d-20ef-b374-d363-8187b0a387eb@vub.be>

On 10/12/19 13:44, R.Wieser wrote:
> Chris,
>
>> Well, that's exactly what happens.
> So, only the reference count gets lowered.  Yep, thats daft.
>
> ... unless you explain why it can only be done that way.
>
>> Also, when you scorn something without knowing your facts,
>> you tend to make yourself look like a fool :)
> I tend to go with logic.   No logic => it most likely doesn't work that way.
>
> Choosing to go with a delayed action like you say will, as I already 
> explained, create problems later on (race conditions everywhere).  And as I 
> do not think the designers of the language where that stupid I must 
> therefore reject your claim to what you think happens.

Well yes that is why it is stupid to rely on the garbage collector to do
those things for you. That is why Greg Ewing already stated:

> If?your?object?has?a?method?for?explicitly?making?it?release?its
> resources,?it?would?be?better?to?use?that?rather?than?rely?on
> the?garbage?collector. 

> But, as you mentioned, I do not know (all) the facts.  Please do present 
> them.   Maybe there is a logic in there I do not yet see.

What would you want to happen in the following case:

   foo1 = Bar()
   foo2 = foo1
   del foo1

Should the object be cleaned up now or not?



From songbird at anthive.com  Tue Dec 10 09:21:20 2019
From: songbird at anthive.com (songbird)
Date: Tue, 10 Dec 2019 09:21:20 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
 <CAPTjJmpJgKuVkpWfWiRmtwCRef1JeRS_2g0U_HrP1+gs+PS4Hw@mail.gmail.com>
 <mailman.392.1575915601.25794.python-list@python.org>
 <7j73cg-50n.ln1@anthive.com>
 <CAPTjJmphytnzZhNk9WnVhCMAn2Vgn3zdkPG0yHw+p+B7qu2sPA@mail.gmail.com>
 <mailman.400.1575941106.25794.python-list@python.org>
Message-ID: <08m4cg-ri1.ln1@anthive.com>

Chris Angelico wrote:
> On Tue, Dec 10, 2019 at 12:15 PM songbird <songbird at anthive.com> wrote:
>>
>> Chris Angelico wrote:
>> ...
>> >
>> > Here's an example piece of code.
>> >
>> > sock = socket.socket(...)
>> > name = input("Enter your username: ")
>> > code = input("Enter the base64 code: ")
>> > code = base64.b64decode(code)
>> > sock.write("""GET /foo HTTP/1.0
>> > Authentication: Demo %s/%s
>> >
>> > """ % (name, code))
>> > match = re.search(r"#[A-Za-z0-9]+#", sock.read())
>> > if match: print("Response: " + match.group(0))
>> >
>> > Your challenge: Figure out which of those strings should be a byte
>> > string and which should be text. Or alternatively, prove that this is
>> > a hard problem. There are only a finite number of types - two, to be
>> > precise - so by your argument, this should be straightforward, right?
>>
>>   this isn't a process of looking at isolated code.  this
>> is a process of looking at the code, but also the test cases
>> or working examples.  so the inputs are known and the code
>> itself gives clues about what it is expecting.
>
> Okay. The test cases are also written in Python, and they use
> unadorned string literals to provide mock values for input() and the
> socket response. Now what?

  wouldn't there be clues in how that string is used in
the program itself (either calls to converters or when
the literal is assigned to some variable or used in a
print statement)?


> What if the test cases are entirely ASCII characters?

  it all goes utf in that case and the string is not 
binary.


> What if the test cases are NOT entirely ASCII characters?

  if the program has more than one language then you may
have to see what the character set falls into.  is it hex
it it octal or binary or some language.  i'd guess there
will be clues in the code as to how that string is used
later.


>>   regular expressions can be matched in finite time as well
>> as a fixed length text of any type can be scanned as a match
>> or rejected.
>>
>>   if you examined a thousand uses of match and found the
>> pattern used above and then examined what those programs did
>> with that match what would you select as the first type, the
>> one used the most first, if that doesn't work go with the 2nd,
>> etc.
>>
>
> That's not really the point. Are your regular expressions working with
> text or bytes? Does your socket return text or bytes?

  clues in the program again.  you're not limited to looking
only at the string itself, but the context of the entire
program.  i'm sure patterns are there to be found if you
can scan enough programs they'll start showing up.  once
you've found a viable pattern then you have a way to
generate a test case to see if it works or not.


> I've deliberately chosen these examples because they are hard. And I
> didn't even get into an extremely hard problem, with the inclusion of
> text inside binary data inside of text inside of bytes. (It does
> happen.)
>
> These problems are fundamentally hard because there is insufficient
> information in the source code alone to determine the programmer's
> intent.

  that is why we would be running the program itself and
examining test case results.

  none of these programs run in isolation, information is
known what they expect as input or produce as output.


  songbird

From songbird at anthive.com  Tue Dec 10 09:51:31 2019
From: songbird at anthive.com (songbird)
Date: Tue, 10 Dec 2019 09:51:31 -0500
Subject: python 2 to 3 converter
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com> <qsm38p$q4k$1@dont-email.me>
 <9n73cg-50n.ln1@anthive.com>
 <CAPTjJmoTB_BDTOWv-tXNxMs-Jh6x6Ux9Mx2N-zV1+7OzS6GaSw@mail.gmail.com>
 <mailman.399.1575940416.25794.python-list@python.org>
 <g8n3cg-5kr.ln1@anthive.com>
 <CAPTjJmpB5UO7YDEuUgpG7r9wNRmc-feC-T+ufLbUVvhBtTm4cA@mail.gmail.com>
 <mailman.0.1575956665.11485.python-list@python.org>
Message-ID: <j0o4cg-ri1.ln1@anthive.com>

Chris Angelico wrote:
> On Tue, Dec 10, 2019 at 4:41 PM songbird <songbird at anthive.com> wrote:
>>
>> Chris Angelico wrote:
>> ...
>> > What if neither works, because there are assumptions that don't work?
>>
>>   then you get stuck doing it by hand, but you would have
>> been stuck doing it before for sure by hand so if you can
>> write something which might get some of the easy cases
>> done then at least you're saving your efforts for the
>> harder stuff.
>
> The easy cases are easy for anything, and don't need AI.

  i consider calling a statistical approach to conversion
"AI" is like calling snobol AI.  it is pattern matching
and applying tests to see what happens.  that's all, it
might even be brute forced.


>> > I get the very strong impression that you've never tried this.
>>
>>   of course not!  i don't have that kind of pipeline
>> or machine power and i'm several years away from being
>> where i'd like to be in terms of understanding the
>> language itself.  i hope to have the time over the
>> next few years to learn enough but i don't know how
>> that will go.
>>
>>   i'm glad in looking around more the past few evenings
>> that the conversion effort is making progress and
>> things are not as dire as some have made it out to be.
>> i just hope the lessons have been learned going
>> forwards.
>
> Never even done it manually, I mean. It's very difficult to try to
> design an AI to do something that you can't do yourself and don't even
> understand the problem.

  for me it would be a way of learning python 2 and python
3 better.  i have enough understanding of how compilers 
work so those parts of the project wouldn't be scary to me
at all.  the statistical aspects i'd need help with and
the generating of tests and how to run them would be new
to me.  but that tests already exist and that they are 
intended to be simple bits of code should be a goldmine 
for conversion scripts to look at IMHO.  so perhaps 
someone who's facing a huge conversion problem might find
this as a worthwhile thing to ponder.

  personally, if i were working again full time and 
facing several million lines of code and a lot of 
recalcitrant workers, well, i'd be stuck trying to do
something to get it done.

  i have gone through conversions before (a major one
at a university where we went from an inhouse system to
a vendor supplied system).  we didn't do the conversion
automatically and it didn't happen overnight, but it did
get done on schedule and i think we also came in under
budget.  i was only part of the team involved as a
general systems person as i still supported the mainframe
we were coming off of to go to the mini but for the new
system i worked with all the conversion efforts going on
in the departments along with any interface issues to 
the printers, how to run jobs in sequence, scanning 
grades, ...).  i pretty much did whatever was needed.
when the conversion was winding down was a good point
for me to retire/quit as i'd been doing nothing but
going to school and programming or working with computers
for 15yrs.  right before the internet took off...

  my own local conversion effort recently was my small
website setup where the theme author had introduced a
lot of breaking changes over several years and no 
conversion utility so i wrote one in a few days.  it 
saved me a few weeks of converting it all by hand (and 
i've posted it to github so anyone else stuck in the 
same spot at least has a workable framework to go from).
no, it's not AI or complex enough to be considered all
that interesting but it worked and saved me enough time 
that i can start looking at python 3 again.


  songbird

From rosuav at gmail.com  Tue Dec 10 10:10:16 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 02:10:16 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <8dba129d-20ef-b374-d363-8187b0a387eb@vub.be>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <8dba129d-20ef-b374-d363-8187b0a387eb@vub.be>
Message-ID: <CAPTjJmp9iA857cC8KxfZr9vOhvVE+sdTAs86BfFjKk3aZYPEgw@mail.gmail.com>

On Wed, Dec 11, 2019 at 1:53 AM Antoon Pardon <antoon.pardon at vub.be> wrote:
> What would you want to happen in the following case:
>
>    foo1 = Bar()
>    foo2 = foo1
>    del foo1
>
> Should the object be cleaned up now or not?
>

TBH both are plausible, and to a Python programmer it's immediately
obvious that "foo1.close()" should close foo2 as well. Logic doesn't
preclude either of them. Imagine if the base object type had a
__destroy__() method that would dereference everything the object
referenced, clear its __dict__ (if it has one), and causes all
attribute access (including methods) to raise DestroyedObjectError. It
would be absolutely plausible to call foo1.__destroy__() and have the
object actually be destroyed.

I know this is plausible because I know of languages that work both
ways - that destroying an object actually destroys it immediately, or
that explicitly deleting a name binding leaves the object till it's
not referenced anywhere. And if there are languages working both ways,
it seems a little presumptive to heap scorn on a language designer for
either of those options.

ChrisA

From rosuav at gmail.com  Tue Dec 10 10:11:40 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 02:11:40 +1100
Subject: python 2 to 3 converter
In-Reply-To: <08m4cg-ri1.ln1@anthive.com>
References: <8toubg-08n.ln1@anthive.com> <h55b5aF2vtcU1@mid.individual.net>
 <db55085d-0d9d-4110-9769-399e8a891010@googlegroups.com>
 <vce2cg-qd7.ln1@anthive.com>
 <CAPTjJmpJgKuVkpWfWiRmtwCRef1JeRS_2g0U_HrP1+gs+PS4Hw@mail.gmail.com>
 <mailman.392.1575915601.25794.python-list@python.org>
 <7j73cg-50n.ln1@anthive.com>
 <CAPTjJmphytnzZhNk9WnVhCMAn2Vgn3zdkPG0yHw+p+B7qu2sPA@mail.gmail.com>
 <mailman.400.1575941106.25794.python-list@python.org>
 <08m4cg-ri1.ln1@anthive.com>
Message-ID: <CAPTjJmpEq9k3g6wyXccbrLQ+wP1wc0nKjn=7jx9AnO9+hR4f5g@mail.gmail.com>

On Wed, Dec 11, 2019 at 1:57 AM songbird <songbird at anthive.com> wrote:
>
> Chris Angelico wrote:
> > On Tue, Dec 10, 2019 at 12:15 PM songbird <songbird at anthive.com> wrote:
> >>
> >> Chris Angelico wrote:
> >> ...
> >> >
> >> > Here's an example piece of code.
> >> >
> >> > sock = socket.socket(...)
> >> > name = input("Enter your username: ")
> >> > code = input("Enter the base64 code: ")
> >> > code = base64.b64decode(code)
> >> > sock.write("""GET /foo HTTP/1.0
> >> > Authentication: Demo %s/%s
> >> >
> >> > """ % (name, code))
> >> > match = re.search(r"#[A-Za-z0-9]+#", sock.read())
> >> > if match: print("Response: " + match.group(0))
> >> >
> >> > Your challenge: Figure out which of those strings should be a byte
> >> > string and which should be text. Or alternatively, prove that this is
> >> > a hard problem. There are only a finite number of types - two, to be
> >> > precise - so by your argument, this should be straightforward, right?
> >>
> >>   this isn't a process of looking at isolated code.  this
> >> is a process of looking at the code, but also the test cases
> >> or working examples.  so the inputs are known and the code
> >> itself gives clues about what it is expecting.
> >
> > Okay. The test cases are also written in Python, and they use
> > unadorned string literals to provide mock values for input() and the
> > socket response. Now what?
>
>   wouldn't there be clues in how that string is used in
> the program itself (either calls to converters or when
> the literal is assigned to some variable or used in a
> print statement)?
>
>
> > What if the test cases are entirely ASCII characters?
>
>   it all goes utf in that case and the string is not
> binary.
>
>
> > What if the test cases are NOT entirely ASCII characters?
>
>   if the program has more than one language then you may
> have to see what the character set falls into.  is it hex
> it it octal or binary or some language.  i'd guess there
> will be clues in the code as to how that string is used
> later.
>
>
> >>   regular expressions can be matched in finite time as well
> >> as a fixed length text of any type can be scanned as a match
> >> or rejected.
> >>
> >>   if you examined a thousand uses of match and found the
> >> pattern used above and then examined what those programs did
> >> with that match what would you select as the first type, the
> >> one used the most first, if that doesn't work go with the 2nd,
> >> etc.
> >>
> >
> > That's not really the point. Are your regular expressions working with
> > text or bytes? Does your socket return text or bytes?
>
>   clues in the program again.  you're not limited to looking
> only at the string itself, but the context of the entire
> program.  i'm sure patterns are there to be found if you
> can scan enough programs they'll start showing up.  once
> you've found a viable pattern then you have a way to
> generate a test case to see if it works or not.
>
>
> > I've deliberately chosen these examples because they are hard. And I
> > didn't even get into an extremely hard problem, with the inclusion of
> > text inside binary data inside of text inside of bytes. (It does
> > happen.)
> >
> > These problems are fundamentally hard because there is insufficient
> > information in the source code alone to determine the programmer's
> > intent.
>
>   that is why we would be running the program itself and
> examining test case results.
>
>   none of these programs run in isolation, information is
> known what they expect as input or produce as output.
>

Go do it. Then come back and revisit your assumptions here.

ChrisA

From stephen_tucker at sil.org  Tue Dec 10 10:18:45 2019
From: stephen_tucker at sil.org (Stephen Tucker)
Date: Tue, 10 Dec 2019 15:18:45 +0000
Subject: The file method read does not "see" CR
In-Reply-To: <CAPTjJmrpjkPfSWKW1_j2rMjob63tXhRjyEdOTeRAS1B_RvyrNw@mail.gmail.com>
References: <CAP=-cKWowYeb5S4W_Qa-tYqLQ5xf5T+pD5mOnESVSmUMP26D5Q@mail.gmail.com>
 <CAPTjJmrpjkPfSWKW1_j2rMjob63tXhRjyEdOTeRAS1B_RvyrNw@mail.gmail.com>
Message-ID: <CAP=-cKURUK+ZV4Gi2f4nk8gN+QDcNjmxZA6ZC5e4hogxtNBvPg@mail.gmail.com>

Chris,

Many thanks. The first part of your answer was spot on. I have modified the
program, opening its input file in "rb" mode, and now the program is
working as I intend it to.

I am puzzled by the second part, where you say that the read call will
return one character, if the file is in text mode.

I was expecting this statement to read

   The read call will return one byte if the file is in binary mode.

Given that I *was *opening the file in "r" mode (which, I am assuming, is
"text" mode), then, if your statement is true, I have two more questions:

   1. If CR is a character and I open the file in text mode, then why does
the program not "see" the CR characters?

   2. Does the program not see CR characters under these circumstances
because they do not "count" as characters or for some other reason?

(You have probably spotted that this question 1 is virtually the same as my
original question.)

Stephen.














On Tue, Dec 10, 2019 at 10:39 AM Chris Angelico <rosuav at gmail.com> wrote:

> On Tue, Dec 10, 2019 at 9:17 PM Stephen Tucker <stephen_tucker at sil.org>
> wrote:
> >
> > I am running Python 2.7.10 on a Windows 10 machine. I have written a
> Python
> > program that counts occurrences of bytes in a text file and have run it
> on
> > a small test file. This file has CR-LF sequences at the ends of its
> lines.
> > The Python program counted the LF bytes, but didn't count any CR bytes.
> > Given that the documentation for the read method claims that exactly size
> > bytes are read by each call to the method (in this case, size is 1) does
> > this behaviour constitute a bug?
> >
>
> Are you trying to treat the file as text, or bytes? Are you looking
> for occurrences of bytes, or characters? Make a decision on that, then
> code accordingly. If you want to look for bytes, then open the file in
> binary mode and read it as bytes. If you want to look for characters,
> then you probably shouldn't care about which sort of line ending it
> is, but if you really do, then disable newline processing and examine
> the end of each logical line.
>
> The read call will return one character, if the file is in text mode.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From antoon.pardon at vub.be  Tue Dec 10 10:35:24 2019
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 10 Dec 2019 16:35:24 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <CAPTjJmp9iA857cC8KxfZr9vOhvVE+sdTAs86BfFjKk3aZYPEgw@mail.gmail.com>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <8dba129d-20ef-b374-d363-8187b0a387eb@vub.be>
 <CAPTjJmp9iA857cC8KxfZr9vOhvVE+sdTAs86BfFjKk3aZYPEgw@mail.gmail.com>
Message-ID: <1af8a524-7a87-8049-1ed6-89be56df341d@vub.be>

On 10/12/19 16:10, Chris Angelico wrote:
> On Wed, Dec 11, 2019 at 1:53 AM Antoon Pardon <antoon.pardon at vub.be> wrote:
>> What would you want to happen in the following case:
>>
>>    foo1 = Bar()
>>    foo2 = foo1
>>    del foo1
>>
>> Should the object be cleaned up now or not?
>>
> TBH both are plausible,

I find that strange because if you cleanup the object in that scenario
it should also
be cleaned up in the following.

    def newbar():
        foo = Bar
        return foo

    bar = newbar()

foo goes out of scope, so that is equivallent to a del foo. But I wouldn't
want the object cleaned up because of that.

-- 
Antoon Pardon.


From rosuav at gmail.com  Tue Dec 10 10:53:14 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 02:53:14 +1100
Subject: The file method read does not "see" CR
In-Reply-To: <CAP=-cKURUK+ZV4Gi2f4nk8gN+QDcNjmxZA6ZC5e4hogxtNBvPg@mail.gmail.com>
References: <CAP=-cKWowYeb5S4W_Qa-tYqLQ5xf5T+pD5mOnESVSmUMP26D5Q@mail.gmail.com>
 <CAPTjJmrpjkPfSWKW1_j2rMjob63tXhRjyEdOTeRAS1B_RvyrNw@mail.gmail.com>
 <CAP=-cKURUK+ZV4Gi2f4nk8gN+QDcNjmxZA6ZC5e4hogxtNBvPg@mail.gmail.com>
Message-ID: <CAPTjJmoEwZ5-1m-N61D6FFkwDSzfKgGTf50CDpcctd0H7wQdfg@mail.gmail.com>

On Wed, Dec 11, 2019 at 2:18 AM Stephen Tucker <stephen_tucker at sil.org> wrote:
>
> Chris,
>
> Many thanks. The first part of your answer was spot on. I have modified the program, opening its input file in "rb" mode, and now the program is working as I intend it to.
>

Cool!

> I am puzzled by the second part, where you say that the read call will return one character, if the file is in text mode.
>
> I was expecting this statement to read
>
>    The read call will return one byte if the file is in binary mode.

Both statements are true.

> Given that I was opening the file in "r" mode (which, I am assuming, is "text" mode), then, if your statement is true, I have two more questions:
>
>    1. If CR is a character and I open the file in text mode, then why does the program not "see" the CR characters?
>

It's kinda a little messy, but because CR + LF means "line ending" on
Windows, the two-byte unit is generally considered to be a single
logical character "end of line". You can disable this by passing
another keyword argument to the open() call, but in general, text
files care about lines, rather than being bothered by exactly what
sort of line ending they're using.

>    2. Does the program not see CR characters under these circumstances because they do not "count" as characters or for some other reason?
>
> (You have probably spotted that this question 1 is virtually the same as my original question.)
>

The Python file handler is interpreting a two-byte sequence as a
single logical unit, and then representing that unit with the single
character "\n". Basically, you're at the tail end of decades of mess
involving line endings, and we're all doing our best to cope with the
morass of craziness that's out in the world. For the most part, what
Python does is what you want; in the situations where it isn't, you
can override it with the parameter.

Be aware that bytes and characters are FAR more different than this.
But if you're confident that your file is encoded ASCII or UTF-8
(which are probably the most common encodings you'll encounter), then
you can at least be certain that the byte value b"\r" corresponds
exactly to the character "\r".

ChrisA

From rosuav at gmail.com  Tue Dec 10 10:56:38 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 02:56:38 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <1af8a524-7a87-8049-1ed6-89be56df341d@vub.be>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <8dba129d-20ef-b374-d363-8187b0a387eb@vub.be>
 <CAPTjJmp9iA857cC8KxfZr9vOhvVE+sdTAs86BfFjKk3aZYPEgw@mail.gmail.com>
 <1af8a524-7a87-8049-1ed6-89be56df341d@vub.be>
Message-ID: <CAPTjJmp0=Te47fh5Yts6jAmo5e8fffOv_RkHEUvUCaRrgHNK5Q@mail.gmail.com>

On Wed, Dec 11, 2019 at 2:36 AM Antoon Pardon <antoon.pardon at vub.be> wrote:
>
> On 10/12/19 16:10, Chris Angelico wrote:
> > On Wed, Dec 11, 2019 at 1:53 AM Antoon Pardon <antoon.pardon at vub.be> wrote:
> >> What would you want to happen in the following case:
> >>
> >>    foo1 = Bar()
> >>    foo2 = foo1
> >>    del foo1
> >>
> >> Should the object be cleaned up now or not?
> >>
> > TBH both are plausible,
>
> I find that strange because if you cleanup the object in that scenario
> it should also
> be cleaned up in the following.
>
>     def newbar():
>         foo = Bar
>         return foo
>
>     bar = newbar()
>
> foo goes out of scope, so that is equivallent to a del foo. But I wouldn't
> want the object cleaned up because of that.
>

Going out of scope isn't the same as explicit destruction. If you want
to simulate "going out of scope" without an actual scope change, the
nearest equivalent is something like "foo = None". In Python, there
isn't any such thing as "explicit destruction" (although
obj.__exit__() is often used for that kind of purpose), so the del
statement is just a removal from the current namespace; but when
explicit destruction does actually exist, it's an operation that
affects an object, not a name binding. (Any names previously bound to
that object will end up bound to the destroyed object.)

(Did you intend for that to be "foo = Bar()" ?)

ChrisA

From antoon.pardon at vub.be  Tue Dec 10 11:21:28 2019
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 10 Dec 2019 17:21:28 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <CAPTjJmp0=Te47fh5Yts6jAmo5e8fffOv_RkHEUvUCaRrgHNK5Q@mail.gmail.com>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <8dba129d-20ef-b374-d363-8187b0a387eb@vub.be>
 <CAPTjJmp9iA857cC8KxfZr9vOhvVE+sdTAs86BfFjKk3aZYPEgw@mail.gmail.com>
 <1af8a524-7a87-8049-1ed6-89be56df341d@vub.be>
 <CAPTjJmp0=Te47fh5Yts6jAmo5e8fffOv_RkHEUvUCaRrgHNK5Q@mail.gmail.com>
Message-ID: <fe01e478-f0ae-e100-9d09-f511a75ae443@vub.be>

On 10/12/19 16:56, Chris Angelico wrote:
> On Wed, Dec 11, 2019 at 2:36 AM Antoon Pardon <antoon.pardon at vub.be> wrote:
>> On 10/12/19 16:10, Chris Angelico wrote:
>>> On Wed, Dec 11, 2019 at 1:53 AM Antoon Pardon <antoon.pardon at vub.be> wrote:
>>>> What would you want to happen in the following case:
>>>>
>>>>    foo1 = Bar()
>>>>    foo2 = foo1
>>>>    del foo1
>>>>
>>>> Should the object be cleaned up now or not?
>>>>
>>> TBH both are plausible,
>> I find that strange because if you cleanup the object in that scenario
>> it should also
>> be cleaned up in the following.
>>
>>     def newbar():
>>         foo = Bar
>>         return foo
>>
>>     bar = newbar()
>>
>> foo goes out of scope, so that is equivallent to a del foo. But I wouldn't
>> want the object cleaned up because of that.
>>
> Going out of scope isn't the same as explicit destruction.

In the context of this discussion it is. We are talking about about
automatic cleanup
and whether it should happen immediatly after a name is no longer
available. or wait
until the object is garbage collected. The fact that I used a del for
illustrating the
possible problems is just a detail.

That other languages may have different semantics with the del statement
is irrelevant.

-- 
Antoon Pardon

From pkpearson at nowhere.invalid  Tue Dec 10 11:36:00 2019
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 10 Dec 2019 16:36:00 GMT
Subject: Randomizing Strings In A Microservices World
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
 <022uued8o9evis6rruhg4g99cslhh0do5f@4ax.com>
 <mailman.404.1575946535.25794.python-list@python.org>
 <3jg3cg-93s1.ln1@oceanview.tundraware.com>
Message-ID: <h59vrfF22j9U1@mid.individual.net>

On Mon, 9 Dec 2019 21:38:43 -0600, Tim Daneliuk <info at tundraware.com> wrote:
> On 12/9/19 8:54 PM, Dennis Lee Bieber wrote:
>> On Mon, 9 Dec 2019 18:52:11 -0600, Tim Daneliuk <info at tundraware.com>
>> declaimed the following:
>> 
>>> - Each of these services needs to produce a string of ten digits
>>> guaranteed to be unique on a per service instance basis AND to not
>>> collide for - oh, let's say - forever :)s
>>>
>>> Can anyone suggest a randomization method that might achieve this
>>> efficiently?
>>>
>>> My first thought was to something like nanonseconds since the epoch
>>> plus something unique about the service instance - like it's IP?
>>> (This is in a K8s cluster) - to see the randomization and
>>> essentially eliminate the string being repeated.
>>>
>>> Ideas welcome ..
>> 
>> 	Well, 10 digits is rather short, but studying
>> https://en.wikipedia.org/wiki/Universally_unique_identifier might provide
>> some ideas.
>
> For a variety of reasons the length of this string cannot exceed 10
> digits.  It is believed that - in this application - the consumption
> of values will be sparse over time.  All I really need is a high
> entropy way to select from among the billion possible values to
> minimize the possibility of collisions (which require retry and time
> we don't want to burn).

Just to be sure: you *are* aware that the "Birthday Paradox" says
that if you pick your 10-digit strings truly randomly, you'll probably
get a collision by the time of your 10**5th string . . . right?

-- 
To email me, substitute nowhere->runbox, invalid->com.

From torriem at gmail.com  Tue Dec 10 11:54:17 2019
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 10 Dec 2019 09:54:17 -0700
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qso3vr$1jk2$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
Message-ID: <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>

On 12/10/19 5:44 AM, R.Wieser wrote:
>> Well, that's exactly what happens.
> 
> So, only the reference count gets lowered.  Yep, thats daft.

Why?  Consider:

a = someobject
b = a

How many references for someobject?  After "del a" what should be be?
It's still someobject (the same object).

Or the example Antoon provided:

def foo()
   b = Bar()
   return b
   # b reference is deleted automatically


> ... unless you explain why it can only be done that way.

That is how a ref-counting resource management system works.

> I tend to go with logic.   No logic => it most likely doesn't work that way.

Interestingly I just saw a podcast recently titled, "Why too much logic
leads to irrationality."  In this case your logic is faulty because, as
you say, you lack information, which others have tried to provide.

> Choosing to go with a delayed action like you say will, as I already 
> explained, create problems later on (race conditions everywhere).  And as I 
> do not think the designers of the language where that stupid I must 
> therefore reject your claim to what you think happens.

No, that is exactly what happens.  And for good reasons.  Google for
reference-counting garbage collection.  This is not just some brand new
Python thing.  Be careful who you call stupid.  Seriously.  Doesn't
reflect well on you, who by your own admission is still learning the
language.  Python is not C++; don't code like it is.  If you need
semantics that are like RAII, then as Chris has said, you need to look
at the "with" statement and context handlers.


> But, as you mentioned, I do not know (all) the facts.  Please do present 
>them.   Maybe there is a logic in there I do not yet see.

And that's exactly what Chris and others did.  They explained the facts
and how relying on "del" to release the GPIO pin only works because you
got lucky.

>> Check out the 'with' statement.
> 
> I'm sorry, but nope.


From poltrone at gmx.net  Tue Dec 10 09:00:46 2019
From: poltrone at gmx.net (poltone)
Date: Tue, 10 Dec 2019 15:00:46 +0100
Subject: Installation Error (0xc000007b)
In-Reply-To: <CAH9pm4SEqb07VxU6=RNGZW5P4uFi0udbQd0p4qNunWgBov8bgw@mail.gmail.com>
References: <CAH9pm4SEqb07VxU6=RNGZW5P4uFi0udbQd0p4qNunWgBov8bgw@mail.gmail.com>
Message-ID: <1215e0d8-7365-c872-7062-c16941732a14@gmx.net>

> i'm getting the error message while installing python in my dell laptop.
> ERROR: the application was unable to start (0xc000007b).

The error code 0xc000007b means STATUS_INVALID_IMAGE_FORMAT, i.e. probably that the program you want to start is not made for the processor architecture of your computer. Is it possible that you are trying to run a 64-bit program on a 32-bit computer?



From address at not.available  Tue Dec 10 12:18:52 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 18:18:52 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
Message-ID: <qsol7k$81m$1@gioia.aioe.org>

Chris,

> Okay. What should happen when you do this?
>
> x = 5
> del x
>
> Should the integer 5 be deleted?

Yep.

What do you think happens instead ?   I've not seen you explain or support 
anything in that regard, not even now.

There is a bit of a problem with the above though: It has got zero to do 
with the __del__ I was talking about.  I've not seen you point out any 
mistake with my example (pointing out race contition problems) either.

Not a smooth move bro.  Not a smooth move /at all/ :-(

> So the language designers couldn't possibly have been so stupid
> as to do things this way, but you're going to ignore what they did?

Actually, they didn't.

Did you know you can disable the garbage collector ?  Well, you can.   Guess 
what I saw when I disabled it, created a class instance and than deleted it 
again.  Yup, the "print" command I placed in the "__del__" method did 
actually show output - something that, according to you, could/should never 
happen ...

Than again, I've used Python 3 for the test.  Maybe you're remembering 
something from an older version ?

Regards,
Rudy Wieser



From address at not.available  Tue Dec 10 12:26:11 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 18:26:11 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <5def9548$0$10400$426a74cc@news.free.fr>
Message-ID: <qsol7p$81m$2@gioia.aioe.org>

Python,

> which contradicts your previous statement.

I don't think so.

> "with" is "more stuff" it is the right way to deal with disposable 
> ressource in the first place.

Than you have missed the point altogether.  It isn't about what you think is 
the perfect way to deal with something, but how an instanciated class 
responds to an explicit "del" command.

Regards,
Rudy Wieser



From address at not.available  Tue Dec 10 12:38:35 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 18:38:35 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <8dba129d-20ef-b374-d363-8187b0a387eb@vub.be>
 <mailman.15.1575989494.11485.python-list@python.org>
Message-ID: <qsol7q$81m$3@gioia.aioe.org>

Antoon,

> Well yes that is why it is stupid to rely on the garbage collector to do
> those things for you. That is why Greg Ewing already stated:
>
>> If your object has a method for explicitly making it release its
>> resources, it would be better to use that rather than rely on
>> the garbage collector.

I think that you are mistaken to the meaning of word "resources" in the 
above ...

>   foo1 = Bar()
>   foo2 = foo1
>   del foo1
>
> Should the object be cleaned up now or not?

Seriously ?    No, as the object is still being referenced by "foo2".    And 
I do not see you explain anything either. :-(

Also, what has that got to do anything with my example talking about the 
"__del__" method  I posted ?    As far as I can tell ?  Nothing.

Regards,
Rudy Wieser

P.s.
Be sure to read my reply to Chris.



From info at tundraware.com  Tue Dec 10 12:27:19 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Tue, 10 Dec 2019 11:27:19 -0600
Subject: Randomizing Strings In A Microservices World
In-Reply-To: <h59vrfF22j9U1@mid.individual.net>
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
 <022uued8o9evis6rruhg4g99cslhh0do5f@4ax.com>
 <mailman.404.1575946535.25794.python-list@python.org>
 <3jg3cg-93s1.ln1@oceanview.tundraware.com> <h59vrfF22j9U1@mid.individual.net>
Message-ID: <o415cg-3gm1.ln1@oceanview.tundraware.com>

On 12/10/19 10:36 AM, Peter Pearson wrote:
> Just to be sure: you *are* aware that the "Birthday Paradox" says
> that if you pick your 10-digit strings truly randomly, you'll probably
> get a collision by the time of your 10**5th string . . . right?

I did not consider this, but the point is taken.

Could you kindly point me to a source for calculating this given
n-digit numeric-only strings?


From python at mrabarnett.plus.com  Tue Dec 10 13:33:31 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 10 Dec 2019 18:33:31 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsol7k$81m$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
Message-ID: <ef21627b-0010-7017-4fe8-c148625f4812@mrabarnett.plus.com>

On 2019-12-10 17:18, R.Wieser wrote:
> Chris,
> 
>> Okay. What should happen when you do this?
>>
>> x = 5
>> del x
>>
>> Should the integer 5 be deleted?
> 
> Yep.
> 
> What do you think happens instead ?   I've not seen you explain or support
> anything in that regard, not even now.
> 
> There is a bit of a problem with the above though: It has got zero to do
> with the __del__ I was talking about.  I've not seen you point out any
> mistake with my example (pointing out race contition problems) either.
> 
> Not a smooth move bro.  Not a smooth move /at all/ :-(
> 
>> So the language designers couldn't possibly have been so stupid
>> as to do things this way, but you're going to ignore what they did?
> 
> Actually, they didn't.
> 
> Did you know you can disable the garbage collector ?  Well, you can.   Guess
> what I saw when I disabled it, created a class instance and than deleted it
> again.  Yup, the "print" command I placed in the "__del__" method did
> actually show output - something that, according to you, could/should never
> happen ...
> 
> Than again, I've used Python 3 for the test.  Maybe you're remembering
> something from an older version ?
> 
You merely disabled the mark-and-sweep collector.

When the reference out reaches zero, the object is deleted, but if an 
object is part of a reference cycle, the reference count will never 
reach zero.

To deal with that, there's a mark-and-sweep collector that's called 
periodically.

From rosuav at gmail.com  Tue Dec 10 13:37:21 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 05:37:21 +1100
Subject: Randomizing Strings In A Microservices World
In-Reply-To: <o415cg-3gm1.ln1@oceanview.tundraware.com>
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
 <022uued8o9evis6rruhg4g99cslhh0do5f@4ax.com>
 <mailman.404.1575946535.25794.python-list@python.org>
 <3jg3cg-93s1.ln1@oceanview.tundraware.com>
 <h59vrfF22j9U1@mid.individual.net> <o415cg-3gm1.ln1@oceanview.tundraware.com>
Message-ID: <CAPTjJmr1BET3A=iLdr5yH6uO4SU0pxEPeR4f-8oxsF0HQ5Dktw@mail.gmail.com>

On Wed, Dec 11, 2019 at 5:01 AM Tim Daneliuk <info at tundraware.com> wrote:
>
> On 12/10/19 10:36 AM, Peter Pearson wrote:
> > Just to be sure: you *are* aware that the "Birthday Paradox" says
> > that if you pick your 10-digit strings truly randomly, you'll probably
> > get a collision by the time of your 10**5th string . . . right?
>
> I did not consider this, but the point is taken.
>
> Could you kindly point me to a source for calculating this given
> n-digit numeric-only strings?
>

The exact formula is pretty gnarly, but you can get remarkably close
by assuming that you're likely to get a collision at the square root -
which is half the exponent (so a 16-bit checksum will collide after
about 2**8 examples, and a 128-bit UUID4 will collide after about
2**64 UUIDs are generated).

https://en.wikipedia.org/wiki/Birthday_problem

ChrisA

From rhodri at kynesim.co.uk  Tue Dec 10 13:44:52 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 10 Dec 2019 18:44:52 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsol7k$81m$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
Message-ID: <989e49d5-78d1-aa85-2b2a-aab809945724@kynesim.co.uk>

On 10/12/2019 17:18, R.Wieser wrote:
> Chris,
> 
>> Okay. What should happen when you do this?
>>
>> x = 5
>> del x
>>
>> Should the integer 5 be deleted?
> 
> Yep.
> 
> What do you think happens instead ?   I've not seen you explain or support
> anything in that regard, not even now.

As it happens, the object that is the integer 5 *isn't* deleted.  Once 
again, you are making assertions based on what you believe to be true, 
despite having been told otherwise.  That's fair enough, but you then 
give those assertions the weighting of fact.

> There is a bit of a problem with the above though: It has got zero to do
> with the __del__ I was talking about.

On the contrary, it's exactly the point.  You are asserting behaviour 
that you are not guaranteed.  It happens that current versions of 
CPython conform to your expectations.  I have a vague and unreliable 
recollection that earlier versions didn't.  Other Python interpreters 
may or may not.  The language description does not give you that 
guarantee, so relying on it is at best foolish.

>  I've not seen you point out any
> mistake with my example (pointing out race contition problems) either.

Greg Ewing did:

"In that case, it was only working by accident. You were unwittingly
relying on the garbage collector to immediately clean up the object
as soon as the last reference to it disappeared. That happens to be
true currently in CPython (which uses reference counting), but it's
not guaranteed by the language."

Unless you're referring to some other example.  It's a bit hard to tell 
without the context.

> Not a smooth move bro.  Not a smooth move /at all/ :-(

Words fail me.

>> So the language designers couldn't possibly have been so stupid
>> as to do things this way, but you're going to ignore what they did?
> 
> Actually, they didn't.
> 
> Did you know you can disable the garbage collector ?  Well, you can.   Guess
> what I saw when I disabled it, created a class instance and than deleted it
> again.  Yup, the "print" command I placed in the "__del__" method did
> actually show output - something that, according to you, could/should never
> happen ...

What you disabled wasn't the garbage collector, it was the garbage 
collector's periodic background run to detect reference cycles and 
delete them when they have no external references.  The garbage 
collector itself ran just fine when your instance's reference count 
reached zero, exactly as everyone has been saying to you.

And to repeat, you have *no* guarantee *at all* in the language spec 
that this will happen.  The garbage collector could have waited until it 
was short of space before deleting the object, for example, which might 
not happen until your script terminates.

-- 
Rhodri James *-* Kynesim Ltd

From address at not.available  Tue Dec 10 13:47:24 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 19:47:24 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
Message-ID: <qsop8g$ri0$1@gioia.aioe.org>

Michael,

>> So, only the reference count gets lowered.  Yep, thats daft.
>
> Why?  Consider:

You missed the point.

It was-and-is not about decrementing a reference but still having it above 
zero, but what happens when the reference becomes zero: is the __del__ 
method called directly (as I find logical), or is it only called when the 
garbage collector actually removes the instance from memory (which Chris 
thinks what happens) ?

> No, that is exactly what happens.

No, it doesn't.  As a simple bit of testcode has shown me (read my reply to 
Chris).

> Be careful who you call stupid.  Seriously.

Who did I call stupid ?    I mentioned that the language doing it as Chris 
thinks it happens would be stupid, and I gave a reason for that (race 
conditions everywhere).  But odd: Neither him nor you nor anyone else who 
complains about me thinking for myself has even /tried/ to shoot holes in my 
example (or explain, let alone underbuild their own stance).  Do you have 
/any/ idea to what that makes me think ?  Yeah, exactly that. :-((

> Doesn't reflect well on you, who by your own admission is still learning
> the language.

True, I'm a newbie learning /Python/.   But it is far from the first 
language I've used.  Experience /does/ count for something you know. :-)

> And that's exactly what Chris and others did.  They explained the facts

No, they didn't.  They just TOLD me /their/ "facts".  Not an explanation 
anywhere. :-(

Regards,
Rudy Wieser 



From rosuav at gmail.com  Tue Dec 10 13:55:13 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 05:55:13 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsop8g$ri0$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org>
Message-ID: <CAPTjJmr3eqRLXABe8wZDHK9RZH4g5imUCBOfE_6Kdrj9rj7A3Q@mail.gmail.com>

On Wed, Dec 11, 2019 at 5:51 AM R.Wieser <address at not.available> wrote:
>
> Michael,
>
> >> So, only the reference count gets lowered.  Yep, thats daft.
> >
> > Why?  Consider:
>
> You missed the point.
>
> It was-and-is not about decrementing a reference but still having it above
> zero, but what happens when the reference becomes zero: is the __del__
> method called directly (as I find logical), or is it only called when the
> garbage collector actually removes the instance from memory (which Chris
> thinks what happens) ?
>
> > No, that is exactly what happens.
>
> No, it doesn't.  As a simple bit of testcode has shown me (read my reply to
> Chris).

You continue to be grossly mistaken and oblivious to this fact.

> > Be careful who you call stupid.  Seriously.
>
> Who did I call stupid ?    I mentioned that the language doing it as Chris
> thinks it happens would be stupid, and I gave a reason for that (race
> conditions everywhere).  But odd: Neither him nor you nor anyone else who
> complains about me thinking for myself has even /tried/ to shoot holes in my
> example (or explain, let alone underbuild their own stance).  Do you have
> /any/ idea to what that makes me think ?  Yeah, exactly that. :-((

x = []
x.append(x)
x = None

At what point does the reference count for that list drop to zero?
When should its __del__ method be called? Have you actually looked
into what you're heaping scorn onto?

> > Doesn't reflect well on you, who by your own admission is still learning
> > the language.
>
> True, I'm a newbie learning /Python/.   But it is far from the first
> language I've used.  Experience /does/ count for something you know. :-)
>
> > And that's exactly what Chris and others did.  They explained the facts
>
> No, they didn't.  They just TOLD me /their/ "facts".  Not an explanation
> anywhere. :-(
>

No, we told you facts. Facts are not owned by anyone. They simply are.

I'm pretty much done with talking to you. You aren't listening, and
you're being abrasive and scornful at every turn.

ChrisA

From address at not.available  Tue Dec 10 14:00:29 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 20:00:29 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <ef21627b-0010-7017-4fe8-c148625f4812@mrabarnett.plus.com>
 <mailman.25.1576002821.11485.python-list@python.org>
Message-ID: <qsoq11$v8k$1@gioia.aioe.org>

MRAB,

> You merely disabled the mark-and-sweep collector.

Nope.   Go check the docs on "gc"

Regards,
Rudy Wieser



From rosuav at gmail.com  Tue Dec 10 14:11:00 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 06:11:00 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsoq11$v8k$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <ef21627b-0010-7017-4fe8-c148625f4812@mrabarnett.plus.com>
 <mailman.25.1576002821.11485.python-list@python.org>
 <qsoq11$v8k$1@gioia.aioe.org>
Message-ID: <CAPTjJmr=dP3RuHzic2R9SUqLQvmjUaFZbjfXQDcf+UmBFgb+PQ@mail.gmail.com>

On Wed, Dec 11, 2019 at 6:06 AM R.Wieser <address at not.available> wrote:
>
> MRAB,
>
> > You merely disabled the mark-and-sweep collector.
>
> Nope.   Go check the docs on "gc"
>

https://docs.python.org/3/library/gc.html

"""
This module provides an interface to the optional garbage collector.
... Since the collector supplements the reference counting already
used in Python, you can disable the collector if you are sure your
program does not create reference cycles.
"""

Once again, you make positive assertions about things you don't understand.

ChrisA

From rhodri at kynesim.co.uk  Tue Dec 10 14:26:45 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 10 Dec 2019 19:26:45 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsoq11$v8k$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <ef21627b-0010-7017-4fe8-c148625f4812@mrabarnett.plus.com>
 <mailman.25.1576002821.11485.python-list@python.org>
 <qsoq11$v8k$1@gioia.aioe.org>
Message-ID: <641c8a9a-c8d1-9ad3-8d68-1b8d9c31a886@kynesim.co.uk>

On 10/12/2019 19:00, R.Wieser wrote:
> MRAB,
> 
>> You merely disabled the mark-and-sweep collector.
> 
> Nope.   Go check the docs on "gc"

Yep.  Go and check the docs on "gc" *carefully*

*plonk*


-- 
Rhodri James *-* Kynesim Ltd

From roel at roelschroeven.net  Tue Dec 10 14:29:36 2019
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 10 Dec 2019 20:29:36 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qso3vr$1jk2$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
Message-ID: <qsorn0$69t$1@blaine.gmane.org>

R.Wieser schreef op 10/12/2019 om 13:44:

>> Also, when you scorn something without knowing your facts,
>> you tend to make yourself look like a fool :)
> 
> I tend to go with logic.   No logic => it most likely doesn't work that way.
> 
> Choosing to go with a delayed action like you say will, as I already
> explained, create problems later on (race conditions everywhere).  And as I
> do not think the designers of the language where that stupid I must
> therefore reject your claim to what you think happens.

Chris: long-time contributor to this mailing list, lots of Python 
experience, knows his stuff.
Rudy: new to Python, still learning the basics.

Chris: explains how things work, states the facts correctly.
Rudy: disregards all that and thinks he knows better.

Me: does not compute

> But, as you mentioned, I do not know (all) the facts.  Please do present
> them.   Maybe there is a logic in there I do not yet see.
> 
>> Check out the 'with' statement.
> 
> I'm sorry, but nope.

That's a very foolish rejection.

Rudy, unless/until you know the language inside out, you'd better listen 
to Chris and other people here who spend a lot of time and effort in 
helping people like you. Don't correct them on things like this unless 
you can cite chapter and verse.
You're doing yourselves a massive disservice by acting this way.

Best regards,
Roel

-- 
"Honest criticism is hard to take, particularly from a relative, a
friend, an acquaintance, or a stranger."
         -- Franklin P. Jones

Roel Schroeven


From address at not.available  Tue Dec 10 14:25:07 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 20:25:07 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <989e49d5-78d1-aa85-2b2a-aab809945724@kynesim.co.uk>
 <mailman.27.1576003497.11485.python-list@python.org>
Message-ID: <qsorf0$16ej$1@gioia.aioe.org>

Rhodri,

> the object that is the integer 5 *isn't* deleted

That was not the question.  And you're now referring to the object as well 
as the integer, which makes it confusing. You also have not explained what 
happens instead.   In short, your above statement has ZERO value to me.

> On the contrary, it's exactly the point.  You are asserting behaviour that 
> you are not guaranteed.

Prove it.  I'm getting a bit fed up with you guys yapping along without 
anything to back anything up.

> What you disabled wasn't the garbage collector,

Prove it.  The docs.python.org page I found says something else, starting 
with the pages title being "Garbage Collector".

> And to repeat, you have *no* guarantee *at all* in the language spec that 
> this will happen.

There is also absolutily no guarantee in those specs that my 'puter will not 
suddenly transform into a bonzai tree.   Should I now expect it to happen ?

Regards,
Rudy Wieser



From python at mrabarnett.plus.com  Tue Dec 10 14:57:46 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 10 Dec 2019 19:57:46 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsorf0$16ej$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <989e49d5-78d1-aa85-2b2a-aab809945724@kynesim.co.uk>
 <mailman.27.1576003497.11485.python-list@python.org>
 <qsorf0$16ej$1@gioia.aioe.org>
Message-ID: <4680b0d1-fa26-abc9-d50d-dfc04018f498@mrabarnett.plus.com>

On 2019-12-10 19:25, R.Wieser wrote:
> Rhodri,
> 
>> the object that is the integer 5 *isn't* deleted
> 
> That was not the question.  And you're now referring to the object as well
> as the integer, which makes it confusing. You also have not explained what
> happens instead.   In short, your above statement has ZERO value to me.
> 
>> On the contrary, it's exactly the point.  You are asserting behaviour that 
>> you are not guaranteed.
> 
> Prove it.  I'm getting a bit fed up with you guys yapping along without
> anything to back anything up.
> 
>> What you disabled wasn't the garbage collector,
> 
> Prove it.  The docs.python.org page I found says something else, starting
> with the pages title being "Garbage Collector".
> 
 From the help:

"""CPython implementation detail: CPython currently uses a 
reference-counting scheme with (optional) delayed detection of 
cyclically linked garbage, which collects most objects as soon as they 
become unreachable, but is not guaranteed to collect garbage containing 
circular references. See the documentation of the gc module for 
information on controlling the collection of cyclic garbage. Other 
implementations act differently and CPython may change. Do not depend on 
immediate finalization of objects when they become unreachable (so you 
should always close files explicitly)."""

Ultimately, the proof of how CPython works is in its source code, which 
is open.

>> And to repeat, you have *no* guarantee *at all* in the language spec that 
>> this will happen.
> 
> There is also absolutily no guarantee in those specs that my 'puter will not
> suddenly transform into a bonzai tree.   Should I now expect it to happen ?
> 

From rhodri at kynesim.co.uk  Tue Dec 10 15:05:55 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 10 Dec 2019 20:05:55 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsorf0$16ej$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <989e49d5-78d1-aa85-2b2a-aab809945724@kynesim.co.uk>
 <mailman.27.1576003497.11485.python-list@python.org>
 <qsorf0$16ej$1@gioia.aioe.org>
Message-ID: <9b647388-0a28-83fe-efc0-822902c60557@kynesim.co.uk>

On 10/12/2019 19:25, R.Wieser wrote:
>> And to repeat, you have*no*  guarantee*at all*  in the language spec that
>> this will happen.
> There is also absolutily no guarantee in those specs that my 'puter will not
> suddenly transform into a bonzai tree.   Should I now expect it to happen ?

That's an implementation detail of your computer.

-- 
Rhodri James *-* Kynesim Ltd

From address at not.available  Tue Dec 10 15:11:53 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 21:11:53 +0100
Subject: Python3 - How do I import a class from another file
References: <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org> <n8pvuehaki5v0ksjq4iltrlube3s8gu6a4@4ax.com>
 <mailman.28.1576003860.11485.python-list@python.org>
Message-ID: <qsou6m$1jq4$1@gioia.aioe.org>

Dennis,

> In common Python, small integers are cached internally for reuse

That is what I imagined could possibly be happening, reading the specific 
"the integer 5" formulation in the question ("reading between the lines" and 
all that).

And thanks for that explanation, underbuild an all.  :-)

> If you had an object on which you invoked "del", then it had a
> reference count, and if that reference count dropped to 0, then any
> __del__ method would be called.

That is exactly what I thought (the most logical thing), but Greg seemed to 
know better:

[quote: greg]
In that case, it was only working by accident. You were unwittingly
relying on the garbage collector to immediately clean up the object
as soon as the last reference to it disappeared.
[/quote]

My doubt to that (explicitily mentioning the __del__ method) was than picked 
up by Chris, who continued in the same vein.  After which the others started 
to pile up on me.

I hope you do realise that you are opening yourself up to those same guys ? 
After a few of those ontop of you quickly ceases to be funny. :-(

> Remember that reference counting, the main garbage collection
> mechanism in Python, can't be disabled.

Even /wanting/ to do so would be rather stupid, as it would mean the program 
would than be hemmoraging memory.

> The only garbage collection behavior you can
> alter is the generational garbage collector in the gc module.

Which I assume just takes care of compacting the available memory (and 
dealing with those (already found?) circular references).

Regards,
Rudy Wieser



From address at not.available  Tue Dec 10 16:08:48 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 22:08:48 +0100
Subject: Python3 - How do I import a class from another file
Message-ID: <qsp1hd$46m$1@gioia.aioe.org>

Chris,

> Once again, you make positive assertions about things you
> don't understand.

And you have refused to bring any kind of help (explanation!) forward that
could have shown me the erring of my ways, as well as refusing to adress my
(attempting to explain) examples.

You might know a thing or two about Python, but you (and a number of others
here) positivily stink as teachers, incapable or even unwilling to place
themselves in the shoes of a newbie.

Only now I know, after Dennis explanation, that there are (at least) /two/
garbage collectors.  One of which is triggered by a reference count becoming
zero, and one periodically called.

And although you have been fighting me over when the __del__ method is
called, it /is/ called directly as a result of an "del instance" and the
refcount goes zero.  There is /no/ delay.    (with the only exception is
when a circular reference exists).

Hence, no "race condition" problem.

But for some reason even my claiming that that would happen didn't trigger
any kind of understanding.

And you  blame /me/ for making certain (logical!) assumptions ?   Really ?

Regards,
Rudy Wieser




From address at not.available  Tue Dec 10 16:24:33 2019
From: address at not.available (R.Wieser)
Date: Tue, 10 Dec 2019 22:24:33 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <qsorn0$69t$1@blaine.gmane.org>
 <mailman.34.1576006185.11485.python-list@python.org>
Message-ID: <qsp2ev$8jr$1@gioia.aioe.org>

Roel,

> Rudy, unless/until you know the language inside out, you'd better listen 
> to Chris and other people here who spend a lot of time and effort in 
> helping people like you.

I tried.   But what he said made no sense to me, and no matter how hard I 
tried I could not get Chris (or others for that matter) to understand.   And 
as you might have seen, I tried. In several different ways.

The only thing I got was regurgitation, without /any/ attempt to figure out 
where my mistake would be.  Do you have /any/ idea how frustrating that that 
is ?   Do you ?

Also, if I would not care about it, why would I than not simply have stopped 
responding ?   Much easier than to try to get someone to understand.

And as it turned out, I /didn't/ make a mistake.    The __del__ method /is/ 
directly called as a result of the "del instance" command (and the reference 
count going zero).  No delay, and thus no "race condition" exist.

Regards,
Rudy Wieser



From rosuav at gmail.com  Tue Dec 10 16:29:28 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 11 Dec 2019 08:29:28 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsp2ev$8jr$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <qsorn0$69t$1@blaine.gmane.org>
 <mailman.34.1576006185.11485.python-list@python.org>
 <qsp2ev$8jr$1@gioia.aioe.org>
Message-ID: <CAPTjJmpt7xTATuAy6gMiLE12oZZW8BxNT0-UanDQa3+OOtqOJw@mail.gmail.com>

On Wed, Dec 11, 2019 at 8:26 AM R.Wieser <address at not.available> wrote:
>
> Roel,
>
> > Rudy, unless/until you know the language inside out, you'd better listen
> > to Chris and other people here who spend a lot of time and effort in
> > helping people like you.
>
> I tried.   But what he said made no sense to me, and no matter how hard I
> tried I could not get Chris (or others for that matter) to understand.   And
> as you might have seen, I tried. In several different ways.
>
> The only thing I got was regurgitation, without /any/ attempt to figure out
> where my mistake would be.  Do you have /any/ idea how frustrating that that
> is ?   Do you ?

Given that you aren't listening when we point out where the mistake
is, yes, I know how frustrating it is.

> Also, if I would not care about it, why would I than not simply have stopped
> responding ?   Much easier than to try to get someone to understand.
>
> And as it turned out, I /didn't/ make a mistake.    The __del__ method /is/
> directly called as a result of the "del instance" command (and the reference
> count going zero).  No delay, and thus no "race condition" exist.
>

And once again, you are maintaining your assumptions despite being
very clearly shown that they are wrong. "del instance" does not
directly call __del__ any more than "instance = 1" does. You HAVE been
shown.

I'm done responding to you. I'm very close to blocking you in my mail client.

ChrisA

From p.f.moore at gmail.com  Tue Dec 10 16:33:12 2019
From: p.f.moore at gmail.com (Paul Moore)
Date: Tue, 10 Dec 2019 21:33:12 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsp1hd$46m$1@gioia.aioe.org>
References: <qsp1hd$46m$1@gioia.aioe.org>
Message-ID: <CACac1F-bjnUuTaZp1D67SQfLW+bv2bj0YhRxjnBDo9JDBEqtGA@mail.gmail.com>

On Tue, 10 Dec 2019 at 21:12, R.Wieser <address at not.available> wrote:
> And although you have been fighting me over when the __del__ method is
> called, it /is/ called directly as a result of an "del instance" and the
> refcount goes zero.  There is /no/ delay.    (with the only exception is
> when a circular reference exists).

You do understand that the reference counting garbage collector is an
implementation detail of the CPython implementation *only*, don't you?
The (implementation independent) language semantics makes no assertion
about what form of garbage collection is used, and under other garbage
collectors, there can be an indefinite delay between the last
reference to a value being lost and the object being collected (which
is when __del__ gets called). There is not even a guarantee that
CPython will retain the reference counting GC in future versions.
Removing it would be a big change, but not impossible.

If all you are interested is the semantics of the current CPython
release, then your statements are true. But why would anyone here know
that you were looking at the situation from such a limited
perspective?

Your "logic" seems to be full of hidden assumptions and unstated
qualifications. And your attitude seems to be confrontational and
aggressive. Frankly, it's unlikely that you're going to learn much
without a change in your approach.

Paul

From python at mrabarnett.plus.com  Tue Dec 10 16:50:50 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Tue, 10 Dec 2019 21:50:50 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsp1hd$46m$1@gioia.aioe.org>
References: <qsp1hd$46m$1@gioia.aioe.org>
Message-ID: <03c89ad3-2cb3-6ec2-c7f1-4e8224746dd5@mrabarnett.plus.com>

On 2019-12-10 21:08, R.Wieser wrote:
> Chris,
> 
>> Once again, you make positive assertions about things you
>> don't understand.
> 
> And you have refused to bring any kind of help (explanation!) forward that
> could have shown me the erring of my ways, as well as refusing to adress my
> (attempting to explain) examples.
> 
> You might know a thing or two about Python, but you (and a number of others
> here) positivily stink as teachers, incapable or even unwilling to place
> themselves in the shoes of a newbie.
> 
> Only now I know, after Dennis explanation, that there are (at least) /two/
> garbage collectors.  One of which is triggered by a reference count becoming
> zero, and one periodically called.
> 
> And although you have been fighting me over when the __del__ method is
> called, it /is/ called directly as a result of an "del instance" and the
> refcount goes zero.  There is /no/ delay.    (with the only exception is
> when a circular reference exists).
> 
You don't "del" an instance, you "del" a reference, which might be in 
the form of a name in a namespace.

If that was the only reference to the instance, then the instance can be 
collected.

When the instance is collected, whenever that happens to be, its 
"__del__" method is called.

CPython uses reference counting, so if del removes the only reference, 
the instance will collected the instance immediately.

The language definition doesn't specify that reference counting must be 
used; that's just what CPython happens to use, and it's nice in that 
collection tends to happen sooner.

Other implementations can use other techniques, and for some of them 
there might be a delay before collection kicks in, so if an instance is 
holding a resource, that resource would not be released as quickly.

> Hence, no "race condition" problem.
> 
> But for some reason even my claiming that that would happen didn't trigger
> any kind of understanding.
> 
> And you  blame /me/ for making certain (logical!) assumptions ?   Really ?
> 

From torriem at gmail.com  Tue Dec 10 16:50:58 2019
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 10 Dec 2019 14:50:58 -0700
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsop8g$ri0$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org>
Message-ID: <b76128e7-47d2-0000-f2e9-c23ef41f30b4@gmail.com>

On 12/10/19 11:47 AM, R.Wieser wrote:
> Who did I call stupid ?    I mentioned that the language doing it as Chris 
> thinks it happens would be stupid, and I gave a reason for that (race 
> conditions everywhere).  But odd: Neither him nor you nor anyone else who 
> complains about me thinking for myself has even /tried/ to shoot holes in my 
> example (or explain, let alone underbuild their own stance).  Do you have 
> /any/ idea to what that makes me think ?  Yeah, exactly that. :-((

You said it by implication.

quote:  "And as I do not think the designers of the language where that
stupid I must therefore reject your claim to what you think happens."

Since the language does behave as Chris described (calling __del__ does
not always happen when you want or think it does, hence the "with"), you
have implied that Guido and friends are stupid and that you are not.

You can imply that I'm stupid all you want because I can't "shoot holes
in your example" to your satisfaction.  Doesn't change the fact that
what we've told you are facts about Python's operation.  I'm stupid
about many things but not this one.

>> Doesn't reflect well on you, who by your own admission is still learning
>> the language.
> 
> True, I'm a newbie learning /Python/.   But it is far from the first 
> language I've used.  Experience /does/ count for something you know. :-)

In this case your experience is perhaps leading you astray when it comes
to Python.

>> And that's exactly what Chris and others did.  They explained the facts
> 
> No, they didn't.  They just TOLD me /their/ "facts".  Not an explanation 
> anywhere. :-(

There's no such thing as "their facts."  There are facts, lies, and just
opinions.  What Chris said was fact.  Even if it isn't supported by your
brief and incomplete testing.

I was quite happy to see your posts up until this point. It appeared
that you were making great headway and maybe even enjoying Python. But
now I fear you're going to end up in a lot of awesome contributors'
killfiles.

From torriem at gmail.com  Tue Dec 10 17:04:53 2019
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 10 Dec 2019 15:04:53 -0700
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsp1hd$46m$1@gioia.aioe.org>
References: <qsp1hd$46m$1@gioia.aioe.org>
Message-ID: <bde71ebd-bc5a-8a7a-e667-05f0f2f0550d@gmail.com>

On 12/10/19 2:08 PM, R.Wieser wrote:
> You might know a thing or two about Python, but you (and a number of others
> here) positivily stink as teachers, incapable or even unwilling to place
> themselves in the shoes of a newbie.

As it happens, I've heard Chris speak about teaching Python to students.
 I suspect they learn rather well from him.  Chris is a very articulate
and great explainer.

It's a two-way street.  It's hard to teach someone that won't be taught.

From python at python.invalid  Tue Dec 10 17:14:47 2019
From: python at python.invalid (Python)
Date: Tue, 10 Dec 2019 23:14:47 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <mailman.42.1576015499.11485.python-list@python.org>
References: <qsp1hd$46m$1@gioia.aioe.org>
 <bde71ebd-bc5a-8a7a-e667-05f0f2f0550d@gmail.com>
 <mailman.42.1576015499.11485.python-list@python.org>
Message-ID: <5df0187f$0$20310$426a34cc@news.free.fr>

Michael Torrie wrote:
> On 12/10/19 2:08 PM, R.Wieser wrote:
>> You might know a thing or two about Python, but you (and a number of others
>> here) positivily stink as teachers, incapable or even unwilling to place
>> themselves in the shoes of a newbie.
> 
> As it happens, I've heard Chris speak about teaching Python to students.
>   I suspect they learn rather well from him.  Chris is a very articulate
> and great explainer.
> 
> It's a two-way street.  It's hard to teach someone that won't be taught.

+1




From frank at chagford.com  Wed Dec 11 02:52:05 2019
From: frank at chagford.com (Frank Millman)
Date: Wed, 11 Dec 2019 09:52:05 +0200
Subject: datetime gotcha
Message-ID: <qsq776$4amq$1@blaine.gmane.org>

Hi all

It took me a while to track down a bug that stemmed from this -

 >>> from datetime import date as dt, time as tm, datetime as dtm
 >>> x = dt.today()
 >>> isinstance(x, dt)
True
 >>> isinstance(x, dtm)
False
 >>> y = dtm.now()
 >>> isinstance(y, dt)
True                   <--- ??
 >>> isinstance(y, dtm)
True
 >>> isinstance(y, tm)
False
 >>>

Why is a dtm instance also an instance of dt?

 From the docs, "A datetime object is a single object containing all the 
information from a date object and a time object."

If it was using multiple inheritance, a dtm should also be an instance 
of tm, but it is not.

This is using Python 3.7.2.

Frank Millman


From antoon.pardon at vub.be  Wed Dec 11 03:03:01 2019
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Wed, 11 Dec 2019 09:03:01 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsp2ev$8jr$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <qsorn0$69t$1@blaine.gmane.org>
 <mailman.34.1576006185.11485.python-list@python.org>
 <qsp2ev$8jr$1@gioia.aioe.org>
Message-ID: <a2419e34-a848-2bb8-cda6-6f52d9ae14da@vub.be>

On 10/12/19 22:24, R.Wieser wrote:
> Roel,
>
>> Rudy, unless/until you know the language inside out, you'd better listen 
>> to Chris and other people here who spend a lot of time and effort in 
>> helping people like you.
> I tried.   But what he said made no sense to me, and no matter how hard I 
> tried I could not get Chris (or others for that matter) to understand.   And 
> as you might have seen, I tried. In several different ways.

There is a difference between not understanding why things are as you
are told, and
assuming because you don't understand, what you are told is wrong.
Instead of trying
to understand, you started to dispute.
> The only thing I got was regurgitation, without /any/ attempt to figure out 
> where my mistake would be.  Do you have /any/ idea how frustrating that that 
> is ?   Do you ?

That is because you started to argue instead of trying to ask for
clarifications.
> Also, if I would not care about it, why would I than not simply have stopped 
> responding ?   Much easier than to try to get someone to understand.
>
> And as it turned out, I /didn't/ make a mistake.    The __del__ method /is/ 
> directly called as a result of the "del instance" command (and the reference 
> count going zero).  No delay, and thus no "race condition" exist.

Yes, you made a mistake. You relied on a specific example where things
turned out as you
expected. But what you expect is not within the language specification.
If next time you
try out an other python implementation, there is no guarantee this will
still work as
you expect. That you think you can infer general behaviour from your
limited experience
is a mistake.

-- 
Antoon Pardon.

From greg.ewing at canterbury.ac.nz  Wed Dec 11 05:01:36 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Wed, 11 Dec 2019 23:01:36 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsop8g$ri0$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org>
Message-ID: <h5bt40Fe64mU1@mid.individual.net>

On 11/12/19 7:47 am, R.Wieser wrote:
> what happens when the reference becomes zero: is the __del__
> method called directly (as I find logical), or is it only called when the
> garbage collector actually removes the instance from memory (which Chris
> thinks what happens) ?

In CPython, these are the same thing. As soon as the reference
count becomes zero, the __del__ method is called *and* the object
is removed from memory.

This remains true even in the presence of reference cycles. As
long as the object is part of a cycle, it's reference count
is not zero. When the cyclic garbage collector gets around to
noticing the cycle, it breaks it, causing the reference counts
of the objects in it to become zero, in turn causing them to
be collected.

In a Python implementation that doesn't use reference counts,
using "del" on the last reference to an object probably isn't
going to do anything to the object.

You seem to think it would be logical for it to call the __del__
method there and then, instead of waiting until the object is
collected. But without reference counting, it has no way of
*knowing* that it's the last reference until the garbage
collector does its thing.

To summarise, your logic on this point is flawed.

> As a simple bit of testcode has shown me (read my reply to
> Chris).

We're not saying that your code won't work -- in current
CPython it will. We're saying that it relies on an
implementation detail. To demonstrate that with a code example,
it would have to be run on a different implementation of Python
that didn't use reference counting, such as Jython.

-- 
Greg

From address at not.available  Wed Dec 11 05:22:33 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 11:22:33 +0100
Subject: Python3 - How do I import a class from another file
References: <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <uqsvuedi6tvhnjo3urtt54eauf5vhbq0fb@4ax.com>
 <mailman.35.1576007779.11485.python-list@python.org>
Message-ID: <qsqh8m$1087$1@gioia.aioe.org>

Dennis,

This is the first time I've seen you post FUD. :-((

> It is called when the language IMPLEMENTATION decides to call it.
> That time is not specified in the language description/reference manual.

I'm rather sure it neither specifies that for any of the other commands. 
Does that mean that it could randomly delay the execution of them too 
(effectivily randomizing the program) and we should all be OK by that ?

I think I will just go out on a limb and just assume that the __del__ method 
/will/ be called as part of a "del instance" request causing the reference 
count to reach zero (directly or indirectly), before the next command is 
executed (circular references excluded - a situation which I assume happens 
by mistake, not on purpose).

Why ?   Because anything else would cause big problems in the predictability 
of the execution of a program.   And I don't think the writers/maintainers 
of the Python language where or are /that/ daft (it would kill their 
language off in no time flat).

@all
But, if anyone has an example of how that presumption will, in regular use 
(non circular references), bite me in the ass than please to post it or 
provide a link.  I do not at all mind being /proven/ wrong.

Regards,
Rudy Wieser



From address at not.available  Wed Dec 11 05:43:23 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 11:43:23 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <989e49d5-78d1-aa85-2b2a-aab809945724@kynesim.co.uk>
 <mailman.27.1576003497.11485.python-list@python.org>
 <qsorf0$16ej$1@gioia.aioe.org>
 <4680b0d1-fa26-abc9-d50d-dfc04018f498@mrabarnett.plus.com>
 <mailman.36.1576007875.11485.python-list@python.org>
Message-ID: <qsqh8n$1087$2@gioia.aioe.org>

MRAB,

> From the help:
...
> Do not depend on immediate finalization of objects when they become 
> unreachable (so you should always close files explicitly).

Do you notice there is not a single word about (the delayed action of) the 
__del__ method in there ?  Why than do you think its talking about it ?

You know how I read that ?   As if its talking about /variables going outof 
scope/.   Makes sense ?    Thought so.  :-)

Hmmm...  Maybe the __del__ method was created exactly to solve this late 
handling of going-outof-scope variables.  What do you think ?

And by the way: /when/ would you close those files explicitily ?    You 
cannot just do it before any "del instance" command, as some other refence 
to the instance might still there ...

Regards,
Rudy Wieser



From address at not.available  Wed Dec 11 07:09:27 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 13:09:27 +0100
Subject: Python3 - How do I import a class from another file
References: <qsp1hd$46m$1@gioia.aioe.org>
 <CACac1F-bjnUuTaZp1D67SQfLW+bv2bj0YhRxjnBDo9JDBEqtGA@mail.gmail.com>
 <mailman.39.1576013607.11485.python-list@python.org>
Message-ID: <qsqm9q$1omv$1@gioia.aioe.org>

Paul,

> You do understand that the reference counting garbage collector is an
> implementation detail of the CPython implementation *only*, don't you?

No, I don't.   But do tell how that matters to me.

> there can be an indefinite delay between the last reference to
> a value being lost and the object being collected (which is
> when __del__ gets called).

Nope.

As I've posted a number of messages back, I've created a test program which 
disables that periodically-called garbage collector and than created and 
destroyed a class instance.  The print command I had put into its __del__ 
method was called regardless.    Which, according to your above claim, 
should not have happened.

I (currently) do not care much for how other implementations do it, but feel 
free to find one which actually does it the way you claim it happens.   But 
if-and-when you find one be sure to also post how they deal with the, also 
mentioned before, inherent race conditions. :-)

> If all you are interested is the semantics of the current CPython
> release, then your statements are true.

Thank you !

Thats, for the moment, /all/ I needed to know.  (no Dennis, I have not 
forgotten you said the same :-) ).

I hope you do realize you are now contradicting Greg, who started all of 
this by his blunt claim that "it was only working by accident" as well as 
Chris who agreed with him ?

>But why would anyone here know that you were looking at the
>situation from such a limited perspective?

Look at the subject line and my initial question.  It pretty-much /screams/ 
that I'm a new to the language (and specifies which version).  Do you think 
that I care much, if anything, about how /other/ implementations work before 
I have got a handle on this one ?

But do tell: How many Python 3 (CPython?  is that the same?) implementations 
are there, and how many do actually lazily call the __del__ method (when its 
trying to free up some memory) ?

> And your attitude seems to be confrontational and aggressive.

I take it you mean "has become".  Yep, that happens when I ask a simple 
question and everyone just keeps posting "your have to take our word for 
it!" posts, while refusing to even address my "but this is what happens!" 
examples.

Besides, I'm Dutch, I'm supposed to be rude. :-)

Regards,
Rudy Wieser



From address at not.available  Wed Dec 11 07:34:00 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 13:34:00 +0100
Subject: Python3 - How do I import a class from another file
References: <qsp1hd$46m$1@gioia.aioe.org>
 <03c89ad3-2cb3-6ec2-c7f1-4e8224746dd5@mrabarnett.plus.com>
 <mailman.40.1576014657.11485.python-list@python.org>
Message-ID: <qsqnnq$1vdl$1@gioia.aioe.org>

MRAB,

> You don't "del" an instance, you "del" a reference, which might be in the 
> form of a name in a namespace.

Remember me, the newbie to the language ?

Did you understand what I tried to to say ?   Good.  Thats al that matters.

> When the instance is collected, whenever that happens to be, its "__del__" 
> method is called.

You're introducing the word "collected", while not giving /any/ explanation 
what it means to you(!) or which of the two(or more ?) garbage collectors 
does that "collecting".   And I'm supposed to figure out what happens 
regardless ?    Really ?

Also, I have explained how that lazily calling of the __del__ method could 
easily create race condition problems.  Care to comment ?

> The language definition doesn't specify that reference counting must be 
> used; that's just what CPython happens to use, and it's nice in that 
> collection tends to happen sooner.

Why is it that you guys keep equating "collection" to "call the __del__ 
method" ?   Explain that to me that please.

I myself can easily imagine that the __del__ method is called as a result of 
the reference count going Zero, and the actual "collection" (freeing up the 
local variables and releasing the occupied memory) takes place only when the 
implemented (single?) garbage collector feels like it (though I could also 
imagine that the releasing (not collecting!) of local variables could also 
be done directly after the above __del__ method has been called).

Regards,
Rudy Wieser



From countryone77 at gmail.com  Wed Dec 11 08:15:18 2019
From: countryone77 at gmail.com (Bev In TX)
Date: Wed, 11 Dec 2019 07:15:18 -0600
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsqm9q$1omv$1@gioia.aioe.org>
References: <qsp1hd$46m$1@gioia.aioe.org>
 <CACac1F-bjnUuTaZp1D67SQfLW+bv2bj0YhRxjnBDo9JDBEqtGA@mail.gmail.com>
 <mailman.39.1576013607.11485.python-list@python.org>
 <qsqm9q$1omv$1@gioia.aioe.org>
Message-ID: <C6B51C07-E5FF-4A05-A6C9-2B656465D984@gmail.com>


> On Dec 11, 2019, at 6:09 AM, R.Wieser <address at not.available> wrote:
> 
> Paul,
> 
>> You do understand that the reference counting garbage collector is an
>> implementation detail of the CPython implementation *only*, don't you?
> 
> No, I don't.   But do tell how that matters to me.
> 
>> there can be an indefinite delay between the last reference to
>> a value being lost and the object being collected (which is
>> when __del__ gets called).
> 
> Nope.
> 
> As I've posted a number of messages back, I've created a test program which 
> disables that periodically-called garbage collector and than created and 
> destroyed a class instance.  The print command I had put into its __del__ 
> method was called regardless.    Which, according to your above claim, 
> should not have happened.
> 
> I (currently) do not care much for how other implementations do it, but feel 
> free to find one which actually does it the way you claim it happens.   But 
> if-and-when you find one be sure to also post how they deal with the, also 
> mentioned before, inherent race conditions. :-)
> 
>> If all you are interested is the semantics of the current CPython
>> release, then your statements are true.
> 
> Thank you !
> 
> Thats, for the moment, /all/ I needed to know.  (no Dennis, I have not 
> forgotten you said the same :-) ).
> 
> I hope you do realize you are now contradicting Greg, who started all of 
> this by his blunt claim that "it was only working by accident" as well as 
> Chris who agreed with him ?
> 
>> But why would anyone here know that you were looking at the
>> situation from such a limited perspective?
> 
> Look at the subject line and my initial question.  It pretty-much /screams/ 
> that I'm a new to the language (and specifies which version).  Do you think 
> that I care much, if anything, about how /other/ implementations work before 
> I have got a handle on this one ?
> 
> But do tell: How many Python 3 (CPython?  is that the same?) implementations 
> are there, and how many do actually lazily call the __del__ method (when its 
> trying to free up some memory) ?
> 
>> And your attitude seems to be confrontational and aggressive.
> 
> I take it you mean "has become".  Yep, that happens when I ask a simple 
> question and everyone just keeps posting "your have to take our word for 
> it!" posts, while refusing to even address my "but this is what happens!" 
> examples.
> 
> Besides, I'm Dutch, I'm supposed to be rude. :-)
> 
> Regards,
> Rudy 

I agree with others who responded to you.  You acknowledge that you are new to Python, yet you claimed to know better than Python experts.  You claim you want an answer and yet you purposefully ignored their response because it didn?t match what you wanted to hear.  You have time to repeatedly vilify everyone connected with Python, but you have no time to read the well written documentation. 

I have no more time to spend on such a ungrateful person.  I?m blocking all messages from you.

Bev in TX

From address at not.available  Wed Dec 11 08:30:52 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 14:30:52 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org>
 <b76128e7-47d2-0000-f2e9-c23ef41f30b4@gmail.com>
 <mailman.41.1576014664.11485.python-list@python.org>
Message-ID: <qsqrnu$isd$1@gioia.aioe.org>

Michael,

> You said it by implication.
>
> quote:  "And as I do not think the designers of the language where that
> stupid I must therefore reject your claim to what you think happens."

I suggest you try reading that again, and imagine it being two centences, 
the first ending after "stupid" and the second starting with the  folowing 
"I".     The first is a reasoning to the rejecting in the second.   Nothing 
more, nothing less.

> Since the language does behave as Chris described (calling __del__
> does not always happen when you want or think it does

No, it doesn't (I described a testprogram that contradicted it a number of 
messages back).  And trying to play of /exceptions of the rule/ as the only 
thing that matters is simply disingenious.

But, feel free to post an example or just a link to supporting your/Chris 
claim.

> You can imply that I'm stupid all you want because I can't "shoot
> holes in your example" to your satisfaction.

Wait, what ?    You actually already tried that ?    When ?

But, If I can shoot holes in your shooting than who's problem is that ?  :-)

And no, I do not try to imply you are stupid, but perhaps just have to much 
of "I remember it this way, so that must be the only truth" in your mind - 
without actually knowing (anymore?) why that truth is just that.

I challenged you to think for yourself, instead of just going blind on 
someone elses say-so.  Maybe you and others are right, but you have done 
little to /explain/ that to me.

> There's no such thing as "their facts."  There are facts, lies, and
> just opinions.  What Chris said was fact.

In my book anything thats unproven is just an opinion.  Its as simple as 
that.

> Even if it isn't supported by your brief and incomplete testing.

Go ahead, shoot holes into it.    Just bluntly, without any kind of 
underbuilding, claiming stuff like that doesn't work with me.  Which by now 
you should have been aware of ...

> I was quite happy to see your posts up until this point. It
> appeared that you were making great headway and maybe
> even enjoying Python

I was thinking so to.

But this morning I seriously contemplating of at least ditching this 
newsgroup, if not also Python, because of the incapability (or 
unwillingness?) of the different contributors to place themselves in the 
shoes of me, a newbie.

Yeah, it works both ways. :-(((

Regards,
Rudy Wieser



From address at not.available  Wed Dec 11 08:42:18 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 14:42:18 +0100
Subject: Python3 - How do I import a class from another file
References: <qsp1hd$46m$1@gioia.aioe.org>
 <bde71ebd-bc5a-8a7a-e667-05f0f2f0550d@gmail.com>
 <mailman.42.1576015499.11485.python-list@python.org>
Message-ID: <qsqrnv$isd$2@gioia.aioe.org>

Michael,

> It's a two-way street.  It's hard to teach someone that won't be taught.

Whacking a student over the head because he doesn't understand has never 
helped the student*.   So, stop whacking and start /teaching/.   Like 
thinking of examples that could show the student where he goes wrong.

*other than learning to stop asking questions and just wing it any-which-way 
he can.   Is that what you are after ?

Regards,
Rudy Wieser

P.s.
What would that "with" example/proof look like according to you ?  As a 
newbie I can ofcourse take a swipe at it, but there is that a rather large 
chance (understatement) that he /ofcourse/ will do it wrong.




From address at not.available  Wed Dec 11 09:05:14 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 15:05:14 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <qsorn0$69t$1@blaine.gmane.org>
 <mailman.34.1576006185.11485.python-list@python.org>
 <qsp2ev$8jr$1@gioia.aioe.org> <a2419e34-a848-2bb8-cda6-6f52d9ae14da@vub.be>
 <mailman.44.1576051383.11485.python-list@python.org>
Message-ID: <qsqt32$pfa$1@gioia.aioe.org>

Antoon,

> There is a difference between not understanding why things are as
> you are told, and assuming because you don't understand, what you
> are told is wrong.

The other side is you guys, expecting from me that, even though I 
appearantly do not understand it, just take whatever has being said as the 
truth.

> Instead of trying to understand, you started to dispute.

Correct.   I didn't understand, so I argued my point, and expected the other 
to argue his.   My arguing could have clarified where I when off my rockers, 
his arguing could have shown me where I did.   Whats wrong with that ?

> Yes, you made a mistake. You relied on a specific example where
> things turned out as you expected.

And /anyone/ was allowed to come up with an example to counter it.  Heck, 
noone even tried to explain, beyond a "there are two garbage collectors", 
why my example was wrong.

> That you think you can infer general behaviour from your limited
> experience is a mistake.

Do I have any other option ?    Most noone here actually tried to even 
understand what I asked, let alone try to explain their own stance.   How am 
I to learn otherwise ?    I just have to create my own experiences.

And no, just parotting someone elses word has never appealed to me. 
Sorry.    I need to see it (not) working , or no deal.

Regards,
Rudy Wieser



From musbur at posteo.org  Wed Dec 11 09:17:14 2019
From: musbur at posteo.org (Musbur)
Date: Wed, 11 Dec 2019 15:17:14 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <CACac1F-bjnUuTaZp1D67SQfLW+bv2bj0YhRxjnBDo9JDBEqtGA@mail.gmail.com>
References: <qsp1hd$46m$1@gioia.aioe.org>
 <CACac1F-bjnUuTaZp1D67SQfLW+bv2bj0YhRxjnBDo9JDBEqtGA@mail.gmail.com>
Message-ID: <c50039a69f7b6e90250763136c99d9c8@posteo.de>

Am 10.12.2019 22:33 schrieb Paul Moore:

> You do understand that the reference counting garbage collector is an
> implementation detail of the CPython implementation *only*, don't you?

I don't think that's true. Here's a sentonce from near the top of the 
"gc" module documentation of Python 3:
https://docs.python.org/3/library/gc.html#module-gc

"Since the collector supplements the reference counting already used in 
Python, you can disable the collector if you are sure your program does 
not create reference cycles."

The way I read this is that Python automatically and immediately deletes 
objects once their refcount goes to zero, and the garbage collector only 
kicks in case of circular references or other obscure circumstances. The 
documentation makes no reference to the specific Python implementation, 
so I believe this is true for CPython as well as others.

To be specific: Within the semantics of the Python documentation, 
freeing the resources used by an object by explicitly or implicitly 
using "del" is not garbage collection. Python garbage collection is like 
street cleaning in real life: If everybody looked after their own trash, 
we wouldn't need a municipal service to do it.

When I first read about the Python garbage collector I was puzzled at 
the possibility of disabling it, thinking that over time a long-running 
program would fill all memory because no object's resources would ever 
be freed. But that is clearly  not the case. Even Instagram can live 
without garbage collecton (although if you look how much garbage is on 
Instagram, maybe they should re-enable it):

https://instagram-engineering.com/dismissing-python-garbage-collection-at-instagram-4dca40b29172

> The (implementation independent) language semantics makes no assertion
> about what form of garbage collection is used, and under other garbage
> collectors, there can be an indefinite delay between the last
> reference to a value being lost and the object being collected (which
> is when __del__ gets called).

Only when there are circular references. Otherwise every Python 
implementation will delete objects once their refcount goes to zero, 
wven when there is no garbage collection at all, see the doc.

> There is not even a guarantee that CPython will retain the reference 
> counting GC in future versions.

There is no "reference counting GC" in Python. Freeing objects based on 
their reference count going to zero happens independently of the GC, see 
the official docs quoted above.



From rhodri at kynesim.co.uk  Wed Dec 11 09:42:14 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 11 Dec 2019 14:42:14 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <c50039a69f7b6e90250763136c99d9c8@posteo.de>
References: <qsp1hd$46m$1@gioia.aioe.org>
 <CACac1F-bjnUuTaZp1D67SQfLW+bv2bj0YhRxjnBDo9JDBEqtGA@mail.gmail.com>
 <c50039a69f7b6e90250763136c99d9c8@posteo.de>
Message-ID: <2fe5e0b1-1d37-9c42-158c-0c3d26f2ae16@kynesim.co.uk>

On 11/12/2019 14:17, Musbur wrote:
> Am 10.12.2019 22:33 schrieb Paul Moore:
> 
>> You do understand that the reference counting garbage collector is an
>> implementation detail of the CPython implementation *only*, don't you?
> 
> I don't think that's true. Here's a sentonce from near the top of the 
> "gc" module documentation of Python 3:
> https://docs.python.org/3/library/gc.html#module-gc
> 
> "Since the collector supplements the reference counting already used in 
> Python, you can disable the collector if you are sure your program does 
> not create reference cycles."
> 
> The way I read this is that Python automatically and immediately deletes 
> objects once their refcount goes to zero, and the garbage collector only 
> kicks in case of circular references or other obscure circumstances. The 
> documentation makes no reference to the specific Python implementation, 
> so I believe this is true for CPython as well as others.

That's a bug in the documentation, and needs fixing; thanks for pointing 
it out!  It is certainly true that some other Python implementations 
(Jython for example) do not use reference counting, and disabling the 
collector may have further-reaching implications for those 
implementations.  I can't speak to the details; the only other 
implementation I use is Micropython, and I don't use that often enough 
to have cared about the details of garbage collection beyond noting that 
it's different to CPython.

-- 
Rhodri James *-* Kynesim Ltd

From address at not.available  Wed Dec 11 09:50:51 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 15:50:51 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
Message-ID: <qsqvol$169q$1@gioia.aioe.org>

Greg,

> In CPython, these are the same thing. As soon as the reference
> count becomes zero, the __del__ method is called

That is what I assumed (the logical thing to do).

> *and* the object is removed from memory.

Which sounds reasonable too, especially in regard to the instances variables 
needing to be removed, which could possibly hold external references.

Than again, releasing those variables could have been done just after 
calling the __del__ method, with the releasing of the used memory and 
compacting done at a later point in time.   Multiple possibilities.

> But without reference counting, it has no way of
> *knowing* that it's the last reference until the garbage
> collector does its thing.

Blimy.  You've certainly got a point there.

> To demonstrate that with a code example, it would have to be run on a 
> different implementation of Python
> that didn't use reference counting, such as Jython.

I was rather clear about what my used version of Python was-and-is.  I have 
no idea why that was ignored. :-(

As a newbie I do not yet have much use for "it isn't true on version X on 
platform Y, so you're wrong" kind of replies.  Especially not when only the 
"you're wrong" part is posted ...

A question though: I have brought up that a delayed calling of the __del__ 
method could/would most likely cause race problems.  Do you have any idea 
how thats solved in environents like Jython ?

It looks to me that if you would want to have the (for example) file closed 
when you close the instance you would need to do quite a bit of manual 
keeping-track-of the instances.

Regards,
Rudy Wieser



From rosuav at gmail.com  Wed Dec 11 10:08:31 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 12 Dec 2019 02:08:31 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsqvol$169q$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
 <qsqvol$169q$1@gioia.aioe.org>
Message-ID: <CAPTjJmovsSJ-D=DCSdbAcNttiQLzS4TjwSFDR-mpONwDcNY0-Q@mail.gmail.com>

On Thu, Dec 12, 2019 at 1:56 AM R.Wieser <address at not.available> wrote:
> A question though: I have brought up that a delayed calling of the __del__
> method could/would most likely cause race problems.  Do you have any idea
> how thats solved in environents like Jython ?

Yes, we know exactly how that's solved, but you specifically said you
weren't interested in learning. In fact, the solution was posted very
early in this thread.

I think it's high time we all stopped feeding the troll.

ChrisA

From address at not.available  Wed Dec 11 10:17:31 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 16:17:31 +0100
Subject: Python3 - How do I import a class from another file
References: <qsp1hd$46m$1@gioia.aioe.org>
 <CACac1F-bjnUuTaZp1D67SQfLW+bv2bj0YhRxjnBDo9JDBEqtGA@mail.gmail.com>
 <mailman.39.1576013607.11485.python-list@python.org>
 <qsqm9q$1omv$1@gioia.aioe.org>
 <C6B51C07-E5FF-4A05-A6C9-2B656465D984@gmail.com>
 <mailman.45.1576070122.11485.python-list@python.org>
Message-ID: <qsr1ae$1etr$1@gioia.aioe.org>

Bev,

> You acknowledge that you are new to Python, yet you claimed
> to know better than Python experts. You claim you want an answer
> and yet you purposefully ignored their response because it didn't match
> what you wanted to hear.

No, I didn't.  I just pointed out that their position simply wasn't logical. 
I have given them plenty of opportunities to prove me wrong.  They refused 
to take them.

I've even /proven/ that what they claimed was incorrect by a bit of 
testcode.   It was just thrown off the table. :-(

And no, me not being right in version X on platform Y doesn't mean that you 
can claim I'm wrong everywhere.  Thats simply disingenious.

> I'm blocking all messages from you.

Thats your choice.

But if you where agreeing with all the "you are wrong!" chanters, without 
realizing that there are Python versions in which I'm actually right, and 
that one of those versions is the very one still visible in my subjectline 
than I'm not so sure you could/would be of any help with other problems I 
might have.

In other words, you might be doing me a favour. :-)

Regards,
Rudy Wieser



From paarjun234 at gmail.com  Wed Dec 11 07:47:59 2019
From: paarjun234 at gmail.com (Arjun pazhanikumar)
Date: Wed, 11 Dec 2019 18:17:59 +0530
Subject: Python3 - How do I import a class from another file
Message-ID: <rqmiqpljjhpfp8uu2y5ui4s4.1576068479005@email.android.com>

You could write the name of the class variable you want to import for example class manager

On December 10, 2019, at 2:46 AM, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

On Mon, 9 Dec 2019 20:21:39 +0100, "R.Wieser" <address at not.available>
declaimed the following:


>
>And than when the instance is deleted the binding to the class is lost, and 
>as a result it is garbage-collected.  Right ?
>
	Quite likely...


-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
	wlfraed at ix.netcom.com    http://wlfraed.microdiversity.freeddns.org/

-- 
https://mail.python.org/mailman/listinfo/python-list

From address at not.available  Wed Dec 11 10:46:01 2019
From: address at not.available (R.Wieser)
Date: Wed, 11 Dec 2019 16:46:01 +0100
Subject: Python3 - How do I import a class from another file
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
 <qsqvol$169q$1@gioia.aioe.org>
 <CAPTjJmovsSJ-D=DCSdbAcNttiQLzS4TjwSFDR-mpONwDcNY0-Q@mail.gmail.com>
 <mailman.48.1576076925.11485.python-list@python.org>
Message-ID: <qsr2vt$1od8$1@gioia.aioe.org>

Chris,

> Yes, we know exactly how that's solved,

Nice.

> but you specifically said you weren't interested in learning.

Try taking a few courses of "understanding what you read".  That is /not/ 
what I said.

Though it goes in par with your amadant "you're wrong" chanting, even if 
there is at least one Python implementation in which it is.   And you have 
been referred to here as being /the/ Python man, which makes it unlikely 
that you didn't know. :-(

Besides, if I would /not/ have wanted to learn, would I have put this much 
effort in trying to clarify my stance and create examples for it ?

> In fact, the solution was posted very early in this thread.

My apologies, I must have missed it.  Both that solution not having been 
relevant at that time as well as me-as-a-newbie not recognisning it for what 
it was could have played a role in it.. Can you quote at least a specific 
part of it ?    That way I can perhaps find it back and read it.

> I think it's high time we all stopped feeding the troll.

And I think its high time you take up a few courses of what it means to be 
teacher to newbies.   You seem to have lost the capability to put yourself 
into their shoes.

Regards,
Rudy Wieser



From musbur at posteo.org  Wed Dec 11 11:08:47 2019
From: musbur at posteo.org (Musbur)
Date: Wed, 11 Dec 2019 17:08:47 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <h5bt40Fe64mU1@mid.individual.net>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
Message-ID: <d638203932555876b6c0e41834221584@posteo.de>

Am 11.12.2019 11:01 schrieb Greg Ewing:
> On 11/12/19 7:47 am, R.Wieser wrote:
>> what happens when the reference becomes zero: is the __del__
>> method called directly (as I find logical), or is it only called when 
>> the
>> garbage collector actually removes the instance from memory (which 
>> Chris
>> thinks what happens) ?
> 
> In CPython, these are the same thing. As soon as the reference
> count becomes zero, the __del__ method is called

Yes

> *and* the object is removed from memory.

Not necessarily. Let's be more precise: The resources used by the object 
are handed back to memory management (marked as free for re-use).

> In a Python implementation that doesn't use reference counts,
> using "del" on the last reference to an object probably isn't
> going to do anything to the object.

It does exactly the same thing: It tells the memory management subsystem 
that the instance's resources may be re-used.



From musbur at posteo.org  Wed Dec 11 11:15:42 2019
From: musbur at posteo.org (Musbur)
Date: Wed, 11 Dec 2019 17:15:42 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsqh8m$1087$1@gioia.aioe.org>
References: <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <uqsvuedi6tvhnjo3urtt54eauf5vhbq0fb@4ax.com>
 <mailman.35.1576007779.11485.python-list@python.org>
 <qsqh8m$1087$1@gioia.aioe.org>
Message-ID: <683b2a9c636611ad0a0a399301dee24b@posteo.de>

Am 11.12.2019 11:22 schrieb R.Wieser:

> I think I will just go out on a limb and just assume that the __del__ 
> method
> /will/ be called as part of a "del instance" request causing the 
> reference
> count to reach zero (directly or indirectly), before the next command 
> is
> executed [...].

That's what I take the word "when" to mean in the documentation:
https://docs.python.org/3/reference/datamodel.html#object.__del__

"Note: del x doesn?t directly call x.__del__() ? the former decrements 
the reference count for x by one, and the latter is only called when x?s 
reference count reaches zero."



From ben.usenet at bsb.me.uk  Wed Dec 11 13:27:42 2019
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Wed, 11 Dec 2019 18:27:42 +0000
Subject: Extract all words between two keywords in .txt file (Python)
References: <e1285619-32f3-46f7-bf68-8da61d25782c@googlegroups.com>
Message-ID: <874ky6zpi9.fsf@bsb.me.uk>

A S <aishan0403 at gmail.com> writes:

> I would like to extract all words within specific keywords in a .txt
> file. For the keywords, there is a starting keyword of "PROC SQL;" (I
> need this to be case insensitive) and the ending keyword could be
> either "RUN;", "quit;" or "QUIT;". This is my sample .txt file.
>
> Thus far, this is my code:
>
> with open('lan sample text file1.txt') as file:
>     text = file.read()
>     regex = re.compile(r'(PROC SQL;|proc sql;(.*?)RUN;|quit;|QUIT;)')
>     k = regex.findall(text)
>     print(k)

Try

  re.compile(r'(?si)(PROC SQL;.*(?:QUIT|RUN);)')

Read up one what (?si) means and what (?:...) means..  You can do the
same by passing flags to the compile method.

> Output:
>
> [('quit;', ''), ('quit;', ''), ('PROC SQL;', '')]

Your main issue is that | binds weakly.  Your whole pattern tries to
match any one of just four short sub-patterns:

PROC SQL;
proc sql;(.*?)RUN;
quit;
QUIT;

-- 
Ben.

From roel at roelschroeven.net  Wed Dec 11 15:44:57 2019
From: roel at roelschroeven.net (Roel Schroeven)
Date: Wed, 11 Dec 2019 21:44:57 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsqh8n$1087$2@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <CAPTjJmpnBiDwqE33sbpeC8zV6oMkNzUM+Y5qO3P2x2C7Hw8unQ@mail.gmail.com>
 <mailman.6.1575982393.11485.python-list@python.org>
 <qsol7k$81m$1@gioia.aioe.org>
 <989e49d5-78d1-aa85-2b2a-aab809945724@kynesim.co.uk>
 <mailman.27.1576003497.11485.python-list@python.org>
 <qsorf0$16ej$1@gioia.aioe.org>
 <4680b0d1-fa26-abc9-d50d-dfc04018f498@mrabarnett.plus.com>
 <mailman.36.1576007875.11485.python-list@python.org>
 <qsqh8n$1087$2@gioia.aioe.org>
Message-ID: <qsrkg9$6dp$1@blaine.gmane.org>

R.Wieser schreef op 11/12/2019 om 11:43:> MRAB,
 >
 >>  From the help:
 > ...
 >> Do not depend on immediate finalization of objects when they become
 >> unreachable (so you should always close files explicitly).
 >
 > Do you notice there is not a single word about (the delayed action 
of) the
 > __del__ method in there ?  Why than do you think its talking about it ?
Hm wait. You're not mixing up del and __del__() here, do you? Calling 
del does not directly lead to __del__() being called. See 
https://docs.python.org/3/reference/datamodel.html?highlight=__del__#object.__del__

"Note: del x doesn?t directly call x.__del__() ? the former decrements 
the reference count for x by one, and the latter is only called when x?s 
reference count reaches zero."
 > You know how I read that ?   As if its talking about /variables going 
outof
 > scope/.   Makes sense ?    Thought so.  :-)
Not only going out of scope. Deleting references using del does the same 
thing.
 > Hmmm...  Maybe the __del__ method was created exactly to solve this late
 > handling of going-outof-scope variables.  What do you think ?
__del__ is not directly related to variables going out of scope, just as 
it is not directly related to the del statement. Going out of scope and 
del have one and only one direct effect: the reference count goes down. 
Once the reference count is zero, the object can be garbage collected. 
That is when __del__() is called.


 > And by the way: /when/ would you close those files explicitily ?
When you're done with them.

def count_lines(filename):
     f = open(filename, 'r')
     try:
         return sum(1 for line in f)
     finally:
         f.close()

Or better with with, making it easier to make sure the file is properly 
closed even in the case of exceptions:

def count_lines(filename):
     with open(filename, 'r') as f:
         return sum(1 for line in f)


HTH

-- 
"Honest criticism is hard to take, particularly from a relative, a
friend, an acquaintance, or a stranger."
         -- Franklin P. Jones

Roel Schroeven


From skip.montanaro at gmail.com  Wed Dec 11 15:51:42 2019
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Wed, 11 Dec 2019 14:51:42 -0600
Subject: datetime gotcha
In-Reply-To: <qsq776$4amq$1@blaine.gmane.org>
References: <qsq776$4amq$1@blaine.gmane.org>
Message-ID: <CANc-5Uy5HZ+RvxXM6brVsS1NyfQO=AYcn-Wvs73_haHLgn0T0g@mail.gmail.com>

> Why is a dtm instance also an instance of dt?

The datetime type is, in fact, a subclass of the date type:

>>> import datetime
>>> datetime.date.__bases__
(<class 'object'>,)
>>> datetime.datetime.__bases__
(<class 'datetime.date'>,)
>>> datetime.time.__bases__
(<class 'object'>,)

Skip

From joel.goldstick at gmail.com  Wed Dec 11 15:55:17 2019
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Wed, 11 Dec 2019 15:55:17 -0500
Subject: Extract all words between two keywords in .txt file (Python)
In-Reply-To: <874ky6zpi9.fsf@bsb.me.uk>
References: <e1285619-32f3-46f7-bf68-8da61d25782c@googlegroups.com>
 <874ky6zpi9.fsf@bsb.me.uk>
Message-ID: <CAPM-O+x-Tim3JPfAHcti0hiS4aAeR4vK0RLUugZzkBSoARPM=A@mail.gmail.com>

On Wed, Dec 11, 2019 at 1:31 PM Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
>
> A S <aishan0403 at gmail.com> writes:
>
> > I would like to extract all words within specific keywords in a .txt
> > file. For the keywords, there is a starting keyword of "PROC SQL;" (I
> > need this to be case insensitive) and the ending keyword could be
> > either "RUN;", "quit;" or "QUIT;". This is my sample .txt file.
> >
> > Thus far, this is my code:
> >
> > with open('lan sample text file1.txt') as file:
> >     text = file.read()
> >     regex = re.compile(r'(PROC SQL;|proc sql;(.*?)RUN;|quit;|QUIT;)')
> >     k = regex.findall(text)
> >     print(k)
>
> Try
>
>   re.compile(r'(?si)(PROC SQL;.*(?:QUIT|RUN);)')
>
> Read up one what (?si) means and what (?:...) means..  You can do the
> same by passing flags to the compile method.
>
> > Output:
> >
> > [('quit;', ''), ('quit;', ''), ('PROC SQL;', '')]
>
> Your main issue is that | binds weakly.  Your whole pattern tries to
> match any one of just four short sub-patterns:
>
> PROC SQL;
> proc sql;(.*?)RUN;
> quit;
> QUIT;
>
> --
> Ben.
> --
> https://mail.python.org/mailman/listinfo/python-list

Consider using python string functions.

1. read your string, lets call it s.
2 . start = s.find("PROC SQL:"
 This will find the starting index point.  It returns and index
3. DO the same for each of the three possible ending  strings.  Use if/else
4. This will give you your ending index.
5 slice the included string, taking into account the start is start +
len("PROC SQL;") and the end is the ending index - the length of
whichever string ended in your case

Regular expressions are powerful, but not so easy to read unless you
are really into them.
-- 
Joel Goldstick
http://joelgoldstick.com/blog
http://cc-baseballstats.info/stats/birthdays

From musbur at posteo.org  Wed Dec 11 16:32:46 2019
From: musbur at posteo.org (musbur at posteo.org)
Date: Wed, 11 Dec 2019 22:32:46 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <uqsvuedi6tvhnjo3urtt54eauf5vhbq0fb@4ax.com>
References: <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org>
 <uqsvuedi6tvhnjo3urtt54eauf5vhbq0fb@4ax.com>
Message-ID: <20191211223246.7b489fb0@nxp10225>

On Tue, 10 Dec 2019 14:56:10 -0500
Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

> 
> 	It is called when the language IMPLEMENTATION decides to call
> it. That time is not specified in the language description/reference
> manual.

Yes it is:

"Note: del x doesn?t directly call x.__del__() ? the former decrements 
the reference count for x by one, and the latter is only called when
x?s reference count reaches zero."

Plain and simple: When the refcount reaches zero. A few lines down,
however, it says:

> 	Any code that is based upon assuming memory reclamation takes
> place at any specific time (other than program exit) is erroneous. 

That is correct, but the decision when to reclaim memory is not made by
__del__ but by the memory management subsystem after (for instance, in
CPython) calls to PyMem_Free()

> 	Some implementations do not use a reference counter -- they
> rely solely upon a periodic mark&sweep garbage collector. cf:

Correct again, but the fray in this thread is about when __del__ is
called, not when memory reclaim takes place. Two different things.

From nad at python.org  Wed Dec 11 18:35:52 2019
From: nad at python.org (Ned Deily)
Date: Wed, 11 Dec 2019 18:35:52 -0500
Subject: [RELEASE] Python 3.7.6rc1 and 3.6.10rc1 are now available for testing
Message-ID: <658F0312-9E16-451A-A716-01EAEE3BD0B9@python.org>

Details here:

https://discuss.python.org/t/python-3-7-6rc1-and-3-6-10rc1-are-now-available-for-testing/2835

https://www.python.org/downloads/release/python-376rc1/
https://www.python.org/downloads/release/python-3610rc1/

--
  Ned Deily
  nad at python.org -- []


From greg.ewing at canterbury.ac.nz  Wed Dec 11 19:47:49 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Thu, 12 Dec 2019 13:47:49 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsqvol$169q$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
 <qsqvol$169q$1@gioia.aioe.org>
Message-ID: <h5dh1nFonb6U1@mid.individual.net>

On 12/12/19 3:50 am, R.Wieser wrote:
> I was rather clear about what my used version of Python was-and-is.  I have
> no idea why that was ignored. :-(

I think we've all been talking at cross purposes for a while.

What I meant to say originally was that you were relying on
an implementation detail of current CPython, and your code
might not work on other versions of Python. I was just
trying to make you aware of something that is considered
"best practice" when writing Python code, for your own
future reference.

However, you seem to have interpreted it as "this may not
work in current CPython". You were quite right to argue
against that, because it's false. But it didn't become
apparent that's what you were thinking until after quite
a lot of heated discussion.

The reason the discussion became heated is that instead of
saying "I don't understand", you said "I don't believe you".
This came across as arrogant and put everyone's back up.

> I have brought up that a delayed calling of the __del__
> method could/would most likely cause race problems.  Do you have any idea
> how thats solved in environents like Jython ?

You deal with it by not relying on __del__ for anything
that needs to be done promptly. There are always alternatives:
e.g. file objects have a close() method, and the "with"
statement was invented to make it easy to do these kinds
of things properly.

-- 
Greg

From python at python.invalid  Wed Dec 11 20:17:17 2019
From: python at python.invalid (Python)
Date: Thu, 12 Dec 2019 02:17:17 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <h5dh1nFonb6U1@mid.individual.net>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
 <qsqvol$169q$1@gioia.aioe.org> <h5dh1nFonb6U1@mid.individual.net>
Message-ID: <5df194be$0$6479$426a74cc@news.free.fr>

Greg Ewing wrote:
...
> You deal with it by not relying on __del__ for anything
> that needs to be done promptly. There are always alternatives:
> e.g. file objects have a close() method, and the "with"
> statement was invented to make it easy to do these kinds
> of things properly.

By the way, I was very impressed back in the day when the
with statement and context manager protocol appeared in
Python. I've always wondered from what language(s) it was
borrowed from (as most of good ideas in Python have been
borrowed, like comprehension from Haskell, and so on, which
is good).




From aishan0403 at gmail.com  Wed Dec 11 12:00:19 2019
From: aishan0403 at gmail.com (A S)
Date: Wed, 11 Dec 2019 09:00:19 -0800 (PST)
Subject: Extract all words between two keywords in .txt file (Python)
Message-ID: <e1285619-32f3-46f7-bf68-8da61d25782c@googlegroups.com>

I would like to extract all words within specific keywords in a .txt file. For the keywords, there is a starting keyword of "PROC SQL;" (I need this to be case insensitive) and the ending keyword could be either "RUN;", "quit;" or "QUIT;". This is my sample .txt file.

Thus far, this is my code:

with open('lan sample text file1.txt') as file:
    text = file.read()
    regex = re.compile(r'(PROC SQL;|proc sql;(.*?)RUN;|quit;|QUIT;)')
    k = regex.findall(text)
    print(k)


Output:

[('quit;', ''), ('quit;', ''), ('PROC SQL;', '')]

However, my intended output is to get the words in between and inclusive of the keywords:

proc sql; ("TRUuuuth");
hhhjhfjs as fdsjfsj:
select * from djfkjd to jfkjs
(
SELECT abc AS abc1, abc_2_ AS efg, abc_fg, fkdkfj_vv, jjsflkl_ff, fjkdsf_jfkj
    FROM &xxx..xxx_xxx_xxE
where ((xxx(xx_ix as format 'xxxx-xx') gff &jfjfsj_jfjfj.) and 
      (xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv.))
 );

1)

jjjjjj;

  select xx("xE'", PUT(xx.xxxx.),"'") jdfjhf:jhfjj from xxxx_x_xx_L ;
quit; 

PROC SQL; ("CUuuiiiiuth");
hhhjhfjs as fdsjfsj:
select * from djfkjd to jfkjs
(SELECT abc AS abc1, abc_2_ AS efg, abc_fg, fkdkfj_vv, jjsflkl_ff, fjkdsf_jfkj
    FROM &xxx..xxx_xxx_xxE
where ((xxx(xx_ix as format 'xxxx-xx') gff &jfjfsj_jfjfj.) and 
      (xxx(xx_ix as format 'xxxx-xx') lec &jgjsd_vnv.))(( ))
 );

2)(

RUN;


__________________________________________________________
Any advice or different ways to go about this would be greatly appreciated!

From dhaude at posteo.de  Wed Dec 11 11:53:16 2019
From: dhaude at posteo.de (Daniel Haude)
Date: Wed, 11 Dec 2019 17:53:16 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <CAPTjJmpt7xTATuAy6gMiLE12oZZW8BxNT0-UanDQa3+OOtqOJw@mail.gmail.com>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <qsorn0$69t$1@blaine.gmane.org>
 <mailman.34.1576006185.11485.python-list@python.org>
 <qsp2ev$8jr$1@gioia.aioe.org>
 <CAPTjJmpt7xTATuAy6gMiLE12oZZW8BxNT0-UanDQa3+OOtqOJw@mail.gmail.com>
Message-ID: <38a473a9321896b4038f1636f35ec5bc@posteo.de>

Am 10.12.2019 22:29 schrieb Chris Angelico:

> And once again, you are maintaining your assumptions despite being
> very clearly shown that they are wrong. "del instance" does not
> directly call __del__ any more than "instance = 1" does. You HAVE been
> shown.

Much of the confusion in this thread comes from the murky distinction 
between "garbage collection" and "memory management." I wouldn't call a 
reference-counting system "garbage collection" per se.

Another bone of contention seems to be the question exactly WHEN 
reference counting and/or garbage collection release an object's 
resources (give it back to memory management). I read the word "when" in 
the non-implementation-specific Python docs as "immediately upon" (quote 
below, caps by me):

"Note: del x doesn?t directly call x.__del__() ? the former decrements 
the reference count for x by one, and the latter is only called WHEN x?s 
reference count reaches zero."

It is then up to Python's memory management (PyMem_Alloc et al in 
CPython) what to do, and when: Give it back to the OS, keep it around 
for later use, whatever.


From musbur at posteo.de  Wed Dec 11 12:14:23 2019
From: musbur at posteo.de (musbur at posteo.de)
Date: Wed, 11 Dec 2019 18:14:23 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsp1hd$46m$1@gioia.aioe.org>
References: <qsp1hd$46m$1@gioia.aioe.org>
Message-ID: <20191211181423.70fa29b4@nxp10225>

On Tue, 10 Dec 2019 22:08:48 +0100
"R.Wieser" <address at not.available> wrote:

> And although you have been fighting me over when the __del__ method is
> called, it /is/ called directly as a result of an "del instance" and
> the refcount goes zero.  There is /no/ delay.    (with the only
> exception is when a circular reference exists).
> 
> Hence, no "race condition" problem.

Under what circumstances would freeing memory in an unspecified order
gerenate race conditions (except when freeing an unused chunk of
memory too late would cause the system to run out of memory)?

Genuinely interested, not loooking for a fight.

From aishan0403 at gmail.com  Wed Dec 11 21:45:20 2019
From: aishan0403 at gmail.com (A S)
Date: Wed, 11 Dec 2019 18:45:20 -0800 (PST)
Subject: Extract all words between two keywords in .txt file (Python)
In-Reply-To: <874ky6zpi9.fsf@bsb.me.uk>
References: <e1285619-32f3-46f7-bf68-8da61d25782c@googlegroups.com>
 <874ky6zpi9.fsf@bsb.me.uk>
Message-ID: <14473d47-81f8-466c-933b-71022da2dec3@googlegroups.com>

On Thursday, 12 December 2019 02:28:09 UTC+8, Ben Bacarisse  wrote:
> A S <aishan0403 at gmail.com> writes:
> 
> > I would like to extract all words within specific keywords in a .txt
> > file. For the keywords, there is a starting keyword of "PROC SQL;" (I
> > need this to be case insensitive) and the ending keyword could be
> > either "RUN;", "quit;" or "QUIT;". This is my sample .txt file.
> >
> > Thus far, this is my code:
> >
> > with open('lan sample text file1.txt') as file:
> >     text = file.read()
> >     regex = re.compile(r'(PROC SQL;|proc sql;(.*?)RUN;|quit;|QUIT;)')
> >     k = regex.findall(text)
> >     print(k)
> 
> Try
> 
>   re.compile(r'(?si)(PROC SQL;.*(?:QUIT|RUN);)')
> 
> Read up one what (?si) means and what (?:...) means..  You can do the
> same by passing flags to the compile method.
> 
> > Output:
> >
> > [('quit;', ''), ('quit;', ''), ('PROC SQL;', '')]
> 
> Your main issue is that | binds weakly.  Your whole pattern tries to
> match any one of just four short sub-patterns:
> 
> PROC SQL;
> proc sql;(.*?)RUN;
> quit;
> QUIT;
> 
> -- 
> Ben.

Hey Ben, this works for my sample .txt file! Thanks:) but it wont work, if I have other multiple text files to parse through that, are similar but have some variations, strangely enough. 

From aishan0403 at gmail.com  Wed Dec 11 21:46:31 2019
From: aishan0403 at gmail.com (A S)
Date: Wed, 11 Dec 2019 18:46:31 -0800 (PST)
Subject: Extract all words between two keywords in .txt file (Python)
In-Reply-To: <mailman.54.1576097731.11485.python-list@python.org>
References: <e1285619-32f3-46f7-bf68-8da61d25782c@googlegroups.com>
 <874ky6zpi9.fsf@bsb.me.uk>
 <CAPM-O+x-Tim3JPfAHcti0hiS4aAeR4vK0RLUugZzkBSoARPM=A@mail.gmail.com>
 <mailman.54.1576097731.11485.python-list@python.org>
Message-ID: <09093dab-1c12-46b7-851c-04e2dfb1b600@googlegroups.com>

On Thursday, 12 December 2019 04:55:46 UTC+8, Joel Goldstick  wrote:
> On Wed, Dec 11, 2019 at 1:31 PM Ben Bacarisse <ben.usenet at bsb.me.uk> wrote:
> >
> > A S <aishan0403 at gmail.com> writes:
> >
> > > I would like to extract all words within specific keywords in a .txt
> > > file. For the keywords, there is a starting keyword of "PROC SQL;" (I
> > > need this to be case insensitive) and the ending keyword could be
> > > either "RUN;", "quit;" or "QUIT;". This is my sample .txt file.
> > >
> > > Thus far, this is my code:
> > >
> > > with open('lan sample text file1.txt') as file:
> > >     text = file.read()
> > >     regex = re.compile(r'(PROC SQL;|proc sql;(.*?)RUN;|quit;|QUIT;)')
> > >     k = regex.findall(text)
> > >     print(k)
> >
> > Try
> >
> >   re.compile(r'(?si)(PROC SQL;.*(?:QUIT|RUN);)')
> >
> > Read up one what (?si) means and what (?:...) means..  You can do the
> > same by passing flags to the compile method.
> >
> > > Output:
> > >
> > > [('quit;', ''), ('quit;', ''), ('PROC SQL;', '')]
> >
> > Your main issue is that | binds weakly.  Your whole pattern tries to
> > match any one of just four short sub-patterns:
> >
> > PROC SQL;
> > proc sql;(.*?)RUN;
> > quit;
> > QUIT;
> >
> > --
> > Ben.
> > --
> > https://mail.python.org/mailman/listinfo/python-list
> 
> Consider using python string functions.
> 
> 1. read your string, lets call it s.
> 2 . start = s.find("PROC SQL:"
>  This will find the starting index point.  It returns and index
> 3. DO the same for each of the three possible ending  strings.  Use if/else
> 4. This will give you your ending index.
> 5 slice the included string, taking into account the start is start +
> len("PROC SQL;") and the end is the ending index - the length of
> whichever string ended in your case
> 
> Regular expressions are powerful, but not so easy to read unless you
> are really into them.
> -- 
> Joel Goldstick
> http://joelgoldstick.com/blog
> http://cc-baseballstats.info/stats/birthdays

Hey Joel, not too sure if i get the idea of your code implementation

From greg.ewing at canterbury.ac.nz  Thu Dec 12 01:07:14 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Thu, 12 Dec 2019 19:07:14 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <5df194be$0$6479$426a74cc@news.free.fr>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
 <qsqvol$169q$1@gioia.aioe.org> <h5dh1nFonb6U1@mid.individual.net>
 <5df194be$0$6479$426a74cc@news.free.fr>
Message-ID: <h5e3okFs860U1@mid.individual.net>

On 12/12/19 2:17 pm, Python wrote:
> I was very impressed back in the day when the
> with statement and context manager protocol appeared in
> Python. I've always wondered from what language(s) it was
> borrowed from

It was partly inspired by the RAII pattern often used
in C++, but as far as I know, all the details are unique
to Python. Some other languages have a "with" statement,
but it does something completely different.

-- 
Greg

From rosuav at gmail.com  Thu Dec 12 01:18:20 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 12 Dec 2019 17:18:20 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <38a473a9321896b4038f1636f35ec5bc@posteo.de>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <qsorn0$69t$1@blaine.gmane.org>
 <mailman.34.1576006185.11485.python-list@python.org>
 <qsp2ev$8jr$1@gioia.aioe.org>
 <CAPTjJmpt7xTATuAy6gMiLE12oZZW8BxNT0-UanDQa3+OOtqOJw@mail.gmail.com>
 <38a473a9321896b4038f1636f35ec5bc@posteo.de>
Message-ID: <CAPTjJmoGYESMFL92paKitkMugvwp4aEesSd2JbGqmibo+URQCw@mail.gmail.com>

On Thu, Dec 12, 2019 at 1:33 PM Daniel Haude <dhaude at posteo.de> wrote:
>
> Am 10.12.2019 22:29 schrieb Chris Angelico:
>
> > And once again, you are maintaining your assumptions despite being
> > very clearly shown that they are wrong. "del instance" does not
> > directly call __del__ any more than "instance = 1" does. You HAVE been
> > shown.
>
> Much of the confusion in this thread comes from the murky distinction
> between "garbage collection" and "memory management." I wouldn't call a
> reference-counting system "garbage collection" per se.

https://en.wikipedia.org/wiki/Garbage_collection_(computer_science)#Reference_counting

It's definitely garbage collection. The alternative to a GC is
explicitly choosing to free something, which is what usually happens
when you program in C.

> Another bone of contention seems to be the question exactly WHEN
> reference counting and/or garbage collection release an object's
> resources (give it back to memory management). I read the word "when" in
> the non-implementation-specific Python docs as "immediately upon" (quote
> below, caps by me):
>
> "Note: del x doesn?t directly call x.__del__() ? the former decrements
> the reference count for x by one, and the latter is only called WHEN x?s
> reference count reaches zero."
>
> It is then up to Python's memory management (PyMem_Alloc et al in
> CPython) what to do, and when: Give it back to the OS, keep it around
> for later use, whatever.

The most important distinction, which that note is emphasizing, is
that the "del" statement removes just one reference, and if there are
other references, then __del__ will not be called. None of this is
about memory per se, but about objects; Python (the language) doesn't
say anything about memory, but CPython (the implementation) does. So,
for instance, *any* conformant Python implementation will have the
semantics that "a = Thing(); b = a; del a" will not call
Thing.__del__, because that thing still exists; but once all
references expire, a conformant implementation is allowed to hand
memory back to the OS immediately, or to manage its own memory pages
and only hand those back when they're empty, or even to just not
relinquish memory at all (granted, that would almost certainly be
suboptimal, but it's not violating Python's semantics).

We've been talking about garbage collection at the level of objects.
When is an object disposed of? In CPython, this happens when its
reference count hits zero, either naturally or when the cycle detector
breaks a cycle. In Jython, I'm not sure, and I think it's based on the
underlying Java interpreter's garbage collector. In a hypothetical but
fully-conformant Python implementation, there could be a
stop-the-world mark-and-sweep GC that runs every time a function
returns, or every 250 bytecode instructions, or something. None of
this cares about actual memory or when it gets returned to the system;
it's all about when objects get destroyed. And regardless of the GC
implementation, "del x" has the same effect as "x = None" as regards
the previous value in x: they both just remove one reference.

ChrisA

From ben.usenet at bsb.me.uk  Thu Dec 12 07:40:24 2019
From: ben.usenet at bsb.me.uk (Ben Bacarisse)
Date: Thu, 12 Dec 2019 12:40:24 +0000
Subject: Extract all words between two keywords in .txt file (Python)
References: <e1285619-32f3-46f7-bf68-8da61d25782c@googlegroups.com>
 <874ky6zpi9.fsf@bsb.me.uk>
 <14473d47-81f8-466c-933b-71022da2dec3@googlegroups.com>
Message-ID: <87y2vhyax3.fsf@bsb.me.uk>

A S <aishan0403 at gmail.com> writes:

> On Thursday, 12 December 2019 02:28:09 UTC+8, Ben Bacarisse  wrote:
>> A S <aishan0403 at gmail.com> writes:
>> 
>> > I would like to extract all words within specific keywords in a .txt
>> > file. For the keywords, there is a starting keyword of "PROC SQL;" (I
>> > need this to be case insensitive) and the ending keyword could be
>> > either "RUN;", "quit;" or "QUIT;". This is my sample .txt file.
>> >
>> > Thus far, this is my code:
>> >
>> > with open('lan sample text file1.txt') as file:
>> >     text = file.read()
>> >     regex = re.compile(r'(PROC SQL;|proc sql;(.*?)RUN;|quit;|QUIT;)')
>> >     k = regex.findall(text)
>> >     print(k)
>> 
>> Try
>> 
>>   re.compile(r'(?si)(PROC SQL;.*(?:QUIT|RUN);)')
<cut> 
>
> Hey Ben, this works for my sample .txt file! Thanks:) but it wont
> work, if I have other multiple text files to parse through that, are
> similar but have some variations, strangely enough.

No one can help without details.  Maybe need the non-greedy .*? rather
than the .* I put in there.  That was not a deliberate change.

-- 
Ben.

From rhodri at kynesim.co.uk  Thu Dec 12 06:33:25 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 12 Dec 2019 11:33:25 +0000
Subject: Python3 - How do I import a class from another file
In-Reply-To: <20191211223246.7b489fb0@nxp10225>
References: <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <uqsvuedi6tvhnjo3urtt54eauf5vhbq0fb@4ax.com>
 <20191211223246.7b489fb0@nxp10225>
Message-ID: <75110727-8c39-9f82-62ed-7e876eb4386f@kynesim.co.uk>

On 11/12/2019 21:32, musbur at posteo.org wrote:
> On Tue, 10 Dec 2019 14:56:10 -0500
> Dennis Lee Bieber<wlfraed at ix.netcom.com>  wrote:
> 
>> 	It is called when the language IMPLEMENTATION decides to call
>> it. That time is not specified in the language description/reference
>> manual.
> Yes it is:
> 
> "Note: del x doesn?t directly call x.__del__() ? the former decrements
> the reference count for x by one, and the latter is only called when
> x?s reference count reaches zero."
> 
> Plain and simple: When the refcount reaches zero.
You are assuming that "when" implies "immediately on the occurence."  It 
doesn't.  This happens to be the behaviour in CPython, but other 
implementations vary as Chris has explained several times now.

-- 
Rhodri James *-* Kynesim Ltd

From musbur at posteo.org  Thu Dec 12 10:48:09 2019
From: musbur at posteo.org (Musbur)
Date: Thu, 12 Dec 2019 16:48:09 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <CAPTjJmoGYESMFL92paKitkMugvwp4aEesSd2JbGqmibo+URQCw@mail.gmail.com>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org> <qsorn0$69t$1@blaine.gmane.org>
 <mailman.34.1576006185.11485.python-list@python.org>
 <qsp2ev$8jr$1@gioia.aioe.org>
 <CAPTjJmpt7xTATuAy6gMiLE12oZZW8BxNT0-UanDQa3+OOtqOJw@mail.gmail.com>
 <38a473a9321896b4038f1636f35ec5bc@posteo.de>
 <CAPTjJmoGYESMFL92paKitkMugvwp4aEesSd2JbGqmibo+URQCw@mail.gmail.com>
Message-ID: <5ba879a785121064f1a00d326e8e7289@posteo.de>

Hi Chris,

> The most important distinction, which that note is emphasizing, is
> that the "del" statement removes just one reference, and if there are
> other references, then __del__ will not be called.

No argument there, that's how reference counting works, and it's clear 
from the docs. What is not clear from the documentation is not if or why 
or how but *when* the __del__ method is eventually called. The doc says: 
"when [an object's] reference count reaches zero." Initially I read that 
to mean "immediately upon the reference count hitting zero," but a 
couple paragraphs down we find this: "In particular:  __del__() can be 
invoked when arbitrary code is being executed, including from any 
arbitrary thread. [...]"

I used to believe that the __del__ method was called immediately after 
refcount = zero, and that only the memory management system's functions 
(typically called from __del__) could take their time doing their 
things. Not true, it seems: Calling __del__() can be deferred, and 
PyMem_Free() et. al. migh not immediately "do"  anything as well.

I've come to see the __del__ method as a tool to get rid of an object 
(and its resources) which can be used by the Python interpreter at its 
own discretion when and if it feels the need to do so, which may be 
anything between immediately after ob_refcnt == 0 and not at all. That 
said, I can't think of any reason to explicitly define __del__() in a 
pure Python class. Do you have an example?

From karthik.sharma at gmail.com  Thu Dec 12 08:47:32 2019
From: karthik.sharma at gmail.com (Karthik Sharma)
Date: Thu, 12 Dec 2019 21:47:32 +0800
Subject: Transfer a file to httpserver via POST command from curl
Message-ID: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>

I have written a python server app (actually copied from somewhere) using
Flask, that I want to act as a http server. I expect this server to recieve
a POST command (of a file) from CURL and save that file on the server. And
I should be able to download that file when required.

My python scripts are shown below.

app.py



from flask import Flask

UPLOAD_FOLDER = 'home/user/uploads'

app = Flask(__name__)
#app.secret_key = "secret key"
app.config['UPLOAD_FOLDER'] = UPLOAD_FOLDER
app.config['MAX_CONTENT_LENGTH'] = 16 * 1024 * 1024


main.py


import os
import urllib.request
from app import app
from flask import Flask, request, redirect, jsonify
from werkzeug.utils import secure_filename


ALLOWED_EXTENSIONS = set(['txt', 'pdf', 'png', 'jpg', 'jpeg', 'gif'])


def allowed_file(filename):
 return '.' in filename and filename.rsplit('.', 1)[1].lower() in
 ALLOWED_EXTENSIONS


@app.route('/file-upload', methods=['POST'])
def upload_file():
 # check if the post request has the file part
 if 'file' not in request.files:
 resp = jsonify({'message' : 'No file part in the request'})
 resp.status_code = 400
 return resp
 file = request.files['file']
 if file.filename == '':
 resp = jsonify({'message' : 'No file selected for uploading'})
 resp.status_code = 400
 return resp
 if file and allowed_file(file.filename):
 filename = secure_filename(file.filename)
 file.save(os.path.join(app.config['UPLOAD_FOLDER'], filename))
 resp = jsonify({'message' : 'File successfully uploaded'})
 resp.status_code = 201
 return resp
 else:
 resp = jsonify({'message' : 'Allowed file types are txt, pdf, png, jpg,
jpeg, gif'})
 resp.status_code = 400
 return resp


if __name__ == "__main__":
    app.run()

I am doing a POST using curl as follows.

curl -X POST --data-binary @/home/user/testfile.txt http://
127.0.0.1:5000/file-upload

Is it really possible to transfer a large binary file from my machine to
the above httpserver via POST command and download it again? If yes, is the
above Flask app enough for that and what am I doing wrong?

Kindly Reply,
Regards,
Karthik.


I am getting 400 Bad Request error from the server. I am new to Flask.
What am I doing wrong. Is it possible to transfer a binary file
(large) from my computer to the above http server via POST command.?
For that purpose is my above code enought? What am I doing wrong?

From miteshp at live.com  Thu Dec 12 10:33:11 2019
From: miteshp at live.com (Mitesh Patel)
Date: Thu, 12 Dec 2019 15:33:11 +0000
Subject: mysqlclient==1.4.6 none wheel doesn't work on ubuntu 18
Message-ID: <BY5PR07MB716049FEA82ACE1C61117BF3DD550@BY5PR07MB7160.namprd07.prod.outlook.com>

I?m using pantsbuild to create a pex with SQLAlchemy==1.3.11 and mysqlclient==1.4.6. I?m going to run the pex on ubuntu 14 trusty and ubuntu 18 bionic.

To first build the wheel, I went to each ubuntu machine and ran this:

pip wheel ?no-cache-dir ?wheel-dir=./ mysqlclient==1.4.6

On the trusty machine, it created https://s3.amazonaws.com/aiq-public/ubuntu14/index.html. However on the bionic machine it created https://s3.amazonaws.com/aiq-public/ubuntu18/index.html.

I was very confused, but I just kept the ?none? wheel since that should be OS independent. I built the pex locally on each box, and it worked fine on trusty, however on bionic I saw this error:

  File "/home/ubuntu/.pex/install/SQLAlchemy-1.0.11-cp27-none-linux_x86_64.whl.2ad4de6e38cfa6e6073ca829b9a827ab4c9a46d8/SQLAlchemy-1.0.11-cp27-none-linux_x86_64.whl/sqlalchemy/engine/strategies.py", line 75, in create
    dbapi = dialect_cls.dbapi(**dbapi_args)
  File "/home/ubuntu/.pex/install/SQLAlchemy-1.0.11-cp27-none-linux_x86_64.whl.2ad4de6e38cfa6e6073ca829b9a827ab4c9a46d8/SQLAlchemy-1.0.11-cp27-none-linux_x86_64.whl/sqlalchemy/dialects/mysql/mysqldb.py", line 92, in dbapi

return __import__('MySQLdb')
  File "/home/ubuntu/.pex/install//mysqlclient-1.4.6-cp27-none-linux_x86_64.whl/MySQLdb/__init__.py", line 19, in <module>

import _mysql
ImportError: libmysqlclient.so.18: cannot open shared object file: No such file or directory

That seemed very strange to me, so then I changed the bionic build to point to the os-specific wheel, and then it started working.

Is there some reason the ?none? wheel does not work on bionic? Somehow it seemed to be picking up the wrong libmysqlclient library? Note I have ?libmysqlclient.so? installed on both trusty (mysql 5.6) and bionic (mysql 5.7). They are different versions, but I didn?t think it mattered, if using a ?none? wheel then it should build on the box using whatever libraries the OS has, right?

Thanks.
?
Mitesh

From rosuav at gmail.com  Thu Dec 12 11:54:53 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 13 Dec 2019 03:54:53 +1100
Subject: Transfer a file to httpserver via POST command from curl
In-Reply-To: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
References: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
Message-ID: <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>

On Fri, Dec 13, 2019 at 3:44 AM Karthik Sharma <karthik.sharma at gmail.com> wrote:
> I am doing a POST using curl as follows.
>
> curl -X POST --data-binary @/home/user/testfile.txt http://
> 127.0.0.1:5000/file-upload
>
> Is it really possible to transfer a large binary file from my machine to
> the above httpserver via POST command and download it again? If yes, is the
> above Flask app enough for that and what am I doing wrong?

I think your Flask code is okay (haven't checked in detail, but at
first glance it looks fine), but for file uploads to be recognized in
request.files, you'll need to change the way you run curl.

Try this:

curl -F 'file=@/home/user/testfile.txt' http://127.0.0.1:5000/file-upload

The word "file" in there ends up as the key in request.files (so if
you used "spam=", you'd get request.files["spam"]), and you can add
other form data as well if you choose.

ChrisA

From cat3morris at gmail.com  Thu Dec 12 19:40:32 2019
From: cat3morris at gmail.com (catherine morris)
Date: Thu, 12 Dec 2019 18:40:32 -0600
Subject: Troubleshooting
Message-ID: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>

Good evening,

My son is trying to download python 3.8.0 on my PC, which has Windows 10,
and it won't install properly. I'm not tech savvy and have no idea where to
start.

Catherine Morris

From torriem at gmail.com  Thu Dec 12 20:37:01 2019
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 12 Dec 2019 18:37:01 -0700
Subject: Troubleshooting
In-Reply-To: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
References: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
Message-ID: <cecb8190-f4e3-0dd7-27b5-5bbc7974fc5a@gmail.com>

On 12/12/19 5:40 PM, catherine morris wrote:
> Good evening,
> 
> My son is trying to download python 3.8.0 on my PC, which has Windows 10,
> and it won't install properly. I'm not tech savvy and have no idea where to
> start.
> 
> Catherine Morris

I just learned today that Python is officially available in the
Microsoft Store app in Windows 10.  If you run the Windows Store and
search for Python, you should find Python 3.8.0 and it will be listed as
free.  Click install (if it asks you to log in, click no thanks).  After
it downloads and installs you should find "Idle" in the start menu,
which is probably where your son will want to start.  Idle is a code
editor and and an environment in which to run the python programs.  See
this url for an introduction to Idle.  https://realpython.com/python-idle/

Hope this helps!

Michael


From python at python.invalid  Thu Dec 12 20:33:52 2019
From: python at python.invalid (Python)
Date: Fri, 13 Dec 2019 02:33:52 +0100
Subject: Troubleshooting
In-Reply-To: <mailman.66.1576198300.11485.python-list@python.org>
References: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
 <mailman.66.1576198300.11485.python-list@python.org>
Message-ID: <5df2ea1b$0$10381$426a74cc@news.free.fr>

catherine morris wrote:
> Good evening,
> 
> My son is trying to download python 3.8.0 on my PC, which has Windows 10,
> and it won't install properly. I'm not tech savvy and have no idea where to
> start.

What happened exactly? Did you download the official installer from
python.org, then click on next, next, next, checking the box (if it's
still there about updating PATH)? There is nothing more to do.



From torriem at gmail.com  Thu Dec 12 21:53:19 2019
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 12 Dec 2019 19:53:19 -0700
Subject: Troubleshooting
In-Reply-To: <5df2ea1b$0$10381$426a74cc@news.free.fr>
References: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
 <mailman.66.1576198300.11485.python-list@python.org>
 <5df2ea1b$0$10381$426a74cc@news.free.fr>
Message-ID: <e5b15f4e-dacf-6037-d3f4-675e71092619@gmail.com>

On 12/12/19 6:33 PM, Python wrote:
> catherine morris wrote:
>> Good evening,
>>
>> My son is trying to download python 3.8.0 on my PC, which has Windows 10,
>> and it won't install properly. I'm not tech savvy and have no idea where to
>> start.
> 
> What happened exactly? Did you download the official installer from
> python.org, then click on next, next, next, checking the box (if it's
> still there about updating PATH)? There is nothing more to do.

I communicated more with the original poster off list and will try to
relate what is happening here.  This type of thing I've never
encountered before and is hard to describe in just plain text,
especially for a non-technical person.  Essentially trying to launch the
official, downloaded installer from Python.org causes a message to pop
up warning about installing third-party applications and opens the
Microsoft Store and apparently points at the Python installation there.
Unfortunately installing through the store fails for some reason.

I've seen github bug reports about Windows launching the store when
trying to run Python, but those appear to be after a successful
installation, and the solution there is making sure the installed
version of Python is set in the $PATH.  It's possible this is the issue
here.  If so she'll have to get someone locally to take a look at her
machine. Not sure about talking her through debugging the PATH.

Another possibility is that she's running a laptop with Windows 10S,
which limits what can be installed. That would explain why the Windows
Store installation fails.  But I don't know.

Just when I think Windows 10 is a pretty decent system, I encounter
something inexplicable like this.

From python at python.invalid  Thu Dec 12 22:03:45 2019
From: python at python.invalid (Python)
Date: Fri, 13 Dec 2019 04:03:45 +0100
Subject: Troubleshooting
In-Reply-To: <mailman.68.1576205679.11485.python-list@python.org>
References: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
 <mailman.66.1576198300.11485.python-list@python.org>
 <5df2ea1b$0$10381$426a74cc@news.free.fr>
 <e5b15f4e-dacf-6037-d3f4-675e71092619@gmail.com>
 <mailman.68.1576205679.11485.python-list@python.org>
Message-ID: <5df2ff2c$0$20324$426a74cc@news.free.fr>

Le 13/12/2019 ? 03:53, Michael Torrie a ?crit?:
> On 12/12/19 6:33 PM, Python wrote:
>> catherine morris wrote:
>>> Good evening,
>>>
>>> My son is trying to download python 3.8.0 on my PC, which has Windows 10,
>>> and it won't install properly. I'm not tech savvy and have no idea where to
>>> start.
>>
>> What happened exactly? Did you download the official installer from
>> python.org, then click on next, next, next, checking the box (if it's
>> still there about updating PATH)? There is nothing more to do.
> 
> I communicated more with the original poster off list and will try to
> relate what is happening here.  This type of thing I've never
> encountered before and is hard to describe in just plain text,
> especially for a non-technical person.  Essentially trying to launch the
> official, downloaded installer from Python.org causes a message to pop
> up warning about installing third-party applications and opens the
> Microsoft Store and apparently points at the Python installation there.
> Unfortunately installing through the store fails for some reason.
> 
> I've seen github bug reports about Windows launching the store when
> trying to run Python, but those appear to be after a successful
> installation, and the solution there is making sure the installed
> version of Python is set in the $PATH.  It's possible this is the issue
> here.  If so she'll have to get someone locally to take a look at her
> machine. Not sure about talking her through debugging the PATH.
> 
> Another possibility is that she's running a laptop with Windows 10S,
> which limits what can be installed. That would explain why the Windows
> Store installation fails.  But I don't know.

Oh dear...

> Just when I think Windows 10 is a pretty decent system, I encounter
> something inexplicable like this.

We've gone through that before, haven't we?




From torriem at gmail.com  Thu Dec 12 23:04:21 2019
From: torriem at gmail.com (Michael Torrie)
Date: Thu, 12 Dec 2019 21:04:21 -0700
Subject: Troubleshooting
In-Reply-To: <5df2ff2c$0$20324$426a74cc@news.free.fr>
References: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
 <mailman.66.1576198300.11485.python-list@python.org>
 <5df2ea1b$0$10381$426a74cc@news.free.fr>
 <e5b15f4e-dacf-6037-d3f4-675e71092619@gmail.com>
 <mailman.68.1576205679.11485.python-list@python.org>
 <5df2ff2c$0$20324$426a74cc@news.free.fr>
Message-ID: <240f922d-b2eb-31de-0904-1518cc567927@gmail.com>

On 12/12/19 8:03 PM, Python wrote:
>> Just when I think Windows 10 is a pretty decent system, I encounter
>> something inexplicable like this.
> 
> We've gone through that before, haven't we?

Yup, Several times.  The good news is her son finally got it installed
by launching the installer from explorer.  So must have been some stupid
MS Edge thing interfering with running the installer. Trying to be
intelligent I'm sure.

From frank at chagford.com  Fri Dec 13 00:21:48 2019
From: frank at chagford.com (Frank Millman)
Date: Fri, 13 Dec 2019 07:21:48 +0200
Subject: datetime gotcha
In-Reply-To: <CANc-5Uy5HZ+RvxXM6brVsS1NyfQO=AYcn-Wvs73_haHLgn0T0g@mail.gmail.com>
References: <qsq776$4amq$1@blaine.gmane.org>
 <CANc-5Uy5HZ+RvxXM6brVsS1NyfQO=AYcn-Wvs73_haHLgn0T0g@mail.gmail.com>
Message-ID: <ea700581-8659-8fd1-8633-c9ab4ac2f456@chagford.com>

On 2019-12-11 10:51 PM, Skip Montanaro wrote:
>> Why is a dtm instance also an instance of dt?
> 
> The datetime type is, in fact, a subclass of the date type:
> 
>>>> import datetime
>>>> datetime.date.__bases__
> (<class 'object'>,)
>>>> datetime.datetime.__bases__
> (<class 'datetime.date'>,)
>>>> datetime.time.__bases__
> (<class 'object'>,)
> 
> Skip
> 

Thanks for that.

I found a workaround.

 >>> from datetime import date as dt, datetime as dtm
 >>> type(dtm.now()) is dtm
True
 >>> type(dtm.now()) is dt
False
 >>>

I will run with this.

Frank



From frank at chagford.com  Fri Dec 13 00:21:48 2019
From: frank at chagford.com (Frank Millman)
Date: Fri, 13 Dec 2019 07:21:48 +0200
Subject: datetime gotcha
In-Reply-To: <CANc-5Uy5HZ+RvxXM6brVsS1NyfQO=AYcn-Wvs73_haHLgn0T0g@mail.gmail.com>
References: <qsq776$4amq$1@blaine.gmane.org>
 <CANc-5Uy5HZ+RvxXM6brVsS1NyfQO=AYcn-Wvs73_haHLgn0T0g@mail.gmail.com>
Message-ID: <ea700581-8659-8fd1-8633-c9ab4ac2f456@chagford.com>

On 2019-12-11 10:51 PM, Skip Montanaro wrote:
>> Why is a dtm instance also an instance of dt?
> 
> The datetime type is, in fact, a subclass of the date type:
> 
>>>> import datetime
>>>> datetime.date.__bases__
> (<class 'object'>,)
>>>> datetime.datetime.__bases__
> (<class 'datetime.date'>,)
>>>> datetime.time.__bases__
> (<class 'object'>,)
> 
> Skip
> 

Thanks for that.

I found a workaround.

 >>> from datetime import date as dt, datetime as dtm
 >>> type(dtm.now()) is dtm
True
 >>> type(dtm.now()) is dt
False
 >>>

I will run with this.

Frank


From songofacandy at gmail.com  Fri Dec 13 01:44:18 2019
From: songofacandy at gmail.com (Inada Naoki)
Date: Fri, 13 Dec 2019 15:44:18 +0900
Subject: mysqlclient==1.4.6 none wheel doesn't work on ubuntu 18
In-Reply-To: <BY5PR07MB716049FEA82ACE1C61117BF3DD550@BY5PR07MB7160.namprd07.prod.outlook.com>
References: <BY5PR07MB716049FEA82ACE1C61117BF3DD550@BY5PR07MB7160.namprd07.prod.outlook.com>
Message-ID: <CAEfz+Ty0NJ1pXUQjHizNbqZ3cP9YBWwUXL2GmHHL_EPEUBHRPQ@mail.gmail.com>

Hi, mysqlclient maintainer is here.

On Fri, Dec 13, 2019 at 1:44 AM Mitesh Patel <miteshp at live.com> wrote:
>
> I was very confused, but I just kept the ?none? wheel since that should be OS independent.

Why do you think it is OS independent?
libmysqlclient.so doesn't keep ABI compatibility.
You need to rebuild mysqlclient when the binary of the
libmysqlclient.so is different.

That's why I don't provide binary wheels for macOS and Linux.
Some people install MySQL from apt, brew, or mysql.com.
Some people use MariaDB instead of MySQL.
mysqlclient should be built on each own environment.

Regards,

-- 
Inada Naoki  <songofacandy at gmail.com>

From arj.python at gmail.com  Fri Dec 13 02:33:06 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Fri, 13 Dec 2019 11:33:06 +0400
Subject: Zipapp can't find sqlite db
In-Reply-To: <D8C36B09-B574-4F4B-83D2-25F887FD6CC0@barrys-emacs.org>
References: <CADrxXXmMCGoJbZ3TT1Ch30EFNgMNVVFSn0g_PEB3m4V1TYCAQg@mail.gmail.com>
 <877e38e9f8.fsf@handshake.de>
 <D8C36B09-B574-4F4B-83D2-25F887FD6CC0@barrys-emacs.org>
Message-ID: <CADrxXX=JDVtkOsjB_UUYBgZSFHzbTxX=dErrcZCnKBOhwVrThw@mail.gmail.com>

Do you have a data files tuto link?

Yours,

Abdur-Rahmaan Janhangeer
pythonmembers.club <http://www.pythonmembers.club/> | github
<https://github.com/Abdur-rahmaanJ>
Mauritius

>
>

From arj.python at gmail.com  Fri Dec 13 02:33:55 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Fri, 13 Dec 2019 11:33:55 +0400
Subject: Zipapp can't find sqlite db
In-Reply-To: <877e38e9f8.fsf@handshake.de>
References: <CADrxXXmMCGoJbZ3TT1Ch30EFNgMNVVFSn0g_PEB3m4V1TYCAQg@mail.gmail.com>
 <877e38e9f8.fsf@handshake.de>
Message-ID: <CADrxXX=by_nT618UHT-e+tqqu5i0p0fWYg92k_yK1Y8dY1_XhQ@mail.gmail.com>

Packaging in this case means converting a folder into a zipapp archive.

Yours,

Abdur-Rahmaan Janhangeer
pythonmembers.club <http://www.pythonmembers.club/> | github
<https://github.com/Abdur-rahmaanJ>
Mauritius

>
>

From Karsten.Hilbert at gmx.net  Fri Dec 13 02:49:48 2019
From: Karsten.Hilbert at gmx.net (Karsten Hilbert)
Date: Fri, 13 Dec 2019 08:49:48 +0100
Subject: Troubleshooting
In-Reply-To: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
References: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
Message-ID: <20191213074948.GA1678@hermes.hilbert.loc>

On Thu, Dec 12, 2019 at 06:40:32PM -0600, catherine morris wrote:

> Good evening,
>
> My son is trying to download python 3.8.0 on my PC, which has Windows 10,
> and it won't install properly. I'm not tech savvy and have no idea where to
> start.

No offense, but, how old is your son ?

Karsten
--
GPG  40BE 5B0E C98E 1713 AFA6  5BC0 3BEA AC80 7D4F C89B

From karthik.sharma at gmail.com  Fri Dec 13 03:46:46 2019
From: karthik.sharma at gmail.com (Karthik Sharma)
Date: Fri, 13 Dec 2019 00:46:46 -0800 (PST)
Subject: Implementing CURL command using libcurl in C/C++
Message-ID: <33829b26-13b8-42f1-8bdb-a332fa7d376e@googlegroups.com>

The `CURL` command that I am using is shown below.

    curl -F 'file=@/home/karthik/Workspace/downloadfile.out' http://127.0.0.1:5000/file-upload --verbose

The response from the server is shown below.

    *   Trying 127.0.0.1...
    * Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
    > POST /file-upload HTTP/1.1
    > Host: 127.0.0.1:5000
    > User-Agent: curl/7.47.0
    > Accept: */*
    > Content-Length: 663876790
    > Expect: 100-continue
    > Content-Type: multipart/form-data; boundary=------------------------4e96ef0714498bd7
    > 
    < HTTP/1.1 100 Continue
    * HTTP 1.0, assume close after body
    < HTTP/1.0 201 CREATED
    < Content-Type: application/json
    < Content-Length: 46
    < Server: Werkzeug/0.16.0 Python/3.5.2
    < Date: Sat, 14 Dec 2019 07:05:15 GMT
    < 
    {
      "message": "File successfully uploaded"
    }
    * Closing connection 0

I want to implement the same command in C/C++ using libcurl. I am using the following function.

    int FileUploadDownload::upload(const std::string &filename, const std::string &url) {
    
        CURL *curl;
        CURLcode res;
        struct stat file_info;
        curl_off_t speed_upload, total_time;
        FILE *fd;
    
        fd = fopen(filename.c_str(), "rb");
        if(!fd) {
            m_logger->errorf("unable to open file: %s\n",strerror(errno));
            return 1;
        }
        if(fstat(fileno(fd), &file_info) != 0) {
            m_logger->errorf("unable to get file stats: %s\n",strerror(errno));
            return 2;
        }
    
        std::cout << "filename : "<< filename << std::endl;
        std::cout << "url : " << url << std::endl;
    
        curl = curl_easy_init();
        if(curl) {
    
            curl_easy_setopt(curl, CURLOPT_URL,
                             url.c_str());
    
            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, filename.c_str());
            curl_easy_setopt(curl, CURLOPT_POST, 1L);
            curl_easy_setopt(curl, CURLOPT_READDATA, fd);
            curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
                             (curl_off_t) file_info.st_size);
            curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
    
            res = curl_easy_perform(curl);
            if (res != CURLE_OK) {
                m_logger->errorf("curl_easy_perform() failed: %s\n",curl_easy_strerror(res));
            } else {
                curl_easy_getinfo(curl, CURLINFO_SPEED_UPLOAD, &speed_upload);
                curl_easy_getinfo(curl, CURLINFO_TOTAL_TIME, &total_time);
                m_logger->infof("Speed: %" CURL_FORMAT_CURL_OFF_T " bytes/sec during %"
                                CURL_FORMAT_CURL_OFF_T ".%06ld seconds\n",
                                speed_upload,
                                (total_time / 1000000), (long) (total_time % 1000000));
            }
        }
        return 0;
    }
The below is the result that I get from the server.

    The result that I get is shown below.
       *   Trying 127.0.0.1...
    * Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
    > POST /file-upload HTTP/1.1
    > Host: 127.0.0.1:5000
    > User-Agent: curl/7.47.0
    > Accept: */*
    > Content-Length: 550
    > Expect: 100-continue
    > Content-Type: multipart/form-data; boundary=------------------------c8ef4837136fca99
    > 
    < HTTP/1.1 100 Continue
    * HTTP 1.0, assume close after body
    < HTTP/1.0 201 CREATED
    < Content-Type: application/json
    < Content-Length: 46
    < Server: Werkzeug/0.16.0 Python/3.5.2
    < Date: Sat, 14 Dec 2019 07:09:47 GMT
    < 
    {
      "message": "File successfully uploaded"
    }
    * Closing connection 0


My aim is to mimic the curl command above in the C/C++ code below. What am I doing wrong ?

From bgailer at gmail.com  Fri Dec 13 04:08:02 2019
From: bgailer at gmail.com (Bob Gailer)
Date: Fri, 13 Dec 2019 04:08:02 -0500
Subject: Implementing CURL command using libcurl in C/C++
In-Reply-To: <33829b26-13b8-42f1-8bdb-a332fa7d376e@googlegroups.com>
References: <33829b26-13b8-42f1-8bdb-a332fa7d376e@googlegroups.com>
Message-ID: <CAP1rxO7VmgB4cLhq8qXaiQQgAX3UMO7Zbbr9bku537684+gMNw@mail.gmail.com>

This list is for Python, not C/C++.

On Dec 13, 2019 3:50 AM, "Karthik Sharma" <karthik.sharma at gmail.com> wrote:

> The `CURL` command that I am using is shown below.
>
>     curl -F 'file=@/home/karthik/Workspace/downloadfile.out'
> http://127.0.0.1:5000/file-upload --verbose
>
> The response from the server is shown below.
>
>     *   Trying 127.0.0.1...
>     * Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
>     > POST /file-upload HTTP/1.1
>     > Host: 127.0.0.1:5000
>     > User-Agent: curl/7.47.0
>     > Accept: */*
>     > Content-Length: 663876790
>     > Expect: 100-continue
>     > Content-Type: multipart/form-data; boundary=---------------------
> ---4e96ef0714498bd7
>     >
>     < HTTP/1.1 100 Continue
>     * HTTP 1.0, assume close after body
>     < HTTP/1.0 201 CREATED
>     < Content-Type: application/json
>     < Content-Length: 46
>     < Server: Werkzeug/0.16.0 Python/3.5.2
>     < Date: Sat, 14 Dec 2019 07:05:15 GMT
>     <
>     {
>       "message": "File successfully uploaded"
>     }
>     * Closing connection 0
>
> I want to implement the same command in C/C++ using libcurl. I am using
> the following function.
>
>     int FileUploadDownload::upload(const std::string &filename, const
> std::string &url) {
>
>         CURL *curl;
>         CURLcode res;
>         struct stat file_info;
>         curl_off_t speed_upload, total_time;
>         FILE *fd;
>
>         fd = fopen(filename.c_str(), "rb");
>         if(!fd) {
>             m_logger->errorf("unable to open file: %s\n",strerror(errno));
>             return 1;
>         }
>         if(fstat(fileno(fd), &file_info) != 0) {
>             m_logger->errorf("unable to get file stats:
> %s\n",strerror(errno));
>             return 2;
>         }
>
>         std::cout << "filename : "<< filename << std::endl;
>         std::cout << "url : " << url << std::endl;
>
>         curl = curl_easy_init();
>         if(curl) {
>
>             curl_easy_setopt(curl, CURLOPT_URL,
>                              url.c_str());
>
>             curl_easy_setopt(curl, CURLOPT_POSTFIELDS, filename.c_str());
>             curl_easy_setopt(curl, CURLOPT_POST, 1L);
>             curl_easy_setopt(curl, CURLOPT_READDATA, fd);
>             curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
>                              (curl_off_t) file_info.st_size);
>             curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
>
>             res = curl_easy_perform(curl);
>             if (res != CURLE_OK) {
>                 m_logger->errorf("curl_easy_perform() failed:
> %s\n",curl_easy_strerror(res));
>             } else {
>                 curl_easy_getinfo(curl, CURLINFO_SPEED_UPLOAD,
> &speed_upload);
>                 curl_easy_getinfo(curl, CURLINFO_TOTAL_TIME, &total_time);
>                 m_logger->infof("Speed: %" CURL_FORMAT_CURL_OFF_T "
> bytes/sec during %"
>                                 CURL_FORMAT_CURL_OFF_T ".%06ld seconds\n",
>                                 speed_upload,
>                                 (total_time / 1000000), (long) (total_time
> % 1000000));
>             }
>         }
>         return 0;
>     }
> The below is the result that I get from the server.
>
>     The result that I get is shown below.
>        *   Trying 127.0.0.1...
>     * Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
>     > POST /file-upload HTTP/1.1
>     > Host: 127.0.0.1:5000
>     > User-Agent: curl/7.47.0
>     > Accept: */*
>     > Content-Length: 550
>     > Expect: 100-continue
>     > Content-Type: multipart/form-data; boundary=---------------------
> ---c8ef4837136fca99
>     >
>     < HTTP/1.1 100 Continue
>     * HTTP 1.0, assume close after body
>     < HTTP/1.0 201 CREATED
>     < Content-Type: application/json
>     < Content-Length: 46
>     < Server: Werkzeug/0.16.0 Python/3.5.2
>     < Date: Sat, 14 Dec 2019 07:09:47 GMT
>     <
>     {
>       "message": "File successfully uploaded"
>     }
>     * Closing connection 0
>
>
> My aim is to mimic the curl command above in the C/C++ code below. What am
> I doing wrong ?
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From antoon.pardon at vub.be  Fri Dec 13 05:23:19 2019
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Fri, 13 Dec 2019 11:23:19 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsqrnv$isd$2@gioia.aioe.org>
References: <qsp1hd$46m$1@gioia.aioe.org>
 <bde71ebd-bc5a-8a7a-e667-05f0f2f0550d@gmail.com>
 <mailman.42.1576015499.11485.python-list@python.org>
 <qsqrnv$isd$2@gioia.aioe.org>
Message-ID: <bde225c7-7ae9-8b10-9d76-6671238db915@vub.be>

On 11/12/19 14:42, R.Wieser wrote:
> Michael,
>
>> It's a two-way street.  It's hard to teach someone that won't be taught.
> Whacking a student over the head because he doesn't understand has never 
> helped the student*.

You were not whacked for not understanding. You were wacked for
pretending to
understand better than the experts here. You were telling the experts
that what
they were telling you about python couldn't be true.

>    So, stop whacking and start /teaching/.   Like 
> thinking of examples that could show the student where he goes wrong.

Stop arguing and start listening.

-- 
Antoon Pardon


From antoon.pardon at vub.be  Fri Dec 13 05:34:24 2019
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Fri, 13 Dec 2019 11:34:24 +0100
Subject: More efficient/elegant branching
In-Reply-To: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
Message-ID: <2c058292-6cc8-39d3-ada5-1a9484aa437a@vub.be>

On 9/12/19 12:27, Musbur wrote:
> Hello,
>
> I have a function with a long if/elif chain that sets a couple of
> variables according to a bunch of test expressions, similar to
> function branch1() below. I never liked that approach much because it
> is clumsy and repetetive, and pylint thinks so as well. I've come up
> with two alternatives which I believe are less efficient due to the
> reasons given in the respective docstrings. Does anybody have a better
> idea?
>
> def branch1(a, b, z):
> ??? """Inelegant, unwieldy, and pylint complains
> ??? about too many branches"""
> ??? if a > 4 and b == 0:
> ??????? result = "first"
> ??? elif len(z) < 2:
> ??????? result = "second"
> ??? elif b + a == 10:
> ??????? result = "third"
> ??? return result
>
> def branch2(a, b, z):
> ??? """Elegant but inefficient because all expressions
> ??? are pre-computed althogh the first one is most likely
> ??? to hit"""
> ??? decision = [
> ??????? (a > 4 and b == 0, "first"),
> ??????? (len(z) < 2,?????? "second"),
> ??????? (b + a == 10,????? "third")]
> ??? for (test, result) in decision:
> ??????? if test: return result
>
> def branch3(a, b, z):
> ??? """Elegant but inefficient because expressions
> ??? need to be parsed each time"""
> ??? decision = [
> ??????? ("a > 4 and b == 0", "first"),
> ??????? ("len(z) < 2",?????? "second"),
> ??????? ("b + a == 10",????? "third")]
> ??? for (test, result) in decision:
> ??????? if eval(test): return result
> (env) [dh at deham01in015:~/python/rscl_fdc/devel]$
>
Well if you really want to go this route, you may consider the following:

def branch4(a, b, z):
    decision = [
        ((lambda: a > 4 and b == 0), "first"),
        ((lambda: len(z) < 2), "second"),
        ((lambda: b + a == 10), "third")]
    for test, result in decision:
        if test(): return result



From barry at barrys-emacs.org  Fri Dec 13 08:29:47 2019
From: barry at barrys-emacs.org (Barry)
Date: Fri, 13 Dec 2019 13:29:47 +0000
Subject: Implementing CURL command using libcurl in C/C++
In-Reply-To: <33829b26-13b8-42f1-8bdb-a332fa7d376e@googlegroups.com>
References: <33829b26-13b8-42f1-8bdb-a332fa7d376e@googlegroups.com>
Message-ID: <6B4D7526-E6D4-48BF-A45B-918775343022@barrys-emacs.org>



> On 13 Dec 2019, at 08:53, Karthik Sharma <karthik.sharma at gmail.com> wrote:
> 
> ?The `CURL` command that I am using is shown below.
> 
>    curl -F 'file=@/home/karthik/Workspace/downloadfile.out' http://127.0.0.1:5000/file-upload --verbose
> 
> The response from the server is shown below.
> 
>    *   Trying 127.0.0.1...
>    * Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
>> POST /file-upload HTTP/1.1
>> Host: 127.0.0.1:5000
>> User-Agent: curl/7.47.0
>> Accept: */*
>> Content-Length: 663876790
>> Expect: 100-continue
>> Content-Type: multipart/form-data; boundary=------------------------4e96ef0714498bd7
>> 
>    < HTTP/1.1 100 Continue
>    * HTTP 1.0, assume close after body
>    < HTTP/1.0 201 CREATED
>    < Content-Type: application/json
>    < Content-Length: 46
>    < Server: Werkzeug/0.16.0 Python/3.5.2
>    < Date: Sat, 14 Dec 2019 07:05:15 GMT
>    < 
>    {
>      "message": "File successfully uploaded"
>    }
>    * Closing connection 0
> 
> I want to implement the same command in C/C++ using libcurl. I am using the following function.
> 
>    int FileUploadDownload::upload(const std::string &filename, const std::string &url) {
> 
>        CURL *curl;
>        CURLcode res;
>        struct stat file_info;
>        curl_off_t speed_upload, total_time;
>        FILE *fd;
> 
>        fd = fopen(filename.c_str(), "rb");
>        if(!fd) {
>            m_logger->errorf("unable to open file: %s\n",strerror(errno));
>            return 1;
>        }
>        if(fstat(fileno(fd), &file_info) != 0) {
>            m_logger->errorf("unable to get file stats: %s\n",strerror(errno));
>            return 2;
>        }
> 
>        std::cout << "filename : "<< filename << std::endl;
>        std::cout << "url : " << url << std::endl;
> 
>        curl = curl_easy_init();
>        if(curl) {
> 
>            curl_easy_setopt(curl, CURLOPT_URL,
>                             url.c_str());
> 
>            curl_easy_setopt(curl, CURLOPT_POSTFIELDS, filename.c_str());
>            curl_easy_setopt(curl, CURLOPT_POST, 1L);
>            curl_easy_setopt(curl, CURLOPT_READDATA, fd);
>            curl_easy_setopt(curl, CURLOPT_INFILESIZE_LARGE,
>                             (curl_off_t) file_info.st_size);
>            curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
> 
>            res = curl_easy_perform(curl);
>            if (res != CURLE_OK) {
>                m_logger->errorf("curl_easy_perform() failed: %s\n",curl_easy_strerror(res));
>            } else {
>                curl_easy_getinfo(curl, CURLINFO_SPEED_UPLOAD, &speed_upload);
>                curl_easy_getinfo(curl, CURLINFO_TOTAL_TIME, &total_time);
>                m_logger->infof("Speed: %" CURL_FORMAT_CURL_OFF_T " bytes/sec during %"
>                                CURL_FORMAT_CURL_OFF_T ".%06ld seconds\n",
>                                speed_upload,
>                                (total_time / 1000000), (long) (total_time % 1000000));
>            }
>        }
>        return 0;
>    }
> The below is the result that I get from the server.
> 
>    The result that I get is shown below.
>       *   Trying 127.0.0.1...
>    * Connected to 127.0.0.1 (127.0.0.1) port 5000 (#0)
>> POST /file-upload HTTP/1.1
>> Host: 127.0.0.1:5000
>> User-Agent: curl/7.47.0
>> Accept: */*
>> Content-Length: 550
>> Expect: 100-continue
>> Content-Type: multipart/form-data; boundary=------------------------c8ef4837136fca99
>> 
>    < HTTP/1.1 100 Continue
>    * HTTP 1.0, assume close after body
>    < HTTP/1.0 201 CREATED
>    < Content-Type: application/json
>    < Content-Length: 46
>    < Server: Werkzeug/0.16.0 Python/3.5.2
>    < Date: Sat, 14 Dec 2019 07:09:47 GMT
>    < 
>    {
>      "message": "File successfully uploaded"
>    }
>    * Closing connection 0
> 
> 
> My aim is to mimic the curl command above in the C/C++ code below. What am I doing wrong ?

My guess Is that there is way to handle the 100 continue and you are missing that code. Or you need to tell curl not to use the send the ?Expect: 100 Continue? header.

The purpose of the 100 Continue is to allow the server to refuse the POST.

https://tools.ietf.org/html/rfc7231#section-6.2.1

Barry

> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 

From akkana at shallowsky.com  Fri Dec 13 12:04:09 2019
From: akkana at shallowsky.com (Akkana Peck)
Date: Fri, 13 Dec 2019 10:04:09 -0700
Subject: Troubleshooting
In-Reply-To: <e5b15f4e-dacf-6037-d3f4-675e71092619@gmail.com>
References: <CADc+DEPvfmoqzVMJ1tMG5HvZfdPpJBVPPVCWFQcwDzu_g_sDrQ@mail.gmail.com>
 <mailman.66.1576198300.11485.python-list@python.org>
 <5df2ea1b$0$10381$426a74cc@news.free.fr>
 <e5b15f4e-dacf-6037-d3f4-675e71092619@gmail.com>
Message-ID: <20191213170409.GB14245@shallowsky.com>

Michael Torrie writes:
> On 12/12/19 6:33 PM, Python wrote:
> > What happened exactly? Did you download the official installer from
> > python.org, then click on next, next, next, checking the box (if it's
> > still there about updating PATH)? There is nothing more to do.
> 
> I've seen github bug reports about Windows launching the store when
> trying to run Python, but those appear to be after a successful
> installation, and the solution there is making sure the installed
> version of Python is set in the $PATH.

I installed Python on a Windows 10 box for the first time a few weeks
ago (normally I'm a Linux user and get Python via distro packages).

Typing "python" at a command prompt before installing anything
gave a prompt for the MS store.

If you run an installer from Python.org, the checkbox to add to the
system path is not at all obvious. It's at the very bottom of a long
scrolled list of options, *and it's the only one not checked by
default*. The first time I installed, I looked at the list, scrolled
down a little way and concluded that all options were checked,
so I didn't scroll down to the bottom to notice the one crucial
un-checked one. (Go ahead and think poorly of me for making
assumptions, but I'm sure I'm not the only person to do that.)
And of course, the install didn't work and I had to reinstall.
Fortunately I know what a path is and knew to hunt for that the
second time through; I doubt a typical Windows person knows about paths.

It would make the install a lot easier for less technical Windows
people if the installer had a separate screen for the path option,
perhaps with an explanation of what path means (and that if you don't
understand the explanation, you really, really should check the box).
Or enable it by default -- would anyone besides an expert user
want it disabled? Or at least put it first in the long list of
options, so it always shows.

        ...Akkana

From arj.python at gmail.com  Fri Dec 13 12:26:09 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Fri, 13 Dec 2019 21:26:09 +0400
Subject: Reading mail getting [<email.message.Message object at
 0x02209970>, ...
In-Reply-To: <bdd66319-7aa4-966f-2401-913019c19d8a@mrabarnett.plus.com>
References: <CADrxXXmwLvqa5QP1vO1HPb13OqMGtUyB3a989jRKXLbP7FP2=w@mail.gmail.com>
 <bdd66319-7aa4-966f-2401-913019c19d8a@mrabarnett.plus.com>
Message-ID: <CADrxXXkKGcNOdMOEsObJcsSgLcWZyxqeJPAZAOfm9tCQD3k1yA@mail.gmail.com>

Can you please indicate where is the header in my code above? Thanks.

Yours,

Abdur-Rahmaan Janhangeer
pythonmembers.club <http://www.pythonmembers.club/> | github
<https://github.com/Abdur-rahmaanJ>
Mauritius


>

From arj.python at gmail.com  Fri Dec 13 12:54:49 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Fri, 13 Dec 2019 21:54:49 +0400
Subject: 3rd party mail package
Message-ID: <CADrxXXn60nM3cDKY+gws=RAuDZa37PYjnh9Bur=LNbOZuLDMOQ@mail.gmail.com>

Greetings everybody,

What is the best 3rd party package for reading mail? Got a  gmail 0.6.x on
pypi but it is highly inconsistent (and last commit 2013). Any
recommendations?

Yours,

Abdur-Rahmaan Janhangeer
pythonmembers.club <http://www.pythonmembers.club/> | github
<https://github.com/Abdur-rahmaanJ>
Mauritius

From brian.j.oney at googlemail.com  Fri Dec 13 16:05:33 2019
From: brian.j.oney at googlemail.com (Brian Oney)
Date: Fri, 13 Dec 2019 22:05:33 +0100
Subject: 3rd party mail package
In-Reply-To: <CADrxXXn60nM3cDKY+gws=RAuDZa37PYjnh9Bur=LNbOZuLDMOQ@mail.gmail.com>
References: <CADrxXXn60nM3cDKY+gws=RAuDZa37PYjnh9Bur=LNbOZuLDMOQ@mail.gmail.com>
Message-ID: <E7D97B95-BDB1-4A47-8CD9-C09A2E2B2970@gmail.com>

How about a 1st party package in the stdlib?
From the hip: Take an example or two from the 'python 2 or 3 standard library by example' book by a guy named Doug.

Hth (really) 

From arj.python at gmail.com  Fri Dec 13 16:10:25 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Sat, 14 Dec 2019 01:10:25 +0400
Subject: 3rd party mail package
In-Reply-To: <E7D97B95-BDB1-4A47-8CD9-C09A2E2B2970@gmail.com>
References: <CADrxXXn60nM3cDKY+gws=RAuDZa37PYjnh9Bur=LNbOZuLDMOQ@mail.gmail.com>
 <E7D97B95-BDB1-4A47-8CD9-C09A2E2B2970@gmail.com>
Message-ID: <CADrxXXnz8_h3tu7yLLwZ7K75e5wu24FeUTHo94i3cUELNX4Xiw@mail.gmail.com>

Wonder where the 2nd party went to. Thanks will look into it!

From arj.python at gmail.com  Fri Dec 13 16:13:13 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Sat, 14 Dec 2019 01:13:13 +0400
Subject: 3rd party mail package
In-Reply-To: <E7D97B95-BDB1-4A47-8CD9-C09A2E2B2970@gmail.com>
References: <CADrxXXn60nM3cDKY+gws=RAuDZa37PYjnh9Bur=LNbOZuLDMOQ@mail.gmail.com>
 <E7D97B95-BDB1-4A47-8CD9-C09A2E2B2970@gmail.com>
Message-ID: <CADrxXXk3NMQr0qQXMe7MMTC1QMZKJ=G2LrhhLX8xofdUn4ZO-A@mail.gmail.com>

That's my starting point au fait. Was asking for a 3rd party package. gmail
from pypi has a nice api ? (filter etc seem awesome). Wondered if
something similar exists.

From robertvstepp at gmail.com  Fri Dec 13 23:13:36 2019
From: robertvstepp at gmail.com (boB Stepp)
Date: Fri, 13 Dec 2019 22:13:36 -0600
Subject: Python3 - How do I import a class from another file
In-Reply-To: <h5dh1nFonb6U1@mid.individual.net>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr>
 <qsjfeh$1nbf$3@gioia.aioe.org> <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
 <h596koFrgm6U1@mid.individual.net> <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
 <qsqvol$169q$1@gioia.aioe.org> <h5dh1nFonb6U1@mid.individual.net>
Message-ID: <CANDiX9KCPpPZKfMdRUUW_HAzgQh-ePcDQ3eyeofB0MgB18a_kw@mail.gmail.com>

On Wed, Dec 11, 2019 at 6:51 PM Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
>
> On 12/12/19 3:50 am, R.Wieser wrote:
> > I was rather clear about what my used version of Python was-and-is.  I have
> > no idea why that was ignored. :-(
>
> I think we've all been talking at cross purposes for a while.
>
> What I meant to say originally was that you were relying on
> an implementation detail of current CPython, and your code
> might not work on other versions of Python. I was just
> trying to make you aware of something that is considered
> "best practice" when writing Python code, for your own
> future reference.

A question:  As these behaviors being discussed are CPython
implementation details, is it true that CPython itself is free to
implement these behaviors differently in its own future versions?



-- 
boB

From greg.ewing at canterbury.ac.nz  Fri Dec 13 23:36:53 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Sat, 14 Dec 2019 17:36:53 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <mailman.86.1576296830.11485.python-list@python.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <h5bt40Fe64mU1@mid.individual.net>
 <qsqvol$169q$1@gioia.aioe.org> <h5dh1nFonb6U1@mid.individual.net>
 <CANDiX9KCPpPZKfMdRUUW_HAzgQh-ePcDQ3eyeofB0MgB18a_kw@mail.gmail.com>
 <mailman.86.1576296830.11485.python-list@python.org>
Message-ID: <h5j775FuftoU1@mid.individual.net>

On 14/12/19 5:13 pm, boB Stepp wrote:
> is it true that CPython itself is free to
> implement these behaviors differently in its own future versions?

Yes. That's why it's not a good idea to rely on them even
if you only intend to run your code on CPython.

-- 
Greg

From dieter at handshake.de  Sat Dec 14 03:49:35 2019
From: dieter at handshake.de (dieter)
Date: Sat, 14 Dec 2019 09:49:35 +0100
Subject: Reading mail getting [<email.message.Message object at
 0x02209970>, ...
References: <CADrxXXmwLvqa5QP1vO1HPb13OqMGtUyB3a989jRKXLbP7FP2=w@mail.gmail.com>
 <bdd66319-7aa4-966f-2401-913019c19d8a@mrabarnett.plus.com>
 <CADrxXXkKGcNOdMOEsObJcsSgLcWZyxqeJPAZAOfm9tCQD3k1yA@mail.gmail.com>
Message-ID: <87tv635m1s.fsf@handshake.de>

Abdur-Rahmaan Janhangeer <arj.python at gmail.com> writes:

> Can you please indicate where is the header in my code above? Thanks.

Python is an object oriented language. As a consequence,
Python functions often return complex objects and not only
elementary objects. Use the documentation of the complex object's class
to find out how to work with them.

In general, Python has two functions to get a readable
description for an object: "repr" and "str".
"<email.message.Message object at 0x02209970>" is a typical
return value for "repr". Apply "str" to this message object
to get a representation which likely fits better your expectations.

Read the documentation for "email.message.Message" to learn how
to work with those "Message" objects on a more granular level.


From barry at barrys-emacs.org  Sat Dec 14 04:13:45 2019
From: barry at barrys-emacs.org (Barry)
Date: Sat, 14 Dec 2019 09:13:45 +0000
Subject: 3rd party mail package
In-Reply-To: <CADrxXXnz8_h3tu7yLLwZ7K75e5wu24FeUTHo94i3cUELNX4Xiw@mail.gmail.com>
References: <CADrxXXnz8_h3tu7yLLwZ7K75e5wu24FeUTHo94i3cUELNX4Xiw@mail.gmail.com>
Message-ID: <C59384AF-7E4C-478B-8591-EEC2231DE5C1@barrys-emacs.org>

I guess the 2nd party is the user.

Barry

> On 13 Dec 2019, at 21:13, Abdur-Rahmaan Janhangeer <arj.python at gmail.com> wrote:
> 
> ?Wonder where the 2nd party went to. Thanks will look into it!
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From prasadautomationtesting at gmail.com  Sat Dec 14 11:00:31 2019
From: prasadautomationtesting at gmail.com (Prasad Rajassekaran)
Date: Sat, 14 Dec 2019 08:00:31 -0800 (PST)
Subject: Setting Pythonpath programmatic
Message-ID: <c86f6dbe-3136-4822-acaa-555be2161cd3@googlegroups.com>

0


Aim:-

I would want to set python path programmatic in my project. So that, all other directories files can be imported without any issues.

Problem statement:-

I used to add all the folders & sub-folders in environment variables under PYTHONPATH but this has two constrains.

1, Any new folders created need to be added in environment variables all the times. After certain limit, environment variables will not be accepted new path reference due to characters limitaion.

- Error: This environment variable is too large. This dialog allows setting values up to 2047 characters long.

2, Secondly, all the team members in my team need to perform the same activity manually all the times.

Tried self solution:-

Created a sample folder and added the below code before main import files and ran from command prompt which worked perfectly fine.

**FilePath: foo/Python/Learning&Development/Pratice/Directory1/File1.py**

class File1():

    def parent(self):
        return "I am from File1"

**FilePath: foo/Python/Learning&Development/Pratice/Directory2/File2.py**

    import sys
try:
    sys.path.index('foo/Python/Learning&Development')
    sys.path.index('foo/Python/Learning&Development/Pratice')
    sys.path.index('foo/Python/Learning&Development/Pratice/Directory1')
    sys.path.index('foo/Python/Learning&Development/Pratice/Directory2')
except ValueError:
    sys.path.append('foo/Python/Learning&Development')
    sys.path.append('foo/Python/Learning&Development/Pratice')
    sys.path.append('foo/Python/Learning&Development/Pratice/Directory1')
    sys.path.append('foo/Python/Learning&Development/Pratice/Directory2')

from Pratice.Directory1.File1 import File1 as f


class File2():

    def child(self):
        return f.parent(self)
Results:

I am from File1

Now I wish to convert the sys.path as a single method and call automatically before running any .py file in the project folder.

So, on trail basis, I created 'init.py' file added the same piece (sys.path) of code, commented the same code in File2.py and run it but ended up with file import error.

**FilePath: foo/Python/Learning&Development/Pratice/Directory2/__init__.py**

import sys
try:
    sys.path.index('foo/Automation/Python/Learning&Development')
    sys.path.index('foo/Automation/Python/Learning&Development/Pratice')
    sys.path.index('foo/Automation/Python/Learning&Development/Pratice/Directory1')
    sys.path.index('foo/Automation/Python/Learning&Development/Pratice/Directory2')
except ValueError:
    sys.path.append('foo/Automation/Python/Learning&Development')
    sys.path.append('foo/Automation/Python/Learning&Development/Pratice')
sys.path.append('foo/Automation/Python/Learning&Development/Pratice/Directory1') sys.path.append('foo/Automation/Python/Learning&Development/Pratice/Directory2')

**FilePath: foo/Python/Learning&Development/Pratice/Directory1/File1.py**

class File1():

    def parent(self):
        return "I am from File1"

**FilePath: foo/Python/Learning&Development/Pratice/Directory2/File2.py**

# import sys
# try:
    # sys.path.index('foo/Python/Learning&Development')
    # sys.path.index('foo/Python/Learning&Development/Pratice')
    # sys.path.index('foo/Python/Learning&Development/Pratice/Directory1')
    # sys.path.index('foo/Python/Learning&Development/Pratice/Directory2')
# except ValueError:
    # sys.path.append('foo/Python/Learning&Development')
    # sys.path.append('foo/Python/Learning&Development/Pratice')
    # sys.path.append('foo/Python/Learning&Development/Pratice/Directory1')
    # sys.path.append('foo/Python/Learning&Development/Pratice/Directory2')

from Pratice.Directory1.File1 import File1 as f


class File2():

    def child(self):
        return f.parent(self)
Results:

Traceback (most recent call last):
  File "File2.py", line 13, in <module>
    from Pratice.Directory1.File1 import File1 as f
ModuleNotFoundError: No module named 'Pratice

Could someone help me on this problem? I would want the same piece of code to be executed before running any of the .py file in my project folder. So that, import error would not come into picture.

Expected: Python path should be set automatically by default and import error should not occur while running any python file in the project.

From tjreedy at udel.edu  Sat Dec 14 11:38:59 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 14 Dec 2019 11:38:59 -0500
Subject: help with tkinter
In-Reply-To: <1ynq9afkgfrqkiywgd31n5osy2m8towhcpil-46wvh685zxv8fdpxl6-qu1lzo-7ksy5yv1p88o657klwtzst3ero5cbno1zkvnesgobr-mb80jhh5auwx-9fscoxdattuu-puybws9qcrph-n5nio8.1565336405666@email.android.com>
References: <5d42e992.1c69fb81.a4d2f.d17e@mx.google.com>
 <mailman.139.1564674763.29302.python-list@python.org>
 <If6dnf4PT-_2yd7AnZ2dnUU7-XnNnZ2d@giganews.com>
 <CALFTwEuH6DFFC0EPegJoj96p4qAP7B-qHxRtLNE0bTC+d8O0Ag@mail.gmail.com>
 <1ynq9afkgfrqkiywgd31n5osy2m8towhcpil-46wvh685zxv8fdpxl6-qu1lzo-7ksy5yv1p88o657klwtzst3ero5cbno1zkvnesgobr-mb80jhh5auwx-9fscoxdattuu-puybws9qcrph-n5nio8.1565336405666@email.android.com>
Message-ID: <qt3374$4qtg$1@blaine.gmane.org>

On 8/9/2019 3:40 AM, Ahmad Adam Kabbara wrote:

>       when I write**from
>       tkinter import*

Please put statements on one line.

     from tkinter import *


>       t=Tk()
>       tkinter.colorchooser.askcolor()
>       I get this error message
>       Traceback (most recent call last):
>       ** File "C:\Users\kabba\Desktop\color and coordinates.py", line 3, in
>       <module>
>       ****** tkinter.colorchooser.askcolor()
>       NameError: name 'tkinter' is not defined

Please reread the sections of the tutorial and reference that explain 
imports and their effect on the names available in the *importing* module.

>       I also tried another way**
>       from tkinter.colorchooser import*
>       colorchooser.askcolor()
>       and I also got an error message
>       Traceback (most recent call last):
>       ** File "<pyshell#1>", line 1, in <module>
>       ****** colorchooser.askcolor()
>       NameError: name 'colorchooser' is not defined

Same issue, which has nothing to do with tkinter as such.  The title 
should be 'Help with imports'.

>       the only time it worked is when I typed**
>       from tkinter import colorchooser
>       colorchooser.askcolor()

When you import the name 'colorchooser', it is defined and usable.  When 
you do not, it is not.  Keep doing experiments until you see the pattern 
and principle.  Learning experiments are really easy with python.

-- 
Terry Jan Reedy


From tjreedy at udel.edu  Sat Dec 14 11:43:00 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 14 Dec 2019 11:43:00 -0500
Subject: Difference between os.path.isdir and Path.is_dir
In-Reply-To: <CABwCVQBpaWtXJWnnRP_YaDOWh3OwSR_XNbY3OBOfQZ5zJSTnLQ@mail.gmail.com>
References: <CABwCVQB3+esTThYvStyibYr8CsZ6zuBkZ_HBGkuniFovBFmrLw@mail.gmail.com>
 <CACL+1atbV_vGF8TNzTYkzUW=t=5vCS9we9BeeSAq=Kb61iMxYQ@mail.gmail.com>
 <CABwCVQBpaWtXJWnnRP_YaDOWh3OwSR_XNbY3OBOfQZ5zJSTnLQ@mail.gmail.com>
Message-ID: <qt33ek$5b97$1@blaine.gmane.org>

On 7/26/2019 3:12 AM, Kirill Balunov wrote:
> ??, 25 ???. 2019 ?. ? 20:28, eryk sun <eryksun at gmail.com>:
> 
>> On 7/25/19, Kirill Balunov <kirillbalunov at gmail.com> wrote:
>>>
>>>>>> import os
>>>>>> from pathlib import Path
>>>>>> dummy = " "   # or "" or "     "
>>>>>> os.path.isdir(dummy)
>>> False
>>>>>> Path(dummy).is_dir()
>>> True
>>
>> I can't reproduce the above result in either Linux or Windows. The
>> results should only be different for an empty path string, since
>> Path('') is the same as Path('.'). The results should be the same for
>> Path(" "), depending on whether a directory named " " exists (normally
>> not allowed in Windows, but Linux allows it).
>>
>>
> I need to confirm that it was my fault and for non-empty strings (`" "` or `"
> "`), both `os.path.isdir(...)` and `Path(...).is_dir()` produce the same
> results.So sorry for the noise.
> 
> Concerning the case with empty path string, I will open a ticket at the bug
> tracker (but for some reason it is blocked in my country :(
> https://isitblockedinrussia.com/?host=https%3A%2F%2Fbugs.python.org%2F).

For me, this now returns 'No, https://bugs.python.org is probably not 
blocked in Russia. Yet.'.

> Obviously
> these are not equivalent forms, so either this should be noted in the
> documentation or corrected in the code.

-- 
Terry Jan Reedy



From ericgonzbz at hotmail.com  Fri Dec 13 21:12:36 2019
From: ericgonzbz at hotmail.com (Eric Gonzalez)
Date: Sat, 14 Dec 2019 02:12:36 +0000
Subject: Fwd: Problem installing pygame
In-Reply-To: <BN8PR05MB65796DFE122721127AFE68BCD6540@BN8PR05MB6579.namprd05.prod.outlook.com>
References: <BN8PR05MB65796DFE122721127AFE68BCD6540@BN8PR05MB6579.namprd05.prod.outlook.com>
Message-ID: <BN8PR05MB6579676B68837270ED60554BD6570@BN8PR05MB6579.namprd05.prod.outlook.com>



Get Outlook for Android<https://aka.ms/ghei36>
________________________________
From: Eric Gonzalez
Sent: Thursday, December 12, 2019 9:35:40 PM
To: python-list at python.org <python-list at python.org>
Subject: Problem installing pygame

Hello, with the above mentioned i am having some serious problems with the installation of "Pygame" on my laptop.
I have tried using the "pip" method and it tells me that ''pip' is not recognized as an internal or external command, operable program or batch file ', i researched but honestly i don't know what to do. I  installed the python program the proper way, but for some reason the 'pip' method doesn't work for me,  I also tried the method whereby you go and find which pygame SDL package that is compatible with my 32 bit windows 10 and it didn't work either. Oh...  i tried using the pip method in pycharm but it was unsuccessful as well.

Am a rookie 1 with python, really love the language its very efficient and easy to learn hence the reason i love it and am focusing on only learning this language for its the BEST
Please help me i would really appreciate it a lot.

Thanks in advance.

From kirillbalunov at gmail.com  Sat Dec 14 13:31:53 2019
From: kirillbalunov at gmail.com (Kirill Balunov)
Date: Sat, 14 Dec 2019 21:31:53 +0300
Subject: Difference between os.path.isdir and Path.is_dir
In-Reply-To: <qt33ek$5b97$1@blaine.gmane.org>
References: <CABwCVQB3+esTThYvStyibYr8CsZ6zuBkZ_HBGkuniFovBFmrLw@mail.gmail.com>
 <CACL+1atbV_vGF8TNzTYkzUW=t=5vCS9we9BeeSAq=Kb61iMxYQ@mail.gmail.com>
 <CABwCVQBpaWtXJWnnRP_YaDOWh3OwSR_XNbY3OBOfQZ5zJSTnLQ@mail.gmail.com>
 <qt33ek$5b97$1@blaine.gmane.org>
Message-ID: <CABwCVQA46MJ8okAB+1xCy8edo_FGdbFOGTR40C+Pjn=UzC-6Hg@mail.gmail.com>

Yeah it is True, for the last two weeks or so I can access bugs.python.org
in normal way. But I totally agree with the site that the best description
of this situation is "Yet".

with kind regards,
-gdg

??, 14 ???. 2019 ?. ? 19:46, Terry Reedy <tjreedy at udel.edu>:

> On 7/26/2019 3:12 AM, Kirill Balunov wrote:
> > ??, 25 ???. 2019 ?. ? 20:28, eryk sun <eryksun at gmail.com>:
> >
> >> On 7/25/19, Kirill Balunov <kirillbalunov at gmail.com> wrote:
> >>>
> >>>>>> import os
> >>>>>> from pathlib import Path
> >>>>>> dummy = " "   # or "" or "     "
> >>>>>> os.path.isdir(dummy)
> >>> False
> >>>>>> Path(dummy).is_dir()
> >>> True
> >>
> >> I can't reproduce the above result in either Linux or Windows. The
> >> results should only be different for an empty path string, since
> >> Path('') is the same as Path('.'). The results should be the same for
> >> Path(" "), depending on whether a directory named " " exists (normally
> >> not allowed in Windows, but Linux allows it).
> >>
> >>
> > I need to confirm that it was my fault and for non-empty strings (`" "`
> or `"
> > "`), both `os.path.isdir(...)` and `Path(...).is_dir()` produce the same
> > results.So sorry for the noise.
> >
> > Concerning the case with empty path string, I will open a ticket at the
> bug
> > tracker (but for some reason it is blocked in my country :(
> > https://isitblockedinrussia.com/?host=https%3A%2F%2Fbugs.python.org%2F).
>
> For me, this now returns 'No, https://bugs.python.org is probably not
> blocked in Russia. Yet.'.
>
> > Obviously
> > these are not equivalent forms, so either this should be noted in the
> > documentation or corrected in the code.
>
> --
> Terry Jan Reedy
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From python at mrabarnett.plus.com  Sat Dec 14 14:38:16 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 14 Dec 2019 19:38:16 +0000
Subject: Fwd: Problem installing pygame
In-Reply-To: <BN8PR05MB6579676B68837270ED60554BD6570@BN8PR05MB6579.namprd05.prod.outlook.com>
References: <BN8PR05MB65796DFE122721127AFE68BCD6540@BN8PR05MB6579.namprd05.prod.outlook.com>
 <BN8PR05MB6579676B68837270ED60554BD6570@BN8PR05MB6579.namprd05.prod.outlook.com>
Message-ID: <e3ec3a45-5d7f-1402-16dd-0aeeeb4db54f@mrabarnett.plus.com>

On 2019-12-14 02:12, Eric Gonzalez wrote:
> 
> 
> Get Outlook for Android<https://aka.ms/ghei36>
> ________________________________
> From: Eric Gonzalez
> Sent: Thursday, December 12, 2019 9:35:40 PM
> To: python-list at python.org <python-list at python.org>
> Subject: Problem installing pygame
> 
> Hello, with the above mentioned i am having some serious problems with the installation of "Pygame" on my laptop.
> I have tried using the "pip" method and it tells me that ''pip' is not recognized as an internal or external command, operable program or batch file ', i researched but honestly i don't know what to do. I  installed the python program the proper way, but for some reason the 'pip' method doesn't work for me,  I also tried the method whereby you go and find which pygame SDL package that is compatible with my 32 bit windows 10 and it didn't work either. Oh...  i tried using the pip method in pycharm but it was unsuccessful as well.
> 
> Am a rookie 1 with python, really love the language its very efficient and easy to learn hence the reason i love it and am focusing on only learning this language for its the BEST
> Please help me i would really appreciate it a lot.
> 
Try running pip via the Python launcher.

Instead of:

     pip install XXX

try:

     py -m pip install XXX

From onlinejudge95 at gmail.com  Sun Dec 15 03:13:17 2019
From: onlinejudge95 at gmail.com (Test Bot)
Date: Sun, 15 Dec 2019 13:43:17 +0530
Subject: Unable to install Flask-Mongoengine
Message-ID: <CAD=M5eSHKgrKxVqW5D4TfBiLSmfja_7aba9LwKKSJK1CPrXe1w@mail.gmail.com>

Hi Guys,

I am unable to install *Flask-Mongoengine* using pip. Here are my
specifications

1. *OS* => OSX 10.14.6
2. *Python* => Python 3.8.0 (Working in a virtualenv)
3. *Dependency Manager* => pip(19.3.1), setuptools(42.0.2)
3. *Flask-Mongoengine* => flask-mongoengine==0.9.5

I am inside my virtualenv and trying to install flask-mongoengine using

> (env) $ pip install flask-mongoengine==0.9.5


Here is my error

>  distutils.errors.DistutilsError: Command
> '['/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python', '-m',
> 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w',
> '/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/tmpgrvp80jd', '--quiet',
> 'rednose']' returned non-zero exit status 1.


Please Find attached my full error log.

I am on a new system in which i installed python through the mac installer
from python.org, i had run the *Install Certificates.command* for SSL
related issues, if it might be of help.

In case there is a more specific mailing list to redirect to, please let me
know.

Thanks,
onlinejudge95
-------------- next part --------------
(env) $ pip install flask-mongoengine
Collecting flask-mongoengine
  Using cached https://files.pythonhosted.org/packages/20/53/1bb8ad34ad5c2047a11651290325e55086bc18fce7cfdbbe6f5522bd0ae5/flask-mongoengine-0.9.5.tar.gz
    ERROR: Command errored out with exit status 1:
     command: /Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python3 -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-install-73496mgp/flask-mongoengine/setup.py'"'"'; __file__='"'"'/private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-install-73496mgp/flask-mongoengine/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' egg_info --egg-base /private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-install-73496mgp/flask-mongoengine/pip-egg-info
         cwd: /private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-install-73496mgp/flask-mongoengine/
    Complete output (44 lines):
    WARNING: The wheel package is not available.
      ERROR: Command errored out with exit status 1:
       command: /Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python3 -u -c 'import sys, setuptools, tokenize; sys.argv[0] = '"'"'/private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-wheel-z44wznx3/rednose/setup.py'"'"'; __file__='"'"'/private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-wheel-z44wznx3/rednose/setup.py'"'"';f=getattr(tokenize, '"'"'open'"'"', open)(__file__);code=f.read().replace('"'"'\r\n'"'"', '"'"'\n'"'"');f.close();exec(compile(code, __file__, '"'"'exec'"'"'))' bdist_wheel -d /private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-wheel-qz9lk008
           cwd: /private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-wheel-z44wznx3/rednose/
      Complete output (6 lines):
      usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
         or: setup.py --help [cmd1 cmd2 ...]
         or: setup.py --help-commands
         or: setup.py cmd --help
    
      error: invalid command 'bdist_wheel'
      ----------------------------------------
      ERROR: Failed building wheel for rednose
    ERROR: Failed to build one or more wheels
    Traceback (most recent call last):
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/setuptools/installer.py", line 128, in fetch_build_egg
        subprocess.check_call(cmd)
      File "/Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/subprocess.py", line 364, in check_call
        raise CalledProcessError(retcode, cmd)
    subprocess.CalledProcessError: Command '['/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python3', '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w', '/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/tmpjzg2lnoc', '--quiet', 'rednose']' returned non-zero exit status 1.
    
    During handling of the above exception, another exception occurred:
    
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/private/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/pip-install-73496mgp/flask-mongoengine/setup.py", line 36, in <module>
        setup(
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/setuptools/__init__.py", line 144, in setup
        _install_setup_requires(attrs)
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/setuptools/__init__.py", line 139, in _install_setup_requires
        dist.fetch_build_eggs(dist.setup_requires)
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/setuptools/dist.py", line 718, in fetch_build_eggs
        resolved_dists = pkg_resources.working_set.resolve(
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/pkg_resources/__init__.py", line 780, in resolve
        dist = best[req.key] = env.best_match(
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/pkg_resources/__init__.py", line 1065, in best_match
        return self.obtain(req, installer)
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/pkg_resources/__init__.py", line 1077, in obtain
        return installer(requirement)
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/setuptools/dist.py", line 777, in fetch_build_egg
        return fetch_build_egg(self, req)
      File "/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/lib/python3.8/site-packages/setuptools/installer.py", line 130, in fetch_build_egg
        raise DistutilsError(str(e))
    distutils.errors.DistutilsError: Command '['/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python3', '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w', '/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/tmpjzg2lnoc', '--quiet', 'rednose']' returned non-zero exit status 1.
    ----------------------------------------
ERROR: Command errored out with exit status 1: python setup.py egg_info Check the logs for full command output.

From bluebox03 at gmail.com  Sun Dec 15 04:19:15 2019
From: bluebox03 at gmail.com (tommy yama)
Date: Sun, 15 Dec 2019 18:19:15 +0900
Subject: Unable to install Flask-Mongoengine
In-Reply-To: <CAD=M5eSHKgrKxVqW5D4TfBiLSmfja_7aba9LwKKSJK1CPrXe1w@mail.gmail.com>
References: <CAD=M5eSHKgrKxVqW5D4TfBiLSmfja_7aba9LwKKSJK1CPrXe1w@mail.gmail.com>
Message-ID: <CANevj7s+4XULgK3UGrFzHe3JkA_aQ5yb_WbPKqeO6AyHVfHvnw@mail.gmail.com>

how about pip3?

On Sun, Dec 15, 2019 at 5:16 PM Test Bot <onlinejudge95 at gmail.com> wrote:

> Hi Guys,
>
> I am unable to install *Flask-Mongoengine* using pip. Here are my
> specifications
>
> 1. *OS* => OSX 10.14.6
> 2. *Python* => Python 3.8.0 (Working in a virtualenv)
> 3. *Dependency Manager* => pip(19.3.1), setuptools(42.0.2)
> 3. *Flask-Mongoengine* => flask-mongoengine==0.9.5
>
> I am inside my virtualenv and trying to install flask-mongoengine using
>
> > (env) $ pip install flask-mongoengine==0.9.5
>
>
> Here is my error
>
> >  distutils.errors.DistutilsError: Command
> > '['/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python', '-m',
> > 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w',
> > '/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/tmpgrvp80jd',
> '--quiet',
> > 'rednose']' returned non-zero exit status 1.
>
>
> Please Find attached my full error log.
>
> I am on a new system in which i installed python through the mac installer
> from python.org, i had run the *Install Certificates.command* for SSL
> related issues, if it might be of help.
>
> In case there is a more specific mailing list to redirect to, please let me
> know.
>
> Thanks,
> onlinejudge95
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From onlinejudge95 at gmail.com  Sun Dec 15 05:36:37 2019
From: onlinejudge95 at gmail.com (Test Bot)
Date: Sun, 15 Dec 2019 16:06:37 +0530
Subject: Unable to install Flask-Mongoengine
In-Reply-To: <CANevj7s+4XULgK3UGrFzHe3JkA_aQ5yb_WbPKqeO6AyHVfHvnw@mail.gmail.com>
References: <CAD=M5eSHKgrKxVqW5D4TfBiLSmfja_7aba9LwKKSJK1CPrXe1w@mail.gmail.com>
 <CANevj7s+4XULgK3UGrFzHe3JkA_aQ5yb_WbPKqeO6AyHVfHvnw@mail.gmail.com>
Message-ID: <CAD=M5eRkQtHU3qBxXPWk_cFmGam6tdqJ2OnwmEjGx4yWAyc56g@mail.gmail.com>

No help with using pip3

On Sun, Dec 15, 2019 at 2:49 PM tommy yama <bluebox03 at gmail.com> wrote:

> how about pip3?
>
> On Sun, Dec 15, 2019 at 5:16 PM Test Bot <onlinejudge95 at gmail.com> wrote:
>
>> Hi Guys,
>>
>> I am unable to install *Flask-Mongoengine* using pip. Here are my
>> specifications
>>
>> 1. *OS* => OSX 10.14.6
>> 2. *Python* => Python 3.8.0 (Working in a virtualenv)
>> 3. *Dependency Manager* => pip(19.3.1), setuptools(42.0.2)
>> 3. *Flask-Mongoengine* => flask-mongoengine==0.9.5
>>
>> I am inside my virtualenv and trying to install flask-mongoengine using
>>
>> > (env) $ pip install flask-mongoengine==0.9.5
>>
>>
>> Here is my error
>>
>> >  distutils.errors.DistutilsError: Command
>> > '['/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python',
>> '-m',
>> > 'pip', '--disable-pip-version-check', 'wheel', '--no-deps', '-w',
>> > '/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/tmpgrvp80jd',
>> '--quiet',
>> > 'rednose']' returned non-zero exit status 1.
>>
>>
>> Please Find attached my full error log.
>>
>> I am on a new system in which i installed python through the mac installer
>> from python.org, i had run the *Install Certificates.command* for SSL
>> related issues, if it might be of help.
>>
>> In case there is a more specific mailing list to redirect to, please let
>> me
>> know.
>>
>> Thanks,
>> onlinejudge95
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>
>

From musbur at posteo.org  Sun Dec 15 06:00:11 2019
From: musbur at posteo.org (musbur at posteo.org)
Date: Sun, 15 Dec 2019 12:00:11 +0100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <75110727-8c39-9f82-62ed-7e876eb4386f@kynesim.co.uk>
References: <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org>
 <uqsvuedi6tvhnjo3urtt54eauf5vhbq0fb@4ax.com>
 <20191211223246.7b489fb0@nxp10225>
 <75110727-8c39-9f82-62ed-7e876eb4386f@kynesim.co.uk>
Message-ID: <20191215120011.4a9dea25@jenna>

On Thu, 12 Dec 2019 11:33:25 +0000
Rhodri James <rhodri at kynesim.co.uk> wrote:

> On 11/12/2019 21:32, musbur at posteo.org wrote:
> > Plain and simple: When the refcount reaches zero.  

> You are assuming that "when" implies "immediately on the occurence."

I'm not implying that. It's the dictionary definition of the word
"when."

> This happens to be the behaviour in CPython, but other 
> implementations vary as Chris has explained several times now.

And he's right. The documentation is unclear. It should be re-worded to
reflect that the point at which the __del__() method is called after
the refcount reaches zero is unspecified. 

From rosuav at gmail.com  Sun Dec 15 06:08:08 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 15 Dec 2019 22:08:08 +1100
Subject: Python3 - How do I import a class from another file
In-Reply-To: <20191215120011.4a9dea25@jenna>
References: <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org> <h596koFrgm6U1@mid.individual.net>
 <qsnt45$i6f$1@gioia.aioe.org>
 <CAPTjJmq=of_G9A4Y8+cvER2G9OTAJueprAppB802bKe0g-V3rQ@mail.gmail.com>
 <mailman.4.1575979981.11485.python-list@python.org>
 <qso3vr$1jk2$1@gioia.aioe.org>
 <bf36d50d-a9a1-569b-4e74-c19f28714f07@gmail.com>
 <mailman.23.1575996872.11485.python-list@python.org>
 <qsop8g$ri0$1@gioia.aioe.org> <uqsvuedi6tvhnjo3urtt54eauf5vhbq0fb@4ax.com>
 <20191211223246.7b489fb0@nxp10225>
 <75110727-8c39-9f82-62ed-7e876eb4386f@kynesim.co.uk>
 <20191215120011.4a9dea25@jenna>
Message-ID: <CAPTjJmrP8LZn=L0wOy5S+WHFkzQqsuCkyZCzbfVT8-CXm7vN9Q@mail.gmail.com>

On Sun, Dec 15, 2019 at 10:01 PM <musbur at posteo.org> wrote:
>
> On Thu, 12 Dec 2019 11:33:25 +0000
> Rhodri James <rhodri at kynesim.co.uk> wrote:
>
> > On 11/12/2019 21:32, musbur at posteo.org wrote:
> > > Plain and simple: When the refcount reaches zero.
>
> > You are assuming that "when" implies "immediately on the occurence."
>
> I'm not implying that. It's the dictionary definition of the word
> "when."
>
> > This happens to be the behaviour in CPython, but other
> > implementations vary as Chris has explained several times now.
>
> And he's right. The documentation is unclear. It should be re-worded to
> reflect that the point at which the __del__() method is called after
> the refcount reaches zero is unspecified.

In Magic: The Gathering, "when" means "after this happens, the next
time its controller has priority, and then once the ability has a
chance to resolve". In common English, "when" can often mean "at some
extremely unspecified time point after" - for instance, "it's garbage
night, so when you get home, put the bins out". Nothing in the word
"when" mandates any sort of immediacy.

Trying to stipulate all of this would make the documentation LESS
clear. The Python documentation should not read like a EULA.

ChrisA

From hchrholm at online.no  Sun Dec 15 07:08:48 2019
From: hchrholm at online.no (hchrholm at online.no)
Date: Sun, 15 Dec 2019 04:08:48 -0800 (PST)
Subject: Server side Blazor-like framework in Python?
Message-ID: <724ab04e-593a-4565-a8d4-e90f65140ffc@googlegroups.com>

I've been doing a lot of development with server side Blazor on .NET recently, and I think it's a very interesting UI model (https://docs.microsoft.com/en-us/aspnet/core/blazor/hosting-models?view=aspnetcore-3.1). What would it take to make something similar in Python? I guess a lot of relevant Python packages already exist.

SSB works by having a component/DOM model running on the server. The client web page sends events and receives DOM diffs over a SignalR/websocket comnection.

From rosuav at gmail.com  Sun Dec 15 07:14:44 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 15 Dec 2019 23:14:44 +1100
Subject: Server side Blazor-like framework in Python?
In-Reply-To: <724ab04e-593a-4565-a8d4-e90f65140ffc@googlegroups.com>
References: <724ab04e-593a-4565-a8d4-e90f65140ffc@googlegroups.com>
Message-ID: <CAPTjJmqdsz2qCELsuuqf8q=_bOFdYHfnBxe_JcMP9fJn-ATOQg@mail.gmail.com>

On Sun, Dec 15, 2019 at 11:11 PM <hchrholm at online.no> wrote:
>
> I've been doing a lot of development with server side Blazor on .NET recently, and I think it's a very interesting UI model (https://docs.microsoft.com/en-us/aspnet/core/blazor/hosting-models?view=aspnetcore-3.1). What would it take to make something similar in Python? I guess a lot of relevant Python packages already exist.
>
> SSB works by having a component/DOM model running on the server. The client web page sends events and receives DOM diffs over a SignalR/websocket comnection.
>

I *much* prefer to have the front end in charge of the UI, and the
back end work as an API. Just send and receive JSON with useful
information in it, and let the front end figure out how it wants to
display that.

But hey, if you want to ship a DOM diff down the wire, go ahead. Just
don't ask me to use your tool. :)

ChrisA

From info at tundraware.com  Sun Dec 15 09:24:35 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Sun, 15 Dec 2019 08:24:35 -0600
Subject: Randomizing Strings In A Microservices World
In-Reply-To: <mailman.26.1576003055.11485.python-list@python.org>
References: <rq63cg-3fp1.ln1@oceanview.tundraware.com>
 <022uued8o9evis6rruhg4g99cslhh0do5f@4ax.com>
 <mailman.404.1575946535.25794.python-list@python.org>
 <3jg3cg-93s1.ln1@oceanview.tundraware.com> <h59vrfF22j9U1@mid.individual.net>
 <o415cg-3gm1.ln1@oceanview.tundraware.com>
 <CAPTjJmr1BET3A=iLdr5yH6uO4SU0pxEPeR4f-8oxsF0HQ5Dktw@mail.gmail.com>
 <mailman.26.1576003055.11485.python-list@python.org>
Message-ID: <3ashcg-8g71.ln1@oceanview.tundraware.com>

On 12/10/19 12:37 PM, Chris Angelico wrote:
> On Wed, Dec 11, 2019 at 5:01 AM Tim Daneliuk <info at tundraware.com> wrote:
>>
>> On 12/10/19 10:36 AM, Peter Pearson wrote:
>>> Just to be sure: you *are* aware that the "Birthday Paradox" says
>>> that if you pick your 10-digit strings truly randomly, you'll probably
>>> get a collision by the time of your 10**5th string . . . right?
>>
>> I did not consider this, but the point is taken.
>>
>> Could you kindly point me to a source for calculating this given
>> n-digit numeric-only strings?
>>
> 
> The exact formula is pretty gnarly, but you can get remarkably close
> by assuming that you're likely to get a collision at the square root -
> which is half the exponent (so a 16-bit checksum will collide after
> about 2**8 examples, and a 128-bit UUID4 will collide after about
> 2**64 UUIDs are generated).
> 
> https://en.wikipedia.org/wiki/Birthday_problem
> 
> ChrisA
> 


Close enough for my purposes.  Thanks.

From onlinejudge95 at gmail.com  Sun Dec 15 10:25:53 2019
From: onlinejudge95 at gmail.com (Test Bot)
Date: Sun, 15 Dec 2019 20:55:53 +0530
Subject: Server side Blazor-like framework in Python?
In-Reply-To: <CAPTjJmqdsz2qCELsuuqf8q=_bOFdYHfnBxe_JcMP9fJn-ATOQg@mail.gmail.com>
References: <724ab04e-593a-4565-a8d4-e90f65140ffc@googlegroups.com>
 <CAPTjJmqdsz2qCELsuuqf8q=_bOFdYHfnBxe_JcMP9fJn-ATOQg@mail.gmail.com>
Message-ID: <CAD=M5eRwqFuM7PSDPBSCo5dVsaSOtX55TttLwVreY0d6XvNbvA@mail.gmail.com>

+1

Though the implementation might be good from an exercise perspective. But
there is a general philosophy in Software Engineering namely

Separation of Concern.

Python as a language is not concerned about the "Front-End" side of things
since it is not meant for that. Though i am a very devote Python
programmer, i would still prefer to limit Python to backend tasks and have
the Front End implemented in React.

On Sun, Dec 15, 2019 at 5:47 PM Chris Angelico <rosuav at gmail.com> wrote:

> On Sun, Dec 15, 2019 at 11:11 PM <hchrholm at online.no> wrote:
> >
> > I've been doing a lot of development with server side Blazor on .NET
> recently, and I think it's a very interesting UI model (
> https://docs.microsoft.com/en-us/aspnet/core/blazor/hosting-models?view=aspnetcore-3.1).
> What would it take to make something similar in Python? I guess a lot of
> relevant Python packages already exist.
> >
> > SSB works by having a component/DOM model running on the server. The
> client web page sends events and receives DOM diffs over a
> SignalR/websocket comnection.
> >
>
> I *much* prefer to have the front end in charge of the UI, and the
> back end work as an API. Just send and receive JSON with useful
> information in it, and let the front end figure out how it wants to
> display that.
>
> But hey, if you want to ship a DOM diff down the wire, go ahead. Just
> don't ask me to use your tool. :)
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From hchrholm at online.no  Sun Dec 15 13:26:34 2019
From: hchrholm at online.no (hchrholm at online.no)
Date: Sun, 15 Dec 2019 10:26:34 -0800 (PST)
Subject: Server side Blazor-like framework in Python?
In-Reply-To: <mailman.101.1576423566.11485.python-list@python.org>
References: <724ab04e-593a-4565-a8d4-e90f65140ffc@googlegroups.com>
 <CAPTjJmqdsz2qCELsuuqf8q=_bOFdYHfnBxe_JcMP9fJn-ATOQg@mail.gmail.com>
 <CAD=M5eRwqFuM7PSDPBSCo5dVsaSOtX55TttLwVreY0d6XvNbvA@mail.gmail.com>
 <mailman.101.1576423566.11485.python-list@python.org>
Message-ID: <9d267af1-c2d1-4b2b-ab6a-869725aa75b1@googlegroups.com>

Separation of concerns is not a question about language, but how your code is organised. Python is a general-purpose language and isn't restricted to certain programming domains. The restrictions are purely practical, such as performance and the availability of the runtime on various platforms.

There are many Python frameworks that could qualify as front end tools, including various attempts at running Python on the JS runtime in browsers. The pyodide project which runs Python and native code on webassembly in the browser, frameworks for desktop applications and even command line interfaces are all front end.

From hchrholm at online.no  Sun Dec 15 13:46:36 2019
From: hchrholm at online.no (hchrholm at online.no)
Date: Sun, 15 Dec 2019 10:46:36 -0800 (PST)
Subject: Server side Blazor-like framework in Python?
In-Reply-To: <724ab04e-593a-4565-a8d4-e90f65140ffc@googlegroups.com>
References: <724ab04e-593a-4565-a8d4-e90f65140ffc@googlegroups.com>
Message-ID: <5eacf40f-ac62-4fa1-b4ee-7d7e611e41ca@googlegroups.com>

Not to mention Flask and Django, both popular tools for making front ends, but the question wasn't about which personal opinions people have about this or that. I was wondering how one could make something similar to server side Blazor in Python. In particular, whether there are libraries that could be helpful. You would at least need some server side websocket code for managing connections and state, and preferably some templating system that could be translated to DOM elements mixed with data and event bindings the way the component model would need them. The component model itself should be possible to port from the Blazor source code.

From nad at python.org  Mon Dec 16 01:16:39 2019
From: nad at python.org (Ned Deily)
Date: Mon, 16 Dec 2019 01:16:39 -0500
Subject: Unable to install Flask-Mongoengine
In-Reply-To: <CAD=M5eSHKgrKxVqW5D4TfBiLSmfja_7aba9LwKKSJK1CPrXe1w@mail.gmail.com>
References: <CAD=M5eSHKgrKxVqW5D4TfBiLSmfja_7aba9LwKKSJK1CPrXe1w@mail.gmail.com>
Message-ID: <qt77g8$6suv$1@blaine.gmane.org>

On 2019-12-15 03:13, Test Bot wrote:
> I am unable to install *Flask-Mongoengine* using pip. Here are my 
> specifications
> 
> 1. *OS* => OSX 10.14.6
> 2. *Python* =>?Python 3.8.0 (Working in a virtualenv)
> 3. *Dependency Manager* => pip(19.3.1), setuptools(42.0.2)
> 3. *Flask-Mongoengine* =>?flask-mongoengine==0.9.5
> 
> I am inside my virtualenv and trying to install flask-mongoengine using
> 
>     (env) $ pip install?flask-mongoengine==0.9.5
> 
> 
> Here is my error
> 
>      ?distutils.errors.DistutilsError: Command
>     '['/Users/onlinejudge95/Workspace/GitHub/alma-serv/env/bin/python',
>     '-m', 'pip', '--disable-pip-version-check', 'wheel', '--no-deps',
>     '-w',
>     '/var/folders/r7/pgqw605n55x5f9018rp72hsm0000gn/T/tmpgrvp80jd',
>     '--quiet', 'rednose']' returned non-zero exit status 1.

You are running into an issue caused by a change in setuptools:

https://github.com/pypa/setuptools/issues/1934

It looks like the simplest solution is to first install the wheel
package in your venv:

pip install wheel
pip install flask-mongoengine==0.9.5

Either that or install a previous version of setuptools.  You may want 
to chime in on the discussion of that issue.




From dieter at handshake.de  Mon Dec 16 02:45:17 2019
From: dieter at handshake.de (dieter)
Date: Mon, 16 Dec 2019 08:45:17 +0100
Subject: Setting Pythonpath programmatic
References: <c86f6dbe-3136-4822-acaa-555be2161cd3@googlegroups.com>
Message-ID: <87a77ssohe.fsf@handshake.de>

Prasad Rajassekaran <prasadautomationtesting at gmail.com> writes:
> I would want to set python path programmatic in my project. So that, all other directories files can be imported without any issues.

You can extend "sys.path" programmatically to control
where Python looks for top level packages/modules (as
you apparently have already tried - it should have worked).

You may also read about ".pth" files (= "path configuration files"),
documented with Python's "site" module. It allows a folder on "sys.path"
to specify where else to look for top level packages/modules.

I have seen cases where "sys.path" extensions had not the
expected effects. This has been with so called "namespace packages"
(this is some kind of distributed package, where package components
can be found in unrelated locations). I never was able to
find the cause: apparently, it was related to the
discrepancy between the modern installation approach (the namespace
package components become centralized on installation) and
the traditional approach (the components remain distributed);
for me, it looked like a Python bug affecting the case when both
approaches have been applied to the same namespace package.
I do not think that your problem is related to this case.


From dieter at handshake.de  Mon Dec 16 02:56:26 2019
From: dieter at handshake.de (dieter)
Date: Mon, 16 Dec 2019 08:56:26 +0100
Subject: Pickle caching objects?
References: <20191130220545.GA12875@equipaje>
Message-ID: <875zigsnyt.fsf@handshake.de>

Jos? Mar?a Mateos <chema at rinzewind.org> writes:
> I just asked this question on the IRC channel but didn't manage to get
> a response, though some people replied with suggestions that expanded
> this question a bit.
>
> I have a program that has to read some pickle files, perform some
> operations on them, and then return. The pickle objects I am reading
> all have the same structure, which consists of a single list with two
> elements: the first one is a long list, the second one is a numpy
> object.
>
> I found out that, after calling that function, the memory taken by the
> Python executable (monitored using htop -- the entire thing runs on
> Python 3.6 on an Ubuntu 16.04, pretty standard conda installation with
> a few packages installed directly using `conda install`) increases in
> proportion to the size of the pickle object being read. My intuition
> is that that memory should be free upon exiting.
>
> Does pickle keep a cache of objects in memory after they have been
> returned?

"pickle.load" does not itself cache objects in memory.
However, Python may cache some (usually small objects, such as some
integer objects).

Note also that Python memeory management is quite elaborate:
not every memory block is immediately obtained from and released
to the operating system: Python has its own memory management
data structures (to fill the gap between the fine grained
memory requirements of a Python application and the mostly crude memory
management services the operating system supports out of hand).
This means that usually, a memory block freed by the Python application
is not returned to the operating system but maintained by Python's
memory management to be reused later. As a consequence, operating system
tools for memory monitoring usually cannot tell the amount of memory
really used by the application.


From songofacandy at gmail.com  Mon Dec 16 03:11:01 2019
From: songofacandy at gmail.com (Inada Naoki)
Date: Mon, 16 Dec 2019 17:11:01 +0900
Subject: Pickle caching objects?
In-Reply-To: <20191130220545.GA12875@equipaje>
References: <20191130220545.GA12875@equipaje>
Message-ID: <CAEfz+TxyYQCZJ4ytov=Ui6HJ891HtSkondupFB4-yh0q=cMEQQ@mail.gmail.com>

Would you try the pull request in this issue?
https://bugs.python.org/issue36694

I'm not sure this issue is relating to you because I don't know about your data.

Regards,

On Sun, Dec 1, 2019 at 10:14 AM Jos? Mar?a Mateos <chema at rinzewind.org> wrote:
>
> Hi,
>
> I just asked this question on the IRC channel but didn't manage to get a
> response, though some people replied with suggestions that expanded this
> question a bit.
>
> I have a program that has to read some pickle files, perform some
> operations on them, and then return. The pickle objects I am reading all
> have the same structure, which consists of a single list with two
> elements: the first one is a long list, the second one is a numpy
> object.
>
> I found out that, after calling that function, the memory taken by the
> Python executable (monitored using htop -- the entire thing runs on
> Python 3.6 on an Ubuntu 16.04, pretty standard conda installation with a
> few packages installed directly using `conda install`) increases in
> proportion to the size of the pickle object being read. My intuition is
> that that memory should be free upon exiting.
>
> Does pickle keep a cache of objects in memory after they have been
> returned? I thought that could be the answer, but then someone suggested
> to measure the time it takes to load the objects. This is a script I
> wrote to test this; nothing(filepath) just loads the pickle file,
> doesn't do anything with the output and returns how long it took to
> perform the load operation.
>
> ---
> import glob
> import pickle
> import timeit
> import os
> import psutil
>
> def nothing(filepath):
>     start = timeit.default_timer()
>     with open(filepath, 'rb') as f:
>         _ = pickle.load(f)
>     return timeit.default_timer() - start
>
> if __name__ == "__main__":
>
>     filelist = glob.glob('/tmp/test/*.pk')
>
>     for i, filepath in enumerate(filelist):
>         print("Size of file {}: {}".format(i, os.path.getsize(filepath)))
>         print("First call:", nothing(filepath))
>         print("Second call:", nothing(filepath))
>         print("Memory usage:", psutil.Process(os.getpid()).memory_info().rss)
>         print()
> ---
>
> This is the output of the second time the script was run, to avoid any
> effects of potential IO caches:
>
> ---
> Size of file 0: 11280531
> First call: 0.1466723980847746
> Second call: 0.10044755204580724
> Memory usage: 49418240
>
> Size of file 1: 8955825
> First call: 0.07904054620303214
> Second call: 0.07996074995025992
> Memory usage: 49831936
>
> Size of file 2: 43727266
> First call: 0.37741047400049865
> Second call: 0.38176894187927246
> Memory usage: 49758208
>
> Size of file 3: 31122090
> First call: 0.271301960805431
> Second call: 0.27462846506386995
> Memory usage: 49991680
>
> Size of file 4: 634456686
> First call: 5.526095286011696
> Second call: 5.558765463065356
> Memory usage: 539324416
>
> Size of file 5: 3349952658
> First call: 29.50982437795028
> Second call: 29.461691531119868
> Memory usage: 3443597312
>
> Size of file 6: 9384929
> First call: 0.0826977719552815
> Second call: 0.08362263604067266
> Memory usage: 3443597312
>
> Size of file 7: 422137
> First call: 0.0057482069823890924
> Second call: 0.005949910031631589
> Memory usage: 3443597312
>
> Size of file 8: 409458799
> First call: 3.562588643981144
> Second call: 3.6001368327997625
> Memory usage: 3441451008
>
> Size of file 9: 44843816
> First call: 0.39132978999987245
> Second call: 0.398518088972196
> Memory usage: 3441451008
> ---
>
> Notice that memory usage increases noticeably specially on files 4 and
> 5, the biggest ones, and doesn't come down as I would expect it to. But
> the loading time is constant, so I think I can disregard any pickle
> caching mechanisms.
>
> So I guess now my question is: can anyone give me any pointers as to why
> is this happening? Any help is appreciated.
>
> Thanks,
>
> --
> Jos? Mar?a (Chema) Mateos || https://rinzewind.org/
> --
> https://mail.python.org/mailman/listinfo/python-list



-- 
Inada Naoki  <songofacandy at gmail.com>

From hjp-python at hjp.at  Mon Dec 16 05:22:06 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 16 Dec 2019 11:22:06 +0100
Subject: Pickle caching objects?
In-Reply-To: <875zigsnyt.fsf@handshake.de>
References: <20191130220545.GA12875@equipaje>
 <875zigsnyt.fsf@handshake.de>
Message-ID: <20191216102206.GA32606@hjp.at>

On 2019-12-16 08:56:26 +0100, dieter wrote:
> Note also that Python memeory management is quite elaborate:
> not every memory block is immediately obtained from and released
> to the operating system: Python has its own memory management
> data structures (to fill the gap between the fine grained
> memory requirements of a Python application and the mostly crude memory
> management services the operating system supports out of hand).
> This means that usually, a memory block freed by the Python application
> is not returned to the operating system but maintained by Python's
> memory management to be reused later. As a consequence, operating system
> tools for memory monitoring usually cannot tell the amount of memory
> really used by the application.

This is all true even if python does nothing special[1]: The C library
itself manages memory like this. So if python just calls malloc and
free you will see this behaviour. In particular the GNU C library (used
on most Linux systems) serves all "small" allocations from a common
pool (called the "heap") which can only grow and shrink at one end and
requests "large" allocations directly from the OS. Since the python
interpreter tends to use lots of small objects, most of the allocations
come from the heap which can't be returned to the OS unless there is a
large unused chunk right at the end.

        hp

[1] I haven't looked at the source code, but ltrace reveals a lot of
small mallocs, so it probably doesn't.

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191216/a1f69d3e/attachment.sig>

From hjp-python at hjp.at  Mon Dec 16 05:44:07 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 16 Dec 2019 11:44:07 +0100
Subject: The file method read does not "see" CR
In-Reply-To: <CAP=-cKWowYeb5S4W_Qa-tYqLQ5xf5T+pD5mOnESVSmUMP26D5Q@mail.gmail.com>
References: <CAP=-cKWowYeb5S4W_Qa-tYqLQ5xf5T+pD5mOnESVSmUMP26D5Q@mail.gmail.com>
Message-ID: <20191216104407.GB32606@hjp.at>

On 2019-12-10 10:15:45 +0000, Stephen Tucker wrote:
> I am running Python 2.7.10 on a Windows 10 machine.

Unless you have a really good reason to stick with Python 2.7, don't:
https://pythonclock.org/

The current version of Python is 3.8, and there have been quite a few
changes between 2.x and 3.x, especially in the treatment of byte and
character strings.

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191216/16be6ce9/attachment.sig>

From duncan at invalid.invalid  Mon Dec 16 11:12:14 2019
From: duncan at invalid.invalid (duncan smith)
Date: Mon, 16 Dec 2019 16:12:14 +0000
Subject: distinguishable matplotlib colours / symbols / line styles
Message-ID: <z1OJF.89881$0X7.2919@fx09.iad>

Hello,
      Not really specific to Python or matplotlib (but that's what I'm
using). I'm looking for a good combination of colours and symbols for
scatter plots, and combination of colours and line styles for line
plots. Too often I find myself producing these when I don't know whether
they will end up being printed in colour or greyscale. It would be a lot
easier if I could produce decent plots that would work well in either
case. I can find various stuff on colour palettes, but pretty much
nothing on symbols or line styles. Is anybody aware of an approach that
works well? I'm aware of issues with colour blindness and RGB versus
CMYK. Ideally I'd have something that I could just use that would deal
with all these issues. TIA.

Duncan

From rosuav at gmail.com  Mon Dec 16 11:19:55 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 17 Dec 2019 03:19:55 +1100
Subject: distinguishable matplotlib colours / symbols / line styles
In-Reply-To: <z1OJF.89881$0X7.2919@fx09.iad>
References: <z1OJF.89881$0X7.2919@fx09.iad>
Message-ID: <CAPTjJmoVYFEq4pa4+Xxgf4THAH5CZ7iPhR0cbuytREpZ+3xS9A@mail.gmail.com>

On Tue, Dec 17, 2019 at 3:16 AM duncan smith <duncan at invalid.invalid> wrote:
>
> Hello,
>       Not really specific to Python or matplotlib (but that's what I'm
> using). I'm looking for a good combination of colours and symbols for
> scatter plots, and combination of colours and line styles for line
> plots. Too often I find myself producing these when I don't know whether
> they will end up being printed in colour or greyscale. It would be a lot
> easier if I could produce decent plots that would work well in either
> case. I can find various stuff on colour palettes, but pretty much
> nothing on symbols or line styles. Is anybody aware of an approach that
> works well? I'm aware of issues with colour blindness and RGB versus
> CMYK. Ideally I'd have something that I could just use that would deal
> with all these issues. TIA.
>

I'd recommend looking at the Web Content Accessibility Guidelines
published by the W3C; there are a number of tools out there that are
designed to help you pick colours for a web page, and the same sorts
of rules will apply here, I think.

Also, thank you for even *thinking* about this. A lot of people don't. :)

ChrisA

From patrick.igwilo at yahoo.com  Sun Dec 15 09:54:29 2019
From: patrick.igwilo at yahoo.com (Patrick Igwilo)
Date: Sun, 15 Dec 2019 14:54:29 +0000 (UTC)
Subject: Problem Running Python
In-Reply-To: <AM5PR10MB162006FB301FE8EEA2AAF5B584560@AM5PR10MB1620.EURPRD10.PROD.OUTLOOK.COM>
References: <AM5PR10MB1620D2DB278590D60F020C3084560@AM5PR10MB1620.EURPRD10.PROD.OUTLOOK.COM>
 <AM5PR10MB162006FB301FE8EEA2AAF5B584560@AM5PR10MB1620.EURPRD10.PROD.OUTLOOK.COM>
Message-ID: <215452112.7876617.1576421669362@mail.yahoo.com>


Hello,I downloaded and tried installing Python 3.8.0 on my windows 8.1 PC?from the websitewww.python.org/downloadsAfter the 32-bit version was automatically downloaded and I successfully installed same (even though my PC has a 64-bit CPU),?I tried opening the installed?program?and I got an error message essentially saying that a certain??ms crt file? with a dll extension was missing from my computer and as a result the program would not run.
kindly assist me through the proper download and installation procedure as I really need to start learning coding with the Python programming language.
Many thanks for the good work.

Patrick.


  

From python at mrabarnett.plus.com  Mon Dec 16 13:28:02 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 16 Dec 2019 18:28:02 +0000
Subject: Problem Running Python
In-Reply-To: <215452112.7876617.1576421669362@mail.yahoo.com>
References: <AM5PR10MB1620D2DB278590D60F020C3084560@AM5PR10MB1620.EURPRD10.PROD.OUTLOOK.COM>
 <AM5PR10MB162006FB301FE8EEA2AAF5B584560@AM5PR10MB1620.EURPRD10.PROD.OUTLOOK.COM>
 <215452112.7876617.1576421669362@mail.yahoo.com>
Message-ID: <dddc8eb9-6a60-dbec-ae5f-d998c83368fe@mrabarnett.plus.com>

On 2019-12-15 14:54, Patrick Igwilo via Python-list wrote:
> 
> Hello,I downloaded and tried installing Python 3.8.0 on my windows 8.1 PC?from the websitewww.python.org/downloadsAfter the 32-bit version was automatically downloaded and I successfully installed same (even though my PC has a 64-bit CPU),?I tried opening the installed?program?and I got an error message essentially saying that a certain??ms crt file? with a dll extension was missing from my computer and as a result the program would not run.
> kindly assist me through the proper download and installation procedure as I really need to start learning coding with the Python programming language.
> Many thanks for the good work.
> 
If it's complaining about this "api-ms-win-crt-runtime-l1-1-0.dll", then
you need the Windows Universal C Runtime:

http://www.microsoft.com/en-us/download/details.aspx?id=48234

From barry at barrys-emacs.org  Mon Dec 16 13:57:57 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Mon, 16 Dec 2019 18:57:57 +0000
Subject: Setting Pythonpath programmatic
In-Reply-To: <c86f6dbe-3136-4822-acaa-555be2161cd3@googlegroups.com>
References: <c86f6dbe-3136-4822-acaa-555be2161cd3@googlegroups.com>
Message-ID: <B1FCC2C0-E445-4A73-BBF7-F426ACAEEA88@barrys-emacs.org>



> On 14 Dec 2019, at 16:00, Prasad Rajassekaran <prasadautomationtesting at gmail.com> wrote:
> 
> 0
> 
> 
> Aim:-
> 
> I would want to set python path programmatic in my project. So that, all other directories files can be imported without any issues.
> 
> Problem statement:-
> 
> I used to add all the folders & sub-folders in environment variables under PYTHONPATH but this has two constrains.
> 
> 1, Any new folders created need to be added in environment variables all the times. After certain limit, environment variables will not be accepted new path reference due to characters limitaion.
> 
> - Error: This environment variable is too large. This dialog allows setting values up to 2047 characters long.
> 
> 2, Secondly, all the team members in my team need to perform the same activity manually all the times.
> 
> Tried self solution:-
> 
> Created a sample folder and added the below code before main import files and ran from command prompt which worked perfectly fine.
> 
> **FilePath: foo/Python/Learning&Development/Pratice/Directory1/File1.py**
> 
> class File1():
> 
>    def parent(self):
>        return "I am from File1"
> 
> **FilePath: foo/Python/Learning&Development/Pratice/Directory2/File2.py**
> 
>    import sys
> try:
>    sys.path.index('foo/Python/Learning&Development')
>    sys.path.index('foo/Python/Learning&Development/Pratice')
>    sys.path.index('foo/Python/Learning&Development/Pratice/Directory1')
>    sys.path.index('foo/Python/Learning&Development/Pratice/Directory2')
> except ValueError:
>    sys.path.append('foo/Python/Learning&Development')

That's your top folder.

>     sys.path.append('foo/Python/Learning&Development/Pratice')
>    sys.path.append('foo/Python/Learning&Development/Pratice/Directory1')
>    sys.path.append('foo/Python/Learning&Development/Pratice/Directory2')

But what are these? Do you have modules so can access from the top folder?

> 
> from Pratice.Directory1.File1 import File1 as f

Only works if you have created modules on the disk.

Do you have __init__.py in Pratice, Practice/Directot1 etc?

Barry


> 
> 
> class File2():
> 
>    def child(self):
>        return f.parent(self)
> Results:
> 
> I am from File1
> 
> Now I wish to convert the sys.path as a single method and call automatically before running any .py file in the project folder.
> 
> So, on trail basis, I created 'init.py' file added the same piece (sys.path) of code, commented the same code in File2.py and run it but ended up with file import error.
> 
> **FilePath: foo/Python/Learning&Development/Pratice/Directory2/__init__.py**
> 
> import sys
> try:
>    sys.path.index('foo/Automation/Python/Learning&Development')
>    sys.path.index('foo/Automation/Python/Learning&Development/Pratice')
>    sys.path.index('foo/Automation/Python/Learning&Development/Pratice/Directory1')
>    sys.path.index('foo/Automation/Python/Learning&Development/Pratice/Directory2')
> except ValueError:
>    sys.path.append('foo/Automation/Python/Learning&Development')
>    sys.path.append('foo/Automation/Python/Learning&Development/Pratice')
> sys.path.append('foo/Automation/Python/Learning&Development/Pratice/Directory1') sys.path.append('foo/Automation/Python/Learning&Development/Pratice/Directory2')
> 
> **FilePath: foo/Python/Learning&Development/Pratice/Directory1/File1.py**
> 
> class File1():
> 
>    def parent(self):
>        return "I am from File1"
> 
> **FilePath: foo/Python/Learning&Development/Pratice/Directory2/File2.py**
> 
> # import sys
> # try:
>    # sys.path.index('foo/Python/Learning&Development')
>    # sys.path.index('foo/Python/Learning&Development/Pratice')
>    # sys.path.index('foo/Python/Learning&Development/Pratice/Directory1')
>    # sys.path.index('foo/Python/Learning&Development/Pratice/Directory2')
> # except ValueError:
>    # sys.path.append('foo/Python/Learning&Development')
>    # sys.path.append('foo/Python/Learning&Development/Pratice')
>    # sys.path.append('foo/Python/Learning&Development/Pratice/Directory1')
>    # sys.path.append('foo/Python/Learning&Development/Pratice/Directory2')
> 
> from Pratice.Directory1.File1 import File1 as f
> 
> 
> class File2():
> 
>    def child(self):
>        return f.parent(self)
> Results:
> 
> Traceback (most recent call last):
>  File "File2.py", line 13, in <module>
>    from Pratice.Directory1.File1 import File1 as f
> ModuleNotFoundError: No module named 'Pratice
> 
> Could someone help me on this problem? I would want the same piece of code to be executed before running any of the .py file in my project folder. So that, import error would not come into picture.
> 
> Expected: Python path should be set automatically by default and import error should not occur while running any python file in the project.
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From PythonList at DancesWithMice.info  Mon Dec 16 16:08:09 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 17 Dec 2019 10:08:09 +1300
Subject: distinguishable matplotlib colours / symbols / line styles
In-Reply-To: <CAPTjJmoVYFEq4pa4+Xxgf4THAH5CZ7iPhR0cbuytREpZ+3xS9A@mail.gmail.com>
References: <z1OJF.89881$0X7.2919@fx09.iad>
 <CAPTjJmoVYFEq4pa4+Xxgf4THAH5CZ7iPhR0cbuytREpZ+3xS9A@mail.gmail.com>
Message-ID: <39a27f1f-f96a-4449-cfc7-06d84d9c81f8@Kapua.Cloud>

On 17/12/19 5:19 am, Chris Angelico wrote:
> On Tue, Dec 17, 2019 at 3:16 AM duncan smith <duncan at invalid.invalid> wrote:
>>
>> Hello,
>>        Not really specific to Python or matplotlib (but that's what I'm
>> using). I'm looking for a good combination of colours and symbols for
>> scatter plots, and combination of colours and line styles for line
>> plots. Too often I find myself producing these when I don't know whether
>> they will end up being printed in colour or greyscale. It would be a lot
>> easier if I could produce decent plots that would work well in either
>> case. I can find various stuff on colour palettes, but pretty much
>> nothing on symbols or line styles. Is anybody aware of an approach that
>> works well? I'm aware of issues with colour blindness and RGB versus
>> CMYK. Ideally I'd have something that I could just use that would deal
>> with all these issues. TIA.
>>
> 
> I'd recommend looking at the Web Content Accessibility Guidelines
> published by the W3C; there are a number of tools out there that are
> designed to help you pick colours for a web page, and the same sorts
> of rules will apply here, I think.
> 
> Also, thank you for even *thinking* about this. A lot of people don't. :)

+1

We spend a lot of time teaching this topic (non-Python courses). It 
receives a lot of often highly-polarised comments/discussion. Many folk 
have their 'eyes opened' to an issue which has not affected them 
personally. Some even have to be informed that it is a legal obligation 
in their jurisdiction. However, it also receives the highest number of 
'why do I have to learn this stuff' complaints...

I learned (way back) that the incidence of "color blindness" is far 
higher than I had imagined. Secondly, that it affects males more than 
females. Thirdly, that calling it "blindness" is a bit of a misnomer, 
because whilst people often can't see red 'correctly' (most common 
symptom), they do see something (it varies). Which is why they are 
permitted to drive vehicles (traffic lights: red, amber/yellow, green - 
and arrows; plus stop/brake lights), but why many smart-phone apps/web 
pages which encode information-relevance (red is 'wrong' and green/blue 
is acceptable) can become almost unusable (without other cues).

Those key-words: "accessibility guidelines" will yield a swag of useful 
tools - ignore the ones which are basically 'help choose the color of my 
web page/color palette, because they are often aiming (only) for 
'pretty'. The best tools enumerate the efficacy of fg/bg 
color-combinations, allowing one to experiment; and will enumerate 
grey-scale variation/comparisons.


Hmmm, note to self (you've inspired me to specifically review/critique 
the printing-from-screen action): what happens when we take a 
color-checked screen display and print same but end-up viewing it as 
monochrome/grey-scale output? Probably not a main-stream demand, but 
worth tossing at the WCAG experts...
-- 
-- 
Regards =dn

From rosuav at gmail.com  Mon Dec 16 17:12:56 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 17 Dec 2019 09:12:56 +1100
Subject: distinguishable matplotlib colours / symbols / line styles
In-Reply-To: <39a27f1f-f96a-4449-cfc7-06d84d9c81f8@Kapua.Cloud>
References: <z1OJF.89881$0X7.2919@fx09.iad>
 <CAPTjJmoVYFEq4pa4+Xxgf4THAH5CZ7iPhR0cbuytREpZ+3xS9A@mail.gmail.com>
 <39a27f1f-f96a-4449-cfc7-06d84d9c81f8@Kapua.Cloud>
Message-ID: <CAPTjJmoFtwmbHRyfzDJOXy_Hvu4pgd+NC31XjCsOMBSfcGRVPA@mail.gmail.com>

On Tue, Dec 17, 2019 at 8:09 AM DL Neil via Python-list
<python-list at python.org> wrote:
>
> On 17/12/19 5:19 am, Chris Angelico wrote:
> > On Tue, Dec 17, 2019 at 3:16 AM duncan smith <duncan at invalid.invalid> wrote:
> >>
> >> Hello,
> >>        Not really specific to Python or matplotlib (but that's what I'm
> >> using). I'm looking for a good combination of colours and symbols for
> >> scatter plots, and combination of colours and line styles for line
> >> plots. Too often I find myself producing these when I don't know whether
> >> they will end up being printed in colour or greyscale. It would be a lot
> >> easier if I could produce decent plots that would work well in either
> >> case. I can find various stuff on colour palettes, but pretty much
> >> nothing on symbols or line styles. Is anybody aware of an approach that
> >> works well? I'm aware of issues with colour blindness and RGB versus
> >> CMYK. Ideally I'd have something that I could just use that would deal
> >> with all these issues. TIA.
> >>
> >
> > I'd recommend looking at the Web Content Accessibility Guidelines
> > published by the W3C; there are a number of tools out there that are
> > designed to help you pick colours for a web page, and the same sorts
> > of rules will apply here, I think.
> >
> > Also, thank you for even *thinking* about this. A lot of people don't. :)
>
> +1
>
> We spend a lot of time teaching this topic (non-Python courses). It
> receives a lot of often highly-polarised comments/discussion. Many folk
> have their 'eyes opened' to an issue which has not affected them
> personally. Some even have to be informed that it is a legal obligation
> in their jurisdiction. However, it also receives the highest number of
> 'why do I have to learn this stuff' complaints...

So true. Although sometimes it pays to just make it an arbitrary
requirement - for instance, if your students submit code for grading,
you could incorporate into your rubric "must have zero errors in aXe
report" (along with "must have zero errors in W3C Validator"). Yes,
that's technically not the point... but it's remarkably helpful in
dealing with those unreadable web sites that, unfortunately, can be
seen in a lot of production environments...

> Those key-words: "accessibility guidelines" will yield a swag of useful
> tools - ignore the ones which are basically 'help choose the color of my
> web page/color palette, because they are often aiming (only) for
> 'pretty'. The best tools enumerate the efficacy of fg/bg
> color-combinations, allowing one to experiment; and will enumerate
> grey-scale variation/comparisons.

Agreed; "accessibility" or "a11y" (and yes, I will pronounce that
"ally", judge me all you like) is the thing to look for. Looking for
"readability" can be a bit hit or miss, but "a11y" does well.

> Hmmm, note to self (you've inspired me to specifically review/critique
> the printing-from-screen action): what happens when we take a
> color-checked screen display and print same but end-up viewing it as
> monochrome/grey-scale output? Probably not a main-stream demand, but
> worth tossing at the WCAG experts...

It's funny how the same considerations come up in different contexts.
Advice from a Twitch emote artist: Always desaturate your image to
greyscale and see how it looks. If your icon still looks like the
thing it's meant to be, great! But if it all blurs away to nothing
when it's greyscaled, chances are it won't be readable even in its
original colour form. This is especially true if you have more than
two colours involved - say, you have a shaped background and text that
goes partly on it and partly off it, so the text needs to be readable
on both the backgrounds.

I'm sure the experts have already looked into that exact concept, and
probably have a much more rigorous way to define the problem and the
solution. But "flip the saturation to zero in your image editor" is a
pretty close approximation. You can do the same thing with a web page
with a bit of CSS:

body {filter: saturate(0);}

Check your page like that and see if it's still readable. A good page
will just look nightvisioned, a bad one will suddenly be unreadable.

(For the fun of it, I just tried that on a few web sites. After doing
that for a while, your brain gets used to it, and then colour starts
to look weird...)

ChrisA

From PythonList at DancesWithMice.info  Mon Dec 16 17:36:40 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 17 Dec 2019 11:36:40 +1300
Subject: Python3 - How do I import a class from another file
In-Reply-To: <qsnlut$1g3l$1@gioia.aioe.org>
References: <qsj8da$ll8$1@gioia.aioe.org>
 <5ded2867$0$20334$426a34cc@news.free.fr> <qsjfeh$1nbf$3@gioia.aioe.org>
 <qsjk1d$13b9$1@blaine.gmane.org>
 <mailman.373.1575834486.25794.python-list@python.org>
 <qskump$eo2$1@gioia.aioe.org> <qsl7sg$1db5$1@blaine.gmane.org>
 <489bdce7-b390-0271-f1da-dd6dfa1eb111@DancesWithMice.info>
 <mailman.397.1575932385.25794.python-list@python.org>
 <qsnlut$1g3l$1@gioia.aioe.org>
Message-ID: <9b50cf3a-8428-1ad6-fb7d-8c5b33369d98@DancesWithMice.info>

Wow, I turned my back to attend to $job and this conversation has 
'exploded' (>80 msgs)!

TLDR;
With apologies, I started to reply to your reply, but then added 'bits' 
as I read the conversation thereafter. The result (below) is a messy 
hodge-podge, for which I can only apologise (as I don't have more 
spare-time to be able to 'fix it' and edit it into some semblance of 
proper order). May I suggest a first quick-read to pick-up the 
'highlights', and then re-reading in order to make sense of the 
cross-references? I regret the appearance of circling-back between topics...



On 10/12/19 9:45 pm, R.Wieser wrote:
...

> Than again, I normally camel-case my variable and function names (to make
> them stand out from the build-in commands), as I normally do not use editors
> with syntax highlighting.
...

> :-) Always start with a descriptive* name for the variable, regardless of if
> it is a compounded one or not.   As said, the type prefix is just a
> reminder.

Remember that PEP-8 is (only?) applied to code submitted for inclusion 
in the Python Standard Library. It's wider application is less 
prescriptive (although many in-house style manuals take an 
embrace-and-extend approach).

Bottom-line (IMHO):
- if you are coding by yourself and only for yourself, you make your own 
'rules'!
- if you are working with others, you (all) come up with 'the rules' - 
one of which may be that you allow 'the other guy' to make his own 
rules, whilst (s)he does the same for you - and simply work-around that 
with your own (and, one assumes, v-v)
- if the organisation/team already has 'rules', then you adapt to the 
group mores...

Have you come across the bit where Guido (I think?) talks about "the 
hobgoblin" of over-applying 'rules'? To which the 'Zen of Python' adds 
(the joke) "unless you're Dutch".

The topic of naming-standards is a massive time-sink/hobgoblin (see also 
- using tabs or spaces to indent, and 'how many spaces')...
(see also: which car is 'best', which language is 'best', which team..., 
which super-hero..., do you really love me? does my bum look big in this...)

That said, there's enough to learn when taking-on a new language, 
without 'sweating the small stuff' ("cognitive load"). So, if it helps 
you to use VS Coding Standards right now, just do it. Later, as you come 
to understand more of the 'philosophies' behind Python, you will/may 
learn/adapt (see also, 'working with others', above).


> *though not /too/ descriptive.   Languages which can easily have
> 40-character names for variables, functions and such are simply the pits,
> especially when they start to differ only for a single/few character(s)
> somewhere in the middle. :-(

Surely it is unlikely that all 40-characters are necessary to 
communicate meaning!? Even in Welsh?Tamil?Dutch?German?

That said, it is *so* easy with modern text editors to make universal 
changes (an error-laden task filled with so much peril it was 
strenuously-avoided in the ?good, old, days) - which ease applies as 
much to variableNMs as it does to interpreting what tab-to-indent 
means/is to mean for this module!

In other words, I play as fast-and-loose as does Python (per earlier 
comment).


>> rudy = Man( etc ) #rudy probably does have class, in this instance
> You almost owed me a new keyboard there. :-p

Normally my lame jokes are greeted with a groan, so I'll take that as a 
compliment (regardless of how it was intended - I'm that desperate!)


Which brings me to a few points, noted throughout the conversation. 
Whereas I do offer training (not Python), hold a qualification in the 
field (specifically vocational training/andragogy), and have a research 
interest in Cognitive Psychology (yeah, yeah, blah, blah, big deal...) 
there will be very few others, similar, who are also (active) members of 
this list. Expecting high-quality 'training materials' as responses is 
probably asking 'a bit much'...


We do have folk (on the list) who are actively developing the language, 
others who use the language professionally and every-day, and still 
more, less specialised, right ?down to 'mere' hobbyists who only get to 
talk-Python at (some) weekends. Answers reflect that. However, a scan of 
(names frequently appearing in) the archives will soon reveal 'much'!

In case of misunderstanding:
There is no-one (to my knowledge) who is paid to be 'here'. All 
contributions are voluntary and provided out of people's 'free time'. It 
is not a manufacturer's 'support site'!

The best way to receive help with coding (as has been said) is to 
copy-paste *your* problematic code into a post. This allows interested 
parties to easily reproduce the problem (or not). It also ensures that 
responses are as specific as possible by providing 'focus'!

It also pays to continue the copy-paste-result pattern when replying to 
advice: 'I've tried it, and 'this' is what happened' - yet I understood 
you to say 'that' should...' Such not only ensures/contributes to 
ensuring that both/all understand the problem and are discussing the 
'same' thing; but incidentally show that you have respected the person's 
contribution, have paid due attention, and have tried/failed it...

If any response appears incomplete or 'insufficient', then is it 
incumbent upon you to research and experiment further, or should the 
person who has already given-up his/her time do more/'do a better job'? 
(another rhetorical question)

As a reference-point: Not so long ago, I was told, by folk on this list, 
that what I expected/requested of a Python library was not 'right', ie 
not congruent with the thinking of the code's authors. I also 
mis-interpreted words within the explanations. Thus my 'experience' and 
understanding was tripping-up my Python-comprehension, and it took a 
couple of 'rounds' before people zero-ed in on exactly why - and thus 
how to pound 'understanding' through my thick skull. In the end I 
realised that the library was not (?good enough) going to do what I 
thought it would?should, and I could either beat my head against its 
'brick wall' or I could 'go elsewhere' (which I did). None of which 
stopped me from learning, nor did it deny the kindness of others 
prepared to 'set me right'...


I was amused to be reminded of (your recollection) the 'rules for 
debugging' but its superficiality does not (necessarily) apply - and you 
knew that!!! Given Python's many allusions to the "Monty Python" 
comedies, you should have no trouble finding the source when I quote 
that you are "a very naughty boy"!

In many cases, within the Python environment (and philosophy), 
extracting a minimal version of the problem and solving that, may even 
remove/ameliorate the effect of 'by-products' and 'unfortunate' 
combinations or assumptions (on my part). Debugging a dynamic language, 
cf FORTRAN, et al; is a quite 'different ball-game'!

On which topic, have you discovered the Python REPL? Whilst we (appear 
to be) are talking 'debugging', there is no equivalent anodyne (that I 
have come-across) in the compiled world, and I frequently use it when 
first coding/designing something (cf debugging-mode) to assure my 
'mental model'. It offers the opportunity to code a couple of lines, 
particularly when using a construct for the very first time, and to 
'see' the results immediately. In other words, to ensure that our 
understanding of 'what the books says' is the same as the way Python 
'sees it'. So, those few lines of creating a class, instantiating it, 
and then deleting (one/other/both)... Really easy (can even copy-paste 
'the answer' into one's editor), and an immensely valuable learning (and 
'reminding') tool!

You may also enjoy the facilities of Philip Gao's web-based 
demonstration at http://pythontutor.com/ (be aware, its objectives are 
to 'show' what happens inside 'the computer', I won't guarantee that any 
'demonstration' of del() or the Garbage Collector are authoritative!)


> :-) The normal newbie progression, off of which I'm in phase #1.   Having a
> working program (riddeled with debugging output) is still (way) more
> important than having the best code I'm afraid.   But reading about how
> others handle it definitily makes it easier for me to progress.

I like to think of (at least) three stages in learning Python: 
'apprentice', 'journeyman', and 'master'. (which, coincidentally, even 
though I've changed from mine to adopt one of their choices of 
terminology are the names of a series of Python-training books)

The words/titles are something of an outline of the learning process. As 
an 'apprentice', and noticing that Python often 'does things 
differently' when compared with other languages-I-have-known, it seemed 
easier to take certain statements 'on faith'. Later to re-visit topics 
as a 'journeyman' (and presumably, again, as a 'master' - am not sure 
that I could claim such lofty heights!). The opposite of solving a 
problem by 'peeling the onion' - putting successive layers on the onion, 
one after the other; if you will.

In this way, we learn a 'little bit' about each facility, and later 
learn 'a bit more', and later..., until we (hopefully) achieve mastery. 
In ComSc we would call this a "width-first" or "breadth-first" approach!

In Cognitive Psychology we talk of creating a framework or "map" in your 
mind - of how things work by fitting-together. We best construct these 
frameworks by starting from 'known knowledge' and bolting-on 
(bite-sized) chunks of new-knowledge.

However, (why is there always a "but"?) sometimes the existing framework 
is inappropriate, eg both a car and a go-kart have four wheels, but if 
you knew a lot about cars and started from a car-chassis, you would soon 
decide that was the wrong 'framework' from which to learn to build your 
first go-kart! Accordingly, (and this is *really* difficult) talking 
(elsewhere) of being prepared to 'take on faith', some new-learning, in 
the expectation of better-seeing how the 'chunks' fit-together later, as 
one gains experience (in Python), becomes a 'journeyman'/'master'...


Perhaps some of the 'heat' in this conversation have been caused by 
taking a depth-first approach on a very, very, narrow (and highly 
specialised) topic? Way-back, I commented that the conversation 
contained some useful information for 'us all' - thinking 'apprentice' 
and 'journeyman' (back then); but since then, many of the contributions 
have come from 'masters' - and were certainly close to sailing right 
over my head/abilities in Python!

Whilst it is *not* my intention to denigrate anything said, I take great 
comfort in knowing that the likelihood that I'll ever have to notice the 
difference between the time del() is executed and the 
garbage-collector's effect, is so small, as to be almost irrelevant. 
(see elsewhere 'fast and loose')

Um, that is, until it is!

Meantime, I luxuriate in my ignorance, keep breathing, and reach for 
another square of chocolate...


Back to 'debugging': Yes, adding 'more code' in an attempt to 'solve' a 
problem certainly was contra-indicated - the 'target' kept changing, and 
the number of balls to be 'juggled' kept increasing.

However, the advice about considering the use of a "Context Manager" 
("with") was not 'adding', but (at worst!) 'replacing' (see 'frameworks' 
comment).

It is *very* unfortunate that almost every example of the use of Context 
Managers features file-management, and few, if any, other applications. 
Context Managers come into their own when there is an 'open' situation 
which must be matched by some 'close' (terminology is "entry" and 
"exit"), hence the 'file' example (assumed "existing knowledge"!).

However, these are serial events (first I open the file, then I process 
it, then I close it); so what's the big deal? The problem comes when 
something goes wrong! If the file was not actually opened, that's 
relatively easily dealt-with, but if it was, it should/must be closed - 
regardless of any error-experienced. Dealing with that sort of thing 
becomes relatively-complex and thus error-prone.

I'm enthusiastic about Context Managers because I do a lot of work with 
RDBMS-es. Here there are two layers of problem-possibility: in first 
gaining access to the RDBMS itself, and secondly dealing with the actual 
query and its "cursor" (result)...

The objective of a Context Manager then, is to relieve some of this 
'overhead' and 'boiler-plate' - the Exit code will be executed 
auto-magically, and regardless of success/error (assuming Python is 
still running). Well, I don't know about you, but that's good news to 
this lazy-boy!

In your situation: the "Entry" point is when you decide it is time to 
look at the GPIO pin's state. The "Exit" is when you've done 'whatever' 
with that value (and don't wish it to be used again until there's a 
state-change, time passes, or whatever). The 'context' is the process 
you wish carried-out, in-between, as a result of/utilising the GPIO 
pin's reading. In this context (hah!) doing something overt in 
__exit__() is *likely* to be more successful/reliable/'pythonic' than 
passively relying upon del().

In other words, this is a (Python) tool-for-the-job - and thus worth the 
investment of your time. Yes, you could use a 'hammer' on a screw, but 
the reliability of the end-result would be better if a screw-driver were 
the tool employed - AND likely easier, AND less frustrating! (see 
earlier 'warning' about 'translating' between languages)

So, if it is the correct tool for this job (the one that you want to 
achieve), then there is little to be gained by limiting your view to 
that of the code you are currently debugging. (particularly if you wrote 
it, as you self-describe, as an 'apprentice'!)


 >> Expanding on 'names' and del(): the first point is that there is seldom
 >> much to be gained by using del(), ie becoming your own 'garbage
 >> collector'.

As mentioned earlier (and confirmed, since), conflating del() and 
garbage-collection is not strictly accurate; but it will 'do' for us 
proto-masters (and likely for many 'masters' too)!

Am wondering what is to be gained by trying to become a 'master' in such 
a narrow portion of Python ("depth first"), when as an 'apprentice', 
time might better be spent learning (something of) the 'breadth' of 
Python? (rhetorical question - answer is 'none of my business'/you 
should do/think what you want to do...)


> In my case deleting the instance was needed to release its hold on something
> that was taken when the instance was initialised (in my case a GPIO pin on a
> Raspberry Pi).   I did not even think of garbage collection.

In talking so-specifically about del(), etc, have we 'disappeared down a 
rabbit hole' and not actually addressed this question? Does deleting the 
instance/class release the GPIO pin, or is there another/a better way?

I haven't started to 'play' with my recently-purchased SoC, but forty 
years after constructing my own Motorola D2 Kit (which gave me a 
'computer' with binary inputs and bar-LED o/p), and much wanting to get 
back to systems-on-a-chip or "microcomputers", even if (only) as a 
hobby, I'm finally 'getting there'...

So, I'd like to request further clarification:
- do we need to 'release' (reset, or whatever) the GPIO pin, or
- are we talking about 'disposing of' a variable which represents/holds 
the GPIO pin's value (as it was when 'read') - presumably in preparation 
to reading it again/next time?


There is also a major implication here (which has been addressed as the 
different behavior of del()/GC within different Python implementations). 
Which Python are you using, under which OpSys - and if you are talking 
about developing in Python on a desktop, will that carry forward to the 
SoC or are there (material) differences in Python and/or OpSys?

I've been noting various contributions to this list, on topics related 
to Python on/for SoCs. One of which is that there is a (at least one) 
specialised version (?sub-set) of Python for SoCs. NB I haven't 
read/done anything much further than that! You may like/need to 
investigate...

Given that we are no longer talking about "How do I import a class...", 
perhaps starting a new post with significant key-words in the Subject: 
might encourage SoC-experienced folk to offer more knowledgeable 
assistance...

-- 
Regards =dn

From duncan at invalid.invalid  Mon Dec 16 19:10:26 2019
From: duncan at invalid.invalid (duncan smith)
Date: Tue, 17 Dec 2019 00:10:26 +0000
Subject: distinguishable matplotlib colours / symbols / line styles
In-Reply-To: <mailman.113.1576530510.11485.python-list@python.org>
References: <z1OJF.89881$0X7.2919@fx09.iad>
 <CAPTjJmoVYFEq4pa4+Xxgf4THAH5CZ7iPhR0cbuytREpZ+3xS9A@mail.gmail.com>
 <39a27f1f-f96a-4449-cfc7-06d84d9c81f8@Kapua.Cloud>
 <mailman.113.1576530510.11485.python-list@python.org>
Message-ID: <T1VJF.414938$kt1.39161@fx46.iad>

On 16/12/2019 21:08, DL Neil wrote:
> On 17/12/19 5:19 am, Chris Angelico wrote:
>> On Tue, Dec 17, 2019 at 3:16 AM duncan smith <duncan at invalid.invalid>
>> wrote:
>>>
>>> Hello,
>>> ?????? Not really specific to Python or matplotlib (but that's what I'm
>>> using). I'm looking for a good combination of colours and symbols for
>>> scatter plots, and combination of colours and line styles for line
>>> plots. Too often I find myself producing these when I don't know whether
>>> they will end up being printed in colour or greyscale. It would be a lot
>>> easier if I could produce decent plots that would work well in either
>>> case. I can find various stuff on colour palettes, but pretty much
>>> nothing on symbols or line styles. Is anybody aware of an approach that
>>> works well? I'm aware of issues with colour blindness and RGB versus
>>> CMYK. Ideally I'd have something that I could just use that would deal
>>> with all these issues. TIA.
>>>
>>
>> I'd recommend looking at the Web Content Accessibility Guidelines
>> published by the W3C; there are a number of tools out there that are
>> designed to help you pick colours for a web page, and the same sorts
>> of rules will apply here, I think.
>>
>> Also, thank you for even *thinking* about this. A lot of people don't. :)
> 
> +1
> 
> We spend a lot of time teaching this topic (non-Python courses). It
> receives a lot of often highly-polarised comments/discussion. Many folk
> have their 'eyes opened' to an issue which has not affected them
> personally. Some even have to be informed that it is a legal obligation
> in their jurisdiction. However, it also receives the highest number of
> 'why do I have to learn this stuff' complaints...
> 
> I learned (way back) that the incidence of "color blindness" is far
> higher than I had imagined. Secondly, that it affects males more than
> females. Thirdly, that calling it "blindness" is a bit of a misnomer,
> because whilst people often can't see red 'correctly' (most common
> symptom), they do see something (it varies). Which is why they are
> permitted to drive vehicles (traffic lights: red, amber/yellow, green -
> and arrows; plus stop/brake lights), but why many smart-phone apps/web
> pages which encode information-relevance (red is 'wrong' and green/blue
> is acceptable) can become almost unusable (without other cues).
> 
> Those key-words: "accessibility guidelines" will yield a swag of useful
> tools - ignore the ones which are basically 'help choose the color of my
> web page/color palette, because they are often aiming (only) for
> 'pretty'. The best tools enumerate the efficacy of fg/bg
> color-combinations, allowing one to experiment; and will enumerate
> grey-scale variation/comparisons.
> 
> 
> Hmmm, note to self (you've inspired me to specifically review/critique
> the printing-from-screen action): what happens when we take a
> color-checked screen display and print same but end-up viewing it as
> monochrome/grey-scale output? Probably not a main-stream demand, but
> worth tossing at the WCAG experts...

A paper I recently published contained a number of colour images (graphs
- of the nodes and edges variety - and line plots). But it turned out
that the funding we used to have for colour printing charges no longer
exists. So the print version is greyscale with links to online colour
images. Anyone accessing the paper online will be able to download a pdf
with colour images. I don't yet know whether there will be funding for
colour printing charges for the paper I'm currently working on, yet I'm
generating plots. So something that would work for all these possible
end points would be ideal. That brings up the issue of distinguishable
symbols / markers (for scatter plots) and distinguishable line styles
(for line plots). i.e. They might help for greyscale without being too
distracting for colour images. So a single image would do for all the
possible end points. I'm not 100% happy about readers of the print
journal (probably) having to go online to make sense of my recent paper,
but that's done now.

BTW, I've gone with the Seaborn qualitative 'colorblind' palette for
now. Still tinkering with different markers / marker sizes / line
weights etc. Cheers.

Duncan

From rosuav at gmail.com  Mon Dec 16 21:44:53 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 17 Dec 2019 13:44:53 +1100
Subject: distinguishable matplotlib colours / symbols / line styles
In-Reply-To: <3negveptduc32pj993bv54vee51er0ifm2@4ax.com>
References: <z1OJF.89881$0X7.2919@fx09.iad>
 <CAPTjJmoVYFEq4pa4+Xxgf4THAH5CZ7iPhR0cbuytREpZ+3xS9A@mail.gmail.com>
 <39a27f1f-f96a-4449-cfc7-06d84d9c81f8@Kapua.Cloud>
 <3negveptduc32pj993bv54vee51er0ifm2@4ax.com>
Message-ID: <CAPTjJmquPgZjxi64sGk9V8WSxAbsO=Tk7hDnykVce6fkgdMN2Q@mail.gmail.com>

On Tue, Dec 17, 2019 at 1:38 PM Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>
>         Not of use to the OP -- my suggestion would have been to generate an
> image with a grid of the "available" (or likely candidate colors), then
> play with desaturating it in something like PhotoShop to see what results.
> I had a web page (lost the web server privileges when I moved and my new
> internet service doesn't offer space) showing examples of various color to
> grey conversions. I moved it to an R-Pi and set up a dynamic DNS, but it
> seems something in my u-Verse service is blocking outside access to the
> R-Pi server (I'd swear it was working when I first set it up, but a few
> months later it started timing out from outside access -- strangely, I can
> use the dynamic DNS address, and access from the LAN side, so my router
> must be recognizing the IP as "itself" and redirecting to the internal
> server).
>

Does it need an actual server, or is it a static file? If it's all
static, toss it up onto GitHub Pages for easy hosting.

That issue with the port-80-redirect is one I've seen with a number of
home-grade routers, unfortunately. One possible sidestep would be to
run it on HTTPS, which the router most likely doesn't support,
although that would cost a bit of extra processing power -  how's an
R-Pi on that?

ChrisA

From bill at baddogconsulting.com  Mon Dec 16 22:02:26 2019
From: bill at baddogconsulting.com (Bill Deegan)
Date: Mon, 16 Dec 2019 22:02:26 -0500
Subject: SCons 3.1.2 Released
Message-ID: <CAEyG4CEahsiZRjM+7KHiQaCdDNLYXKSbbXfQhQsmFFAnj7KECQ@mail.gmail.com>

  A new SCons checkpoint release, 3.1.2, is now available
  on the SCons download page:

          https://scons.org/pages/download.html

  Here is a summary of the changes since 3.1.1:

  NOTE: The 4.0.0 Release of SCons will drop Python 2.7 Support

  NEW FUNCTIONALITY
    - Added debug option "action_timestamps" which outputs to stdout the
absolute start and end time for each target.

  REMOVED FUNCTIONALITY
    - Turn previously deprecated debug options into failures:
      --debug=tree, --debug=dtree, --debug=stree, --debug=nomemoizer.
    - Remove deprecated SourceSignatures, TargetSignatures
    - Remove deprecated Builder keywords: overrides and scanner
    - Remove deprecated env.Copy
    - Remove deprecated BuildDir plus SConscript keyword build_dir


  CHANGED/ENHANCED EXISTING FUNCTIONALITY
    - Update Command() function to accept target_scanner, source_factory,
and target_factory arguments.
      This makes Command act more like a one-off builder.
    - Added support for "-imacros" to ParseFlags
    - EXPERIMENTAL NEW FEATURE: Enable caching MSVC configuration
      If SCONS_CACHE_MSVC_CONFIG shell environment variable is set,
      SCons will cache the results of past calls to vcvarsall.bat to
      a file; integrates with existing memoizing of such vars.
      On vs2019 saves 5+ seconds per SCons invocation, which really
      helps test suite runs.

  FIXES
    - Fix suncxx tool (Oracle Studio compiler) when using Python 3.
Previously would throw an exception.
      Resolved by properly handling tool version string output as unicode.
    - Resolved a race condition in multithreaded Windows builds with Python
2
      in the case where a child process is spawned while a Python action
has a
      file open. Original author: Ryan Beasley.
    - Fix CheckFunc detection code for Visual 2019. Some functions
      (e.g. memmove) were incorrectly recognized as not available.
    - Fix stacktrace when using SCons with Python 3.5+ and SunOS/Solaris
related tools.
    - Latex: Avoid crash with UnicodeDecodeError on Python 3 when a Latex
log file in
      non-UTF-8 encoding (e.g. containing umlauts in Latin-1 encoding when
      the fontenc package is included with \usepackage[T1]{fontenc}) is
read.
    - CmdStringHolder fix from issue #3428

  IMPROVEMENTS
    - Improved threading performance by ensuring NodeInfo is shared
      across threads. Results in ~13% improvement for parallel builds
      (-j# > 1) with many shared nodes.
    - Improve performance of Entry.disambiguate() by making check for
      most common case first, preventing unnecessary IO.
    - Improved DAG walk performance by reducing unnecessary work when
      there are no un-visited children.


  PACKAGING

     - N/A

  DOCUMENTATION

    -  N/A

  DEVELOPMENT

    - N/A


Thanks to the following developers for their contributions to this release.
git shortlog --no-merges -ns 3.1.1..HEAD
    59  Mats Wichmann
    21  William Deegan
     8  Edoardo Bezzeccheri
     5  Adam Gross
     5  maiphi
     4  Ivan Kravets
     4  Mathew Robinson
     2  Jakub Kul?k
     2  Jacek Kuczera
     2  Rob Boehne
     2  Jason Kenny
     2  Tim Gates
     1  Jakub Kulik
     1  Theogen Ratkin
     1  jw0k

From PythonList at DancesWithMice.info  Mon Dec 16 22:41:04 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 17 Dec 2019 16:41:04 +1300
Subject: distinguishable matplotlib colours / symbols / line styles
In-Reply-To: <3negveptduc32pj993bv54vee51er0ifm2@4ax.com>
References: <z1OJF.89881$0X7.2919@fx09.iad>
 <CAPTjJmoVYFEq4pa4+Xxgf4THAH5CZ7iPhR0cbuytREpZ+3xS9A@mail.gmail.com>
 <39a27f1f-f96a-4449-cfc7-06d84d9c81f8@Kapua.Cloud>
 <3negveptduc32pj993bv54vee51er0ifm2@4ax.com>
Message-ID: <9a663bc4-334e-d12e-08ef-44cfa74d496e@DancesWithMice.info>

On 17/12/19 3:37 pm, Dennis Lee Bieber wrote:
> If, by some chance, external nodes can get to it:
> http://wlfraed.microdiversity.freeddns.org/BW/BWConv.html }

Works for me, no hacking necessary!
(photo of ppl dressed-up in Mickey Mouse type costumes)

-- 
Regards =dn

From ml at fam-goebel.de  Tue Dec 17 05:37:34 2019
From: ml at fam-goebel.de (Ulrich Goebel)
Date: Tue, 17 Dec 2019 11:37:34 +0100
Subject: strptime for different languages
Message-ID: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>

Hi,

I need to interpret a date string to get a datetime object. That should 
be done with strptime from the module datetime.

But I don't know enough about the locale settings from where the date 
sting comes. Actually the date_string cames from different contact forms 
inside websites made by different content management systems. So it could be
   13. Januar 1965
   13. January 1965
   13.01.1965
   1965-01-13
or even some known other formats.

What I tried is a cascade of try's:

try:
   d = strptime(date_string, format_string_1)
except:
   try:
     d = strptime(date_string, format_string_2)
   except:
     try:
       d = strptime(date_string, format_string_3)
     except:
       ...

That works, as long the month comes as number.

But how to cover name of months in different language?

(Shure, it would not be possible to cover all possibilities and 
languages. But I know the possible languages.)

Best regards
Ulrich

-- 
Ulrich Goebel
Am B?chel 57, 53173 Bonn

From jon+usenet at unequivocal.eu  Tue Dec 17 05:53:48 2019
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Tue, 17 Dec 2019 10:53:48 -0000 (UTC)
Subject: strptime for different languages
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <mailman.122.1576579627.11485.python-list@python.org>
Message-ID: <slrnqvhctr.3ib.jon+usenet@sable.unequivocal.eu>

On 2019-12-17, Ulrich Goebel <ml at fam-goebel.de> wrote:
> I need to interpret a date string to get a datetime object. That should 
> be done with strptime from the module datetime.
>
> But I don't know enough about the locale settings from where the date 
> sting comes. Actually the date_string cames from different contact forms 
> inside websites made by different content management systems. So it could be
>    13. Januar 1965
>    13. January 1965
>    13.01.1965
>    1965-01-13

https://pypi.org/project/dateparser/

From niktnobodynikt at gmail.com  Tue Dec 17 06:56:39 2019
From: niktnobodynikt at gmail.com (niktnobodynikt at gmail.com)
Date: Tue, 17 Dec 2019 03:56:39 -0800 (PST)
Subject: strptime for different languages
In-Reply-To: <mailman.122.1576579627.11485.python-list@python.org>
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <mailman.122.1576579627.11485.python-list@python.org>
Message-ID: <401b4a78-957e-4d28-b89a-f0ebc20b9f45@googlegroups.com>

W dniu wtorek, 17 grudnia 2019 11:47:23 UTC+1 u?ytkownik Ulrich Goebel napisa?:
>    13. Januar 1965
>    13. January 1965
>    13.01.1965
>    1965-01-13

02.03.2000

Is it Mar, 2nd 2000 or Feb, 3rd 2000?

From ml at fam-goebel.de  Tue Dec 17 11:47:26 2019
From: ml at fam-goebel.de (Ulrich Goebel)
Date: Tue, 17 Dec 2019 17:47:26 +0100
Subject: strptime for different languages
In-Reply-To: <slrnqvhctr.3ib.jon+usenet@sable.unequivocal.eu>
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <mailman.122.1576579627.11485.python-list@python.org>
 <slrnqvhctr.3ib.jon+usenet@sable.unequivocal.eu>
Message-ID: <44e326b7-2c7e-b735-2cb4-fe1d26e2f9e7@fam-goebel.de>

That's absolutely great, thank You!

Am 17.12.19 um 11:53 schrieb Jon Ribbens via Python-list:
> On 2019-12-17, Ulrich Goebel <ml at fam-goebel.de> wrote:
>> I need to interpret a date string to get a datetime object. That should
>> be done with strptime from the module datetime.
>>
>> But I don't know enough about the locale settings from where the date
>> sting comes. Actually the date_string cames from different contact forms
>> inside websites made by different content management systems. So it could be
>>     13. Januar 1965
>>     13. January 1965
>>     13.01.1965
>>     1965-01-13
> 
> https://pypi.org/project/dateparser/
> 

-- 
Ulrich Goebel
Am B?chel 57, 53173 Bonn

From ml at fam-goebel.de  Tue Dec 17 11:49:58 2019
From: ml at fam-goebel.de (Ulrich Goebel)
Date: Tue, 17 Dec 2019 17:49:58 +0100
Subject: strptime for different languages
In-Reply-To: <401b4a78-957e-4d28-b89a-f0ebc20b9f45@googlegroups.com>
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <mailman.122.1576579627.11485.python-list@python.org>
 <401b4a78-957e-4d28-b89a-f0ebc20b9f45@googlegroups.com>
Message-ID: <61737abc-ba60-748f-4081-16afde30f3b4@fam-goebel.de>

I think I have to live with this problem and the resulting date-errors. 
It seems to be possible to bring dateparse to better results if one 
knows a bit more about the source of a date string.

Am 17.12.19 um 12:56 schrieb niktnobodynikt at gmail.com:
> W dniu wtorek, 17 grudnia 2019 11:47:23 UTC+1 u?ytkownik Ulrich Goebel napisa?:
>>     13. Januar 1965
>>     13. January 1965
>>     13.01.1965
>>     1965-01-13
> 
> 02.03.2000
> 
> Is it Mar, 2nd 2000 or Feb, 3rd 2000?
> 

-- 
Ulrich Goebel
Am B?chel 57, 53173 Bonn

From musbur at posteo.org  Tue Dec 17 12:44:04 2019
From: musbur at posteo.org (musbur at posteo.org)
Date: Tue, 17 Dec 2019 18:44:04 +0100
Subject: Transfer a file to httpserver via POST command from curl
In-Reply-To: <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>
References: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
 <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>
Message-ID: <20191217184404.298104a4@nxp10225>

On Fri, 13 Dec 2019 03:54:53 +1100
Chris Angelico <rosuav at gmail.com> wrote:

> On Fri, Dec 13, 2019 at 3:44 AM Karthik Sharma
> <karthik.sharma at gmail.com> wrote:
> >
> > Is it really possible to transfer a large binary file from my
> > machine to the above httpserver via POST command and download it
> > again? If yes, is the above Flask app enough for that and what am I
> > doing wrong?  
> 
> I think your Flask code is okay (haven't checked in detail, but at
> first glance it looks fine), but for file uploads to be recognized in
> request.files, you'll need to change the way you run curl.

BTW, the canonical way to upload files via http is PUT, not POST. You
might want to look into that, but here it is off-topic.

From musbur at posteo.org  Tue Dec 17 12:46:38 2019
From: musbur at posteo.org (musbur at posteo.org)
Date: Tue, 17 Dec 2019 18:46:38 +0100
Subject: More efficient/elegant branching
In-Reply-To: <2c058292-6cc8-39d3-ada5-1a9484aa437a@vub.be>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <2c058292-6cc8-39d3-ada5-1a9484aa437a@vub.be>
Message-ID: <20191217184638.448c9b2f@nxp10225>

On Fri, 13 Dec 2019 11:34:24 +0100
Antoon Pardon <antoon.pardon at vub.be> wrote:

> Well if you really want to go this route, you may consider the
> following:
> 
> def branch4(a, b, z):
>     decision = [
>         ((lambda: a > 4 and b == 0), "first"),
>         ((lambda: len(z) < 2), "second"),
>         ((lambda: b + a == 10), "third")]
>     for test, result in decision:
>         if test(): return result

Nice. But as I've said before, in this case code legibility is more
important than out-clevering myself, so I'll stick with if/elif.

From rosuav at gmail.com  Tue Dec 17 12:52:33 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 18 Dec 2019 04:52:33 +1100
Subject: Transfer a file to httpserver via POST command from curl
In-Reply-To: <20191217184404.298104a4@nxp10225>
References: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
 <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>
 <20191217184404.298104a4@nxp10225>
Message-ID: <CAPTjJmo_6WLdKvb5FUrU1moZ4+7G7irYyzJ2F60gbk83_3EQnQ@mail.gmail.com>

On Wed, Dec 18, 2019 at 4:45 AM <musbur at posteo.org> wrote:
>
> On Fri, 13 Dec 2019 03:54:53 +1100
> Chris Angelico <rosuav at gmail.com> wrote:
>
> > On Fri, Dec 13, 2019 at 3:44 AM Karthik Sharma
> > <karthik.sharma at gmail.com> wrote:
> > >
> > > Is it really possible to transfer a large binary file from my
> > > machine to the above httpserver via POST command and download it
> > > again? If yes, is the above Flask app enough for that and what am I
> > > doing wrong?
> >
> > I think your Flask code is okay (haven't checked in detail, but at
> > first glance it looks fine), but for file uploads to be recognized in
> > request.files, you'll need to change the way you run curl.
>
> BTW, the canonical way to upload files via http is PUT, not POST. You
> might want to look into that, but here it is off-topic.

Citation needed. Plenty of file uploads are done through POST
requests. Are you talking specifically about a RESTful API? Because
that's only one of many patterns you can follow.

ChrisA

From barry at barrys-emacs.org  Tue Dec 17 13:56:22 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Tue, 17 Dec 2019 18:56:22 +0000
Subject: strptime for different languages
In-Reply-To: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
Message-ID: <4859DC53-9126-4B59-B5CF-5D598C0125F6@barrys-emacs.org>



> On 17 Dec 2019, at 10:37, Ulrich Goebel <ml at fam-goebel.de> wrote:
> 
> Hi,
> 
> I need to interpret a date string to get a datetime object. That should be done with strptime from the module datetime.
> 
> But I don't know enough about the locale settings from where the date sting comes. Actually the date_string cames from different contact forms inside websites made by different content management systems. So it could be

Can side step the issue?

I would change the web site to collect the date in a form that is not ambiguous.
For example use a Javascript date picker widget.

Barry


>  13. Januar 1965
>  13. January 1965
>  13.01.1965
>  1965-01-13
> or even some known other formats.
> 
> What I tried is a cascade of try's:
> 
> try:
>  d = strptime(date_string, format_string_1)
> except:
>  try:
>    d = strptime(date_string, format_string_2)
>  except:
>    try:
>      d = strptime(date_string, format_string_3)
>    except:
>      ...
> 
> That works, as long the month comes as number.
> 
> But how to cover name of months in different language?
> 
> (Shure, it would not be possible to cover all possibilities and languages. But I know the possible languages.)
> 
> Best regards
> Ulrich
> 
> -- 
> Ulrich Goebel
> Am B?chel 57, 53173 Bonn
> -- 
> https://mail.python.org/mailman/listinfo/python-list


From rosuav at gmail.com  Tue Dec 17 14:04:15 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 18 Dec 2019 06:04:15 +1100
Subject: strptime for different languages
In-Reply-To: <4859DC53-9126-4B59-B5CF-5D598C0125F6@barrys-emacs.org>
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <4859DC53-9126-4B59-B5CF-5D598C0125F6@barrys-emacs.org>
Message-ID: <CAPTjJmoz6E_romYpx-C6Syfrh026_36=QV-ZrCEehjOwKN6zmA@mail.gmail.com>

On Wed, Dec 18, 2019 at 5:57 AM Barry Scott <barry at barrys-emacs.org> wrote:
>
>
>
> > On 17 Dec 2019, at 10:37, Ulrich Goebel <ml at fam-goebel.de> wrote:
> >
> > Hi,
> >
> > I need to interpret a date string to get a datetime object. That should be done with strptime from the module datetime.
> >
> > But I don't know enough about the locale settings from where the date sting comes. Actually the date_string cames from different contact forms inside websites made by different content management systems. So it could be
>
> Can side step the issue?
>
> I would change the web site to collect the date in a form that is not ambiguous.
> For example use a Javascript date picker widget.
>
> Barry

No JavaScript needed, just use <input type=date>.

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/date

You get back an unambiguous yyyy-mm-dd.

ChrisA

From soyeomul at doraji.xyz  Wed Dec 18 01:13:28 2019
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Wed, 18 Dec 2019 15:13:28 +0900
Subject: Problem Running Python
References: <AM5PR10MB1620D2DB278590D60F020C3084560@AM5PR10MB1620.EURPRD10.PROD.OUTLOOK.COM>
 <AM5PR10MB162006FB301FE8EEA2AAF5B584560@AM5PR10MB1620.EURPRD10.PROD.OUTLOOK.COM>
 <215452112.7876617.1576421669362@mail.yahoo.com>
 <mailman.110.1576517839.11485.python-list@python.org>
Message-ID: <yw87axn3rvu.fsf@chrys.birch.chromebook>

Hello Patrick^^^

> kindly assist me through the proper download and installation procedure as I really need to start learning coding with the Python programming language.

In next year 2020, Ubuntu 20.04 LTS will be released with a New Hope, i
guess. At there base Python will be 3.x version. If you are startman, i
recommand you to start Python 3 with Ubuntu 20.04 LTS.

And Ubuntu is easy^^^
Yes Ubuntu is easy^^^
HaH Ubuntu is easy^^^

Sincerely, from Ubuntu-Python guy ;;;

-- 
^????? _????_ ?????_^))//

From anthony.graziano0112 at gmail.com  Wed Dec 11 21:51:10 2019
From: anthony.graziano0112 at gmail.com (Anthony Graziano)
Date: Wed, 11 Dec 2019 21:51:10 -0500
Subject: This is the email address I Believe I should email for support.
Message-ID: <5df982ce.1c69fb81.cba06.121f@mx.google.com>

   When I try to uninstall python 3.8.0 to reinstall, it says that the
   program is currsntly running.

   ?

   Please help

   ?

   Sent from [1]Mail for Windows 10

   ?

References

   Visible links
   1. https://go.microsoft.com/fwlink/?LinkId=550986

From bluebox03 at gmail.com  Tue Dec 17 21:23:42 2019
From: bluebox03 at gmail.com (tommy yama)
Date: Wed, 18 Dec 2019 11:23:42 +0900
Subject: hexdump module installation error
Message-ID: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>

Hi,

This sounds familiar to somebody?
After upgrading my mac OS to Catalina, this persists even after pip3
install hexdump.

[image: image.png]

thanks.

From ikorot01 at gmail.com  Tue Dec 17 20:47:25 2019
From: ikorot01 at gmail.com (Igor Korot)
Date: Tue, 17 Dec 2019 19:47:25 -0600
Subject: This is the email address I Believe I should email for support.
In-Reply-To: <5df982ce.1c69fb81.cba06.121f@mx.google.com>
References: <5df982ce.1c69fb81.cba06.121f@mx.google.com>
Message-ID: <CA+FnnTwGbVuC6X0Bb8OJwUpy0hhqhfe619XDpwMd6tjNYcBuUg@mail.gmail.com>

Hi,

On Wed, Dec 18, 2019 at 7:03 AM Anthony Graziano
<anthony.graziano0112 at gmail.com> wrote:
>
>    When I try to uninstall python 3.8.0 to reinstall, it says that the
>    program is currsntly running.

Why do you want to reinstall it?
Does python interpreter actually running?
Can you go to the "Task Manager" and see it punning?

Thank you.

>
>
>
>    Please help
>
>
>
>    Sent from [1]Mail for Windows 10
>
>
>
> References
>
>    Visible links
>    1. https://go.microsoft.com/fwlink/?LinkId=550986
> --
> https://mail.python.org/mailman/listinfo/python-list

From rhodri at kynesim.co.uk  Wed Dec 18 09:37:14 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 18 Dec 2019 14:37:14 +0000
Subject: hexdump module installation error
In-Reply-To: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
Message-ID: <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>

On 18/12/2019 02:23, tommy yama wrote:
> Hi,
> 
> This sounds familiar to somebody?
> After upgrading my mac OS to Catalina, this persists even after pip3
> install hexdump.
> 
> [image: image.png]

I'm afraid this is a text-only mailing list.  Your screenshot has been 
stripped out before any of us saw it.  Could you copy and paste (DON'T 
retype!) the error instead, so we can all read it?

-- 
Rhodri James *-* Kynesim Ltd

From toby at tobiah.org  Wed Dec 18 12:27:23 2019
From: toby at tobiah.org (Tobiah)
Date: Wed, 18 Dec 2019 09:27:23 -0800
Subject: 3rd party mail package
References: <CADrxXXnz8_h3tu7yLLwZ7K75e5wu24FeUTHo94i3cUELNX4Xiw@mail.gmail.com>
 <C59384AF-7E4C-478B-8591-EEC2231DE5C1@barrys-emacs.org>
 <mailman.88.1576316965.11485.python-list@python.org>
Message-ID: <qtdnhr$n8a$1@gioia.aioe.org>

On 12/14/19 1:13 AM, Barry wrote:
> I guess the 2nd party is the user.

I think of the user as the first party.

1) I want a thing for python.

2) Python doesn't have a very good one

3) Someone else will give it to you




> Barry
> 
>> On 13 Dec 2019, at 21:13, Abdur-Rahmaan Janhangeer <arj.python at gmail.com> wrote:
>>
>> ?Wonder where the 2nd party went to. Thanks will look into it!
>> -- 
>> https://mail.python.org/mailman/listinfo/python-list
>>
> 


From toby at tobiah.org  Wed Dec 18 12:29:28 2019
From: toby at tobiah.org (Tobiah)
Date: Wed, 18 Dec 2019 09:29:28 -0800
Subject: 3rd party mail package
References: <CADrxXXnz8_h3tu7yLLwZ7K75e5wu24FeUTHo94i3cUELNX4Xiw@mail.gmail.com>
 <C59384AF-7E4C-478B-8591-EEC2231DE5C1@barrys-emacs.org>
 <mailman.88.1576316965.11485.python-list@python.org>
 <qtdnhr$n8a$1@gioia.aioe.org>
Message-ID: <qtdnlm$n8a$2@gioia.aioe.org>

On 12/18/19 9:27 AM, Tobiah wrote:
> On 12/14/19 1:13 AM, Barry wrote:
>> I guess the 2nd party is the user.
> 
> I think of the user as the first party.
> 
> 1) I want a thing for python.
> 
> 2) Python doesn't have a very good one
> 
> 3) Someone else will give it to you

Wikipedia disagrees with me:

   https://en.wikipedia.org/wiki/Third-party_source

From toby at tobiah.org  Wed Dec 18 13:12:53 2019
From: toby at tobiah.org (Tobiah)
Date: Wed, 18 Dec 2019 10:12:53 -0800
Subject: strptime for different languages
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <mailman.122.1576579627.11485.python-list@python.org>
Message-ID: <qtdq76$148j$1@gioia.aioe.org>

> What I tried is a cascade of try's:
> 
> try:
>    d = strptime(date_string, format_string_1)
> except:
>    try:
>      d = strptime(date_string, format_string_2)
>    except:
>      try:
>        d = strptime(date_string, format_string_3)
>      except:
>        ...


This is not about dates, but for the above, I'd try:

     for f in (format1, format2, format3):
         try:
             d = strptime(date_string, f)
         except:
             continue
         else:
             break

That way you can manipulate the content and number
of the formats, or pull them from a database or whatever
without having to edit your code in a messy way.


Tobiah



From barry at barrys-emacs.org  Wed Dec 18 13:36:59 2019
From: barry at barrys-emacs.org (Barry)
Date: Wed, 18 Dec 2019 18:36:59 +0000
Subject: 3rd party mail package
In-Reply-To: <qtdnhr$n8a$1@gioia.aioe.org>
References: <qtdnhr$n8a$1@gioia.aioe.org>
Message-ID: <7A7A481C-ADE9-4376-B8AD-06EFC252EF6E@barrys-emacs.org>



> On 18 Dec 2019, at 17:33, Tobiah <toby at tobiah.org> wrote:
> 
> ?On 12/14/19 1:13 AM, Barry wrote:
>> I guess the 2nd party is the user.
> 
> I think of the user as the first party

But that is not what Wikipedia article you linked says.

? In commerce, a "third-party source" means a supplier (or service provider) who is not directly controlled by either the seller (first party) nor the customer/buyer (second party) in a business transaction.?

Barry


> 1) I want a thing for python.
> 
> 2) Python doesn't have a very good one
> 
> 3) Someone else will give it to you
> 
> 
> 
> 
>> Barry
>>>> On 13 Dec 2019, at 21:13, Abdur-Rahmaan Janhangeer <arj.python at gmail.com> wrote:
>>> 
>>> ?Wonder where the 2nd party went to. Thanks will look into it!
>>> -- 
>>> https://mail.python.org/mailman/listinfo/python-list
>>> 
> 
> -- 
> https://mail.python.org/mailman/listinfo/python-list

From toby at tobiah.org  Wed Dec 18 14:00:23 2019
From: toby at tobiah.org (Tobiah)
Date: Wed, 18 Dec 2019 11:00:23 -0800
Subject: 3rd party mail package
References: <qtdnhr$n8a$1@gioia.aioe.org>
 <7A7A481C-ADE9-4376-B8AD-06EFC252EF6E@barrys-emacs.org>
 <mailman.135.1576694225.11485.python-list@python.org>
Message-ID: <qtdt06$1gpu$1@gioia.aioe.org>

>> I think of the user as the first party
> 
> But that is not what Wikipedia article you linked says.
> 
> ? In commerce, a "third-party source" means a supplier (or service provider) who is not directly controlled by either the seller (first party) nor the customer/buyer (second party) in a business transaction.?

I know.  I admitted that the Wikipedia article disagreed with me,
forcing me into a retraction of my previous assertion.  I didn't
post that link to reinforce my original argument.


Tobiah

From python at mrabarnett.plus.com  Wed Dec 18 14:06:35 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 18 Dec 2019 19:06:35 +0000
Subject: strptime for different languages
In-Reply-To: <qtdq76$148j$1@gioia.aioe.org>
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <mailman.122.1576579627.11485.python-list@python.org>
 <qtdq76$148j$1@gioia.aioe.org>
Message-ID: <d6994535-f7b2-f0bd-d6cd-cd79b278e401@mrabarnett.plus.com>

On 2019-12-18 18:12, Tobiah wrote:
>> What I tried is a cascade of try's:
>> 
>> try:
>>    d = strptime(date_string, format_string_1)
>> except:
>>    try:
>>      d = strptime(date_string, format_string_2)
>>    except:
>>      try:
>>        d = strptime(date_string, format_string_3)
>>      except:
>>        ...
> 
> 
> This is not about dates, but for the above, I'd try:
> 
>       for f in (format1, format2, format3):
>           try:
>               d = strptime(date_string, f)
>           except:
>               continue
>           else:
>               break
> 
> That way you can manipulate the content and number
> of the formats, or pull them from a database or whatever
> without having to edit your code in a messy way.
> 
A couple of point about your code:

1. Don't use a bare 'except' because it'll catch _any_ exception. See 
what exception strptime will raise and catch only that.

2. Why use 'continue' instead of 'pass'?

From toby at tobiah.org  Wed Dec 18 14:27:25 2019
From: toby at tobiah.org (Tobiah)
Date: Wed, 18 Dec 2019 11:27:25 -0800
Subject: strptime for different languages
References: <f7b68c38-c36d-7e51-7474-06104b50612a@fam-goebel.de>
 <mailman.122.1576579627.11485.python-list@python.org>
 <qtdq76$148j$1@gioia.aioe.org>
 <d6994535-f7b2-f0bd-d6cd-cd79b278e401@mrabarnett.plus.com>
 <mailman.136.1576696005.11485.python-list@python.org>
Message-ID: <qtduit$1png$1@gioia.aioe.org>


> A couple of point about your code:
> 
> 1. Don't use a bare 'except' because it'll catch _any_ exception. See
> what exception strptime will raise and catch only that.

I'm well aware of this, but I was too lazy to write something
to generate the exception to find out what datetime would throw
in this case.  It crossed my mind when posting, but I was illustrating
an idea rather than submitting usable code.
  
> 2. Why use 'continue' instead of 'pass'?

No reason.  Does one have a benefit over the other?


Tobiah

From tjreedy at udel.edu  Wed Dec 18 17:12:50 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Wed, 18 Dec 2019 17:12:50 -0500
Subject: 3rd party mail package
In-Reply-To: <qtdnlm$n8a$2@gioia.aioe.org>
References: <CADrxXXnz8_h3tu7yLLwZ7K75e5wu24FeUTHo94i3cUELNX4Xiw@mail.gmail.com>
 <C59384AF-7E4C-478B-8591-EEC2231DE5C1@barrys-emacs.org>
 <mailman.88.1576316965.11485.python-list@python.org>
 <qtdnhr$n8a$1@gioia.aioe.org> <qtdnlm$n8a$2@gioia.aioe.org>
Message-ID: <qte893$2gh8$1@blaine.gmane.org>

On 12/18/2019 12:29 PM, Tobiah wrote:
> On 12/18/19 9:27 AM, Tobiah wrote:
>> On 12/14/19 1:13 AM, Barry wrote:
>>> I guess the 2nd party is the user.
>>
>> I think of the user as the first party.
>>
>> 1) I want a thing for python.
>>
>> 2) Python doesn't have a very good one
>>
>> 3) Someone else will give it to you
> 
> Wikipedia disagrees with me:
> 
>  ? https://en.wikipedia.org/wiki/Third-party_source

Each person in a transaction thinks of self as 'first person', other as 
'second person'.  But to avoid confusion, the convention for 
asymmetrical transactions, something for money, is to call the 
'something' provider the 'first person' or 'first party'.  I believe 
legal contracts are generally written this way.


-- 
Terry Jan Reedy



From zidan.roony at yahoo.com  Wed Dec 18 23:10:00 2019
From: zidan.roony at yahoo.com (vahid asadi)
Date: Thu, 19 Dec 2019 04:10:00 +0000 (UTC)
Subject: INHERITANCE in python3
References: <1681866660.1226419.1576728600632.ref@mail.yahoo.com>
Message-ID: <1681866660.1226419.1576728600632@mail.yahoo.com>

HI guys this is my first post on python mailing lists ever and i glad to do this.
my problem here is why this attribute is not recognize by python and it raise an traceback error that said 'there is no such p.family attribute'. although i use multiple ??inheritance with 'super ' it not works. thanks for your help.

```?class Username:? ? def __init__(self,name,*args):? ? ? ? self.name = name
class Userfamily:? ? def __init__(self,family,*args):? ? ? ? self.family = family
class Person(Username,Userfamily):? ? def __init__(self,*args):? ? ? ? super().__init__(*args)


p = Person("v","aaa")print(p.name)print(p.family)```

From random832 at fastmail.com  Thu Dec 19 01:24:18 2019
From: random832 at fastmail.com (Random832)
Date: Thu, 19 Dec 2019 01:24:18 -0500
Subject: INHERITANCE in python3
In-Reply-To: <1681866660.1226419.1576728600632@mail.yahoo.com>
References: <1681866660.1226419.1576728600632.ref@mail.yahoo.com>
 <1681866660.1226419.1576728600632@mail.yahoo.com>
Message-ID: <250232d0-d5ce-4007-89a0-32e0fc23590a@www.fastmail.com>

On Wed, Dec 18, 2019, at 23:10, vahid asadi via Python-list wrote:
> HI guys this is my first post on python mailing lists ever and i glad 
> to do this.
> my problem here is why this attribute is not recognize by python and it 
> raise an traceback error that said 'there is no such p.family 
> attribute'. although i use multiple ??inheritance with 'super ' it not 
> works. thanks for your help.
> 
> ```?class Username:? ? def __init__(self,name,*args):? ? ? ? self.name 
> = name
> class Userfamily:? ? def __init__(self,family,*args):? ? ? ? 
> self.family = family
> class Person(Username,Userfamily):? ? def __init__(self,*args):? ? ? ? 
> super().__init__(*args)
> 
> 
> p = Person("v","aaa")print(p.name)print(p.family)```

The Username class also needs to call super(). In general, super() is intended to be used with all classes that might be part of a multiple inheritance hierarchy, not just the derived one.

From onlinejudge95 at gmail.com  Thu Dec 19 01:32:28 2019
From: onlinejudge95 at gmail.com (onlinejudge95)
Date: Thu, 19 Dec 2019 12:02:28 +0530
Subject: Using generators in Django
Message-ID: <CAD=M5eSsCtNGh_MFRX2DM6dY1nTmS8vehWWaQHqeH1Jfo1VujQ@mail.gmail.com>

Hi Devs,

A quick question. I am using Django to schedule some commands to populate
my PostgreSQL(Apart from using it as a web framework). I am currently
fetching records from a particular table and for each of those records
doing some calculation and storing the processed data in some other
database. The skeleton code looks like this

```
...
def fetch_needs(project_id):
    for item in MyNeedsModel.filter(project_id=project_id).all():
        yield item
...

class Command(django.core.management.base.BaseCommand):
    def add_argument(self, parser):
        ...
    def handler(self, *args, **kwargs):
        project = (args[0], args[1])
        project_id = MyProject.filter(...).id
        for need in fetch_needs(project_id):
            ....
```

I need to know whether the use of generators is correct here, in the sense
that would it have any performance issues. The point that I am having
trouble understanding is a comment on my code review.

Also don?t use generator you are bypassing django inbuilt caching
> mechanism. Using integrator it will create another list and get them one by
> one


Any help would be appreciated.

Thanks,
onlinejudge95

From rosuav at gmail.com  Thu Dec 19 01:57:22 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 19 Dec 2019 17:57:22 +1100
Subject: Using generators in Django
In-Reply-To: <CAD=M5eSsCtNGh_MFRX2DM6dY1nTmS8vehWWaQHqeH1Jfo1VujQ@mail.gmail.com>
References: <CAD=M5eSsCtNGh_MFRX2DM6dY1nTmS8vehWWaQHqeH1Jfo1VujQ@mail.gmail.com>
Message-ID: <CAPTjJmqCSGn48pVdRJvSi2fTZ3RZ4mSRMSKkFfqQz3LWNzxYFw@mail.gmail.com>

On Thu, Dec 19, 2019 at 5:34 PM onlinejudge95 <onlinejudge95 at gmail.com> wrote:
>
> Hi Devs,
>
> A quick question. I am using Django to schedule some commands to populate
> my PostgreSQL(Apart from using it as a web framework). I am currently
> fetching records from a particular table and for each of those records
> doing some calculation and storing the processed data in some other
> database. The skeleton code looks like this
>
>
> I need to know whether the use of generators is correct here, in the sense
> that would it have any performance issues. The point that I am having
> trouble understanding is a comment on my code review.

Performance should be dominated by the database speed. Whether you use
a generator or not should be insignificant compared to the time taken
by Postgres itself to perform the transaction. This should be done as
a single transaction for reliability, and that also means that it will
be a single transaction for performance.

ChrisA

From * at eli.users.panix.com  Thu Dec 19 02:31:38 2019
From: * at eli.users.panix.com (Eli the Bearded)
Date: Thu, 19 Dec 2019 07:31:38 +0000 (UTC)
Subject: on sorting things
Message-ID: <eli$1912190219@qaz.wtf>

I recently saw a link to an old post on a blog and then started looking
at the newer posts. This one:

https://leancrew.com/all-this/2019/11/the-key-to-sorting-in-python/

discusses ways to deal with useful sorting of movie / television show
titles. Some initial words should be re-ordered for sorting purposes
(_Adventures of Huckleberry Finn, The_), roman numbers should sort like
regular numbers (_Rocky V_ comes before _Rocky IX_), and something needs
to be done about sorting accented vowels. 

But what caught my eye most, as someone relatively new to Python but
with long experience in C in Perl, is sorting doesn't take a
*comparison* function, it takes a *key generator* function, and that
function is supposed to transform the thing into something that the
native comparison knows how to compare.

This seems a strange choice, and I'm wondering if someone can explain
the benefits of doing it that way to me.

Elijah
------
imagines it could make porting some code in or out of Python trickier

From oscar.j.benjamin at gmail.com  Thu Dec 19 02:49:21 2019
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Thu, 19 Dec 2019 07:49:21 +0000
Subject: on sorting things
In-Reply-To: <eli$1912190219@qaz.wtf>
References: <eli$1912190219@qaz.wtf>
Message-ID: <CAHVvXxTShsh3gjPt+GC6D2tS_J47z0Z6Mvn-f4yOVafE5buvYQ@mail.gmail.com>

On Thu, 19 Dec 2019 at 07:37, Eli the Bearded <*@eli.users.panix.com> wrote:
>
...
> But what caught my eye most, as someone relatively new to Python but
> with long experience in C in Perl, is sorting doesn't take a
> *comparison* function, it takes a *key generator* function, and that
> function is supposed to transform the thing into something that the
> native comparison knows how to compare.
>
> This seems a strange choice, and I'm wondering if someone can explain
> the benefits of doing it that way to me.
>
> Elijah
> ------
> imagines it could make porting some code in or out of Python trickier

Python 2 used comparison functions but Python 3 uses key functions.
There is a helper called cmp_to_key that can convert a comparison
function into a key function:
https://docs.python.org/3.8/library/functools.html#functools.cmp_to_key

--
Oscar

From rosuav at gmail.com  Thu Dec 19 03:22:35 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 19 Dec 2019 19:22:35 +1100
Subject: on sorting things
In-Reply-To: <eli$1912190219@qaz.wtf>
References: <eli$1912190219@qaz.wtf>
Message-ID: <CAPTjJmqbkkOGHfxAcAH_-6vdkEMEJ7GWNec3V93NFmKp3b09nw@mail.gmail.com>

On Thu, Dec 19, 2019 at 6:36 PM Eli the Bearded <*@eli.users.panix.com> wrote:
>
> I recently saw a link to an old post on a blog and then started looking
> at the newer posts. This one:
>
> https://leancrew.com/all-this/2019/11/the-key-to-sorting-in-python/
>
> discusses ways to deal with useful sorting of movie / television show
> titles. Some initial words should be re-ordered for sorting purposes
> (_Adventures of Huckleberry Finn, The_), roman numbers should sort like
> regular numbers (_Rocky V_ comes before _Rocky IX_), and something needs
> to be done about sorting accented vowels.
>
> But what caught my eye most, as someone relatively new to Python but
> with long experience in C in Perl, is sorting doesn't take a
> *comparison* function, it takes a *key generator* function, and that
> function is supposed to transform the thing into something that the
> native comparison knows how to compare.
>
> This seems a strange choice, and I'm wondering if someone can explain
> the benefits of doing it that way to me.
>

If you provide a comparison function, it has to be called for every
pair that need to be compared. Plus, it usually has to be written such
that it does the same thing twice:

arrayInJavaScript.sort((x, y) => x.some_attr[0] > y.some_attr[0])

python_list.sort(key=lambda x: x.some_attr[0])

Thirdly, a key function can easily handle three-way comparisons,
whereas a comparison function usually just offers two-way - it's
harder to write a comparison function for -1, 0, 1 returns. So the
sort is much less likely to be stable.

ChrisA

From __peter__ at web.de  Thu Dec 19 03:46:51 2019
From: __peter__ at web.de (Peter Otten)
Date: Thu, 19 Dec 2019 09:46:51 +0100
Subject: on sorting things
References: <eli$1912190219@qaz.wtf>
Message-ID: <qtfdds$5nll$1@blaine.gmane.org>

Eli the Bearded wrote:

> I recently saw a link to an old post on a blog and then started looking
> at the newer posts. This one:
> 
> https://leancrew.com/all-this/2019/11/the-key-to-sorting-in-python/
> 
> discusses ways to deal with useful sorting of movie / television show
> titles. Some initial words should be re-ordered for sorting purposes
> (_Adventures of Huckleberry Finn, The_), roman numbers should sort like
> regular numbers (_Rocky V_ comes before _Rocky IX_), and something needs
> to be done about sorting accented vowels.
> 
> But what caught my eye most, as someone relatively new to Python but
> with long experience in C in Perl, is sorting doesn't take a
> *comparison* function, it takes a *key generator* function, and that
> function is supposed to transform the thing into something that the
> native comparison knows how to compare.
> 
> This seems a strange choice, and I'm wondering if someone can explain
> the benefits of doing it that way to me.

Python 2 started with a comparison function and then grew a key function.
With a key function you still have to compare items, you are just breaking 
the comparison into two steps:

- Calculate the key. This can be slow as it has to be done once per item.
- Compare the items. The key is usually a string or tuple, and for those
  the comparison runs C code which is a bit faster. The gain is even greater
  as the comparison is performed much more often.

The disadvantages of the key-based approach are that some comparison 
functions cannot naturally be rewritten in this way and that memory usage is 
a bit higher. Both are typically "expert" problems, so the developers 
decided to "nudge" users to consider keys first.

Now take a look at this example written in Python 2:

import random
import time
import contextlib

@contextlib.contextmanager
def measure(message):
    start = time.time()
    yield
    span = time.time() - start
    print message.format(span)

with open("/usr/share/dict/words") as f:
    words = f.read().splitlines()
random.shuffle(words)

def key_lower(a):
    global key_calls
    key_calls += 1
    return a.lower()

def cmp_lower(a, b):
    global cmp_calls
    cmp_calls += 1
    return cmp(a.lower(), b.lower())

key_calls = 0
cmp_calls = 0

with measure("cmp-based sort took {} secs"):
    words[:].sort(cmp_lower)

with measure("key-bases sort took {} secs"):
    words[:].sort(key=key_lower)

print "cmp called", cmp_calls, "times"
print "key called", key_calls, "times"

$ python2 sort_demo.py 
cmp-based sort took 1.50221800804 secs
key-bases sort took 0.293763160706 secs
cmp called 1516111 times
key called 99171 times



From lukasz at langa.pl  Thu Dec 19 04:00:53 2019
From: lukasz at langa.pl (=?utf-8?Q?=C5=81ukasz_Langa?=)
Date: Thu, 19 Dec 2019 10:00:53 +0100
Subject: [RELEASE] Python 3.8.1, 3.7.6, 3.6.10, and 3.9.0a2 are now available!
Message-ID: <7FEA2F96-7748-4B87-8D7D-48583792B11A@langa.pl>

from locale import seasons_greetings
seasons_greetings()

On behalf of the entire Python development community, and the currently serving Python release team in particular, I'm pleased to announce the unprecedented combined release of no less than four versions of Python. Let's dig in!


Python 3.8.1

Python 3.8.1 is the first maintenance release of Python 3.8.

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. You can find Python 3.8.1 here:

https://www.python.org/downloads/release/python-381/ <https://www.python.org/downloads/release/python-381/>

See the ?What?s New in Python 3.8 <https://docs.python.org/3.8/whatsnew/3.8.html>? document for more information about features included in the 3.8 series. Detailed information about all changes made in 3.8.1 can be found in its change log <https://docs.python.org/release/3.8.1/whatsnew/changelog.html#changelog>.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.2 planned for February 2020.



Python 3.7.6

Python 3.7.6, the next bugfix release of Python 3.7, is also available. You can find the release files, a link to the change log, and more information here:

https://www.python.org/downloads/release/python-376/ <https://www.python.org/downloads/release/python-376/>



Python 3.9.0a2

An early developer preview of Python 3.9 is also ready: https://www.python.org/downloads/release/python-390a2/ <https://www.python.org/downloads/release/python-390a2/>

Python 3.9 is still in development. This releasee, 3.9.0a2 is the second of six planned alpha releases. Alpha releases are intended to make it easier to test the current state of new features and bug fixes and to test the release process. During the alpha phase, features may be added up until the start of the beta phase (2020-05-18) and, if necessary, may be modified or deleted up until the release candidate phase (2020-08-10). Please keep in mind that this is a preview release and its use is not recommended for production environments.


Python 3.6.10

And, one more thing: Python 3.6.10, the next security fix release of Python 3.6, is also available:

https://www.python.org/downloads/release/python-3610/ <https://www.python.org/downloads/release/python-3610/>



We hope you enjoy all those!

Thanks to all of the many volunteers who help make Python Development and these releases possible! Please consider supporting our efforts by volunteering yourself or through organization contributions to the Python Software Foundation.

https://www.python.org/psf/ <https://www.python.org/psf/>


Your friendly release team,
Ned Deily
Steve Dower
?ukasz Langa
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Message signed with OpenPGP
URL: <http://mail.python.org/pipermail/python-list/attachments/20191219/a552bc10/attachment.sig>

From pahome.chen at mirlab.org  Thu Dec 19 05:52:10 2019
From: pahome.chen at mirlab.org (lampahome)
Date: Thu, 19 Dec 2019 18:52:10 +0800
Subject: How to specific multiple dtypes in numpy.ndarray?
Message-ID: <CAB3eZfvoLN=rZFRG2_CWPMQjG=UK8mgDPOkZPrXh0dXaa5mnRw@mail.gmail.com>

I meet performance is low when I use struct.unpack to unpack binary data.

So I tried to use numpy.ndarray
But meet error when I want to unpack multiple dtypes

Can anyone teach me~

Code like below:
# python3
import struct
import numpy as np
s1 = struct.Struct("@QIQ")
ss1 = s1.pack(1,11,111)
np.ndarray((3,), [('Q','I','Q')], ss1)
# ValueError: mismatch in size of old and new data-descriptor.

From bluebox03 at gmail.com  Thu Dec 19 06:23:22 2019
From: bluebox03 at gmail.com (tommy yama)
Date: Thu, 19 Dec 2019 20:23:22 +0900
Subject: hexdump module installation error
In-Reply-To: <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
Message-ID: <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>

Thanks for your kind response.
The error was simply "module Hexdump was not found".

Regards,


On Wed, Dec 18, 2019 at 11:39 PM Rhodri James <rhodri at kynesim.co.uk> wrote:

> On 18/12/2019 02:23, tommy yama wrote:
> > Hi,
> >
> > This sounds familiar to somebody?
> > After upgrading my mac OS to Catalina, this persists even after pip3
> > install hexdump.
> >
> > [image: image.png]
>
> I'm afraid this is a text-only mailing list.  Your screenshot has been
> stripped out before any of us saw it.  Could you copy and paste (DON'T
> retype!) the error instead, so we can all read it?
>
> --
> Rhodri James *-* Kynesim Ltd
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From tjol at tjol.eu  Thu Dec 19 06:39:18 2019
From: tjol at tjol.eu (Thomas Jollans)
Date: Thu, 19 Dec 2019 12:39:18 +0100
Subject: How to specific multiple dtypes in numpy.ndarray?
In-Reply-To: <CAB3eZfvoLN=rZFRG2_CWPMQjG=UK8mgDPOkZPrXh0dXaa5mnRw@mail.gmail.com>
References: <CAB3eZfvoLN=rZFRG2_CWPMQjG=UK8mgDPOkZPrXh0dXaa5mnRw@mail.gmail.com>
Message-ID: <f5e45fb8-af99-57e5-3095-83d995c51b89@tjol.eu>

On 19/12/2019 11.52, lampahome wrote:
> I meet performance is low when I use struct.unpack to unpack binary data.
>
> So I tried to use numpy.ndarray
> But meet error when I want to unpack multiple dtypes
>
> Can anyone teach me~
>
> Code like below:
> # python3
> import struct
> import numpy as np
> s1 = struct.Struct("@QIQ")
> ss1 = s1.pack(1,11,111)
> np.ndarray((3,), [('Q','I','Q')], ss1)
> # ValueError: mismatch in size of old and new data-descriptor.

A numpy array always has ONE dtype for ALL array elements.

If you read an array of structs, you can define a structured type, where
each element of your struct must have a name.

The error you're seeing is (as you know) because you're not setting up
your dtype in the right way. Let's fix it:

> In [2]: np.dtype([('Q', 'I',
> 'Q')])?????????????????????????????????????????????????????????????????????????????????????????????????
>
> ---------------------------------------------------------------------------
> ValueError??????????????????????????????? Traceback (most recent call
> last)
> <ipython-input-2-cecc70c78408> in <module>
> ----> 1 np.dtype([('Q', 'I', 'Q')])
>
> ValueError: mismatch in size of old and new data-descriptor
>
> In [3]: np.dtype([('field1', 'Q'), ('field2', 'I'), ('field3',
> 'Q')])???????????????????????????????????????????????????????????????
> Out[3]: dtype([('field1', '<u8'), ('field2', '<u4'), ('field3', '<u8')])
>
> In [4]:???
>
>

... and now let's put it all together!

s1 = struct.Struct("@QIQ")
ss1 = s1.pack(1,11,111)
struct_dtype = np.dtype([('field1', 'Q'), ('field2', 'I'), ('field3', 'Q')])
a = np.frombuffer(ss1, dtype=struct_dtype)

I'm using the frombuffer() function deliberately so I don't have to
figure out the shape of the final array (which is (1,), not (3,), by the
way).

And hey presto: it raises an exception!

> ValueError: buffer size must be a multiple of element size

Your example shows a difference between the default behaviour of numpy's
structured dtype and the struct module: packing! By default, numpy
structured dtypes are closely packed, i.e. nothing is aligned to useful
memory boundaries.

struct_type.itemsize == 20

The struct module, on the other hand, tries to guess where the C
compiler would put its padding.

len(ss1) == 24

We can tell numpy to do the same:

struct_dtype = np.dtype([('field1', 'Q'), ('field2', 'I'), ('field3',
'Q')], align=True)

and then

a = np.frombuffer(ss1, dtype=struct_dtype)

works and produces

array([(1, 11, 111)],
????? dtype={'names':['field1','field2','field3'],
'formats':['<u8','<u4','<u8'], 'offsets':[0,8,16], 'itemsize':24,
'aligned':True})

with a .shape of (1,)

#####

It's worth noting that in your example, all three fields are aligned to
8 bytes, meaning that on a little-endian machine, you could quite simply
have interpreted the data as an array of uint64's instead:

In [30]: np.frombuffer(ss1,
dtype='u8')?????????????????????????????????????????????????????????????????????????????????????????????

Out[30]: array([? 1,? 11, 111], dtype=uint64)


-- Thomas



From rhodri at kynesim.co.uk  Thu Dec 19 07:21:08 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 19 Dec 2019 12:21:08 +0000
Subject: hexdump module installation error
In-Reply-To: <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
Message-ID: <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>

On 19/12/2019 11:23, tommy yama wrote:
> Thanks for your kind response.
> The error was simply "module Hexdump was not found".

Several things:

a) Did it really say "module Hexdump was not found"?  "hexdump" and 
"Hexdump" are not the same things; module names are case-sensitive.

b) There will have been a whole load more stack trace that might be 
useful to us.  I should have been clearer when I asked you to copy and 
paste the error that I really meant the whole of the complaint that 
Python made to you, not just the final error message!  Apologies for that.

c) I would much prefer it if you didn't top-post, but interleaved your 
replies like I've done here.  I find it hard to follow top-posted 
messages because they reverse the normal flow of conversation.

> 
> 
> On Wed, Dec 18, 2019 at 11:39 PM Rhodri James <rhodri at kynesim.co.uk> wrote:
> 
>> On 18/12/2019 02:23, tommy yama wrote:
>>> Hi,
>>>
>>> This sounds familiar to somebody?
>>> After upgrading my mac OS to Catalina, this persists even after pip3
>>> install hexdump.
>>>
>>> [image: image.png]
>>
>> I'm afraid this is a text-only mailing list.  Your screenshot has been
>> stripped out before any of us saw it.  Could you copy and paste (DON'T
>> retype!) the error instead, so we can all read it?
>>
>> --
>> Rhodri James *-* Kynesim Ltd
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>
> 


-- 
Rhodri James *-* Kynesim Ltd

From bluebox03 at gmail.com  Thu Dec 19 07:43:11 2019
From: bluebox03 at gmail.com (tommy yama)
Date: Thu, 19 Dec 2019 12:43:11 +0000
Subject: hexdump module installation error
In-Reply-To: <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
 <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
Message-ID: <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>

Hi Rhodri,

Thanks for your quick response i did not expect.
I hope you see the error below in my response as i just copy and paste it.

"no module named 'hexdump'."

In addition, i tried to execute python3 hexdump.py. However, no such file
directory.

   from hexdump import hexdump

ModuleNotFoundError: No module named 'hexdump'

user at USERnoMacBook-Air LibraBrowser % python3 hexdump.py

/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python:
can't open file 'hexdump.py': [Errno 2] No such file or directory

user at USERnoMacBook-Air LibraBrowser %

Cheers,



On Thu, Dec 19, 2019 at 12:21 PM Rhodri James <rhodri at kynesim.co.uk> wrote:

> On 19/12/2019 11:23, tommy yama wrote:
> > Thanks for your kind response.
> > The error was simply "module Hexdump was not found".
>
> Several things:
>
> a) Did it really say "module Hexdump was not found"?  "hexdump" and
> "Hexdump" are not the same things; module names are case-sensitive.
>
> b) There will have been a whole load more stack trace that might be
> useful to us.  I should have been clearer when I asked you to copy and
> paste the error that I really meant the whole of the complaint that
> Python made to you, not just the final error message!  Apologies for that.
>
> c) I would much prefer it if you didn't top-post, but interleaved your
> replies like I've done here.  I find it hard to follow top-posted
> messages because they reverse the normal flow of conversation.
>
> >
> >
> > On Wed, Dec 18, 2019 at 11:39 PM Rhodri James <rhodri at kynesim.co.uk>
> wrote:
> >
> >> On 18/12/2019 02:23, tommy yama wrote:
> >>> Hi,
> >>>
> >>> This sounds familiar to somebody?
> >>> After upgrading my mac OS to Catalina, this persists even after pip3
> >>> install hexdump.
> >>>
> >>> [image: image.png]
> >>
> >> I'm afraid this is a text-only mailing list.  Your screenshot has been
> >> stripped out before any of us saw it.  Could you copy and paste (DON'T
> >> retype!) the error instead, so we can all read it?
> >>
> >> --
> >> Rhodri James *-* Kynesim Ltd
> >> --
> >> https://mail.python.org/mailman/listinfo/python-list
> >>
> >
>
>
> --
> Rhodri James *-* Kynesim Ltd
>

From rhodri at kynesim.co.uk  Thu Dec 19 07:46:01 2019
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 19 Dec 2019 12:46:01 +0000
Subject: hexdump module installation error
In-Reply-To: <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
 <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
 <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
Message-ID: <218a46b0-520b-aa2e-b02f-9621605b9a52@kynesim.co.uk>

On 19/12/2019 12:43, tommy yama wrote:
> Thanks for your quick response i did not expect.
> I hope you see the error below in my response as i just copy and paste it.
> 
> "no module named 'hexdump'."
> 
> In addition, i tried to execute python3 hexdump.py. However, no such file
> directory.
> 
>     from hexdump import hexdump
> 
> ModuleNotFoundError: No module named 'hexdump'
> 
> user at USERnoMacBook-Air LibraBrowser % python3 hexdump.py
> 
> /usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python:
> can't open file 'hexdump.py': [Errno 2] No such file or directory
> 
> user at USERnoMacBook-Air LibraBrowser %

Huh.  You've done a "pip3 install hexdump" so I don't know what might be 
happening here.  Sorry.

-- 
Rhodri James *-* Kynesim Ltd

From lele at metapensiero.it  Thu Dec 19 08:16:48 2019
From: lele at metapensiero.it (Lele Gaifax)
Date: Thu, 19 Dec 2019 14:16:48 +0100
Subject: Cython, producing different modules from the same .pyx
Message-ID: <87a77osben.fsf@metapensiero.it>

Hi all,

in my package, I would like to compile and distribute two different extension
modules starting from the same .pyx file, just with different compilation
flags and libraries.

My first approach has been duplicating the Extension() entry in the
setup.py(*), changing the first argument (that is, the name of the module).
Although that did produce the alternative binary module, it could not be
loaded because it contains the wrong PyInit_XXX(), where XXX is computed from
the .pyx name, in my case "parser".

I tried looking at Cython documentation, and even its sources, but couldn't
find a way to alter that name.

Did I miss something, or is the only way to duplicate the source .pyx file to
a different name?

Thanks in advance,
ciao, lele.

(*) https://github.com/lelit/pglast/blob/master/setup.py#L76
-- 
nickname: Lele Gaifax | Quando vivr? di quello che ho pensato ieri
real: Emanuele Gaifas | comincer? ad aver paura di chi mi copia.
lele at metapensiero.it  |                 -- Fortunato Depero, 1929.


From rosuav at gmail.com  Thu Dec 19 09:08:00 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 20 Dec 2019 01:08:00 +1100
Subject: hexdump module installation error
In-Reply-To: <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
 <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
 <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
Message-ID: <CAPTjJmrqV0zZVKiJFDMbJLtH+1HkTPjb8zBY+81CbfpV0AXgNw@mail.gmail.com>

On Thu, Dec 19, 2019 at 11:44 PM tommy yama <bluebox03 at gmail.com> wrote:
>
> Hi Rhodri,
>
> Thanks for your quick response i did not expect.
> I hope you see the error below in my response as i just copy and paste it.
>
> "no module named 'hexdump'."
>
> In addition, i tried to execute python3 hexdump.py. However, no such file
> directory.
>
>    from hexdump import hexdump
>

Did you, at some point, have a file called hexdump.py that you were
playing with? Sometimes, even after you delete a file with a
conflicting name, its .pyc file hangs around. Blow away the
__pycache__ directory to get rid of it.

ChrisA

From bluebox03 at gmail.com  Thu Dec 19 09:09:12 2019
From: bluebox03 at gmail.com (tommy yama)
Date: Thu, 19 Dec 2019 14:09:12 +0000
Subject: hexdump module installation error
In-Reply-To: <218a46b0-520b-aa2e-b02f-9621605b9a52@kynesim.co.uk>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
 <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
 <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
 <218a46b0-520b-aa2e-b02f-9621605b9a52@kynesim.co.uk>
Message-ID: <CANevj7tjTLk3X+iK+9_X=X3U5kUU0Ft0i8JTasX-TVR73z6bfw@mail.gmail.com>

Yes. thanks for your enthusiasm. i may raise this in the git

On Thu, Dec 19, 2019 at 12:46 PM Rhodri James <rhodri at kynesim.co.uk> wrote:

> On 19/12/2019 12:43, tommy yama wrote:
> > Thanks for your quick response i did not expect.
> > I hope you see the error below in my response as i just copy and paste
> it.
> >
> > "no module named 'hexdump'."
> >
> > In addition, i tried to execute python3 hexdump.py. However, no such file
> > directory.
> >
> >     from hexdump import hexdump
> >
> > ModuleNotFoundError: No module named 'hexdump'
> >
> > user at USERnoMacBook-Air LibraBrowser % python3 hexdump.py
> >
> >
> /usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python:
> > can't open file 'hexdump.py': [Errno 2] No such file or directory
> >
> > user at USERnoMacBook-Air LibraBrowser %
>
> Huh.  You've done a "pip3 install hexdump" so I don't know what might be
> happening here.  Sorry.
>
> --
> Rhodri James *-* Kynesim Ltd
>

From onlinejudge95 at gmail.com  Thu Dec 19 09:11:40 2019
From: onlinejudge95 at gmail.com (onlinejudge95)
Date: Thu, 19 Dec 2019 19:41:40 +0530
Subject: Understanding of GIL
Message-ID: <CAD=M5eRWh9-EB180f2OzvnPLHh969vgaCzFyniFRSFa1-CwUHA@mail.gmail.com>

Hi Devs,

I am currently writing some custom Django commands for data updation, my
workflow is like

Fetch data from *PostgreSQL*.
Call *Elasticsearch* for searching based on the data fetched from
*PostgreSQL*.
Query *PostgreSQL* and do an upsert behavior.
I am using pandas data frame to hold my data during processing.

The host we are using to run this jobs has a *CPython* interpreter as given
by

`platform.python_implementation()`

I want to confirm whether *multithreading* would be a better choice here,
given the fact that GIL is the biggest blocker(I agree it has to be there)
for the same in CPython interpreters.

In case further information is required do let me know.

Thanks
onlinejudge95

From pieter-l at vanoostrum.org  Thu Dec 19 09:22:39 2019
From: pieter-l at vanoostrum.org (Pieter van Oostrum)
Date: Thu, 19 Dec 2019 15:22:39 +0100
Subject: INHERITANCE in python3
References: <1681866660.1226419.1576728600632.ref@mail.yahoo.com>
 <1681866660.1226419.1576728600632@mail.yahoo.com>
 <250232d0-d5ce-4007-89a0-32e0fc23590a@www.fastmail.com>
 <mailman.139.1576736685.11485.python-list@python.org>
Message-ID: <lxv9qcpf80.fsf@cochabamba.vanoostrum.org>

Random832 <random832 at fastmail.com> writes:

> On Wed, Dec 18, 2019, at 23:10, vahid asadi via Python-list wrote:
>> HI guys this is my first post on python mailing lists ever and i glad 
>> to do this.
>> my problem here is why this attribute is not recognize by python and it 
>> raise an traceback error that said 'there is no such p.family 
>> attribute'. although i use multiple ??inheritance with 'super ' it not 
>> works. thanks for your help.
>> 
>> ```?class Username:? ? def __init__(self,name,*args):? ? ? ? self.name 
>> = name
>> class Userfamily:? ? def __init__(self,family,*args):? ? ? ? 
>> self.family = family
>> class Person(Username,Userfamily):? ? def __init__(self,*args):? ? ? ? 
>> super().__init__(*args)
>> 
>> 
>> p = Person("v","aaa")print(p.name)print(p.family)```

Please next time, supply a properly indented Python source, with only normal ASCII spaces, not no-break spaces, i.e. exactly like in your Python source code.
>
> The Username class also needs to call super(). In general, super() is
> intended to be used with all classes that might be part of a multiple
> inheritance hierarchy, not just the derived one.

Just for safety, also add it to the Userfamily class.
-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]

From pieter-l at vanoostrum.org  Thu Dec 19 09:30:52 2019
From: pieter-l at vanoostrum.org (Pieter van Oostrum)
Date: Thu, 19 Dec 2019 15:30:52 +0100
Subject: hexdump module installation error
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
 <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
 <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
 <mailman.150.1576759405.11485.python-list@python.org>
Message-ID: <lxr210peub.fsf@cochabamba.vanoostrum.org>

tommy yama <bluebox03 at gmail.com> writes:

> user at USERnoMacBook-Air LibraBrowser % python3 hexdump.py
>
> /usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python:
> can't open file 'hexdump.py': [Errno 2] No such file or directory
>
> user at USERnoMacBook-Air LibraBrowser %

Could it be that your pip3 belongs to a different Python than the one above (for example a Python 3.8 or 3.6)? What is the output of 'pip3 --version' (without quotes)?

-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]

From ethan at stoneleaf.us  Thu Dec 19 12:35:49 2019
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 19 Dec 2019 09:35:49 -0800
Subject: Cython, producing different modules from the same .pyx
In-Reply-To: <87a77osben.fsf@metapensiero.it>
References: <87a77osben.fsf@metapensiero.it>
Message-ID: <897ebc73-44f1-461f-28e1-9119c76538a4@stoneleaf.us>

On 12/19/2019 05:16 AM, Lele Gaifax wrote:

> in my package, I would like to compile and distribute two different extension
> modules starting from the same .pyx file, just with different compilation
> flags and libraries.

If you don't get an answer here, you can try the Cython Users group:

   https://groups.google.com/forum/#!forum/cython-users

--
~Ethan~

From ethan at stoneleaf.us  Thu Dec 19 12:28:21 2019
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 19 Dec 2019 09:28:21 -0800
Subject: INHERITANCE in python3
In-Reply-To: <lxv9qcpf80.fsf@cochabamba.vanoostrum.org>
References: <1681866660.1226419.1576728600632.ref@mail.yahoo.com>
 <1681866660.1226419.1576728600632@mail.yahoo.com>
 <250232d0-d5ce-4007-89a0-32e0fc23590a@www.fastmail.com>
 <mailman.139.1576736685.11485.python-list@python.org>
 <lxv9qcpf80.fsf@cochabamba.vanoostrum.org>
Message-ID: <3e2e66f4-f5e4-0bf2-b9fc-93e71cbc3755@stoneleaf.us>

On 12/19/2019 06:22 AM, Pieter van Oostrum wrote:
> Random832 writes:
>> On Wed, Dec 18, 2019, at 23:10, wrote:

[vahid asadi]
>>> my problem here is why this attribute is not recognize by python and it
>>> raise an traceback error that said 'there is no such p.family
>>> attribute'. although i use multiple   inheritance with 'super ' it not
>>> works. thanks for your help.
>>>
>>>     class Username:
>>>         def __init__(self, name, *args):
>>>              self.name= name
>>>
>>>     class Userfamily:
>>>          def __init__(self, family, *args):
>>>             self.family = family
>>>
>>>     class Person(Username, Userfamily):
>>>          def __init__(self, *args):
>>>             super().__init__(*args)
>>>
>>>     p = Person("v", "aaa")
>>>     print(p.name)
>>>     print(p.family)

[Random32]
>> The Username class also needs to call super(). In general, super() is
>> intended to be used with all classes that might be part of a multiple
>> inheritance hierarchy, not just the derived one.

[Pieter van Oostrum]
> Just for safety, also add it* to the Userfamily class.


* a call to super()  (in case anybody else misreads that like I did)

--
~Ethan~

From * at eli.users.panix.com  Thu Dec 19 16:04:57 2019
From: * at eli.users.panix.com (Eli the Bearded)
Date: Thu, 19 Dec 2019 21:04:57 +0000 (UTC)
Subject: on sorting things
References: <eli$1912190219@qaz.wtf> <qtfdds$5nll$1@blaine.gmane.org>
 <mailman.144.1576745221.11485.python-list@python.org>
Message-ID: <eli$1912191553@qaz.wtf>

In comp.lang.python, Peter Otten  <__peter__ at web.de> wrote:
> Eli the Bearded wrote:
>> But what caught my eye most, as someone relatively new to Python but
>> with long experience in C in Perl, is sorting doesn't take a

s/C in /C and/

Ugh.

>> *comparison* function, it takes a *key generator* function, and that
>> function is supposed to transform the thing into something that the
>> native comparison knows how to compare.
>> 
>> This seems a strange choice, and I'm wondering if someone can explain
>> the benefits of doing it that way to me.
> 
> Python 2 started with a comparison function and then grew a key function.
> With a key function you still have to compare items, you are just breaking 
> the comparison into two steps:

[snip]

Thanks for that good explanation. The benchmark comparison makes it
very thorough.

In my mind I gravitate towards the complicated sorts of sort that can be
quickly compared for some sorts of keys and not as quickly for others.

Consider a sort that first compares file size and if the same number of
bytes, then compares file checksum. Any decently scaled real world
implementation would memoize the checksum for speed, but only work it out
for files that do not have a unique file size. The key method requires
it worked out in advance for everything.

But I see the key method handles the memoization under the hood for you,
so those simpler, more common sorts of sort get an easy to see benefit.

Elijah
------
even memoizing the stat() calls would help for large lists

From rosuav at gmail.com  Thu Dec 19 16:23:44 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 20 Dec 2019 08:23:44 +1100
Subject: on sorting things
In-Reply-To: <eli$1912191553@qaz.wtf>
References: <eli$1912190219@qaz.wtf> <qtfdds$5nll$1@blaine.gmane.org>
 <mailman.144.1576745221.11485.python-list@python.org> <eli$1912191553@qaz.wtf>
Message-ID: <CAPTjJmqUNmj5yeNqtn37iwZR4p08EmTgx=bp+fvqzj39bHwH2g@mail.gmail.com>

On Fri, Dec 20, 2019 at 8:06 AM Eli the Bearded <*@eli.users.panix.com> wrote:
>
> In comp.lang.python, Peter Otten  <__peter__ at web.de> wrote:
> > Eli the Bearded wrote:
> >> But what caught my eye most, as someone relatively new to Python but
> >> with long experience in C in Perl, is sorting doesn't take a
>
> s/C in /C and/
>
> Ugh.
>
> >> *comparison* function, it takes a *key generator* function, and that
> >> function is supposed to transform the thing into something that the
> >> native comparison knows how to compare.
> >>
> >> This seems a strange choice, and I'm wondering if someone can explain
> >> the benefits of doing it that way to me.
> >
> > Python 2 started with a comparison function and then grew a key function.
> > With a key function you still have to compare items, you are just breaking
> > the comparison into two steps:
>
> [snip]
>
> Thanks for that good explanation. The benchmark comparison makes it
> very thorough.
>
> In my mind I gravitate towards the complicated sorts of sort that can be
> quickly compared for some sorts of keys and not as quickly for others.
>
> Consider a sort that first compares file size and if the same number of
> bytes, then compares file checksum. Any decently scaled real world
> implementation would memoize the checksum for speed, but only work it out
> for files that do not have a unique file size. The key method requires
> it worked out in advance for everything.
>
> But I see the key method handles the memoization under the hood for you,
> so those simpler, more common sorts of sort get an easy to see benefit.
>

I guess that's a strange situation that might actually need this kind
of optimization, but if you really do have that situation, you can
make a magical key that behaves the way you want.

class SizeChecksum:
    def __init__(self, fn):
        self.size = os.stat(fn).st_size
        self._checksum = None
    @property
    def checksum(self):
        if self._checksum is not None: return self._checksum
        ...
    def __lt__(self, other):
        if self.size != other.size: return self.size < other.size
        return self.checksum < other.checksum

I can't remember exactly which comparison operators list.sort() uses,
so you'd want to add another function here for an equality check, or
maybe <=, or whichever is used. In any case, what matters is that the
weird situations can still be handled, albeit by largely falling back
on comparison semantics. But for the vast majority of situations, all
you need is a key function that returns a number, a string, or a tuple
of numbers and strings.

ChrisA

From pahome.chen at mirlab.org  Thu Dec 19 23:33:25 2019
From: pahome.chen at mirlab.org (lampahome)
Date: Fri, 20 Dec 2019 12:33:25 +0800
Subject: How to improve epoll speed when recv from kernel via netlink?
Message-ID: <CAB3eZfsJyH-KGf=pTXzk=rGJZkHH8M4si9+zyrOnE7cag0ursA@mail.gmail.com>

I tried to receive msg from kernel via netlink of socket.

And I use epoll to receive netlink events whenever it comes from kernel to
user space.

But I found the performance is poor e.g. epoll costs 90% time of execution
time after I profile it by cProfile module.

Are there any tips to improve this?

From greg.ewing at canterbury.ac.nz  Fri Dec 20 00:58:55 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Fri, 20 Dec 2019 18:58:55 +1300
Subject: Cython, producing different modules from the same .pyx
In-Reply-To: <mailman.152.1576761418.11485.python-list@python.org>
References: <87a77osben.fsf@metapensiero.it>
 <mailman.152.1576761418.11485.python-list@python.org>
Message-ID: <h6368vFa1mqU1@mid.individual.net>

On 20/12/19 2:16 am, Lele Gaifax wrote:
> My first approach has been duplicating the Extension() entry in the
> setup.py(*), changing the first argument (that is, the name of the module).
> Although that did produce the alternative binary module, it could not be
> loaded because it contains the wrong PyInit_XXX(), where XXX is computed from
> the .pyx name,

You could try creating a set of top-level .pyx stubs, each of
which just 'include' the real code.

-- 
Greg

From p4j at j4d.net  Fri Dec 20 07:12:24 2019
From: p4j at j4d.net (Pankaj Jangid)
Date: Fri, 20 Dec 2019 17:42:24 +0530
Subject: [HN] How to Make Python Wait
Message-ID: <m2v9qbryaf.fsf@j4d.net>

https://news.ycombinator.com/item?id=21834408




From rosuav at gmail.com  Fri Dec 20 08:58:22 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Dec 2019 00:58:22 +1100
Subject: [HN] How to Make Python Wait
In-Reply-To: <m2v9qbryaf.fsf@j4d.net>
References: <m2v9qbryaf.fsf@j4d.net>
Message-ID: <CAPTjJmo3aL-YJVHcRUozgWnFMhFTt9HKUhn4a_rnAwyLuZM83g@mail.gmail.com>

On Fri, Dec 20, 2019 at 11:16 PM Pankaj Jangid <p4j at j4d.net> wrote:
>
> https://news.ycombinator.com/item?id=21834408
>
>

Did you just post a blog article, then spam everywhere to try to get
traffic, where your entire blog post is telling people worse ways to
do a time.sleep()?

ChrisA

From arj.python at gmail.com  Fri Dec 20 09:22:26 2019
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Fri, 20 Dec 2019 18:22:26 +0400
Subject: [HN] How to Make Python Wait
In-Reply-To: <CAPTjJmo3aL-YJVHcRUozgWnFMhFTt9HKUhn4a_rnAwyLuZM83g@mail.gmail.com>
References: <m2v9qbryaf.fsf@j4d.net>
 <CAPTjJmo3aL-YJVHcRUozgWnFMhFTt9HKUhn4a_rnAwyLuZM83g@mail.gmail.com>
Message-ID: <CADrxXXk+_-sPc528gqUzYMWoj9TVwKqwnzXnNMRhZYHx7Hb5dQ@mail.gmail.com>

Original from miguel grinberg

From nt_mahmood at yahoo.com  Fri Dec 20 02:22:00 2019
From: nt_mahmood at yahoo.com (Mahmood Naderan)
Date: Fri, 20 Dec 2019 07:22:00 +0000 (UTC)
Subject: Unable to install "collect" via pip3
References: <414413727.1095151.1576826520979.ref@mail.yahoo.com>
Message-ID: <414413727.1095151.1576826520979@mail.yahoo.com>

Hi
 
I can install collect with pip for python2.7
$ pip install --user collect                                         
 Collecting collect
  Using cached https://files.pythonhosted.org/packages/cf/5e/c0f0f51d081665374a2c219ea4ba23fb1e179b70dded96dc16606786d828/collect-0.1.1.tar.gz
Collecting couchdbkit>=0.5.7 (from collect)
  Using cached https://files.pythonhosted.org/packages/a1/13/9e9ff695a385c44f62b4766341b97f2bd8b596962df2a0beabf358468b70/couchdbkit-0.6.5.tar.gz
Collecting restkit>=4.2.2 (from couchdbkit>=0.5.7->collect)
  Downloading https://files.pythonhosted.org/packages/76/b9/d90120add1be718f853c53008cf5b62d74abad1d32bd1e7097dd913ae053/restkit-4.2.2.tar.gz (1.3MB)
    100% |????????????????????????????????| 1.3MB 633kB/s
Collecting http-parser>=0.8.3 (from restkit>=4.2.2->couchdbkit>=0.5.7->collect)
  Downloading https://files.pythonhosted.org/packages/07/c4/22e3c76c2313c26dd5f84f1205b916ff38ea951aab0c4544b6e2f5920d64/http-parser-0.8.3.tar.gz (83kB)
    100% |????????????????????????????????| 92kB 2.4MB/s
Collecting socketpool>=0.5.3 (from restkit>=4.2.2->couchdbkit>=0.5.7->collect)
  Downloading https://files.pythonhosted.org/packages/d1/39/fae99a735227234ffec389b252c6de2bc7816bf627f56b4c558dc46c85aa/socketpool-0.5.3.tar.gz
Building wheels for collected packages: collect, couchdbkit, restkit, http-parser, socketpool
  Running setup.py bdist_wheel for collect ... done
  Stored in directory: /home/mnaderan/.cache/pip/wheels/b9/7c/7c/b09b334cc0e27b4f63ee9f6f19ca1f3db8672666a7e0f3d9cd
  Running setup.py bdist_wheel for couchdbkit ... done
  Stored in directory: /home/mnaderan/.cache/pip/wheels/f6/05/1b/f8f576ef18564bc68ab6e64f405e1263448036208cafb221e0
  Running setup.py bdist_wheel for restkit ... done
  Stored in directory: /home/mnaderan/.cache/pip/wheels/48/c5/32/d0d25fb272791a68c49c26150f332d9b9492d0bc9ea0cdd2c7
  Running setup.py bdist_wheel for http-parser ... done
  Stored in directory: /home/mnaderan/.cache/pip/wheels/22/db/06/cb609a3345e7aa87206de160f00cc6af364650d1139d904a25
  Running setup.py bdist_wheel for socketpool ... done
  Stored in directory: /home/mnaderan/.cache/pip/wheels/93/f6/8c/65924848766618647078cb66b1d964e8b80876536e84517469
Successfully built collect couchdbkit restkit http-parser socketpool
Installing collected packages: http-parser, socketpool, restkit, couchdbkit, collect
Successfully installed collect-0.1.1 couchdbkit-0.6.5 http-parser-0.8.3 restkit-4.2.2 socketpool-0.5.3
However, pip3 fails with this error
$ pip3 install --user collect
Collecting collect
  Using cached https://files.pythonhosted.org/packages/cf/5e/c0f0f51d081665374a2c219ea4ba23fb1e179b70dded96dc16606786d828/collect-0.1.1.tar.gz
Collecting couchdbkit>=0.5.7 (from collect)
  Using cached https://files.pythonhosted.org/packages/a1/13/9e9ff695a385c44f62b4766341b97f2bd8b596962df2a0beabf358468b70/couchdbkit-0.6.5.tar.gz
    Complete output from command python setup.py egg_info:
    Traceback (most recent call last):
      File "<string>", line 1, in <module>
      File "/tmp/pip-build-qf95n0tt/couchdbkit/setup.py", line 25, in <module>
        long_description = file(
    NameError: name 'file' is not defined

    ----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-qf95n0tt/couchdbkit/
I can not figure out what is the problem. Any way to fix that?

More info:
$ which python
/usr/bin/python
$ ls -l /usr/bin/python
lrwxrwxrwx 1 root root 9 Apr 16  2018 /usr/bin/python -> python2.7
$ which python3
/usr/bin/python3
$ ls -l /usr/bin/python3
lrwxrwxrwx 1 root root 9 Jun 21  2018 /usr/bin/python3 -> python3.6 



Regards,
Mahmood

From rainer.woitok at gmail.com  Fri Dec 20 07:19:26 2019
From: rainer.woitok at gmail.com (Dr Rainer Woitok)
Date: Fri, 20 Dec 2019 13:19:26 +0100
Subject: Problems with "Tarfile.close()"
Message-ID: <24060.48206.298944.886236@woitok.gmail.com>

Greetings,

One of my Python scripts basically does the following:

source = tarfile.open(name=tar_archive  , mode='r|*')
dest   = tarfile.open(fileobj=sys.stdout, mode='w|', format=fmt)

 .
 .
 .

source.close()
dest.close()

In an attempt to move my Python scripts  from Python 2.7 to Python 3.6 I
ran into the problem  that under Python 3.6  the call to  "dest.close()"
fails:

Traceback (most recent call last):
 File ".../tar_archive.copy", line 137, in <module>
 dest.close()
 File "/usr/lib64/python3.6/tarfile.py", line 1742, in close
 self.fileobj.close()
 File "/usr/lib64/python3.6/tarfile.py", line 467, in close
 self.fileobj.write(self.buf)
TypeError: write() argument must be str, not bytes

What am I doing wrong?   By the way:  since on some hosts this script is
running on  the transition from Python 2.7 to Python 3.x will not happen
immediately, I need a solution which works with both versions.

Sincerely,
  Rainer

From rosuav at gmail.com  Fri Dec 20 10:30:39 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Dec 2019 02:30:39 +1100
Subject: Unable to install "collect" via pip3
In-Reply-To: <414413727.1095151.1576826520979@mail.yahoo.com>
References: <414413727.1095151.1576826520979.ref@mail.yahoo.com>
 <414413727.1095151.1576826520979@mail.yahoo.com>
Message-ID: <CAPTjJmp6L_qB0-PF+FPPeaeZk0JsbL+Fmc7EiP4zTur6ySC9dA@mail.gmail.com>

On Sat, Dec 21, 2019 at 2:25 AM Mahmood Naderan via Python-list
<python-list at python.org> wrote:
>
> Hi
>
> I can install collect with pip for python2.7
> $ pip install --user collect

> However, pip3 fails with this error
> $ pip3 install --user collect
>     NameError: name 'file' is not defined
>
> I can not figure out what is the problem. Any way to fix that?
>

Are you trying to install this package?

https://pypi.org/project/collect/

It's alpha software that does not claim to support Python 3. The last
release was in 2011. The web site it links to is defunct.

Maybe that wasn't what you intended to install? Check the spelling of
the package you're trying to install - maybe it's named slightly
differently.

ChrisA

From rosuav at gmail.com  Fri Dec 20 10:34:28 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Dec 2019 02:34:28 +1100
Subject: Problems with "Tarfile.close()"
In-Reply-To: <24060.48206.298944.886236@woitok.gmail.com>
References: <24060.48206.298944.886236@woitok.gmail.com>
Message-ID: <CAPTjJmpGP48rZDRGgax4+CVD5yat6S+akjN8YA4oooPf_b0ZNA@mail.gmail.com>

On Sat, Dec 21, 2019 at 2:29 AM Dr Rainer Woitok
<rainer.woitok at gmail.com> wrote:
>
> Greetings,
>
> One of my Python scripts basically does the following:
>
> source = tarfile.open(name=tar_archive  , mode='r|*')
> dest   = tarfile.open(fileobj=sys.stdout, mode='w|', format=fmt)
>
>  .
>  .
>  .
>
> source.close()
> dest.close()
>
> In an attempt to move my Python scripts  from Python 2.7 to Python 3.6 I
> ran into the problem  that under Python 3.6  the call to  "dest.close()"
> fails:

(I think the fact that it fails when you close the file is a red
herring; it would fail at some point, and it happens to hold things
over until it closes.)

> Traceback (most recent call last):
>  File ".../tar_archive.copy", line 137, in <module>
>  dest.close()
>  File "/usr/lib64/python3.6/tarfile.py", line 1742, in close
>  self.fileobj.close()
>  File "/usr/lib64/python3.6/tarfile.py", line 467, in close
>  self.fileobj.write(self.buf)
> TypeError: write() argument must be str, not bytes
>
> What am I doing wrong?   By the way:  since on some hosts this script is
> running on  the transition from Python 2.7 to Python 3.x will not happen
> immediately, I need a solution which works with both versions.
>

Possibly the easiest fix would be to open all files in binary mode. I
think your content is binary anyway by the look of it. Just add the
letter "b" to the end of your open file modes, and on Py2, it'll
ensure that no newline conversion happens (mainly an issue on Windows,
which is why you probably don't feel the need to do this), but on Py3,
it means that it expects bytestrings everywhere.

If that *doesn't* work, then you may need to mark some of your strings
as binary, if you have unadorned strings containing ASCII data.

ChrisA

From ethan at stoneleaf.us  Fri Dec 20 10:41:51 2019
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 20 Dec 2019 07:41:51 -0800
Subject: Problems with "Tarfile.close()"
In-Reply-To: <24060.48206.298944.886236@woitok.gmail.com>
References: <24060.48206.298944.886236@woitok.gmail.com>
Message-ID: <213f5084-5007-8a87-5ac3-83cbd734e585@stoneleaf.us>

On 12/20/2019 04:19 AM, Dr Rainer Woitok wrote:

> One of my Python scripts basically does the following:
> 
> source = tarfile.open(name=tar_archive  , mode='r|*')
> dest   = tarfile.open(fileobj=sys.stdout, mode='w|', format=fmt)
> 
>   .
>   .
>   .
> 
> source.close()
> dest.close()
> 
> In an attempt to move my Python scripts  from Python 2.7 to Python 3.6 I
> ran into the problem  that under Python 3.6  the call to  "dest.close()"
> fails:
> 
> Traceback (most recent call last):
>   File ".../tar_archive.copy", line 137, in <module>
>   dest.close()
>   File "/usr/lib64/python3.6/tarfile.py", line 1742, in close
>   self.fileobj.close()
>   File "/usr/lib64/python3.6/tarfile.py", line 467, in close
>   self.fileobj.write(self.buf)
> TypeError: write() argument must be str, not bytes

In Python 3 `sys.stdout` is a character interface, not bytes.

There are a couple solutions to the Python 3 aspect of the problem here:

   https://stackoverflow.com/q/908331/208880

If those answers do not work on Python 2 you'll need to detect which version you are on and act appropriately, perhaps hiding that bit of complexity in a function or class.

--
~Ethan~

From barry at barrys-emacs.org  Fri Dec 20 10:01:41 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Fri, 20 Dec 2019 15:01:41 +0000
Subject: How to improve epoll speed when recv from kernel via netlink?
In-Reply-To: <CAB3eZfsJyH-KGf=pTXzk=rGJZkHH8M4si9+zyrOnE7cag0ursA@mail.gmail.com>
References: <CAB3eZfsJyH-KGf=pTXzk=rGJZkHH8M4si9+zyrOnE7cag0ursA@mail.gmail.com>
Message-ID: <D9D5EE25-BA1C-4FC4-9527-15028CE86A98@barrys-emacs.org>



> On 20 Dec 2019, at 04:33, lampahome <pahome.chen at mirlab.org> wrote:
> 
> I tried to receive msg from kernel via netlink of socket.
> 
> And I use epoll to receive netlink events whenever it comes from kernel to
> user space.
> 
> But I found the performance is poor e.g. epoll costs 90% time of execution
> time after I profile it by cProfile module.
> 
> Are there any tips to improve this?

cProfile is telling you how long the code is waiting for epoll to return.
It is not telling that epoll is a problem.

Barry



> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From p4j at j4d.net  Fri Dec 20 12:16:38 2019
From: p4j at j4d.net (p4j at j4d.net)
Date: Fri, 20 Dec 2019 22:46:38 +0530
Subject: [HN] How to Make Python Wait
References: <m2v9qbryaf.fsf@j4d.net>
 <CAPTjJmo3aL-YJVHcRUozgWnFMhFTt9HKUhn4a_rnAwyLuZM83g@mail.gmail.com>
 <mailman.161.1576850316.11485.python-list@python.org>
Message-ID: <m2r20ysyrt.fsf@j4d.net>

>> https://news.ycombinator.com/item?id=21834408
> Did you just post a blog article, then spam everywhere to try to get
> traffic, where your entire blog post is telling people worse ways to
> do a time.sleep()?

Blog post is not mine. I have a habit of posting good things to HN. When
I got notification that it is getting good traction, people are
discussing, then I posted the discussion link here. If that is not liked
here then I won't post again.

From rainer.woitok at gmail.com  Fri Dec 20 12:20:11 2019
From: rainer.woitok at gmail.com (Dr Rainer Woitok)
Date: Fri, 20 Dec 2019 18:20:11 +0100
Subject: Problems with "Tarfile.close()"
In-Reply-To: Msg <213f5084-5007-8a87-5ac3-83cbd734e585@stoneleaf.us> of
 2019-12-20 07:41:51 -0800 from ethan@stoneleaf.us
References: <24060.48206.298944.886236@woitok.gmail.com>
 <213f5084-5007-8a87-5ac3-83cbd734e585@stoneleaf.us>
Message-ID: <24061.715.861556.185941@woitok.gmail.com>

Ethan,

On Friday, 2019-12-20 07:41:51 -0800, you wrote:

> ...
> In Python 3 `sys.stdout` is a character interface, not bytes.

Does that mean that with Python  3 "Tarfile" is  no longer able to write
the "tar" file  to a pipe?   Or is there now  another way  to write to a
pipe?   And if that new way also  worked with Python  2, it would be even
better ... :-)

> There are a couple solutions to the Python 3 aspect of the problem here:
> 
>    https://stackoverflow.com/q/908331/208880

Using "sys.stdout.buffer"  seems to work  in Python 3  (at least with my
current rather trivial test case) but does not work in Python 2.  Quest-
ion: what is the cheapest way  to retrieve the Python version the script
is executing in?

Sincerely,
  Rainer

From __peter__ at web.de  Fri Dec 20 13:01:34 2019
From: __peter__ at web.de (Peter Otten)
Date: Fri, 20 Dec 2019 19:01:34 +0100
Subject: on sorting things
References: <eli$1912190219@qaz.wtf> <qtfdds$5nll$1@blaine.gmane.org>
 <mailman.144.1576745221.11485.python-list@python.org>
 <eli$1912191553@qaz.wtf>
Message-ID: <qtj2a1$3m45$1@blaine.gmane.org>

Eli the Bearded wrote:

> In comp.lang.python, Peter Otten  <__peter__ at web.de> wrote:
>> Eli the Bearded wrote:
>>> But what caught my eye most, as someone relatively new to Python but
>>> with long experience in C in Perl, is sorting doesn't take a
> 
> s/C in /C and/
> 
> Ugh.
> 
>>> *comparison* function, it takes a *key generator* function, and that
>>> function is supposed to transform the thing into something that the
>>> native comparison knows how to compare.
>>> 
>>> This seems a strange choice, and I'm wondering if someone can explain
>>> the benefits of doing it that way to me.
>> 
>> Python 2 started with a comparison function and then grew a key function.
>> With a key function you still have to compare items, you are just
>> breaking the comparison into two steps:
> 
> [snip]
> 
> Thanks for that good explanation. The benchmark comparison makes it
> very thorough.
> 
> In my mind I gravitate towards the complicated sorts of sort that can be
> quickly compared for some sorts of keys and not as quickly for others.
> 
> Consider a sort that first compares file size and if the same number of
> bytes, then compares file checksum. Any decently scaled real world
> implementation would memoize the checksum for speed, but only work it out
> for files that do not have a unique file size. The key method requires
> it worked out in advance for everything.

Oscar already mentioned the functools.cmp_to_key decorator which makes this 
a non-issue:

def mycmp(a, b): ...

files.sort(key=cmp_to_key(mycmp))


Applied to your example, with memoization:

# untested

def cmp(a, b):
    return (a > b)-(a < b)

def make_file_key():
    size = functools.lru_cache(None)(getsize)
    checksum = functools.lru_cache(None)(getchecksum)

    @functools.cmp_to_key
    def file_key(a, b):
        return cmp(size(a), size(b)) or cmp(checksum(a), checksum(b))
    return file_key

files.sort(key=make_file_key())

> But I see the key method handles the memoization under the hood for you,
> so those simpler, more common sorts of sort get an easy to see benefit.
> 
> Elijah
> ------
> even memoizing the stat() calls would help for large lists

PS: If you are sorting files by size and checksum as part of a deduplication 
effort consider using dict-s instead:

def grouped(items, key):
    result = defaultdict(list)
    for item in items:
        result[key(item)].append(item)
    return result

for same_size in grouped(files, key=getsize).values():
    if len(same_size) > 1:
        for same_checksum in grouped(same_size, key=getchecksum).values():
            if len(same_checksum) > 1:
                print(same_checksum)



From rosuav at gmail.com  Fri Dec 20 13:11:21 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Dec 2019 05:11:21 +1100
Subject: on sorting things
In-Reply-To: <qtj2a1$3m45$1@blaine.gmane.org>
References: <eli$1912190219@qaz.wtf> <qtfdds$5nll$1@blaine.gmane.org>
 <mailman.144.1576745221.11485.python-list@python.org> <eli$1912191553@qaz.wtf>
 <qtj2a1$3m45$1@blaine.gmane.org>
Message-ID: <CAPTjJmqw+yMOFNP2KfVOF2v-BF5V7+xo5tdudUY-VL4pqdywTw@mail.gmail.com>

On Sat, Dec 21, 2019 at 5:03 AM Peter Otten <__peter__ at web.de> wrote:
> PS: If you are sorting files by size and checksum as part of a deduplication
> effort consider using dict-s instead:

Yeah, I'd agree if that's the purpose. But let's say the point is to
have a guaranteed-stable ordering of files that are primarily to be
sorted by file size - in order to ensure that two files are in the
same order every time you refresh the view, they get sorted by their
checksums.

There ARE good reasons to do weird things with sorting, and a custom
key object (either with cmp_to_key or directly implemented) can do
that.

ChrisA

From lele at metapensiero.it  Fri Dec 20 13:33:47 2019
From: lele at metapensiero.it (Lele Gaifax)
Date: Fri, 20 Dec 2019 19:33:47 +0100
Subject: Cython, producing different modules from the same .pyx
References: <87a77osben.fsf@metapensiero.it>
 <mailman.152.1576761418.11485.python-list@python.org>
 <h6368vFa1mqU1@mid.individual.net>
Message-ID: <87h81uyhh0.fsf@metapensiero.it>

Greg Ewing <greg.ewing at canterbury.ac.nz> writes:

> You could try creating a set of top-level .pyx stubs, each of
> which just 'include' the real code.

Thank you, will try this approach!

ciao, lele.
-- 
nickname: Lele Gaifax | Quando vivr? di quello che ho pensato ieri
real: Emanuele Gaifas | comincer? ad aver paura di chi mi copia.
lele at metapensiero.it  |                 -- Fortunato Depero, 1929.


From lele at metapensiero.it  Fri Dec 20 13:35:04 2019
From: lele at metapensiero.it (Lele Gaifax)
Date: Fri, 20 Dec 2019 19:35:04 +0100
Subject: Cython, producing different modules from the same .pyx
References: <87a77osben.fsf@metapensiero.it>
 <897ebc73-44f1-461f-28e1-9119c76538a4@stoneleaf.us>
Message-ID: <87a77myhev.fsf@metapensiero.it>

Ethan Furman <ethan at stoneleaf.us> writes:

> If you don't get an answer here, you can try the Cython Users group:

Thanks, reposted the same question there.

ciao, lele.
-- 
nickname: Lele Gaifax | Quando vivr? di quello che ho pensato ieri
real: Emanuele Gaifas | comincer? ad aver paura di chi mi copia.
lele at metapensiero.it  |                 -- Fortunato Depero, 1929.


From __peter__ at web.de  Fri Dec 20 13:59:53 2019
From: __peter__ at web.de (Peter Otten)
Date: Fri, 20 Dec 2019 19:59:53 +0100
Subject: on sorting things
References: <eli$1912190219@qaz.wtf> <qtfdds$5nll$1@blaine.gmane.org>
 <mailman.144.1576745221.11485.python-list@python.org>
 <eli$1912191553@qaz.wtf> <qtj2a1$3m45$1@blaine.gmane.org>
 <CAPTjJmqw+yMOFNP2KfVOF2v-BF5V7+xo5tdudUY-VL4pqdywTw@mail.gmail.com>
Message-ID: <qtj5ne$2u9t$1@blaine.gmane.org>

Chris Angelico wrote:

> On Sat, Dec 21, 2019 at 5:03 AM Peter Otten <__peter__ at web.de> wrote:
>> PS: If you are sorting files by size and checksum as part of a
>> deduplication effort consider using dict-s instead:
> 
> Yeah, I'd agree if that's the purpose. But let's say the point is to
> have a guaranteed-stable ordering of files that are primarily to be
> sorted by file size - in order to ensure that two files are in the
> same order every time you refresh the view, they get sorted by their
> checksums.

One thing that struck me about Eli's example is that it features two key 
functions rather than a complex comparison. 

If sort() would accept a sequence of key functions each function could be 
used to sort slices that compare equal when using the previous key.

> There ARE good reasons to do weird things with sorting, and a custom
> key object (either with cmp_to_key or directly implemented) can do
> that.

Indeed.


From __peter__ at web.de  Fri Dec 20 14:12:11 2019
From: __peter__ at web.de (Peter Otten)
Date: Fri, 20 Dec 2019 20:12:11 +0100
Subject: Problems with "Tarfile.close()"
References: <24060.48206.298944.886236@woitok.gmail.com>
 <213f5084-5007-8a87-5ac3-83cbd734e585@stoneleaf.us>
 <24061.715.861556.185941@woitok.gmail.com>
Message-ID: <qtj6ec$4glk$1@blaine.gmane.org>

Dr Rainer Woitok wrote:

> Ethan,
> 
> On Friday, 2019-12-20 07:41:51 -0800, you wrote:
> 
>> ...
>> In Python 3 `sys.stdout` is a character interface, not bytes.
> 
> Does that mean that with Python  3 "Tarfile" is  no longer able to write
> the "tar" file  to a pipe?   Or is there now  another way  to write to a
> pipe?   And if that new way also  worked with Python  2, it would be even
> better ... :-)
> 
>> There are a couple solutions to the Python 3 aspect of the problem here:
>> 
>>    https://stackoverflow.com/q/908331/208880
> 
> Using "sys.stdout.buffer"  seems to work  in Python 3  (at least with my
> current rather trivial test case) but does not work in Python 2.  Quest-
> ion: what is the cheapest way  to retrieve the Python version the script
> is executing in?

While I didn't look into the stackoverflow page an easy way to get something 
that accepts bytes may be

# untested
stdout = sys.stdout
try:
    stdout = stdout.buffer
except AttributeError:
    pass

tarfile.open(fileobj=stdout, ...)


From rosuav at gmail.com  Fri Dec 20 14:44:03 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Dec 2019 06:44:03 +1100
Subject: on sorting things
In-Reply-To: <qtj5ne$2u9t$1@blaine.gmane.org>
References: <eli$1912190219@qaz.wtf> <qtfdds$5nll$1@blaine.gmane.org>
 <mailman.144.1576745221.11485.python-list@python.org> <eli$1912191553@qaz.wtf>
 <qtj2a1$3m45$1@blaine.gmane.org>
 <CAPTjJmqw+yMOFNP2KfVOF2v-BF5V7+xo5tdudUY-VL4pqdywTw@mail.gmail.com>
 <qtj5ne$2u9t$1@blaine.gmane.org>
Message-ID: <CAPTjJmpvsW6Ao3MVr4z0TauMJA73=11RsLEvhJYocnZEJf1wGw@mail.gmail.com>

On Sat, Dec 21, 2019 at 6:01 AM Peter Otten <__peter__ at web.de> wrote:
>
> Chris Angelico wrote:
>
> > On Sat, Dec 21, 2019 at 5:03 AM Peter Otten <__peter__ at web.de> wrote:
> >> PS: If you are sorting files by size and checksum as part of a
> >> deduplication effort consider using dict-s instead:
> >
> > Yeah, I'd agree if that's the purpose. But let's say the point is to
> > have a guaranteed-stable ordering of files that are primarily to be
> > sorted by file size - in order to ensure that two files are in the
> > same order every time you refresh the view, they get sorted by their
> > checksums.
>
> One thing that struck me about Eli's example is that it features two key
> functions rather than a complex comparison.
>
> If sort() would accept a sequence of key functions each function could be
> used to sort slices that compare equal when using the previous key.
>

That would basically make it a comparison function, not a key function
:) The value of the key function is that it's called exactly once per
element, and the result is what you sort by. There's no correlation to
any other element. It's effectively this:

# sortme.sort(key=keyfunc)
keys = sortme.map(keyfunc)
keys.sort(keep_in_parallel=sortme)

Which is why cmp_to_key is the correct solution to that problem.

(For cases where you don't mind pre-calling both key functions, of
course, it's equivalent to a single key function that returns a
tuple.)

ChrisA

From rosuav at gmail.com  Fri Dec 20 14:45:24 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 21 Dec 2019 06:45:24 +1100
Subject: Problems with "Tarfile.close()"
In-Reply-To: <qtj6ec$4glk$1@blaine.gmane.org>
References: <24060.48206.298944.886236@woitok.gmail.com>
 <213f5084-5007-8a87-5ac3-83cbd734e585@stoneleaf.us>
 <24061.715.861556.185941@woitok.gmail.com> <qtj6ec$4glk$1@blaine.gmane.org>
Message-ID: <CAPTjJmoR2gaHSBCifqC7oCro3_wS1Kddo_-Sg8L=231nujoMfA@mail.gmail.com>

On Sat, Dec 21, 2019 at 6:13 AM Peter Otten <__peter__ at web.de> wrote:
>
> Dr Rainer Woitok wrote:
>
> > Ethan,
> >
> > On Friday, 2019-12-20 07:41:51 -0800, you wrote:
> >
> >> ...
> >> In Python 3 `sys.stdout` is a character interface, not bytes.
> >
> > Does that mean that with Python  3 "Tarfile" is  no longer able to write
> > the "tar" file  to a pipe?   Or is there now  another way  to write to a
> > pipe?   And if that new way also  worked with Python  2, it would be even
> > better ... :-)
> >
> >> There are a couple solutions to the Python 3 aspect of the problem here:
> >>
> >>    https://stackoverflow.com/q/908331/208880
> >
> > Using "sys.stdout.buffer"  seems to work  in Python 3  (at least with my
> > current rather trivial test case) but does not work in Python 2.  Quest-
> > ion: what is the cheapest way  to retrieve the Python version the script
> > is executing in?
>
> While I didn't look into the stackoverflow page an easy way to get something
> that accepts bytes may be
>
> # untested
> stdout = sys.stdout
> try:
>     stdout = stdout.buffer
> except AttributeError:
>     pass

This construct can be simplified down to:

stdout = getattr(sys.stdout, "buffer", sys.stdout)

ChrisA

From tjreedy at udel.edu  Fri Dec 20 14:54:49 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 20 Dec 2019 14:54:49 -0500
Subject: Unable to install "collect" via pip3
In-Reply-To: <414413727.1095151.1576826520979@mail.yahoo.com>
References: <414413727.1095151.1576826520979.ref@mail.yahoo.com>
 <414413727.1095151.1576826520979@mail.yahoo.com>
Message-ID: <qtj8ua$1mol$1@blaine.gmane.org>

On 12/20/2019 2:22 AM, Mahmood Naderan via Python-list wrote:

> However, pip3 fails with this error
> $ pip3 install --user collect
> Collecting collect
>    Using cached https://files.pythonhosted.org/packages/cf/5e/c0f0f51d081665374a2c219ea4ba23fb1e179b70dded96dc16606786d828/collect-0.1.1.tar.gz
> Collecting couchdbkit>=0.5.7 (from collect)
>    Using cached https://files.pythonhosted.org/packages/a1/13/9e9ff695a385c44f62b4766341b97f2bd8b596962df2a0beabf358468b70/couchdbkit-0.6.5.tar.gz
>      Complete output from command python setup.py egg_info:
>      Traceback (most recent call last):
>        File "<string>", line 1, in <module>
>        File "/tmp/pip-build-qf95n0tt/couchdbkit/setup.py", line 25, in <module>
>          long_description = file(
>      NameError: name 'file' is not defined

The builtin function 'file' does not exist in 3.x.  pip3 is trying to 
install 2.x code.  I suspect this is because the package is not properly 
labelled as 2.x only.  (Some 2.x code will run unaltered on 3.x, so pip 
should try even if 3.x is not specified.)


-- 
Terry Jan Reedy


From barry at barrys-emacs.org  Fri Dec 20 17:10:24 2019
From: barry at barrys-emacs.org (Barry)
Date: Fri, 20 Dec 2019 22:10:24 +0000
Subject: Unable to install "collect" via pip3
In-Reply-To: <414413727.1095151.1576826520979@mail.yahoo.com>
References: <414413727.1095151.1576826520979@mail.yahoo.com>
Message-ID: <DC3A02D1-6E09-4C69-AE0C-C7A32675B83F@barrys-emacs.org>



> On 20 Dec 2019, at 15:27, Mahmood Naderan via Python-list <python-list at python.org> wrote:
> 
> ?Hi
> 
> I can install collect with pip for python2.7
> $ pip install --user collect                                         
> Collecting collect
>  Using cached https://files.pythonhosted.org/packages/cf/5e/c0f0f51d081665374a2c219ea4ba23fb1e179b70dded96dc16606786d828/collect-0.1.1.tar.gz
> Collecting couchdbkit>=0.5.7 (from collect)
>  Using cached https://files.pythonhosted.org/packages/a1/13/9e9ff695a385c44f62b4766341b97f2bd8b596962df2a0beabf358468b70/couchdbkit-0.6.5.tar.gz
> Collecting restkit>=4.2.2 (from couchdbkit>=0.5.7->collect)
>  Downloading https://files.pythonhosted.org/packages/76/b9/d90120add1be718f853c53008cf5b62d74abad1d32bd1e7097dd913ae053/restkit-4.2.2.tar.gz (1.3MB)
>    100% |????????????????????????????????| 1.3MB 633kB/s
> Collecting http-parser>=0.8.3 (from restkit>=4.2.2->couchdbkit>=0.5.7->collect)
>  Downloading https://files.pythonhosted.org/packages/07/c4/22e3c76c2313c26dd5f84f1205b916ff38ea951aab0c4544b6e2f5920d64/http-parser-0.8.3.tar.gz (83kB)
>    100% |????????????????????????????????| 92kB 2.4MB/s
> Collecting socketpool>=0.5.3 (from restkit>=4.2.2->couchdbkit>=0.5.7->collect)
>  Downloading https://files.pythonhosted.org/packages/d1/39/fae99a735227234ffec389b252c6de2bc7816bf627f56b4c558dc46c85aa/socketpool-0.5.3.tar.gz
> Building wheels for collected packages: collect, couchdbkit, restkit, http-parser, socketpool
>  Running setup.py bdist_wheel for collect ... done
>  Stored in directory: /home/mnaderan/.cache/pip/wheels/b9/7c/7c/b09b334cc0e27b4f63ee9f6f19ca1f3db8672666a7e0f3d9cd
>  Running setup.py bdist_wheel for couchdbkit ... done
>  Stored in directory: /home/mnaderan/.cache/pip/wheels/f6/05/1b/f8f576ef18564bc68ab6e64f405e1263448036208cafb221e0
>  Running setup.py bdist_wheel for restkit ... done
>  Stored in directory: /home/mnaderan/.cache/pip/wheels/48/c5/32/d0d25fb272791a68c49c26150f332d9b9492d0bc9ea0cdd2c7
>  Running setup.py bdist_wheel for http-parser ... done
>  Stored in directory: /home/mnaderan/.cache/pip/wheels/22/db/06/cb609a3345e7aa87206de160f00cc6af364650d1139d904a25
>  Running setup.py bdist_wheel for socketpool ... done
>  Stored in directory: /home/mnaderan/.cache/pip/wheels/93/f6/8c/65924848766618647078cb66b1d964e8b80876536e84517469
> Successfully built collect couchdbkit restkit http-parser socketpool
> Installing collected packages: http-parser, socketpool, restkit, couchdbkit, collect
> Successfully installed collect-0.1.1 couchdbkit-0.6.5 http-parser-0.8.3 restkit-4.2.2 socketpool-0.5.3
> However, pip3 fails with this error
> $ pip3 install --user collect
> Collecting collect
>  Using cached https://files.pythonhosted.org/packages/cf/5e/c0f0f51d081665374a2c219ea4ba23fb1e179b70dded96dc16606786d828/collect-0.1.1.tar.gz
> Collecting couchdbkit>=0.5.7 (from collect)
>  Using cached https://files.pythonhosted.org/packages/a1/13/9e9ff695a385c44f62b4766341b97f2bd8b596962df2a0beabf358468b70/couchdbkit-0.6.5.tar.gz
>    Complete output from command python setup.py egg_info:
>    Traceback (most recent call last):
>      File "<string>", line 1, in <module>
>      File "/tmp/pip-build-qf95n0tt/couchdbkit/setup.py", line 25, in <module>
>        long_description = file(
>    NameError: name 'file' is not defined

My guess is that file is python 2 only. Couchdbkit needs porting to python 3.

Barry

> 
>    ----------------------------------------
> Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-qf95n0tt/couchdbkit/
> I can not figure out what is the problem. Any way to fix that?
> 
> More info:
> $ which python
> /usr/bin/python
> $ ls -l /usr/bin/python
> lrwxrwxrwx 1 root root 9 Apr 16  2018 /usr/bin/python -> python2.7
> $ which python3
> /usr/bin/python3
> $ ls -l /usr/bin/python3
> lrwxrwxrwx 1 root root 9 Jun 21  2018 /usr/bin/python3 -> python3.6 
> 
> 
> 
> Regards,
> Mahmood
> -- 
> https://mail.python.org/mailman/listinfo/python-list


From greg.ewing at canterbury.ac.nz  Fri Dec 20 20:50:45 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Sat, 21 Dec 2019 14:50:45 +1300
Subject: How to extend an object?
In-Reply-To: <extend-20191220134211@ram.dialup.fu-berlin.de>
References: <extend-20191220134211@ram.dialup.fu-berlin.de>
Message-ID: <h65c3pFo2kbU1@mid.individual.net>

On 21/12/19 1:59 am, Stefan Ram wrote:
>    I would like to add a method to a string.
> 
>    This is not possible in Python?

It's not possible. Built-in classes can't have methods added
to them.

You can define your own subclass of str and give it whatever
methods you want.

But in your case:

> for s in 'abc'.like( '(.)' ):

I would recommend making it a stand-alone function instead,
so that you would write

   for s in like('abc', '(.)'):

-- 
Greg

From wanghao7915 at gmail.com  Sat Dec 21 00:04:20 2019
From: wanghao7915 at gmail.com (wanghao7915 at gmail.com)
Date: Fri, 20 Dec 2019 21:04:20 -0800 (PST)
Subject: How to combine a group of lists together
Message-ID: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>

I utilized .get_text() + .split() functions and obtain this:
spe=
['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 'Details']
['4.7', 'inches']
['750', 'x', '1334']
['64', 'GB']
['2', 'GB']
['Apple', 'A11', 'Bionic,', 'Hexa-Core,', '(2x', 'Monsoon', '+', '4x', 'Mistral)']
['5.22', 'ounces']
['No']
['No']
['12', 'MP']
['7', 'MP']
['1821', 'mah']
['No']
['Yes,', 'on', 'the', 'front']
['None']
['iOS', '(Last', 'OS', 'info:', 'IOS', '11)']
['September', '2017']

They have a shared name 'spe', but no concrete names for each list.
If I use spe[0], I can only get all the first element of each list.

How can I mix all of these elements into a single list like:
['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 'Details','4.7', 'inches'......]

Thanks!

From cs at cskk.id.au  Sat Dec 21 00:31:36 2019
From: cs at cskk.id.au (Cameron Simpson)
Date: Sat, 21 Dec 2019 16:31:36 +1100
Subject: How to combine a group of lists together
In-Reply-To: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>
References: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>
Message-ID: <20191221053136.GA95909@cskk.homeip.net>

On 20Dec2019 21:04, wanghao7915 at gmail.com <wanghao7915 at gmail.com> wrote:
>I utilized .get_text() + .split() functions and obtain this:
>spe=
>['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 'Details']
>['4.7', 'inches']
>['750', 'x', '1334']
>['64', 'GB']
>['2', 'GB']
>['Apple', 'A11', 'Bionic,', 'Hexa-Core,', '(2x', 'Monsoon', '+', '4x', 'Mistral)']
>['5.22', 'ounces']
>['No']
>['No']
>['12', 'MP']
>['7', 'MP']
>['1821', 'mah']
>['No']
>['Yes,', 'on', 'the', 'front']
>['None']
>['iOS', '(Last', 'OS', 'info:', 'IOS', '11)']
>['September', '2017']
>
>They have a shared name 'spe', but no concrete names for each list.

Does that mean you have a loop, with spe being computed in each loop 
pass?

It would help to see your code.

>If I use spe[0], I can only get all the first element of each list.

Indeed, since that designates the first element.

>How can I mix all of these elements into a single list like:
>['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 
>'Details','4.7', 'inches'......]

Have a look at the chain() function from the itertools module. Or at the 
extend() method of the list class. Either will help you compose a longer 
list from a collection of individual lists.

If you're still stuck, post your code in a followup message and ask 
sepecific questions about your attempts to build a bigger list from 
various smaller ones.

Cheers,
Cameron Simpson <cs at cskk.id.au>

From PythonList at DancesWithMice.info  Sat Dec 21 00:48:43 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 21 Dec 2019 18:48:43 +1300
Subject: How to combine a group of lists together
In-Reply-To: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>
References: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>
Message-ID: <636aa1d7-7fd4-b59d-f511-8d7084669022@DancesWithMice.info>

On 21/12/19 6:04 pm, wanghao7915 at gmail.com wrote:
> I utilized .get_text() + .split() functions and obtain this:
> spe=
> ['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 'Details']
> ['4.7', 'inches']
> ['750', 'x', '1334']
> ['64', 'GB']
> ['2', 'GB']
> ['Apple', 'A11', 'Bionic,', 'Hexa-Core,', '(2x', 'Monsoon', '+', '4x', 'Mistral)']
> ['5.22', 'ounces']
> ['No']
> ['No']
> ['12', 'MP']
> ['7', 'MP']
> ['1821', 'mah']
> ['No']
> ['Yes,', 'on', 'the', 'front']
> ['None']
> ['iOS', '(Last', 'OS', 'info:', 'IOS', '11)']
> ['September', '2017']
> 
> They have a shared name 'spe', but no concrete names for each list.
> If I use spe[0], I can only get all the first element of each list.
> 
> How can I mix all of these elements into a single list like:
> ['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 'Details','4.7', 'inches'......]

What is type( spe )? Please copy-paste code/session into your email msg 
- the above is NOT Python.

Your best solution may be to use a loop (instead of the constant 0, as 
list-argument).

The answer to your specific question is 'in the manual': list.extend()
(but a loop will likely still be required...)


WebRef:
https://docs.python.org/3/library/stdtypes.html#sequence-types-list-tuple-range


-- 
Regards =dn

From PythonList at DancesWithMice.info  Sat Dec 21 01:00:04 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 21 Dec 2019 19:00:04 +1300
Subject: How to extend an object?
In-Reply-To: <h65c3pFo2kbU1@mid.individual.net>
References: <extend-20191220134211@ram.dialup.fu-berlin.de>
 <h65c3pFo2kbU1@mid.individual.net>
Message-ID: <9bb4965d-47f7-dabc-93a4-62f673faf62c@DancesWithMice.info>

On 21/12/19 2:50 pm, Greg Ewing wrote:
> On 21/12/19 1:59 am, Stefan Ram wrote:
>> ?? I would like to add a method to a string.
>>
>> ?? This is not possible in Python?
> 
> It's not possible. Built-in classes can't have methods added
> to them.
> 
> You can define your own subclass of str and give it whatever
> methods you want.
> 
> But in your case:
> 
>> for s in 'abc'.like( '(.)' ):
> 
> I would recommend making it a stand-alone function instead,
> so that you would write
> 
>  ? for s in like('abc', '(.)'):


Contrarily: sub-classing str and making like() a method strikes me as 
the way to go, particularly if the 'abc' disappears into the instance's 
__init__() - and better still if the '(.)' may also be absorbed as a 
class/instance attribute, and even more-so if like() is not the only 
method/stand-alone function required for this category of strings...

but...

choose a self-documenting name for the class, and
choose a better-documenting name for the method.

instance = class( "abc" )
...
for s in instance.method():

is clean, self-documenting (or will be once you've done your thing), 
easier to test (fewer args => easier assured testing).

-- 
Regards =dn

From wanghao7915 at gmail.com  Sat Dec 21 01:47:31 2019
From: wanghao7915 at gmail.com (wanghao7915 at gmail.com)
Date: Fri, 20 Dec 2019 22:47:31 -0800 (PST)
Subject: How to combine a group of lists together
In-Reply-To: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>
References: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>
Message-ID: <1497d8b4-3875-436d-b0da-90e4448197e7@googlegroups.com>

thanks for responding!
Now I've solved this problem!

My former code is:
for j in data:
    spe = j.get_text()
    l_spe = spe.split()
    print(l_spe)        

Then I get the result:
['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 'Details']
['4.7', 'inches']
['750', 'x', '1334']
['64', 'GB']
['2', 'GB']
['Apple', 'A11', 'Bionic,', 'Hexa-Core,', '(2x', 'Monsoon', '+', '4x', 'Mistral)']
['5.22', 'ounces']
['No']
['No']
['12', 'MP']
['7', 'MP']
['1821', 'mah']
['No']
['Yes,', 'on', 'the', 'front']
['None']
['iOS', '(Last', 'OS', 'info:', 'IOS', '11)']
['September', '2017']

Now my code is:
for j in data:
    spe = j.get_text()
    temp_li.extend(spe.split())
print(temp_li)

Then: 
['$278.86as', 'of', 'Dec', '20,', '2019,', '06:47', 'PST', '-', 'Details', '4.7', 'inches', '750', 'x', '1334', '64', 'GB', '2', 'GB', 'Apple', 'A11', 'Bionic,', 'Hexa-Core,', '(2x', 'Monsoon', '+', '4x', 'Mistral)', '5.22', 'ounces', 'No', 'No', '12', 'MP', '7', 'MP', '1821', 'mah', 'No', 'Yes,', 'on', 'the', 'front', 'None', 'iOS', '(Last', 'OS', 'info:', 'IOS', '11)', 'September', '2017']

Bravo!

From wanghao7915 at gmail.com  Sat Dec 21 01:52:08 2019
From: wanghao7915 at gmail.com (wanghao7915 at gmail.com)
Date: Fri, 20 Dec 2019 22:52:08 -0800 (PST)
Subject: How to combine a group of lists together
In-Reply-To: <mailman.180.1576906690.11485.python-list@python.org>
References: <4bd40fe1-b703-491a-a573-cfb4d44403fb@googlegroups.com>
 <20191221053136.GA95909@cskk.homeip.net>
 <mailman.180.1576906690.11485.python-list@python.org>
Message-ID: <700e2b65-67b7-4e3e-b5bf-4a2b033862ff@googlegroups.com>

Thanks!
Actually, I neglected that my "print" is in the "for", so I get a group of lists.
Now I put the "print" out of the iteration then use .extend to append each list I produce. Finally, print and get my ideal result.

Haha, I'm too naive, so is my English.

From rainer.woitok at gmail.com  Sat Dec 21 03:15:54 2019
From: rainer.woitok at gmail.com (Dr Rainer Woitok)
Date: Sat, 21 Dec 2019 09:15:54 +0100
Subject: Problems with "Tarfile.close()"
In-Reply-To: Msg
 <CAPTjJmoR2gaHSBCifqC7oCro3_wS1Kddo_-Sg8L=231nujoMfA@mail.gmail.com> of
 2019-12-21 06:45:24 +1100 from rosuav@gmail.com
References: <24060.48206.298944.886236@woitok.gmail.com>
 <213f5084-5007-8a87-5ac3-83cbd734e585@stoneleaf.us>
 <24061.715.861556.185941@woitok.gmail.com>
 <qtj6ec$4glk$1@blaine.gmane.org>
 <CAPTjJmoR2gaHSBCifqC7oCro3_wS1Kddo_-Sg8L=231nujoMfA@mail.gmail.com>
Message-ID: <24061.54458.482156.152148@woitok.gmail.com>

Chris,

On Saturday, 2019-12-21 06:45:24 +1100, you wrote:

> ...
> This construct can be simplified down to:
> 
> stdout = getattr(sys.stdout, "buffer", sys.stdout)

Nice!  And with my admittedly trivial test case it correctly works under
both, Python 2 and Python 3.

Now I'll do some more serious testing ...

Sincerely,
  Rainer

From bluebox03 at gmail.com  Sat Dec 21 03:44:51 2019
From: bluebox03 at gmail.com (tommy yama)
Date: Sat, 21 Dec 2019 08:44:51 +0000
Subject: hexdump module installation error
In-Reply-To: <ilbnveh7ahej3a8fsrdsc91i9s31e67cb9@4ax.com>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
 <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
 <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
 <ilbnveh7ahej3a8fsrdsc91i9s31e67cb9@4ax.com>
Message-ID: <CANevj7u8rgG8W9A4+ra7eFD01Xx53--3TU9n3i3_=xOYdg6ETw@mail.gmail.com>

Thanks to all giving me helpful comments.
Multiple hexdump files are found. Maybe that"s the reason.

I guess i can figure out




On Thu, Dec 19, 2019 at 5:29 PM Dennis Lee Bieber <wlfraed at ix.netcom.com>
wrote:

> On Thu, 19 Dec 2019 12:43:11 +0000, tommy yama <bluebox03 at gmail.com>
> declaimed the following:
>
> >
> >user at USERnoMacBook-Air LibraBrowser % python3 hexdump.py
> >
>
> >/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python:
> >can't open file 'hexdump.py': [Errno 2] No such file or directory
> >
> >user at USERnoMacBook-Air LibraBrowser %
> >
>
>         Well... what does
>
>                 find / -iname hexdump.py
>
> return? If found, is it in the Python search path?
>
> {Debian system here, but... (after doing apt install python3-pip)}
>
> wulfraed at debian:~$ pip3 install hexdump
> Collecting hexdump
>   Downloading
>
> https://files.pythonhosted.org/packages/55/b3/279b1d57fa3681725d0db8820405cdcb4e62a9239c205e4ceac4391c78e4/hexdump-3.3.zip
> Building wheels for collected packages: hexdump
>   Running setup.py bdist_wheel for hexdump ... done
>   Stored in directory:
>
> /home/wulfraed/.cache/pip/wheels/d5/d1/f2/c8183b5863b3df595c2eeafd8e015a43dae13d403a959467c6
> Successfully built hexdump
> Installing collected packages: hexdump
> Successfully installed hexdump-3.3
> wulfraed at debian:~$ sudo find / -iname hexdump.py
> /home/wulfraed/.local/lib/python3.7/site-packages/hexdump.py
> find: ?/run/user/1000/gvfs?: Permission denied
> /usr/lib/python3/dist-packages/pygments/lexers/hexdump.py
> /usr/lib/python2.7/dist-packages/pygments/lexers/hexdump.py
> wulfraed at debian:~$ python3
> Python 3.7.3 (default, Apr  3 2019, 05:39:12)
> [GCC 8.3.0] on linux
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import hexdump
> >>> dir(hexdump)
> ['PY3K', '__author__', '__builtins__', '__cached__', '__doc__', '__file__',
> '__history__', '__license__', '__loader__', '__name__', '__package__',
> '__spec__', '__version__', 'binascii', 'chunkread', 'chunks', 'dehex',
> 'dump', 'dumpgen', 'genchunks', 'hexdump', 'main', 'normalize_py',
> 'restore', 'runtest', 'sys']
> >>> hexdump.__file__
> '/home/wulfraed/.local/lib/python3.7/site-packages/hexdump.py'
> >>>
>
>         Note that there are "hexdump.py" files involved with the pygments
> package, which likely are not what you are looking for (quick glance -- the
> pygments hexdump READS dump files).
>
>
> --
>         Wulfraed                 Dennis Lee Bieber         AF6VN
>         wlfraed at ix.netcom.com
> http://wlfraed.microdiversity.freeddns.org/
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From barry at barrys-emacs.org  Sat Dec 21 04:58:42 2019
From: barry at barrys-emacs.org (Barry)
Date: Sat, 21 Dec 2019 09:58:42 +0000
Subject: Problems with "Tarfile.close()"
In-Reply-To: <24060.48206.298944.886236@woitok.gmail.com>
References: <24060.48206.298944.886236@woitok.gmail.com>
Message-ID: <673433FC-434D-4AE2-83CE-B292F0584C38@barrys-emacs.org>



> On 20 Dec 2019, at 15:31, Dr Rainer Woitok <rainer.woitok at gmail.com> wrote:
> 
> ?Greetings,
> 
> One of my Python scripts basically does the following:
> 
> source = tarfile.open(name=tar_archive  , mode='r|*')
> dest   = tarfile.open(fileobj=sys.stdout, mode='w|', format=fmt)
> 
> .
> .
> .
> 
> source.close()
> dest.close()
> 
> In an attempt to move my Python scripts  from Python 2.7 to Python 3.6 I
> ran into the problem  that under Python 3.6  the call to  "dest.close()"
> fails:
> 
> Traceback (most recent call last):
> File ".../tar_archive.copy", line 137, in <module>
> dest.close()
> File "/usr/lib64/python3.6/tarfile.py", line 1742, in close
> self.fileobj.close()
> File "/usr/lib64/python3.6/tarfile.py", line 467, in close
> self.fileobj.write(self.buf)
> TypeError: write() argument must be str, not bytes
> 
> What am I doing wrong?   By the way:  since on some hosts this script is
> running on  the transition from Python 2.7 to Python 3.x will not happen
> immediately, I need a solution which works with both versions.

Stdout on python 3 is a text stream. Tarfiles need a binary stream.

I searched for ?python 3 binary stdout? and found this
 stack over flow question that has suggested fixes.

https://stackoverflow.com/questions/908331/how-to-write-binary-data-to-stdout-in-python-3#908440

Barry

> 
> Sincerely,
>  Rainer
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 

From barry at barrys-emacs.org  Sat Dec 21 05:05:22 2019
From: barry at barrys-emacs.org (Barry)
Date: Sat, 21 Dec 2019 10:05:22 +0000
Subject: Understanding of GIL
In-Reply-To: <CAD=M5eRWh9-EB180f2OzvnPLHh969vgaCzFyniFRSFa1-CwUHA@mail.gmail.com>
References: <CAD=M5eRWh9-EB180f2OzvnPLHh969vgaCzFyniFRSFa1-CwUHA@mail.gmail.com>
Message-ID: <919498FD-709C-4C8A-B87E-AA2B8C2789DF@barrys-emacs.org>



> On 19 Dec 2019, at 14:19, onlinejudge95 <onlinejudge95 at gmail.com> wrote:
> 
> ?Hi Devs,
> 
> I am currently writing some custom Django commands for data updation, my
> workflow is like
> 
> Fetch data from *PostgreSQL*.
> Call *Elasticsearch* for searching based on the data fetched from
> *PostgreSQL*.
> Query *PostgreSQL* and do an upsert behavior.
> I am using pandas data frame to hold my data during processing.
> 
> The host we are using to run this jobs has a *CPython* interpreter as given
> by
> 
> `platform.python_implementation()`
> 
> I want to confirm whether *multithreading* would be a better choice here,
> given the fact that GIL is the biggest blocker(I agree it has to be there)
> for the same in CPython interpreters.

You mean multi process vs. Threaded?

The GIL is only a problem if you are executing pure python compute bound code on multiple threads. When your code does lots of I/O and uses extensions it?s not the limiting factor. I guess you app will spent if time waiting of PostgreSQL etc.

Barry

> 
> In case further information is required do let me know.
> 
> Thanks
> onlinejudge95
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From bluebox03 at gmail.com  Sat Dec 21 08:55:05 2019
From: bluebox03 at gmail.com (tommy yama)
Date: Sat, 21 Dec 2019 13:55:05 +0000
Subject: hexdump module installation error
In-Reply-To: <CANevj7u8rgG8W9A4+ra7eFD01Xx53--3TU9n3i3_=xOYdg6ETw@mail.gmail.com>
References: <CANevj7u6o+4+n3Ee9kXPiR+Xi=2YbMsHg0xgjQbdsPjz0h4DnA@mail.gmail.com>
 <303a8c7b-1c1b-12c0-bb0c-4cd70be8611a@kynesim.co.uk>
 <CANevj7tWKPio3YVVvWhE53=BfD6LvEf31pDpqPTyb_M8Z_m_vQ@mail.gmail.com>
 <6ff313c1-d38b-5c5b-99cc-743413416f2f@kynesim.co.uk>
 <CANevj7t8-1Ds-49zcKiH5QN04HkS1c59DjwA05Tr=KCadOnDJA@mail.gmail.com>
 <ilbnveh7ahej3a8fsrdsc91i9s31e67cb9@4ax.com>
 <CANevj7u8rgG8W9A4+ra7eFD01Xx53--3TU9n3i3_=xOYdg6ETw@mail.gmail.com>
Message-ID: <CANevj7uWtjjcoRi-Xyn2Qwg8ELUMztfD+LriBu=bs8P68gdpnA@mail.gmail.com>

fixed now. I guess pip3 is linked to pip2 and installed python3 again.

On Sat, Dec 21, 2019 at 8:44 AM tommy yama <bluebox03 at gmail.com> wrote:

> Thanks to all giving me helpful comments.
> Multiple hexdump files are found. Maybe that"s the reason.
>
> I guess i can figure out
>
>
>
>
> On Thu, Dec 19, 2019 at 5:29 PM Dennis Lee Bieber <wlfraed at ix.netcom.com>
> wrote:
>
>> On Thu, 19 Dec 2019 12:43:11 +0000, tommy yama <bluebox03 at gmail.com>
>> declaimed the following:
>>
>> >
>> >user at USERnoMacBook-Air LibraBrowser % python3 hexdump.py
>> >
>>
>> >/usr/local/Cellar/python/3.7.5/Frameworks/Python.framework/Versions/3.7/Resources/Python.app/Contents/MacOS/Python:
>> >can't open file 'hexdump.py': [Errno 2] No such file or directory
>> >
>> >user at USERnoMacBook-Air LibraBrowser %
>> >
>>
>>         Well... what does
>>
>>                 find / -iname hexdump.py
>>
>> return? If found, is it in the Python search path?
>>
>> {Debian system here, but... (after doing apt install python3-pip)}
>>
>> wulfraed at debian:~$ pip3 install hexdump
>> Collecting hexdump
>>   Downloading
>>
>> https://files.pythonhosted.org/packages/55/b3/279b1d57fa3681725d0db8820405cdcb4e62a9239c205e4ceac4391c78e4/hexdump-3.3.zip
>> Building wheels for collected packages: hexdump
>>   Running setup.py bdist_wheel for hexdump ... done
>>   Stored in directory:
>>
>> /home/wulfraed/.cache/pip/wheels/d5/d1/f2/c8183b5863b3df595c2eeafd8e015a43dae13d403a959467c6
>> Successfully built hexdump
>> Installing collected packages: hexdump
>> Successfully installed hexdump-3.3
>> wulfraed at debian:~$ sudo find / -iname hexdump.py
>> /home/wulfraed/.local/lib/python3.7/site-packages/hexdump.py
>> find: ?/run/user/1000/gvfs?: Permission denied
>> /usr/lib/python3/dist-packages/pygments/lexers/hexdump.py
>> /usr/lib/python2.7/dist-packages/pygments/lexers/hexdump.py
>> wulfraed at debian:~$ python3
>> Python 3.7.3 (default, Apr  3 2019, 05:39:12)
>> [GCC 8.3.0] on linux
>> Type "help", "copyright", "credits" or "license" for more information.
>> >>> import hexdump
>> >>> dir(hexdump)
>> ['PY3K', '__author__', '__builtins__', '__cached__', '__doc__',
>> '__file__',
>> '__history__', '__license__', '__loader__', '__name__', '__package__',
>> '__spec__', '__version__', 'binascii', 'chunkread', 'chunks', 'dehex',
>> 'dump', 'dumpgen', 'genchunks', 'hexdump', 'main', 'normalize_py',
>> 'restore', 'runtest', 'sys']
>> >>> hexdump.__file__
>> '/home/wulfraed/.local/lib/python3.7/site-packages/hexdump.py'
>> >>>
>>
>>         Note that there are "hexdump.py" files involved with the pygments
>> package, which likely are not what you are looking for (quick glance --
>> the
>> pygments hexdump READS dump files).
>>
>>
>> --
>>         Wulfraed                 Dennis Lee Bieber         AF6VN
>>         wlfraed at ix.netcom.com
>> http://wlfraed.microdiversity.freeddns.org/
>>
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>
>

From john_ladasky at sbcglobal.net  Sat Dec 21 14:16:59 2019
From: john_ladasky at sbcglobal.net (John Ladasky)
Date: Sat, 21 Dec 2019 11:16:59 -0800 (PST)
Subject: How to specific multiple dtypes in numpy.ndarray?
In-Reply-To: <mailman.146.1576752784.11485.python-list@python.org>
References: <CAB3eZfvoLN=rZFRG2_CWPMQjG=UK8mgDPOkZPrXh0dXaa5mnRw@mail.gmail.com>
 <mailman.146.1576752784.11485.python-list@python.org>
Message-ID: <38991919-f1c9-42c4-9b49-55b8e002572a@googlegroups.com>

On Thursday, December 19, 2019 at 2:53:18 AM UTC-8, lampahome wrote:
> I meet performance is low when I use struct.unpack to unpack binary data.
> 
> So I tried to use numpy.ndarray
> But meet error when I want to unpack multiple dtypes
> 
> Can anyone teach me~
> 
> Code like below:
> # python3
> import struct
> import numpy as np
> s1 = struct.Struct("@QIQ")
> ss1 = s1.pack(1,11,111)
> np.ndarray((3,), [('Q','I','Q')], ss1)
> # ValueError: mismatch in size of old and new data-descriptor.

Is there some reason that you're calling the np.ndarray constructor directly instead of the np.array convenience function?  The arguments that you pass to each are slightly different.  Generally, you want to use np.array.

The first argument to np.ndarray is the shape.  You appear to want three elements.

The second argument to np.ndarray is the data type (dtype).  It needs to be a SINGLE data type, like 'float' or 'int' or 'object'.  All elements in in array are of the same dtype.  If you want different behavior, I think that you want lists, not arrays.  You can set the dtype to 'object' and you should be able to store any data type as an array element.  But I don't think that offers you any advantages over using ordinary Python lists.

In any case, it appears that you aren't passing a dtype as your second argument.  You're trying to pass the data itself, as a tuple wrapped in a single list.  This seems to be certain to raise an error.

The third argument to np.ndarray is supposed to be the buffer which contains your data.

https://docs.scipy.org/doc/numpy/reference/generated/numpy.array.html#numpy.array

ile:///usr/share/doc/python-numpy-doc/html/reference/generated/numpy.array.html#numpy.array

From bill at baddogconsulting.com  Sat Dec 21 15:57:24 2019
From: bill at baddogconsulting.com (Bill Deegan)
Date: Sat, 21 Dec 2019 12:57:24 -0800
Subject: [Scons-dev] SCons 3.1.2 Released
In-Reply-To: <CAP2Qz+U1EbZJ0u7tCFiVYX9uXjY+7_2Ru48Fuga4d4b0ynvrrQ@mail.gmail.com>
References: <CAEyG4CEahsiZRjM+7KHiQaCdDNLYXKSbbXfQhQsmFFAnj7KECQ@mail.gmail.com>
 <CAP2Qz+U1EbZJ0u7tCFiVYX9uXjY+7_2Ru48Fuga4d4b0ynvrrQ@mail.gmail.com>
Message-ID: <CAEyG4CFuygo5dspd1=cgMT-M6Z9HgJHjxF-FM1U=t8xpACYiUA@mail.gmail.com>

Glad that helped!
Big thanks to Mats Wichmann for that one!

On Sat, Dec 21, 2019 at 10:41 AM Eric Fahlgren <ericfahlgren at gmail.com>
wrote:

> On Mon, Dec 16, 2019 at 7:02 PM Bill Deegan <bill at baddogconsulting.com>
> wrote:
>
>>     - EXPERIMENTAL NEW FEATURE: Enable caching MSVC configuration
>>       If SCONS_CACHE_MSVC_CONFIG shell environment variable is set,
>>       SCons will cache the results of past calls to vcvarsall.bat to
>>       a file; integrates with existing memoizing of such vars.
>>       On vs2019 saves 5+ seconds per SCons invocation, which really
>>       helps test suite runs.
>>
>
> Thanks a bunch for this one!  Our bare, no-target 'scons' invocation is
> down to about 0.8 seconds now, and we can do a single DLL build in ~2.5 s,
> which makes things very snappy indeed.
> _______________________________________________
> Scons-dev mailing list
> Scons-dev at scons.org
> https://pairlist2.pair.net/mailman/listinfo/scons-dev
>

From benandrewhearn at gmail.com  Sat Dec 21 16:46:31 2019
From: benandrewhearn at gmail.com (Ben Hearn)
Date: Sat, 21 Dec 2019 13:46:31 -0800 (PST)
Subject: urllib unqoute providing string mismatch between string found using
 os.walk (Python3)
Message-ID: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>

Hello all,

I am having a bit of trouble with a string mismatch operation in my tool I am writing.

I am comparing a database collection or url quoted paths to the paths on the users drive.

These 2 paths look identical, one from the drive & the other from an xml url:
a = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav'
b = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav'

But after realising it was failing on them I ran a difflib and these differences popped up.

import difflib
print('\n'.join(difflib.ndiff([a], [b])))
- /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav
?                                                                                                      ^^
+ /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav
?                                                                                                      ^


What am I missing when it comes to unquoting the string, or should I do some other fancy operation on the drive string?

Cheers,

Ben

From pieter-l at vanoostrum.org  Sat Dec 21 17:23:17 2019
From: pieter-l at vanoostrum.org (Pieter van Oostrum)
Date: Sat, 21 Dec 2019 23:23:17 +0100
Subject: urllib unqoute providing string mismatch between string found
 using os.walk (Python3)
References: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
Message-ID: <lxa77lpbca.fsf@cochabamba.vanoostrum.org>

Ben Hearn <benandrewhearn at gmail.com> writes:

> Hello all,
>
> I am having a bit of trouble with a string mismatch operation in my tool I am writing.
>
> I am comparing a database collection or url quoted paths to the paths on the users drive.
>
> These 2 paths look identical, one from the drive & the other from an xml url:
> a = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav'
> b = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav'
>
> But after realising it was failing on them I ran a difflib and these differences popped up.
>
> import difflib
> print('\n'.join(difflib.ndiff([a], [b])))
> - /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav
> ? ^^
> + /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav
> ? ^
>
>
> What am I missing when it comes to unquoting the string, or should I do
> some other fancy operation on the drive string?
>

In [8]: len(a)
Out[8]: 79

In [9]: len(b)
Out[9]: 78

The difference is in the ?. In (b) it is a single character, Unicode 0xF3,
LATIN SMALL LETTER O WITH ACUTE.
In (a) it is composed of the letter o and the accent "?" (Unicode 0x301).
So you would have to do Unicode normalisation before comparing.

For example:

In [16]: from unicodedata import normalize

In [17]: a == b
Out[17]: False

In [18]: normalize('NFC', a) == normalize('NFC', b)
Out[18]: True

-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]

From 2QdxY4RzWzUUiLuE at potatochowder.com  Sat Dec 21 17:15:47 2019
From: 2QdxY4RzWzUUiLuE at potatochowder.com (Dan Sommers)
Date: Sat, 21 Dec 2019 17:15:47 -0500
Subject: urllib unqoute providing string mismatch between string found
 using os.walk (Python3)
In-Reply-To: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
References: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
Message-ID: <d3fa120c-e33a-e225-d241-434c30b4a17a@potatochowder.com>

On 12/21/19 4:46 PM, Ben Hearn wrote:

> import difflib
> print('\n'.join(difflib.ndiff([a], [b])))
> - /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav
> ?                                                                                                      ^^
> + /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav
> ?                                                                                                      ^
> 
> 
> What am I missing when it comes to unquoting the string, or should I do some other fancy operation on the drive string?

I'm going to guess that the trailing characters are newline
(U+0010) and/or carriage return (U+001D) characters.  Use
str.strip() to remove them before comparing:

     a = a.strip()

Dan

From ericfahlgren at gmail.com  Sat Dec 21 13:41:34 2019
From: ericfahlgren at gmail.com (Eric Fahlgren)
Date: Sat, 21 Dec 2019 10:41:34 -0800
Subject: [Scons-dev] SCons 3.1.2 Released
In-Reply-To: <CAEyG4CEahsiZRjM+7KHiQaCdDNLYXKSbbXfQhQsmFFAnj7KECQ@mail.gmail.com>
References: <CAEyG4CEahsiZRjM+7KHiQaCdDNLYXKSbbXfQhQsmFFAnj7KECQ@mail.gmail.com>
Message-ID: <CAP2Qz+U1EbZJ0u7tCFiVYX9uXjY+7_2Ru48Fuga4d4b0ynvrrQ@mail.gmail.com>

On Mon, Dec 16, 2019 at 7:02 PM Bill Deegan <bill at baddogconsulting.com>
wrote:

>     - EXPERIMENTAL NEW FEATURE: Enable caching MSVC configuration
>       If SCONS_CACHE_MSVC_CONFIG shell environment variable is set,
>       SCons will cache the results of past calls to vcvarsall.bat to
>       a file; integrates with existing memoizing of such vars.
>       On vs2019 saves 5+ seconds per SCons invocation, which really
>       helps test suite runs.
>

Thanks a bunch for this one!  Our bare, no-target 'scons' invocation is
down to about 0.8 seconds now, and we can do a single DLL build in ~2.5 s,
which makes things very snappy indeed.

From torriem at gmail.com  Sat Dec 21 19:22:55 2019
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 21 Dec 2019 17:22:55 -0700
Subject: urllib unqoute providing string mismatch between string found
 using os.walk (Python3)
In-Reply-To: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
References: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
Message-ID: <451e70f7-187a-684b-789d-dd35060d69bb@gmail.com>

On 12/21/19 2:46 PM, Ben Hearn wrote:
> These 2 paths look identical, one from the drive & the other from an xml url:
> a = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav'
                                                               ^^
> b = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav'
                                                               ^^
They are actually are different strings.  The name is spelled
differently between the two.  Mo?chate vs M?chate (the former seems to
be the correct spelling according to my inline spell checker).  Is this
from your own program? I wonder how it got switched?

From rosuav at gmail.com  Sat Dec 21 20:14:01 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 22 Dec 2019 12:14:01 +1100
Subject: urllib unqoute providing string mismatch between string found
 using os.walk (Python3)
In-Reply-To: <451e70f7-187a-684b-789d-dd35060d69bb@gmail.com>
References: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
 <451e70f7-187a-684b-789d-dd35060d69bb@gmail.com>
Message-ID: <CAPTjJmrAkL30A3uhcgUeeFpZ6h2ZkywQi2S=QGXgHNaYB+xsZw@mail.gmail.com>

On Sun, Dec 22, 2019 at 11:33 AM Michael Torrie <torriem at gmail.com> wrote:
>
> On 12/21/19 2:46 PM, Ben Hearn wrote:
> > These 2 paths look identical, one from the drive & the other from an xml url:
> > a = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav'
>                                                                ^^
> > b = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav'
>                                                                ^^
> They are actually are different strings.  The name is spelled
> differently between the two.  Mo?chate vs M?chate (the former seems to
> be the correct spelling according to my inline spell checker).  Is this
> from your own program? I wonder how it got switched?

Then your inline spell checker is flawed, because the two strings
differ only in whether a single "o with acute" or a pair "o" and
"combining acute" is used to represent the accented letter. The word
is the same either way.

ChrisA

From python at mrabarnett.plus.com  Sat Dec 21 20:25:11 2019
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 22 Dec 2019 01:25:11 +0000
Subject: urllib unqoute providing string mismatch between string found
 using os.walk (Python3)
In-Reply-To: <451e70f7-187a-684b-789d-dd35060d69bb@gmail.com>
References: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
 <451e70f7-187a-684b-789d-dd35060d69bb@gmail.com>
Message-ID: <b6ffcaa1-c0ed-68e5-0b04-ac1c859bbea8@mrabarnett.plus.com>

On 2019-12-22 00:22, Michael Torrie wrote:
> On 12/21/19 2:46 PM, Ben Hearn wrote:
>> These 2 paths look identical, one from the drive & the other from an xml url:
>> a = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav'
>                                                                 ^^
>> b = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav'
>                                                                 ^^
> They are actually are different strings.  The name is spelled
> differently between the two.  Mo?chate vs M?chate (the former seems to
> be the correct spelling according to my inline spell checker).  Is this
> from your own program? I wonder how it got switched?
> 
Use the 'ascii' function to see what's different:

 >>> ascii(a)
"'/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - 
\\xa1Mo\\u0301chate! _PromoMix_.wav'"
 >>> ascii(b)
"'/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - 
\\xa1M\\xf3chate! _PromoMix_.wav'"
 >>>

From Richard at Damon-Family.org  Sat Dec 21 21:36:16 2019
From: Richard at Damon-Family.org (Richard Damon)
Date: Sat, 21 Dec 2019 21:36:16 -0500
Subject: urllib unqoute providing string mismatch between string found
 using os.walk (Python3)
In-Reply-To: <b6ffcaa1-c0ed-68e5-0b04-ac1c859bbea8@mrabarnett.plus.com>
References: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
 <451e70f7-187a-684b-789d-dd35060d69bb@gmail.com>
 <b6ffcaa1-c0ed-68e5-0b04-ac1c859bbea8@mrabarnett.plus.com>
Message-ID: <3c2b29f3-9654-a5a1-b328-e8e79812a62e@Damon-Family.org>

On 12/21/19 8:25 PM, MRAB wrote:
> On 2019-12-22 00:22, Michael Torrie wrote:
>> On 12/21/19 2:46 PM, Ben Hearn wrote:
>>> These 2 paths look identical, one from the drive & the other from an
>>> xml url:
>>> a = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf -
>>> ?Mo?chate! _PromoMix_.wav'
>> ??????????????????????????????????????????????????????????????? ^^
>>> b = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate!
>>> _PromoMix_.wav'
>> ??????????????????????????????????????????????????????????????? ^^
>> They are actually are different strings.? The name is spelled
>> differently between the two.? Mo?chate vs M?chate (the former seems to
>> be the correct spelling according to my inline spell checker).? Is this
>> from your own program? I wonder how it got switched?
>>
> Use the 'ascii' function to see what's different:
>
> >>> ascii(a)
> "'/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf -
> \\xa1Mo\\u0301chate! _PromoMix_.wav'"
> >>> ascii(b)
> "'/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf -
> \\xa1M\\xf3chate! _PromoMix_.wav'"
> >>>

It is a Unicode Normalization issue. A number of characters can be
'spelled' different ways.

? can be either a single codepoint U+00F3, or it can be the pair of
codepoints, the o and U+0301 (the accent).

If you want to make the strings compare equal then you need to make sure
that you have normalized both strings the same way. I beleive that the
Mac OS always converts file names into the NFD format when it uses them
(that is what the first (a) string is in)

-- 
Richard Damon


From nt_mahmood at yahoo.com  Sun Dec 22 09:07:36 2019
From: nt_mahmood at yahoo.com (Mahmood Naderan)
Date: Sun, 22 Dec 2019 14:07:36 +0000 (UTC)
Subject: Unable to install "collect" via pip3
In-Reply-To: <DC3A02D1-6E09-4C69-AE0C-C7A32675B83F@barrys-emacs.org>
References: <414413727.1095151.1576826520979@mail.yahoo.com>
 <DC3A02D1-6E09-4C69-AE0C-C7A32675B83F@barrys-emacs.org>
Message-ID: <31468466.1581608.1577023656377@mail.yahoo.com>

Yes thank you. The package is not compatible with 3.x.

Regards,
Mahmood 

    On Saturday, December 21, 2019, 1:40:29 AM GMT+3:30, Barry <barry at barrys-emacs.org> wrote:  
 
 

> On 20 Dec 2019, at 15:27, Mahmood Naderan via Python-list <python-list at python.org> wrote:
> 
> ?Hi
> 
> I can install collect with pip for python2.7
> $ pip install --user collect? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? 
> Collecting collect
>? Using cached https://files.pythonhosted.org/packages/cf/5e/c0f0f51d081665374a2c219ea4ba23fb1e179b70dded96dc16606786d828/collect-0.1.1.tar.gz
> Collecting couchdbkit>=0.5.7 (from collect)
>? Using cached https://files.pythonhosted.org/packages/a1/13/9e9ff695a385c44f62b4766341b97f2bd8b596962df2a0beabf358468b70/couchdbkit-0.6.5.tar.gz
> Collecting restkit>=4.2.2 (from couchdbkit>=0.5.7->collect)
>? Downloading https://files.pythonhosted.org/packages/76/b9/d90120add1be718f853c53008cf5b62d74abad1d32bd1e7097dd913ae053/restkit-4.2.2.tar.gz (1.3MB)
>? ? 100% |????????????????????????????????| 1.3MB 633kB/s
> Collecting http-parser>=0.8.3 (from restkit>=4.2.2->couchdbkit>=0.5.7->collect)
>? Downloading https://files.pythonhosted.org/packages/07/c4/22e3c76c2313c26dd5f84f1205b916ff38ea951aab0c4544b6e2f5920d64/http-parser-0.8.3.tar.gz (83kB)
>? ? 100% |????????????????????????????????| 92kB 2.4MB/s
> Collecting socketpool>=0.5.3 (from restkit>=4.2.2->couchdbkit>=0.5.7->collect)
>? Downloading https://files.pythonhosted.org/packages/d1/39/fae99a735227234ffec389b252c6de2bc7816bf627f56b4c558dc46c85aa/socketpool-0.5.3.tar.gz
> Building wheels for collected packages: collect, couchdbkit, restkit, http-parser, socketpool
>? Running setup.py bdist_wheel for collect ... done
>? Stored in directory: /home/mnaderan/.cache/pip/wheels/b9/7c/7c/b09b334cc0e27b4f63ee9f6f19ca1f3db8672666a7e0f3d9cd
>? Running setup.py bdist_wheel for couchdbkit ... done
>? Stored in directory: /home/mnaderan/.cache/pip/wheels/f6/05/1b/f8f576ef18564bc68ab6e64f405e1263448036208cafb221e0
>? Running setup.py bdist_wheel for restkit ... done
>? Stored in directory: /home/mnaderan/.cache/pip/wheels/48/c5/32/d0d25fb272791a68c49c26150f332d9b9492d0bc9ea0cdd2c7
>? Running setup.py bdist_wheel for http-parser ... done
>? Stored in directory: /home/mnaderan/.cache/pip/wheels/22/db/06/cb609a3345e7aa87206de160f00cc6af364650d1139d904a25
>? Running setup.py bdist_wheel for socketpool ... done
>? Stored in directory: /home/mnaderan/.cache/pip/wheels/93/f6/8c/65924848766618647078cb66b1d964e8b80876536e84517469
> Successfully built collect couchdbkit restkit http-parser socketpool
> Installing collected packages: http-parser, socketpool, restkit, couchdbkit, collect
> Successfully installed collect-0.1.1 couchdbkit-0.6.5 http-parser-0.8.3 restkit-4.2.2 socketpool-0.5.3
> However, pip3 fails with this error
> $ pip3 install --user collect
> Collecting collect
>? Using cached https://files.pythonhosted.org/packages/cf/5e/c0f0f51d081665374a2c219ea4ba23fb1e179b70dded96dc16606786d828/collect-0.1.1.tar.gz
> Collecting couchdbkit>=0.5.7 (from collect)
>? Using cached https://files.pythonhosted.org/packages/a1/13/9e9ff695a385c44f62b4766341b97f2bd8b596962df2a0beabf358468b70/couchdbkit-0.6.5.tar.gz
>? ? Complete output from command python setup.py egg_info:
>? ? Traceback (most recent call last):
>? ? ? File "<string>", line 1, in <module>
>? ? ? File "/tmp/pip-build-qf95n0tt/couchdbkit/setup.py", line 25, in <module>
>? ? ? ? long_description = file(
>? ? NameError: name 'file' is not defined

My guess is that file is python 2 only. Couchdbkit needs porting to python 3.

Barry

> 
>? ? ----------------------------------------
> Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-qf95n0tt/couchdbkit/
> I can not figure out what is the problem. Any way to fix that?
> 
> More info:
> $ which python
> /usr/bin/python
> $ ls -l /usr/bin/python
> lrwxrwxrwx 1 root root 9 Apr 16? 2018 /usr/bin/python -> python2.7
> $ which python3
> /usr/bin/python3
> $ ls -l /usr/bin/python3
> lrwxrwxrwx 1 root root 9 Jun 21? 2018 /usr/bin/python3 -> python3.6 
> 
> 
> 
> Regards,
> Mahmood
> -- 
> https://mail.python.org/mailman/listinfo/python-list
  

From benandrewhearn at gmail.com  Sun Dec 22 10:38:08 2019
From: benandrewhearn at gmail.com (Ben Hearn)
Date: Sun, 22 Dec 2019 07:38:08 -0800 (PST)
Subject: urllib unqoute providing string mismatch between string found
 using os.walk (Python3)
In-Reply-To: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
References: <2c2f5420-00ec-483e-95bb-0b5a1bcde363@googlegroups.com>
Message-ID: <87c26489-3185-446c-8dc1-14f78c83e6a2@googlegroups.com>

On Saturday, 21 December 2019 21:46:43 UTC, Ben Hearn  wrote:
> Hello all,
> 
> I am having a bit of trouble with a string mismatch operation in my tool I am writing.
> 
> I am comparing a database collection or url quoted paths to the paths on the users drive.
> 
> These 2 paths look identical, one from the drive & the other from an xml url:
> a = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav'
> b = '/Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav'
> 
> But after realising it was failing on them I ran a difflib and these differences popped up.
> 
> import difflib
> print('\n'.join(difflib.ndiff([a], [b])))
> - /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?Mo?chate! _PromoMix_.wav
> ?                                                                                                      ^^
> + /Users/macbookpro/Music/tracks_new/_NS_2018/J.Staaf - ?M?chate! _PromoMix_.wav
> ?                                                                                                      ^
> 
> 
> What am I missing when it comes to unquoting the string, or should I do some other fancy operation on the drive string?
> 
> Cheers,
> 
> Ben

Thanks for the help on this, normalizing my string fixed up the problem cheers!

From wojtek.dominicana at gmail.com  Sun Dec 22 10:40:09 2019
From: wojtek.dominicana at gmail.com (wojtek.dominicana at gmail.com)
Date: Sun, 22 Dec 2019 07:40:09 -0800 (PST)
Subject: Execute python script from VB6 to display Outlook Window
Message-ID: <ff4eefce-e24b-4862-94a4-e31739060908@googlegroups.com>

I have to prepare e-mail in python (e-mail address, body html, attachments etc.) and show Outlook window for user who will check everything and correct if necessary and will be able to send it.
My script work well :


o = win32com.client.Dispatch("Outlook.Application")
Msg = o.CreateItem(0)
Msg.To = "aa at gmail.com"
Msg.CC = ""
Msg.Subject = "The random subject"
Msg.HtmlBody = "<h1>content of e-mail</h1>"
Msg.Attachments.Add(attachment1)
Msg.Display()

This script work well but I have some problem with my Outlook 2019 or Command window (Win 10, 64). When Outlook is closed i can call my script using Shell() or ShellExecute() and everything is ok but when MS Outlook is open my script doesnt work. I use the same  Shell() or ShellExecute() function and still does not work although windows executing this script. It stops in the loine "win32com.client.Dispatch("Outlook.Application")". I tried many tricks and I gave up. The most important is that when I use windows command line and run my script manyally (python sendoutlookmail.py) everything works well regardless of state of Outlook (open or closed).
I think there is a different between calling script via Shell() function and run it directly from command line.
I tried of course solution as follows:

Set obj = CreateObject("WScript.Shell")
obj.Run sPythonFile 

but its the same situation. I createt bat file and I execute this bat file which has inside commant to execute my python script.

I have no idea how to run python script on my system that works the same as I call it directly from windows command line.

regards
Wojtek

From musbur at posteo.org  Sun Dec 22 12:18:38 2019
From: musbur at posteo.org (musbur at posteo.org)
Date: Sun, 22 Dec 2019 18:18:38 +0100
Subject: Transfer a file to httpserver via POST command from curl
In-Reply-To: <CAPTjJmo_6WLdKvb5FUrU1moZ4+7G7irYyzJ2F60gbk83_3EQnQ@mail.gmail.com>
References: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
 <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>
 <20191217184404.298104a4@nxp10225>
 <CAPTjJmo_6WLdKvb5FUrU1moZ4+7G7irYyzJ2F60gbk83_3EQnQ@mail.gmail.com>
Message-ID: <20191222181838.3918384c@nxp10225>

On Wed, 18 Dec 2019 04:52:33 +1100
Chris Angelico <rosuav at gmail.com> wrote:

> On Wed, Dec 18, 2019 at 4:45 AM <musbur at posteo.org> wrote:
> > BTW, the canonical way to upload files via http is PUT, not POST.
> > You might want to look into that, but here it is off-topic.  
> 
> Citation needed.

https://tools.ietf.org/html/rfc2616#page-55
	
> Plenty of file uploads are done through POST
> requests.

Of course. Both work. It's just that the OP wanted to "upload a large
binary file" using curl and in such cases I find that PUT can make for
a cleaner, simpler interface. 

> Are you talking specifically about a RESTful API? Because
> that's only one of many patterns you can follow.

Sure. It's just that people sometimes aren't even aware of http
methods besides GET and POST, and there's a chance for the OP
to investigate this and maybe to find that PUT fits his needs better
than POST in this case.

From rosuav at gmail.com  Sun Dec 22 12:24:22 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 23 Dec 2019 04:24:22 +1100
Subject: Transfer a file to httpserver via POST command from curl
In-Reply-To: <20191222181838.3918384c@nxp10225>
References: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
 <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>
 <20191217184404.298104a4@nxp10225>
 <CAPTjJmo_6WLdKvb5FUrU1moZ4+7G7irYyzJ2F60gbk83_3EQnQ@mail.gmail.com>
 <20191222181838.3918384c@nxp10225>
Message-ID: <CAPTjJmoaUMp7R8TEx25BzHDO8o-mL8_MqoqgzBzgS_4gUODn=Q@mail.gmail.com>

On Mon, Dec 23, 2019 at 4:20 AM <musbur at posteo.org> wrote:
>
> On Wed, 18 Dec 2019 04:52:33 +1100
> Chris Angelico <rosuav at gmail.com> wrote:
>
> > On Wed, Dec 18, 2019 at 4:45 AM <musbur at posteo.org> wrote:
> > > BTW, the canonical way to upload files via http is PUT, not POST.
> > > You might want to look into that, but here it is off-topic.
> >
> > Citation needed.
>
> https://tools.ietf.org/html/rfc2616#page-55

Yes, that's the definition of PUT - but what does that mean in terms
of file uploads? POST is also valid. Look at its example usages.

> > Plenty of file uploads are done through POST
> > requests.
>
> Of course. Both work. It's just that the OP wanted to "upload a large
> binary file" using curl and in such cases I find that PUT can make for
> a cleaner, simpler interface.

Given that curl lets you specify any method for a request, I doubt
that PUT is going to be any cleaner or simpler.

> > Are you talking specifically about a RESTful API? Because
> > that's only one of many patterns you can follow.
>
> Sure. It's just that people sometimes aren't even aware of http
> methods besides GET and POST, and there's a chance for the OP
> to investigate this and maybe to find that PUT fits his needs better
> than POST in this case.

True, it's worth knowing about other HTTP methods. But stating that
PUT is "the canonical way to upload files" implies that what the OP is
doing is somehow violating the spec, which simply isn't true.

ChrisA

From PythonList at DancesWithMice.info  Sun Dec 22 14:35:50 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 23 Dec 2019 08:35:50 +1300
Subject: More efficient/elegant branching
In-Reply-To: <cabcf64dbb845791154c694832c858d2@posteo.de>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <a892e74d-04c6-8bc0-15d9-0e537b26a955@DancesWithMice.info>
 <cabcf64dbb845791154c694832c858d2@posteo.de>
Message-ID: <9823ad20-6c92-6606-6268-845ec144c5cf@DancesWithMice.info>

On 11/12/19 1:07 AM, Daniel Haude wrote:
> Hello Neil,
> thanks for the detailed answer.
> 
>> Question: are there other people/factors who/which should be regarded
>> as more important than the linter's opinion?
> Yes. Mine.

Um, see below...
(unless humor)


> I was just puzzled at the linter's output (took me a while to figure out 
> what it actually meant), and that got me started on the track if there 
> was maybe a more Pythonic way of dealing with that decision chain.
...

>> One reason why this code looks a bit strange (and possibly why PyLint
>> reacts?) is because it is trivial. When we look at the overall
>> picture, the question becomes: what will the 'mainline' do with
>> "result" (the returned value)? Immediately one suspects it will be fed
>> into another decision, eg:
> 
> No, the "result" is a text message that actually means something and is 
> eventually output for human consumption.
> 
> The whole thing is rather academic. Also my efficiency argument doesn't 
> hold water because this routine is executed just a few times per hour. I 
> like the "condition table" approach for its lower line count but I'll 
> stick with if/elif because it's more conventional and therefore easier 
> to understand for the casual reader.

+1 (except that it's your future-self or another maintainer who is 
important rather than anyone 'casual')


A reason we are having difficulty making suggestions is because the 
example has been abstracted. Thus we had no idea that the objective was 
to (possibly) output to SMS, nor more importantly, the meanings of a, b, 
and z. (it's all algebra to me!)

In some/another application you may like to consider constructing the 
source-data for this decision within a class. Then the conditions can 
become methods or even properties of the class - remembering that a 
property could be some combination of attributes, eg a > 4 and b == 0. 
Alternatively, the class could maintain some idea of 'status', where 
"first" corresponds to the preceding 'state', "second" when len(z) falls 
below 2, etc. The class's property/ies thus simplify the 
SMS-transmission process/class...

Appropriate name-choices will make the code self-documenting - per the 
'reading' objective:

	if employee.worked_overtime:
		sms.send( "We're in the money...!" )

-- 
Regards =dn

From isidentical at gmail.com  Sun Dec 22 15:34:46 2019
From: isidentical at gmail.com (Batuhan Taskaya)
Date: Sun, 22 Dec 2019 23:34:46 +0300
Subject: Most elegant way to do something N times
Message-ID: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>

I encounter with cases like doing a function 6 time with no argument, or
same arguments over and over or doing some structral thing N times and I
dont know how elegant I can express that to the code. I dont know why but I
dont like this for _ in range(n): do() thing. Any suggestions?

From Richard at Damon-Family.org  Sun Dec 22 16:23:31 2019
From: Richard at Damon-Family.org (Richard Damon)
Date: Sun, 22 Dec 2019 16:23:31 -0500
Subject: Most elegant way to do something N times
In-Reply-To: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
Message-ID: <97245842-171f-4e20-20b4-8dd31cd62ca1@Damon-Family.org>

On 12/22/19 3:34 PM, Batuhan Taskaya wrote:
> I encounter with cases like doing a function 6 time with no argument, or
> same arguments over and over or doing some structral thing N times and I
> dont know how elegant I can express that to the code. I dont know why but I
> dont like this for _ in range(n): do() thing. Any suggestions?

For me, the statement

for _ in range(n): do()

is the most straight forward and clearest expression of that idea.

If you don't like the _, you can always use some 'worthless' variable to
get rid of the special _ syntax.

You could of course use something like a while loop to build this, but
in my mind that is just making things less clear.

-- 
Richard Damon


From mirkok.lists at googlemail.com  Sun Dec 22 16:39:48 2019
From: mirkok.lists at googlemail.com (Mirko)
Date: Sun, 22 Dec 2019 22:39:48 +0100
Subject: Most elegant way to do something N times
In-Reply-To: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
Message-ID: <5DFFE2A4.5010508@googlemail.com>

Am 22.12.2019 um 21:34 schrieb Batuhan Taskaya:
> I encounter with cases like doing a function 6 time with no argument, or
> same arguments over and over or doing some structral thing N times and I
> dont know how elegant I can express that to the code. I dont know why but I
> dont like this for _ in range(n): do() thing. Any suggestions?
> 

Looks like perfectly legitimate code to me and 'for' is meant to do
exactly this, execute something N times.

However, you can always to something like this:

In [28]: def f(a, b, c):
    ...:     print(a, b, c)
    ...:

In [29]: def repeat(func, times, *args):
    ...:     for _ in range(times): func(*args)
    ...:

In [30]: repeat(f, 6, 1, 2, 3)
(1, 2, 3)
(1, 2, 3)
(1, 2, 3)
(1, 2, 3)
(1, 2, 3)
(1, 2, 3)

From python.list at tim.thechases.com  Sun Dec 22 16:09:42 2019
From: python.list at tim.thechases.com (Tim Chase)
Date: Sun, 22 Dec 2019 15:09:42 -0600
Subject: Most elegant way to do something N times
In-Reply-To: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
Message-ID: <20191222150942.01a47791@bigbox.attlocal.net>

On 2019-12-22 23:34, Batuhan Taskaya wrote:
> I encounter with cases like doing a function 6 time with no
> argument, or same arguments over and over or doing some structral
> thing N times and I dont know how elegant I can express that to the
> code. I dont know why but I dont like this
>
> for _ in range(n): do()

The best way to improve it would be to clarify readibility.  Why 6
times instead of 5 or 7?  Are they retries?

  MAX_RETRIES = 6 # defined in RFC-3141592
  for _ in range(MAX_RETRIES):
    if successful(do_thing()):
      break
  else:
    error_condition()

or because someone likes the number 6?

  MY_FAVORITE_NUMBER = 6
  for _ in range(MY_FAVORITE_NUMBER):
    print(f"I love the number {MY_FAVORITE_NUMBER}!")

or days of the week that aren't Sunday?
  
  for day in calendar.c.iterweekdays():
    if day == calendar.SUNDAY: continue
    do_thing()

or is it because it's the number of whole columns that fit?

  screen_cols = 80 # get this from curses?
  chars_per_col = 13
  for _ in range(screen_cols // chars_per_col):
    do_thing()

or because that's how many people there are in a paticular grouping?

  family = "Dad Mom Sis Brother Me Baby".split()
  for _ in family:
    do_thing()

Note how each of those conveys what "6" means, not just some
arbitrary number.

-tkc



From python at python.invalid  Sun Dec 22 18:02:02 2019
From: python at python.invalid (Python)
Date: Mon, 23 Dec 2019 00:02:02 +0100
Subject: Most elegant way to do something N times
In-Reply-To: <loop-n-20191222233244@ram.dialup.fu-berlin.de>
References: <mailman.199.1577046900.11485.python-list@python.org>
 <loop-n-20191222233244@ram.dialup.fu-berlin.de>
Message-ID: <5dfff5b9$0$5893$426a74cc@news.free.fr>

Le 22/12/2019 ? 23:50, Stefan Ram a ?crit?:
> Batuhan Taskaya <isidentical at gmail.com> writes:
>> dont like this for _ in range(n): do() thing. Any suggestions?
> 
>    The participants of my beginner classes like to write:
> 
> n * do()
> 
>    for that purpose, but usuallythis does not work as intended!
> 
>    What would work sometimes is
> 
> eval( n * 'do();' )
> 

or:

class repeatly_do:
     def __init__(self,n):
         self.n = n
     def __mul__(self,action):
         for _ in range(self.n):
             action()

def do():
     print('Here I am...')

repeatly_do(5) * do

From hjp-python at hjp.at  Mon Dec 23 10:43:18 2019
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 23 Dec 2019 16:43:18 +0100
Subject: Transfer a file to httpserver via POST command from curl
In-Reply-To: <CAPTjJmoaUMp7R8TEx25BzHDO8o-mL8_MqoqgzBzgS_4gUODn=Q@mail.gmail.com>
References: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
 <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>
 <20191217184404.298104a4@nxp10225>
 <CAPTjJmo_6WLdKvb5FUrU1moZ4+7G7irYyzJ2F60gbk83_3EQnQ@mail.gmail.com>
 <20191222181838.3918384c@nxp10225>
 <CAPTjJmoaUMp7R8TEx25BzHDO8o-mL8_MqoqgzBzgS_4gUODn=Q@mail.gmail.com>
Message-ID: <20191223154318.GA20612@hjp.at>

On 2019-12-23 04:24:22 +1100, Chris Angelico wrote:
> On Mon, Dec 23, 2019 at 4:20 AM <musbur at posteo.org> wrote:
> > On Wed, 18 Dec 2019 04:52:33 +1100
> > Chris Angelico <rosuav at gmail.com> wrote:
> >
> > > On Wed, Dec 18, 2019 at 4:45 AM <musbur at posteo.org> wrote:
> > > > BTW, the canonical way to upload files via http is PUT, not POST.
> > > > You might want to look into that, but here it is off-topic.
> > >
> > > Citation needed.
> >
> > https://tools.ietf.org/html/rfc2616#page-55
> 
> Yes, that's the definition of PUT - but what does that mean in terms
> of file uploads? POST is also valid. Look at its example usages.

ACK. Also the first sentence reads:

| The PUT method requests that the enclosed entity be stored under the
| supplied Request-URI.

I understand this to mean that when I send a 

    PUT https://example.com/foo/bar

request and receive a 201 or 204 response, a subsequent

    GET https://example.com/foo/bar

will return the body I sent in the PUT request.

This is fine if the client can determine the URI of the response.

Quite often this not what you want. You want the client to supply the
data but let the server determine what to do with it. For example, the
server might just number the uploaded files (or use a timestamp or a
hash). Or the uploaded file may not be available under any URL at all,
but is used to modify other resources and then discarded.

In these cases PUT is inappropriate and POST is appropriate.

And sometimes the uploaded file is only part of the data (think of HTML
forms with a file input field). Then POST is also the correct choice.

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://mail.python.org/pipermail/python-list/attachments/20191223/d2dcc234/attachment.sig>

From rosuav at gmail.com  Mon Dec 23 12:08:33 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Dec 2019 04:08:33 +1100
Subject: Transfer a file to httpserver via POST command from curl
In-Reply-To: <20191223154318.GA20612@hjp.at>
References: <CAJQZjgOe0xz82h9FzW0-+4-oi7ZPxRPgANZ552LeprYNdAbFMw@mail.gmail.com>
 <CAPTjJmpsnLj8hU4+ydC3sSMoe5oo4+Sr1-pxCppfyj6tYn7xHQ@mail.gmail.com>
 <20191217184404.298104a4@nxp10225>
 <CAPTjJmo_6WLdKvb5FUrU1moZ4+7G7irYyzJ2F60gbk83_3EQnQ@mail.gmail.com>
 <20191222181838.3918384c@nxp10225>
 <CAPTjJmoaUMp7R8TEx25BzHDO8o-mL8_MqoqgzBzgS_4gUODn=Q@mail.gmail.com>
 <20191223154318.GA20612@hjp.at>
Message-ID: <CAPTjJmpkuFRSp1Yq9YEgy=Jo+T4hzJnk8xY3W3OmHW--kNg-tA@mail.gmail.com>

On Tue, Dec 24, 2019 at 2:44 AM Peter J. Holzer <hjp-python at hjp.at> wrote:
>
> On 2019-12-23 04:24:22 +1100, Chris Angelico wrote:
> > On Mon, Dec 23, 2019 at 4:20 AM <musbur at posteo.org> wrote:
> > > On Wed, 18 Dec 2019 04:52:33 +1100
> > > Chris Angelico <rosuav at gmail.com> wrote:
> > >
> > > > On Wed, Dec 18, 2019 at 4:45 AM <musbur at posteo.org> wrote:
> > > > > BTW, the canonical way to upload files via http is PUT, not POST.
> > > > > You might want to look into that, but here it is off-topic.
> > > >
> > > > Citation needed.
> > >
> > > https://tools.ietf.org/html/rfc2616#page-55
> >
> > Yes, that's the definition of PUT - but what does that mean in terms
> > of file uploads? POST is also valid. Look at its example usages.
>
> ACK. Also the first sentence reads:
>
> | The PUT method requests that the enclosed entity be stored under the
> | supplied Request-URI.
>
> I understand this to mean that when I send a
>
>     PUT https://example.com/foo/bar
>
> request and receive a 201 or 204 response, a subsequent
>
>     GET https://example.com/foo/bar
>
> will return the body I sent in the PUT request.
>
> This is fine if the client can determine the URI of the response.
>
> Quite often this not what you want. You want the client to supply the
> data but let the server determine what to do with it. For example, the
> server might just number the uploaded files (or use a timestamp or a
> hash). Or the uploaded file may not be available under any URL at all,
> but is used to modify other resources and then discarded.
>
> In these cases PUT is inappropriate and POST is appropriate.

Your understanding is exactly correct. PUT is appropriate when you
already know the URI, POST is appropriate when you want to create a
brand new item. The latter is actually far more common.

> And sometimes the uploaded file is only part of the data (think of HTML
> forms with a file input field). Then POST is also the correct choice.

Right, although APIs will often work differently from forms. For
instance, the Twitch video uploading protocol starts with a simple
POST request with some metadata to create a video, followed by a
series of PUT requests to submit each section of the file, and finally
a POST to complete the upload. But that only works because all the PUT
requests use a predictable URI based on an upload token (created by
the initial POST request), which isn't a normal way to build a file
upload. (Twitch's video upload can take some pretty ginormous files.
You don't want a simple connection glitch to force you to reupload the
entire thing from scratch.)

But your analysis of POST vs PUT is absolutely correct. File uploads
can be done either way, but only use PUT if you know the URI that the
object is to live at, which usually means that you can subsequently
GET that and retrieve your original file.

ChrisA

From elbarbun at gmail.com  Mon Dec 23 18:12:25 2019
From: elbarbun at gmail.com (Marco Sulla)
Date: Tue, 24 Dec 2019 00:12:25 +0100
Subject: Most elegant way to do something N times
In-Reply-To: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
Message-ID: <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>

>
> I encounter with cases like doing a function 6 time with no argument, or
> same arguments over and over or doing some structral thing N times and I
> dont know how elegant I can express that to the code.
>

??? Excuse me, but why you needed to call the same function SIX times? This
seems to me not elegant in primis.

Can you give us a practical example?


On Sun, 22 Dec 2019 at 21:38, Batuhan Taskaya <isidentical at gmail.com> wrote:

> I encounter with cases like doing a function 6 time with no argument, or
> same arguments over and over or doing some structral thing N times and I
> dont know how elegant I can express that to the code. I dont know why but I
> dont like this for _ in range(n): do() thing. Any suggestions?
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From rosuav at gmail.com  Mon Dec 23 19:04:22 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Dec 2019 11:04:22 +1100
Subject: Most elegant way to do something N times
In-Reply-To: <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
 <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
Message-ID: <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>

On Tue, Dec 24, 2019 at 10:45 AM Marco Sulla <elbarbun at gmail.com> wrote:
>
> >
> > I encounter with cases like doing a function 6 time with no argument, or
> > same arguments over and over or doing some structral thing N times and I
> > dont know how elegant I can express that to the code.
> >
>
> ??? Excuse me, but why you needed to call the same function SIX times? This
> seems to me not elegant in primis.
>
> Can you give us a practical example?
>

File parsing. You read a section header and want to ignore that
section, so you ignore the next 15 lines.

ChrisA

From morphex at gmail.com  Mon Dec 23 19:16:49 2019
From: morphex at gmail.com (Morten W. Petersen)
Date: Tue, 24 Dec 2019 01:16:49 +0100
Subject: Most elegant way to do something N times
In-Reply-To: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
Message-ID: <CAEtLV=oggMyjVRJLZiv4i9KRFTtfLgPhf-=AEaXCjKUQUzOcDg@mail.gmail.com>

It depends on what's elegant, and beauty is in the eye of the beholder..

def recurse(n):
  print(?do be do be do?)
  if n>0: recurse(n-1)

Regards,

Morten

s?n. 22. des. 2019, 21:37 skrev Batuhan Taskaya <isidentical at gmail.com>:

> I encounter with cases like doing a function 6 time with no argument, or
> same arguments over and over or doing some structral thing N times and I
> dont know how elegant I can express that to the code. I dont know why but I
> dont like this for _ in range(n): do() thing. Any suggestions?
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From PythonList at DancesWithMice.info  Mon Dec 23 19:27:09 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 24 Dec 2019 13:27:09 +1300
Subject: Most elegant way to do something N times
In-Reply-To: <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
 <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
 <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>
Message-ID: <189be71f-477d-4f32-8c97-f989d8a8862c@DancesWithMice.info>

On 24/12/19 1:04 PM, Chris Angelico wrote:
> On Tue, Dec 24, 2019 at 10:45 AM Marco Sulla <elbarbun at gmail.com> wrote:
>>
>>>
>>> I encounter with cases like doing a function 6 time with no argument, or
>>> same arguments over and over or doing some structral thing N times and I
>>> dont know how elegant I can express that to the code.
>>>
>>
>> ??? Excuse me, but why you needed to call the same function SIX times? This
>> seems to me not elegant in primis.
>>
>> Can you give us a practical example?

Taking the top/bottom six from a sorted list of occurrences.

eg in Accounts Payable, a clerk might be given the task of 'chasing' the 
six largest debtors (people who owe us money), as today's work 
assignment/priority.


> File parsing. You read a section header and want to ignore that
> section, so you ignore the next 15 lines.

(just to be cheeky to @Chris)

Perhaps better as a Finite State Machine, with one state being 'seeking 
section header'.
1 can we guarantee that the 'magic constant' of 15 will always apply?
2 presumably the total routine will involve more than identifying a 
single header and skipping (only) that section.
-- 
Regards =dn

From rosuav at gmail.com  Mon Dec 23 19:41:51 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Dec 2019 11:41:51 +1100
Subject: Most elegant way to do something N times
In-Reply-To: <189be71f-477d-4f32-8c97-f989d8a8862c@DancesWithMice.info>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
 <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
 <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>
 <189be71f-477d-4f32-8c97-f989d8a8862c@DancesWithMice.info>
Message-ID: <CAPTjJmpkEQ2y-j-eEL8WNR7aKnkujpkyX1JkzpxXP5FLFeWERg@mail.gmail.com>

On Tue, Dec 24, 2019 at 11:34 AM DL Neil via Python-list
<python-list at python.org> wrote:
>
> On 24/12/19 1:04 PM, Chris Angelico wrote:
> > File parsing. You read a section header and want to ignore that
> > section, so you ignore the next 15 lines.
>
> (just to be cheeky to @Chris)
>
> Perhaps better as a Finite State Machine, with one state being 'seeking
> section header'.
> 1 can we guarantee that the 'magic constant' of 15 will always apply?

That number came from the header itself. Okay, so more commonly this
kind of thing is a *byte* count, but I have known some that count
lines, or entries, or something else that you'd have a function to
grab one of.

> 2 presumably the total routine will involve more than identifying a
> single header and skipping (only) that section.

Of course. But after skipping that section (by ignoring X lines), you
go do something else.

ChrisA

From info at tundraware.com  Mon Dec 23 19:48:52 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 23 Dec 2019 18:48:52 -0600
Subject: Lists And Missing Commas
Message-ID: <ls38dg-sni2.ln1@oceanview.tundraware.com>

If I do this:

    foo = [ "bar", "baz" "slop", "crud" ]

Python silently accepts that and makes the middle term "bazslop".

BUT, if I do this:

    foo = [ "bar", "baz" 1, "crud" ]

or this:

    foo = [ "bar", 2 1, "crud" ]

The interpreter throws a syntax error.

This is more of an intellectual curiosity than anything else, but why do strings silently
concatenate like that, while all other case blow up with an error.  i.e., What is about
the language the promotes this behavior.  At first blush, it seems inconsistent, but what
do I know ...





From aaronngray.lists at gmail.com  Mon Dec 23 20:01:22 2019
From: aaronngray.lists at gmail.com (Aaron Gray)
Date: Tue, 24 Dec 2019 01:01:22 +0000
Subject: Lists And Missing Commas
In-Reply-To: <ls38dg-sni2.ln1@oceanview.tundraware.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
Message-ID: <CANkmNDcOdof=X1h=hSNZ2TR4FRB9sAJTFY+t8_wOfr4RZ=yVqQ@mail.gmail.com>

On Tuesday, 24 December 2019, Tim Daneliuk <info at tundraware.com> wrote:

> If I do this:
>
>     foo = [ "bar", "baz" "slop", "crud" ]
>
> Python silently accepts that and makes the middle term "bazslop".


Strings concatinate over line endings so this case is only sensible really.


>
> BUT, if I do this:
>
>     foo = [ "bar", "baz" 1, "crud" ]
>
> or this:
>
>     foo = [ "bar", 2 1, "crud" ]
>
> The interpreter throws a syntax error.
>
> This is more of an intellectual curiosity than anything else, but why do
> strings silently
> concatenate like that, while all other case blow up with an error.  i.e.,
> What is about
> the language the promotes this behavior.  At first blush, it seems
> inconsistent, but what
> do I know ...
>
>
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>


-- 
Independent Software Engineer and amateur Computer Scientist

From avigross at verizon.net  Mon Dec 23 20:51:24 2019
From: avigross at verizon.net (Avi Gross)
Date: Mon, 23 Dec 2019 20:51:24 -0500
Subject: Most elegant way to do something N times
In-Reply-To: <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
 <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
Message-ID: <006701d5b9fc$a6183880$f248a980$@verizon.net>

I would like some examples of how one does what is requested in some other
programming languages. I doubt there is much need of a shorter way to do
anything N times and throw away any return values.

Python has many ways to do just about anything. It has some features which
suggest a particular way that many accept as pythonic. If there was a need
to do something like:

	repeat_n( times=6, funct=fun, moreargs=whatever)

then someone probably would have included it.

So, yes, a fairly short and often clear method is:

	for _ in range(6): ...

And others have shown multiple ways to get something similar to what you
want. Want real clarity for exactly six times?

# Do this six times:
whatever()
whatever()
whatever()
whatever()
whatever()
whatever()

Heck, the above may even run faster without loop overhead.

Like Marco, it would be interesting to hear actual examples where it makes
sense to repeat something the same way N times. Many such examples do have
ways to do it trivially. I mean if you want to line up text and need N
copies of say an asterisk or space, you can often use something like 

"*" * 5

And the techniques to repeat some function call N times with the arguments
varying each time, can be handled many other ways too including map
functions and comprehensions.

I am left wondering if this is not about the real world but simply an
academic exercise.
-----Original Message-----
From: Python-list <python-list-bounces+avigross=verizon.net at python.org> On
Behalf Of Marco Sulla
Sent: Monday, December 23, 2019 6:12 PM
To: Batuhan Taskaya
<isidentical.gmail.com-mail.python.org.marco.sulla.e4ward.com at jq2z635tc37.re
ply.e4ward.com>
Cc: Ian Kelly ian.g.kelly-at-gmail.com |python-list at python.org|
<python-list at python.org>
Subject: Re: Most elegant way to do something N times

>
> I encounter with cases like doing a function 6 time with no argument, 
> or same arguments over and over or doing some structral thing N times 
> and I dont know how elegant I can express that to the code.
>

??? Excuse me, but why you needed to call the same function SIX times? This
seems to me not elegant in primis.

Can you give us a practical example?


On Sun, 22 Dec 2019 at 21:38, Batuhan Taskaya <isidentical at gmail.com> wrote:

> I encounter with cases like doing a function 6 time with no argument, 
> or same arguments over and over or doing some structral thing N times 
> and I dont know how elegant I can express that to the code. I dont 
> know why but I dont like this for _ in range(n): do() thing. Any
suggestions?
> --
> https://mail.python.org/mailman/listinfo/python-list
>
--
https://mail.python.org/mailman/listinfo/python-list


From PythonList at DancesWithMice.info  Mon Dec 23 20:52:41 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 24 Dec 2019 14:52:41 +1300
Subject: Lists And Missing Commas
In-Reply-To: <ls38dg-sni2.ln1@oceanview.tundraware.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
Message-ID: <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>

On 24/12/19 1:48 PM, Tim Daneliuk wrote:
> If I do this:
> 
>      foo = [ "bar", "baz" "slop", "crud" ]
> 
> Python silently accepts that and makes the middle term "bazslop".
> 
> BUT, if I do this:
> 
>      foo = [ "bar", "baz" 1, "crud" ]
> 
> or this:
> 
>      foo = [ "bar", 2 1, "crud" ]
> 
> The interpreter throws a syntax error.
> 
> This is more of an intellectual curiosity than anything else, but why do strings silently
> concatenate like that, while all other case blow up with an error.  i.e., What is about
> the language the promotes this behavior.  At first blush, it seems inconsistent, but what
> do I know ...

Restricting our conversation to numbers/integers and strings, 
"concatenate" only ever seems to apply to string objects.
(there are meanings of "concatenate" for matrices, for example)

For fun, try:

help( str )	# and
help( int )

They both mention __add__(self, value, /) In both cases such is defined 
as "self+value" - but remember that the "+" operator is "over-loaded". 
Thus (and I'm telling you nothing new here) when dealing with strings we 
read "+" as "concatenate"; whereas with integers it is plainly "add". 
Two quite different operators/operations!


However, your point involves the fact that whereas:

1 + 2		# 3 is *clearly* addition, and
"a" + "b"	# "ab" is *clearly* concatenation

"a" "b"		# also evaluates to "ab"

and is thus, concatenation without any explicit infix operator! Just one 
cotton-picking minute - what's going on here?

The answer to all your dreams (um, maybe...) lies in "The Python 
Language Reference" docs, particularly Section 2 "Lexical Analysis" (the 
process of taking "tokens" and making sense of how they go-together!).

<<<
2.4.2. String literal concatenation
Multiple adjacent string or bytes literals (delimited by whitespace), 
possibly using different quoting conventions, are allowed, and their 
meaning is the same as their concatenation. Thus, "hello" 'world' is 
equivalent to "helloworld". This feature can be used to reduce the 
number of backslashes needed, to split long strings conveniently across 
long lines, or even to add comments to parts of strings, for example:

re.compile("[A-Za-z_]"       # letter or underscore
            "[A-Za-z0-9_]*"   # letter, digit or underscore
           )

Note that this feature is defined at the syntactical level, but 
implemented at compile time. The ?+? operator must be used to 
concatenate string expressions at run time. Also note that literal 
concatenation can use different quoting styles for each component (even 
mixing raw strings and triple quoted strings), and formatted string 
literals may be concatenated with plain string literals.
 >>>


Thus, the adjacency of two literals explicitly only implies 
concatenation for strings. There is no equivalent/similar mention for 
numbers.


WebRef: https://docs.python.org/3/reference/lexical_analysis.html
-- 
Regards =dn

From avigross at verizon.net  Mon Dec 23 21:17:17 2019
From: avigross at verizon.net (Avi Gross)
Date: Mon, 23 Dec 2019 21:17:17 -0500
Subject: Most elegant way to do something N times
In-Reply-To: <189be71f-477d-4f32-8c97-f989d8a8862c@DancesWithMice.info>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
 <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
 <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>
 <189be71f-477d-4f32-8c97-f989d8a8862c@DancesWithMice.info>
Message-ID: <006801d5ba00$44179460$cc46bd20$@verizon.net>

What others have answered is tangential. Nobody doubts there are places
where you want to repeat something N times. Just to add an example, if you
are parsing something nested by parentheses or perhaps HTML, and you reach a
point where you have seen N opening symbols and start seeing a closing
symbols, you might want to swallow the next N-1 such symbols before moving
on to whatever comes next. Yes, I know that can be more complex.

But in many such cases, people do not just count lines or whatever, but
actively examine each line. This is especially true where it is valid to
have say a comment embedded or other things that make the count uncertain.

Again, what language does something simpler?

Example, in R, is this much better?

for(n_times in 1:6) {print("hi")}
[1] "hi"
[1] "hi"
[1] "hi"
[1] "hi"
[1] "hi"
[1] "hi"

Using R, again, you can make a repeat function that calls your designated
function with a fizxed argument N times:

repetito = function(n, func, arg) {
  for (i in 1:n) {
    func(arg)
  }
}

 repetito(6, print, "hi")
[1] "hi"
[1] "hi"
[1] "hi"
[1] "hi"
[1] "hi"
[1] "hi"

Python allows similar ways:

>>> def repetito(n, func, args) :
	for _ in range(n):
		func(args)

		
>>> repetito(6, print, "hi")
hi
hi
hi
hi
hi
hi

You can modify these ideas to having no arguments or multiple arguments or
even varying numbers of arguments with varying numbers of positional and
keyword arguments. You need to be careful at times to make sure that the
calls are not evaluated once but each time.

I suspect the request boils down to wanting yet another keyword or two added
to a language that does not need more bloat.


-----Original Message-----
From: Python-list <python-list-bounces+avigross=verizon.net at python.org> On
Behalf Of DL Neil via Python-list
Sent: Monday, December 23, 2019 7:27 PM
To: Python <python-list at python.org>
Subject: Re: Most elegant way to do something N times

On 24/12/19 1:04 PM, Chris Angelico wrote:
> On Tue, Dec 24, 2019 at 10:45 AM Marco Sulla <elbarbun at gmail.com> wrote:
>>
>>>
>>> I encounter with cases like doing a function 6 time with no 
>>> argument, or same arguments over and over or doing some structral 
>>> thing N times and I dont know how elegant I can express that to the
code.
>>>
>>
>> ??? Excuse me, but why you needed to call the same function SIX 
>> times? This seems to me not elegant in primis.
>>
>> Can you give us a practical example?

Taking the top/bottom six from a sorted list of occurrences.

eg in Accounts Payable, a clerk might be given the task of 'chasing' the six
largest debtors (people who owe us money), as today's work
assignment/priority.


> File parsing. You read a section header and want to ignore that 
> section, so you ignore the next 15 lines.

(just to be cheeky to @Chris)

Perhaps better as a Finite State Machine, with one state being 'seeking
section header'.
1 can we guarantee that the 'magic constant' of 15 will always apply?
2 presumably the total routine will involve more than identifying a single
header and skipping (only) that section.
--
Regards =dn
--
https://mail.python.org/mailman/listinfo/python-list


From rosuav at gmail.com  Mon Dec 23 21:35:04 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 24 Dec 2019 13:35:04 +1100
Subject: Lists And Missing Commas
In-Reply-To: <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
Message-ID: <CAPTjJmq1tBhRM_wkhC2mmQw84bfG4u6dAO-1UdLAR70Vm9GHQw@mail.gmail.com>

On Tue, Dec 24, 2019 at 12:56 PM DL Neil via Python-list
<python-list at python.org> wrote:
> However, your point involves the fact that whereas:
>
> 1 + 2           # 3 is *clearly* addition, and
> "a" + "b"       # "ab" is *clearly* concatenation
>
> "a" "b"         # also evaluates to "ab"
>
> and is thus, concatenation without any explicit infix operator! Just one
> cotton-picking minute - what's going on here?

1_2    # Clearly concatenation. Right?
0_0    # Clearly an emoticon

Just another cotton-picking minute......

ChrisA

From PythonList at DancesWithMice.info  Mon Dec 23 22:34:47 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 24 Dec 2019 16:34:47 +1300
Subject: Lists And Missing Commas
In-Reply-To: <CAPTjJmq1tBhRM_wkhC2mmQw84bfG4u6dAO-1UdLAR70Vm9GHQw@mail.gmail.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <CAPTjJmq1tBhRM_wkhC2mmQw84bfG4u6dAO-1UdLAR70Vm9GHQw@mail.gmail.com>
Message-ID: <49476692-6aa9-e017-69d5-6c53cb89fc46@DancesWithMice.info>

On 24/12/19 3:35 PM, Chris Angelico wrote:
> On Tue, Dec 24, 2019 at 12:56 PM DL Neil via Python-list
> <python-list at python.org> wrote:
>> However, your point involves the fact that whereas:
>>
>> 1 + 2           # 3 is *clearly* addition, and
>> "a" + "b"       # "ab" is *clearly* concatenation
>>
>> "a" "b"         # also evaluates to "ab"
>>
>> and is thus, concatenation without any explicit infix operator! Just one
>> cotton-picking minute - what's going on here?
> 
> 1_2    # Clearly concatenation. Right?
> 0_0    # Clearly an emoticon
> 
> Just another cotton-picking minute......


Shows what you know: 1_2 is marching orders

- and here are yours...
-- 
Regards =dn

From info at tundraware.com  Mon Dec 23 23:20:53 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 23 Dec 2019 22:20:53 -0600
Subject: Lists And Missing Commas
In-Reply-To: <mailman.212.1577152374.11485.python-list@python.org>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <mailman.212.1577152374.11485.python-list@python.org>
Message-ID: <5ag8dg-lcn2.ln1@oceanview.tundraware.com>

On 12/23/19 7:52 PM, DL Neil wrote:
> 
> WebRef:?https://docs.python.org/3/reference/lexical_analysis.html


Yep, that explains it, but it still feels non-regular to me.  From a pointy headed academic
POV, I'd like to see behavior consistent across types. Again ... what do I know?


From info at tundraware.com  Mon Dec 23 23:21:40 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Mon, 23 Dec 2019 22:21:40 -0600
Subject: Lists And Missing Commas
In-Reply-To: <mailman.214.1577154918.11485.python-list@python.org>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <CAPTjJmq1tBhRM_wkhC2mmQw84bfG4u6dAO-1UdLAR70Vm9GHQw@mail.gmail.com>
 <mailman.214.1577154918.11485.python-list@python.org>
Message-ID: <kbg8dg-lcn2.ln1@oceanview.tundraware.com>

On 12/23/19 8:35 PM, Chris Angelico wrote:
> On Tue, Dec 24, 2019 at 12:56 PM DL Neil via Python-list
> <python-list at python.org> wrote:
>> However, your point involves the fact that whereas:
>>
>> 1 + 2           # 3 is *clearly* addition, and
>> "a" + "b"       # "ab" is *clearly* concatenation
>>
>> "a" "b"         # also evaluates to "ab"
>>
>> and is thus, concatenation without any explicit infix operator! Just one
>> cotton-picking minute - what's going on here?
> 
> 1_2    # Clearly concatenation. Right?
> 0_0    # Clearly an emoticon
> 
> Just another cotton-picking minute......
> 
> ChrisA
> 

You are excused and required to do 30 days penance writing .NET.

From frank at chagford.com  Tue Dec 24 00:46:00 2019
From: frank at chagford.com (Frank Millman)
Date: Tue, 24 Dec 2019 07:46:00 +0200
Subject: Lists And Missing Commas
In-Reply-To: <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <mailman.212.1577152374.11485.python-list@python.org>
 <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
Message-ID: <fd74dbce-b5e9-3a83-140b-bfda4cabd522@chagford.com>

On 2019-12-24 6:20 AM, Tim Daneliuk wrote:
> On 12/23/19 7:52 PM, DL Neil wrote:
>>
>> WebRef:?https://docs.python.org/3/reference/lexical_analysis.html
> 
> 
> Yep, that explains it, but it still feels non-regular to me.  From a pointy headed academic
> POV, I'd like to see behavior consistent across types. Again ... what do I know?
> 

 From the Zen, 'Practicality beats purity'.

 From the docs -

"""
String literals that are part of a single expression and have only 
whitespace between them will be implicitly converted to a single string 
literal. That is, ("spam " "eggs") == "spam eggs".
"""

I do not see it as 'concatenation', rather as a way of constructing a 
single string from a number of smaller chunks. The docs talk about 
'whitespace', but I would guess that the use of a single space is 
uncommon. More likely is the use of a newline.

I use this from time to time when constructing long string literals -

long_string = (
     "this is the first chunk "
     "this is the second chunk "
     "etc etc"
     )

My 0.02c

Frank Millman

From PythonList at DancesWithMice.info  Tue Dec 24 00:46:34 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 24 Dec 2019 18:46:34 +1300
Subject: Lists And Missing Commas
In-Reply-To: <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <mailman.212.1577152374.11485.python-list@python.org>
 <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
Message-ID: <97d9350c-3f4a-1143-a5fb-ffaec2661c4c@DancesWithMice.info>

On 24/12/19 5:20 PM, Tim Daneliuk wrote:
> On 12/23/19 7:52 PM, DL Neil wrote:
>>
>> WebRef:?https://docs.python.org/3/reference/lexical_analysis.html
> 
> 
> Yep, that explains it, but it still feels non-regular to me.  From a pointy headed academic
> POV, I'd like to see behavior consistent across types. Again ... what do I know?


I thought it was 'the boss' who has the "pointy head'? (so that any 
'difficult' idea will not land, but simply slide-off to one side or the 
other?)

It is an interesting lateral-thinking enquiry, and we should not simply 
accept 'stuff', but question how it best works/we can best use it.


That said, on the surface, I might agree.

Venturing into compiler-writing/lexical analysis, and comparing with 
other languages, we rapidly realise that it is 'odd' (or special).


However, keep reading (the above web.ref) and find the section where 
"white space" is described. Combine that with the idea/nuisance-value of 
splitting long strings over multiple lines.

Rather than puzzling-over an 'only/special/weird concatenation' 
allowance, perhaps we should see a 'convenience factor'?
-- 
Regards =dn

From frank at chagford.com  Tue Dec 24 00:46:00 2019
From: frank at chagford.com (Frank Millman)
Date: Tue, 24 Dec 2019 07:46:00 +0200
Subject: Lists And Missing Commas
In-Reply-To: <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <mailman.212.1577152374.11485.python-list@python.org>
 <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
Message-ID: <fd74dbce-b5e9-3a83-140b-bfda4cabd522@chagford.com>

On 2019-12-24 6:20 AM, Tim Daneliuk wrote:
> On 12/23/19 7:52 PM, DL Neil wrote:
>>
>> WebRef:?https://docs.python.org/3/reference/lexical_analysis.html
> 
> 
> Yep, that explains it, but it still feels non-regular to me.  From a pointy headed academic
> POV, I'd like to see behavior consistent across types. Again ... what do I know?
> 

 From the Zen, 'Practicality beats purity'.

 From the docs -

"""
String literals that are part of a single expression and have only 
whitespace between them will be implicitly converted to a single string 
literal. That is, ("spam " "eggs") == "spam eggs".
"""

I do not see it as 'concatenation', rather as a way of constructing a 
single string from a number of smaller chunks. The docs talk about 
'whitespace', but I would guess that the use of a single space is 
uncommon. More likely is the use of a newline.

I use this from time to time when constructing long string literals -

long_string = (
     "this is the first chunk "
     "this is the second chunk "
     "etc etc"
     )

My 0.02c

Frank Millman


From info at tundraware.com  Tue Dec 24 10:45:42 2019
From: info at tundraware.com (Tim Daneliuk)
Date: Tue, 24 Dec 2019 09:45:42 -0600
Subject: Lists And Missing Commas
In-Reply-To: <concatenation-20191224133550@ram.dialup.fu-berlin.de>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <mailman.212.1577152374.11485.python-list@python.org>
 <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
 <concatenation-20191224133550@ram.dialup.fu-berlin.de>
Message-ID: <6eo9dg-jve2.ln1@oceanview.tundraware.com>

On 12/24/19 6:37 AM, Stefan Ram wrote:
>  And you all are aware that this kind of string concatenation
>   happens in C and C++, too, aren't you?
> 
>   main.c
> 
> #include <stdio.h>
> int main( void ){ puts( "a" "b" ); }
> 
>   transcript
> 
> ab

Noting that it has been a long time since I looked at the C specification ...

Is the above an artifact of how puts() is implemented or is it innate in the language spec?

From Richard at Damon-Family.org  Tue Dec 24 11:14:25 2019
From: Richard at Damon-Family.org (Richard Damon)
Date: Tue, 24 Dec 2019 11:14:25 -0500
Subject: Lists And Missing Commas
In-Reply-To: <6eo9dg-jve2.ln1@oceanview.tundraware.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <mailman.212.1577152374.11485.python-list@python.org>
 <5ag8dg-lcn2.ln1@oceanview.tundraware.com>
 <concatenation-20191224133550@ram.dialup.fu-berlin.de>
 <6eo9dg-jve2.ln1@oceanview.tundraware.com>
Message-ID: <440f9741-6fc5-80d0-0d61-9a275d3365a4@Damon-Family.org>

On 12/24/19 10:45 AM, Tim Daneliuk wrote:
> On 12/24/19 6:37 AM, Stefan Ram wrote:
>>   And you all are aware that this kind of string concatenation
>>    happens in C and C++, too, aren't you?
>>
>>    main.c
>>
>> #include <stdio.h>
>> int main( void ){ puts( "a" "b" ); }
>>
>>    transcript
>>
>> ab
> Noting that it has been a long time since I looked at the C specification ...
>
> Is the above an artifact of how puts() is implemented or is it innate in the language spec?

The automatic concatenation of adjacent strings is an innate part of the 
C language spec.

One important reason this was included in the C language was so that 
some of the predefined macros with a string value (like the compilation 
time __TIME__) could be built into a string constant.

A second is that C had no equivalent to """ as a multi-line string 
constant, and using line continuation was problematical on some systems 
using fixed length lines, so allowing a constant to be built on multiple 
lines was useful.

-- 
Richard Damon


From guido at python.org  Tue Dec 24 11:20:05 2019
From: guido at python.org (Guido van Rossum)
Date: Tue, 24 Dec 2019 09:20:05 -0700
Subject: [ANN] Retrospective of Python compilation efforts
In-Reply-To: <20191224115535.565697cc@x230>
References: <20191224115535.565697cc@x230>
Message-ID: <CAP7+vJ+kp=Dugp=raVyDN0hdSUBE=SqD15y=_9ys3=Jsvc13YQ@mail.gmail.com>

Nice work.

On Tue, Dec 24, 2019 at 2:59 AM Paul Sokolovsky <pmiscml at gmail.com> wrote:

> Hello,
>
> Over the years, the Python community produced many compiler projects for
> the language, second to probably only C and LISP. Majority are of
> course of research and proof of concept quality, but there're a number
> of quite advanced projects.
>
> For some time, I was trying to compile a retrospective of these
> efforts, formatted as a github "awesome" list:
>
> https://github.com/pfalcon/awesome-python-compilers
>
>
> Happy holidays,
> Paul
> --
> Python-announce-list mailing list -- python-announce-list at python.org
> To unsubscribe send an email to python-announce-list-leave at python.org
> https://mail.python.org/mailman3/lists/python-announce-list.python.org/
>
>         Support the Python Software Foundation:
>         http://www.python.org/psf/donations/
>


-- 
--Guido van Rossum (python.org/~guido)
*Pronouns: he/him **(why is my pronoun here?)*
<http://feministing.com/2015/02/03/how-using-they-as-a-singular-pronoun-can-change-the-world/>

From avigross at verizon.net  Tue Dec 24 13:02:03 2019
From: avigross at verizon.net (Avi Gross)
Date: Tue, 24 Dec 2019 13:02:03 -0500
Subject: Lists And Missing Commas
In-Reply-To: <kbg8dg-lcn2.ln1@oceanview.tundraware.com>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <CAPTjJmq1tBhRM_wkhC2mmQw84bfG4u6dAO-1UdLAR70Vm9GHQw@mail.gmail.com>
 <mailman.214.1577154918.11485.python-list@python.org>
 <kbg8dg-lcn2.ln1@oceanview.tundraware.com>
Message-ID: <007601d5ba84$3f270970$bd751c50$@verizon.net>

As a purist, it makes people uncomfortable if all 'objects' are not treated
alike.

But I look at the question from a definition and parsing mechanism view.

When an interpreter (or compiler) reads a program, it often does it in
phases and tries to tokenize parts.

So, the definition of something often makes it look ahead or back or even
sideways to see how much of the program text makes up a single entity. 

The definition of a NUMBER is complex but clearly it needs to allow
underscores or designations that make it octal versus decimal or a floating
point number or even scientific notation. The point is it does some looking
ahead to make sure it gets the entire number and then sets it aside as a
token for a single entity.

The definition of a fixed string is also complex as it can be a binary
string or other formats but the focus here is that string literals were
DESIGNED to be able to span multiple lines or be put in piecewise. So the
parser does not stop when it sees "Hello " but continues to see if there is
more that can be used to make a full string literal. It has to skip past
whitespace and see what follows. If what follows is "World!" then it makes
"Hello World!" and keeps scanning beyond more whitespace until something is
found that cannot be considered part of the same literal. Other languages
use this technique such as C++ 

An analogy might be how a compiler in a language that supports constants
will look at a line declaring something like this:

	const int volume = 5 * 6 * 7

Would it not be possible that the compiler, knowing this is a constant,
would not pre-calculate the result and act as if you had written:

	const int volume = 210

The run time, would not know or care.

So, if the analogy makes sense, in python the early evaluation phase is
required to combine as much as possible into a single string literal. It is
a bit like a regular expression that matches a pattern greedily unless asked
not to. This tokenization probably precedes the point where it sees a series
of commas in a context such as a list definition or function call argument
list. 

Again, a purist might want all objects, within reason, to look alike. There
are other mechanisms to gain this concatenation functionality in strings.
This being Python (which lies about how there should be one unique way to
logically do something) there may be dozens of ways to get this
functionality starting with using a PLUS operator and continuing with one of
5 or so ways to build a string from other objects as well as strategic uses
of the backslash character and so on.

But it is a feature that is there and seems to also be in some other
languages. It is generally easy to avoid using this implicit concatenation
but I think an important point is that you may inadvertently get the wrong
result when accidentally leaving out a comma. That is true. I note this is
an old known issue:

https://www.python.org/dev/peps/pep-3126/

There are some lint programs that check your code and supply warnings and I
see some languages have the option to generate warnings when the two strings
are on the same line. I wonder if a Python lint does that. It may at least
warn of this usage in time to check the code and put back the comma.


-----Original Message-----
From: Python-list <python-list-bounces+avigross=verizon.net at python.org> On
Behalf Of Tim Daneliuk
Sent: Monday, December 23, 2019 11:22 PM
To: python-list at python.org
Subject: Re: Lists And Missing Commas

On 12/23/19 8:35 PM, Chris Angelico wrote:
> On Tue, Dec 24, 2019 at 12:56 PM DL Neil via Python-list 
> <python-list at python.org> wrote:
>> However, your point involves the fact that whereas:
>>
>> 1 + 2           # 3 is *clearly* addition, and
>> "a" + "b"       # "ab" is *clearly* concatenation
>>
>> "a" "b"         # also evaluates to "ab"
>>
>> and is thus, concatenation without any explicit infix operator! Just 
>> one cotton-picking minute - what's going on here?
> 
> 1_2    # Clearly concatenation. Right?
> 0_0    # Clearly an emoticon
> 
> Just another cotton-picking minute......
> 
> ChrisA
> 

You are excused and required to do 30 days penance writing .NET.
--
https://mail.python.org/mailman/listinfo/python-list


From ethan at stoneleaf.us  Tue Dec 24 13:26:27 2019
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 24 Dec 2019 10:26:27 -0800
Subject: Lists And Missing Commas
In-Reply-To: <007601d5ba84$3f270970$bd751c50$@verizon.net>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <CAPTjJmq1tBhRM_wkhC2mmQw84bfG4u6dAO-1UdLAR70Vm9GHQw@mail.gmail.com>
 <mailman.214.1577154918.11485.python-list@python.org>
 <kbg8dg-lcn2.ln1@oceanview.tundraware.com>
 <007601d5ba84$3f270970$bd751c50$@verizon.net>
Message-ID: <aab7cd9f-6922-7409-e68f-17fb960a77e2@stoneleaf.us>

On 12/24/2019 10:02 AM, Avi Gross via Python-list wrote:

> This being Python (which lies about how there should be one unique way to
> logically do something)

The koan is:

   There should be one-- and preferably only one --obvious way to do it.

It is not:

- only one way
- one unique way
- the one true way
- the way to end all ways  ;)
- etc


It is also `preferable`, not:

- absolute
- eternal
- fixed
- exclusive

--
~Ethan~

From mail.python.org at marco.sulla.e4ward.com  Tue Dec 24 15:41:49 2019
From: mail.python.org at marco.sulla.e4ward.com (Marco Sulla)
Date: Tue, 24 Dec 2019 21:41:49 +0100
Subject: Most elegant way to do something N times
In-Reply-To: <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
 <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
 <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>
Message-ID: <CABbU2U9vwWxt8hPNCRydPETuKKeO8M6BR7Ov2E68K_mkG7wE=g@mail.gmail.com>

On Tue, 24 Dec 2019 at 01:07, Chris Angelico <rosuav at gmail.com> wrote:
> On Tue, Dec 24, 2019 at 10:45 AM Marco Sulla <...> wrote:
> > ??? Excuse me, but why you needed to call the same function SIX times? This
> > seems to me not elegant in primis.
> >
> > Can you give us a practical example?
>
> File parsing. You read a section header and want to ignore that
> section, so you ignore the next 15 lines.

mmap and find?


On Tue, 24 Dec 2019 at 01:35, DL Neil via Python-list
<python-list at python.org> wrote:
> Taking the top/bottom six from a sorted list of occurrences.

Slicing?

From avigross at verizon.net  Tue Dec 24 16:48:26 2019
From: avigross at verizon.net (Avi Gross)
Date: Tue, 24 Dec 2019 16:48:26 -0500
Subject: Lists And Extra Commas at end
References: <00ba01d5baa3$df8db7a0$9ea926e0$.ref@verizon.net>
Message-ID: <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>

Marco,

Python is used by some in an interactive mode but also in more of a batch mode such as on a server. The former can possibly see a SyntaxWarning. Do you want that as a default or something you set when you start the Python Interpreter or perhaps a command within it? I note a brief search to see about Warnings in Jupyter keeps talking about how to turn warnings off!  My point is that warnings about what is not a real problem tend to make people ignore all warnings.

Let me switch gears to the terminal comma situation. Unlike many languages, Python decided a dangling comma is perfectly allowable in many situations, perhaps all.

>>> a=[1,2,3,]
>>> a
[1, 2, 3]

The above does not work for an empty comma at the beginning or middle or a double comma at the end. It is clear why they allowed this as it makes some things easier like building up a list in a loop and not needing to figure out the special case when you are done and suppressing the last comma. Since a function argument list is just a list in Python, the following works fine:

def testink(a,b,): pass

And, of course, you can use the same dangling comma in making a tuple, dictionary or set and who knows where else.

So, is that a feature you want warnings about? After all, a dangling comma may simply mean you left something out and meant to add later? 

As I see it, languages have tradeoffs and nobody will be completely satisfied so you choose and hope. But, warnings you can turn on an off do indeed make sense. But at what level? If the main interpreter has to do all kinds of testing even for a VALID use of the language so it can warn, that is extra overhead each time it is run. I would prefer something less intrusive. Some languages have a way of saying "use strict" (such as JavaScript or Perl) or a "use warnings" that tells to interpreter to warn about things. Since Python did not go this route, with perhaps a tad of that regarding the __future__ setting, I figured a good place to do this is in a Lint type of program that can be set to look for things that are not so much errors as places to check to make sure things are OK. You would not run that every time, just when the code has been changed.

And, if you look for a list of places people make mistakes that are often maddening to trace, there are so many. Would you like a warning that multiple NAMES are almost the same except for capitalization or that you have long_variable_1_of_2 as well as long_variable_2_of_2 which only differ by a tad deep in the middle?

At some point, you have to take the training wheels off. Not clear what that point is, sometimes, so I try to only drive vehicles with 4 or six tires, LOL!

-----Original Message-----
From: forwardedby at e4ward.com <forwardedby at e4ward.com> On Behalf Of Marco Sulla
Sent: Tuesday, December 24, 2019 4:03 PM
To: Avi Gross <avigross at verizon.net>
Cc: Python-list.python.org-mail.python.org.marco.sulla.e4ward.com at jq38efsu937.reply.e4ward.com
Subject: Re: Lists And Missing Commas

On Tue, 24 Dec 2019 at 19:05, Avi Gross via Python-list <python-list at python.org> wrote:
> There are some lint programs that check your code and supply warnings 
> and I see some languages have the option to generate warnings when the 
> two strings are on the same line. I wonder if a Python lint does that. 
> It may at least warn of this usage in time to check the code and put back the comma.

IMHO it's not something that should be delegated to linter, but to the AST compiler itself. A SyntaxWarning should be displayed.

One time I spent HOURS because I forgot one single comma in a list of strings. After that, my life is changed. I'm no more an ingenuous, little boy, that trusted the stacktrace.


From cs at cskk.id.au  Tue Dec 24 17:12:28 2019
From: cs at cskk.id.au (Cameron Simpson)
Date: Wed, 25 Dec 2019 09:12:28 +1100
Subject: Lists And Extra Commas at end
In-Reply-To: <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>
References: <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>
Message-ID: <20191224221228.GA23410@cskk.homeip.net>

On 24Dec2019 16:48, Avi Gross <avigross at verizon.net> wrote:
>Let me switch gears to the terminal comma situation. Unlike many 
>languages, Python decided a dangling comma is perfectly allowable in 
>many situations, perhaps all.
>
>>>> a=[1,2,3,]
>>>> a
>[1, 2, 3]
[...]
>And, of course, you can use the same dangling comma in making a tuple, 
>dictionary or set and who knows where else.
>So, is that a feature you want warnings about? After all, a dangling 
>comma may simply mean you left something out and meant to add later?

To my mind the killer argument for trailing commas is things like 
multiline lists, dicts or parameters. Example:

  def function(
      arg1=None,
      arg2=FOO,
  ):

Imagine this for a comewhat extended set of parameters. Or similar for a 
big list or dict (eg a "table" as part of a class definition).

By always including the trailing comma it is easier to insert or delete 
lines, and it reduces diff noise if you're using revision control (no 
commas flickering on and off in the diff output).

Cheers,
Cameron Simpson <cs at cskk.id.au>

From mail.python.org at marco.sulla.e4ward.com  Tue Dec 24 17:35:40 2019
From: mail.python.org at marco.sulla.e4ward.com (Marco Sulla)
Date: Tue, 24 Dec 2019 23:35:40 +0100
Subject: Lists And Extra Commas at end
In-Reply-To: <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>
References: <00ba01d5baa3$df8db7a0$9ea926e0$.ref@verizon.net>
 <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>
Message-ID: <CABbU2U-j0CCfnJjP1r6f7UEXY8t4rzLLS9f068dm3n4rvM-Haw@mail.gmail.com>

On Tue, 24 Dec 2019 at 22:51, Avi Gross via Python-list
<python-list at python.org> wrote:
> So, is that a feature you want warnings about? After all, a dangling comma may simply mean you left something out and meant to add later?

.....completely OT. I responded to a topic named "List and missing
commas", and suggested a warning for implicit concatenation between
adjacent strings. I don't really know why you renamed it "Lists And
Extra Commas at end". Have you read the thread and my post?

Cheers.

From mail.python.org at marco.sulla.e4ward.com  Tue Dec 24 16:02:44 2019
From: mail.python.org at marco.sulla.e4ward.com (Marco Sulla)
Date: Tue, 24 Dec 2019 22:02:44 +0100
Subject: Lists And Missing Commas
In-Reply-To: <007601d5ba84$3f270970$bd751c50$@verizon.net>
References: <ls38dg-sni2.ln1@oceanview.tundraware.com>
 <b7f6dbba-855f-d03f-b4fd-d94ab68efc18@DancesWithMice.info>
 <CAPTjJmq1tBhRM_wkhC2mmQw84bfG4u6dAO-1UdLAR70Vm9GHQw@mail.gmail.com>
 <mailman.214.1577154918.11485.python-list@python.org>
 <kbg8dg-lcn2.ln1@oceanview.tundraware.com>
 <007601d5ba84$3f270970$bd751c50$@verizon.net>
Message-ID: <CABbU2U_YOvsSOCgzw+L5VN_CC2ML4x5YpOg4NQfmSEq_=kvmRQ@mail.gmail.com>

On Tue, 24 Dec 2019 at 19:05, Avi Gross via Python-list
<python-list at python.org> wrote:
> There are some lint programs that check your code and supply warnings and I
> see some languages have the option to generate warnings when the two strings
> are on the same line. I wonder if a Python lint does that. It may at least
> warn of this usage in time to check the code and put back the comma.

IMHO it's not something that should be delegated to linter, but to the
AST compiler itself. A SyntaxWarning should be displayed.

One time I spent HOURS because I forgot one single comma in a list of
strings. After that, my life is changed. I'm no more an ingenuous,
little boy, that trusted the stacktrace.

From mail.python.org at marco.sulla.e4ward.com  Tue Dec 24 18:41:56 2019
From: mail.python.org at marco.sulla.e4ward.com (Marco Sulla)
Date: Wed, 25 Dec 2019 00:41:56 +0100
Subject: More efficient/elegant branching
In-Reply-To: <9823ad20-6c92-6606-6268-845ec144c5cf@DancesWithMice.info>
References: <4c0405e8fe1ca0af482048c60e9ee2f4@posteo.de>
 <a892e74d-04c6-8bc0-15d9-0e537b26a955@DancesWithMice.info>
 <cabcf64dbb845791154c694832c858d2@posteo.de>
 <9823ad20-6c92-6606-6268-845ec144c5cf@DancesWithMice.info>
Message-ID: <CABbU2U9q_NsW1gL-moL1k+71HCfO8GtW3yBq7946Ux5ya4P6yw@mail.gmail.com>

I agree with Chris Angelico, branch1 is "the way to go". Maybe you
have to add a default at start, maybe None, and maybe raise an
exception if
res is None. Anyway, despite I'm a pain in the... arse and I usually
activate ALL the possible warnings in the world, I always disable
cyclomatic complexity warnings in all linters, in any language :D

# Off topic - START

I proposed a switch-case some years ago. I was brutally condemned like
an heretic :D It was something like:

when expr match arg1, arg2, ....:
    [...]
match *args:
    [...]
[...]
else: # optional
    [...]

expr was evaluated, and checked if equal to one of the arguments. At
the first positive check, the relative code was evaluated, and the
when breaks. No break keyword, like if-elif. If no check passed and an
else clause is present, its code will be evaluated.

Anyway this is not helpful in your case, since you have more
complicated checks. Mine was only a suggestion to introduce the simple
C switch-case in Python, for making easier trivial if-elif chains and
for code optimization (C switch-case is optimized by C compilers)

# Of topic - END

From avigross at verizon.net  Tue Dec 24 18:48:48 2019
From: avigross at verizon.net (Avi Gross)
Date: Tue, 24 Dec 2019 18:48:48 -0500
Subject: Lists And Extra Commas at end
In-Reply-To: <20191224221228.GA23410@cskk.homeip.net>
References: <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>
 <20191224221228.GA23410@cskk.homeip.net>
Message-ID: <00da01d5bab4$b011bdd0$10353970$@verizon.net>

Cameron,

I am not at all against the feature. I like it as my programming style is
like you describe. One entry per line indented at the same level, in
multiple languages. I often do graphics where I generate an image then
fine-tune additional parameters to get the effect I want. Some functions
take literally hundreds of options to adjust anything from text labels to
line types to colors and the high/low values on axes and so on. In languages
like R, I tend to put in a final entry with no trailing comma that is
something harmless that can be left in position and the same for the first
entry. Then my adding/deleting/editing of fields happens in the middle where
I always have a terminal comma.

My point is the convenience comes with a price for people who make a mistake
and are not told perhaps the dangling comma was a placeholder for something
to add that they forgot or ...

Again, the convenience is in some sense removing a mathematical symmetry,
but so what?

-----Original Message-----
From: Cameron Simpson <cs at cskk.id.au> 
Sent: Tuesday, December 24, 2019 5:12 PM
To: Avi Gross <avigross at verizon.net>
Cc: python-list at python.org
Subject: Re: Lists And Extra Commas at end

On 24Dec2019 16:48, Avi Gross <avigross at verizon.net> wrote:
>Let me switch gears to the terminal comma situation. Unlike many 
>languages, Python decided a dangling comma is perfectly allowable in 
>many situations, perhaps all.
>
>>>> a=[1,2,3,]
>>>> a
>[1, 2, 3]
[...]
>And, of course, you can use the same dangling comma in making a tuple, 
>dictionary or set and who knows where else.
>So, is that a feature you want warnings about? After all, a dangling 
>comma may simply mean you left something out and meant to add later?

To my mind the killer argument for trailing commas is things like multiline
lists, dicts or parameters. Example:

  def function(
      arg1=None,
      arg2=FOO,
  ):

Imagine this for a comewhat extended set of parameters. Or similar for a big
list or dict (eg a "table" as part of a class definition).

By always including the trailing comma it is easier to insert or delete
lines, and it reduces diff noise if you're using revision control (no commas
flickering on and off in the diff output).

Cheers,
Cameron Simpson <cs at cskk.id.au>


From rosuav at gmail.com  Tue Dec 24 18:58:22 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 25 Dec 2019 10:58:22 +1100
Subject: Lists And Extra Commas at end
In-Reply-To: <00da01d5bab4$b011bdd0$10353970$@verizon.net>
References: <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>
 <20191224221228.GA23410@cskk.homeip.net>
 <00da01d5bab4$b011bdd0$10353970$@verizon.net>
Message-ID: <CAPTjJmoS9iTcOWo1iqUZoCXxSAAe5WsD+b8WVPx=HGq2vJ0t5w@mail.gmail.com>

On Wed, Dec 25, 2019 at 10:50 AM Avi Gross via Python-list
<python-list at python.org> wrote:
>
> Cameron,
>
> I am not at all against the feature. I like it as my programming style is
> like you describe. One entry per line indented at the same level, in
> multiple languages. I often do graphics where I generate an image then
> fine-tune additional parameters to get the effect I want. Some functions
> take literally hundreds of options to adjust anything from text labels to
> line types to colors and the high/low values on axes and so on. In languages
> like R, I tend to put in a final entry with no trailing comma that is
> something harmless that can be left in position and the same for the first
> entry. Then my adding/deleting/editing of fields happens in the middle where
> I always have a terminal comma.

IOW you recreate the same feature by having a meaningless line at the
end.  Unideal but sometimes necessary.

> My point is the convenience comes with a price for people who make a mistake
> and are not told perhaps the dangling comma was a placeholder for something
> to add that they forgot or ...

People can learn. It's an extremely common idiom. If it's laid out
vertically, include the trailing comma. It's not exactly hard to
figure out.

ChrisA

From mail.python.org at marco.sulla.e4ward.com  Tue Dec 24 19:20:25 2019
From: mail.python.org at marco.sulla.e4ward.com (Marco Sulla)
Date: Wed, 25 Dec 2019 01:20:25 +0100
Subject: Lists And Extra Commas at end
In-Reply-To: <00db01d5bab5$b9761c30$2c625490$@verizon.net>
References: <00ba01d5baa3$df8db7a0$9ea926e0$.ref@verizon.net>
 <00ba01d5baa3$df8db7a0$9ea926e0$@verizon.net>
 <CABbU2U-j0CCfnJjP1r6f7UEXY8t4rzLLS9f068dm3n4rvM-Haw@mail.gmail.com>
 <00db01d5bab5$b9761c30$2c625490$@verizon.net>
Message-ID: <CABbU2U_sVPvRf6NF1RRGCsL04wi0gNZZw6tGS83ZgLcCCAxt+A@mail.gmail.com>

On Wed, 25 Dec 2019 at 00:56, Avi Gross
<avigross at verizon.net.via.e4ward.com> wrote:
> I may not be understanding what you are objecting to

I, sir, am objecting that I replied to a topic, and you answered to
me, but in another topic. You could have respond to me in the correct
topic, and then  create this other one (that I'm not really
interested).

Anyway.

About the extra comma, it's da**ed useful:

a = (
    42,
    1981,
    8,
    19,
    23,
)

If I have to comment out the last line, I can, **without having to
remove the comma before**. And if I have to add another number at the
end, I have not to remember to add the comma before.

########

The real problem is this one:

a = 1,

Unreadable and prone to subtle errors, because maybe you added the
comma by mistake. Caution: Debugging Nightmares.
The solution, IMHO?

DeprecationWarning, use (1, )

Explicit is better blablabla.

From mail.python.org at marco.sulla.e4ward.com  Tue Dec 24 21:09:09 2019
From: mail.python.org at marco.sulla.e4ward.com (Marco Sulla)
Date: Wed, 25 Dec 2019 03:09:09 +0100
Subject: Most elegant way to do something N times
In-Reply-To: <CABbU2U9vwWxt8hPNCRydPETuKKeO8M6BR7Ov2E68K_mkG7wE=g@mail.gmail.com>
References: <CAAEJ-VGE3Bu4Wo6QyA=rMhe4X4YRzt7k3VV+QNX47MQFmwg5jQ@mail.gmail.com>
 <CABbU2U_Cjp2KYMUk=NZBEV08Hp+K-Xhz3A3FEKf3nPYrN43f+Q@mail.gmail.com>
 <CAPTjJmrtpYptNHbOf7Et2WZDZRCK9gm-Lbb4_BtH9ZW0+jRzZg@mail.gmail.com>
 <CABbU2U9vwWxt8hPNCRydPETuKKeO8M6BR7Ov2E68K_mkG7wE=g@mail.gmail.com>
Message-ID: <CABbU2U-k+AobxJ2bu9zXC=niRA8WjO=NqvSTqoP_cnoo8AysmA@mail.gmail.com>

Anyway, from itertools recipes:

def repeatfunc(func, times=None, *args):
    """Repeat calls to func with specified arguments.

    Example:  repeatfunc(random.random)
    """
    if times is None:
        return starmap(func, repeat(args))
    return starmap(func, repeat(args, times))

On Tue, 24 Dec 2019 at 21:41, Marco Sulla <elbarbun at gmail.com> wrote:
>
> On Tue, 24 Dec 2019 at 01:07, Chris Angelico <rosuav at gmail.com> wrote:
> > On Tue, Dec 24, 2019 at 10:45 AM Marco Sulla <...> wrote:
> > > ??? Excuse me, but why you needed to call the same function SIX times? This
> > > seems to me not elegant in primis.
> > >
> > > Can you give us a practical example?
> >
> > File parsing. You read a section header and want to ignore that
> > section, so you ignore the next 15 lines.
>
> mmap and find?
>
>
> On Tue, 24 Dec 2019 at 01:35, DL Neil via Python-list
> <python-list at python.org> wrote:
> > Taking the top/bottom six from a sorted list of occurrences.
>
> Slicing?

From cs at cskk.id.au  Tue Dec 24 21:40:14 2019
From: cs at cskk.id.au (Cameron Simpson)
Date: Wed, 25 Dec 2019 13:40:14 +1100
Subject: Lists And Extra Commas at end
In-Reply-To: <CABbU2U_sVPvRf6NF1RRGCsL04wi0gNZZw6tGS83ZgLcCCAxt+A@mail.gmail.com>
References: <CABbU2U_sVPvRf6NF1RRGCsL04wi0gNZZw6tGS83ZgLcCCAxt+A@mail.gmail.com>
Message-ID: <20191225024014.GA1946@cskk.homeip.net>

On 25Dec2019 01:20, mail.python.org at marco.sulla.e4ward.com <mail.python.org at marco.sulla.e4ward.com> wrote:
>About the extra comma, it's da**ed useful:
[...]
>The real problem is this one:
>
>a = 1,
>
>Unreadable and prone to subtle errors, because maybe you added the
>comma by mistake. Caution: Debugging Nightmares.

Hoo, yes. Only the other week I spent _way_ too long debugging exactly 
that mistake because I'd cut/pasted a parameter into some inline code.  
Suddenly a int was a tuple.

With luck I'll recognise that mistake faster next time.

Cheers,
Cameron Simpson <cs at cskk.id.au>

From jeff.gitlin at gmail.com  Wed Dec 25 09:12:54 2019
From: jeff.gitlin at gmail.com (Jeff Gitlin)
Date: Wed, 25 Dec 2019 06:12:54 -0800 (PST)
Subject: Python 3.8 and :=
Message-ID: <c6629df4-46e7-4263-a982-68417dc5211a@googlegroups.com>

With the new operator := in Python 3.8
that allows you to do things like

if ( x := f() ) == 1:

Is there any reason to use just the assignment operator?

From rosuav at gmail.com  Wed Dec 25 09:22:31 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 26 Dec 2019 01:22:31 +1100
Subject: Python 3.8 and :=
In-Reply-To: <c6629df4-46e7-4263-a982-68417dc5211a@googlegroups.com>
References: <c6629df4-46e7-4263-a982-68417dc5211a@googlegroups.com>
Message-ID: <CAPTjJmrmPdddXz6wHmX-oXcrbrUCWxSWy3whvnLhnjaYL-xQyQ@mail.gmail.com>

On Thu, Dec 26, 2019 at 1:16 AM Jeff Gitlin <jeff.gitlin at gmail.com> wrote:
>
> With the new operator := in Python 3.8
> that allows you to do things like
>
> if ( x := f() ) == 1:
>
> Is there any reason to use just the assignment operator?

I don't understand the question. Are you asking why the normal "="
operator should be used? For starters, "=" is far more flexible than
":=" in terms of what it can assign to.

ChrisA

From manomugdha at gmail.com  Wed Dec 25 07:43:44 2019
From: manomugdha at gmail.com (Manomugdha Biswas)
Date: Wed, 25 Dec 2019 18:13:44 +0530
Subject: How to call C functions from Linux C executable and vice-versa
Message-ID: <CACaFRBHbiZA5DZj6--tre5ydHPUsApLFbWtXUX==kO788RSczQ@mail.gmail.com>

Hi,
I have a Linux C binary (executable, not .so file). i can update (add new
files/folders if it is required) but after compilation i will get a binary
executable file.
I want to access/call few functions of this executable from python. for
this i want to use cython interface (most probably cython is the best
option!). Any other possible options are also acceptable.  the
example/documentation of cython i have seen till now, they talk about
calling c functions from c library (.so file).

can you please point me to a documentation/source code which talks about
how to call c functions from c-executable?

Regards,
Mano

From rosuav at gmail.com  Wed Dec 25 11:44:00 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 26 Dec 2019 03:44:00 +1100
Subject: How to call C functions from Linux C executable and vice-versa
In-Reply-To: <CACaFRBHbiZA5DZj6--tre5ydHPUsApLFbWtXUX==kO788RSczQ@mail.gmail.com>
References: <CACaFRBHbiZA5DZj6--tre5ydHPUsApLFbWtXUX==kO788RSczQ@mail.gmail.com>
Message-ID: <CAPTjJmocoQB_G8SCG+NMtrY1RV-_O5hWA3DBbVkN=N23CvtRYQ@mail.gmail.com>

On Thu, Dec 26, 2019 at 3:41 AM Manomugdha Biswas <manomugdha at gmail.com> wrote:
>
> Hi,
> I have a Linux C binary (executable, not .so file). i can update (add new
> files/folders if it is required) but after compilation i will get a binary
> executable file.
> I want to access/call few functions of this executable from python. for
> this i want to use cython interface (most probably cython is the best
> option!). Any other possible options are also acceptable.  the
> example/documentation of cython i have seen till now, they talk about
> calling c functions from c library (.so file).
>
> can you please point me to a documentation/source code which talks about
> how to call c functions from c-executable?
>

Once it's an executable, you can't call functions in it. So your
options are either:

1) Go back to the source code and compile it differently. Use it as a
library instead of an executable.

2) Run the program with parameters that make it do what you want, and
then get a result back via stdout.

The first one is almost certainly easier. You'll need to figure out
how the project is structured, and probably learn a bit about the
process of compiling C code to either an executable or a library.

ChrisA

From jeff.gitlin at gmail.com  Wed Dec 25 12:15:21 2019
From: jeff.gitlin at gmail.com (Jeff Gitlin)
Date: Wed, 25 Dec 2019 09:15:21 -0800 (PST)
Subject: Python 3.8 and :=
In-Reply-To: <mailman.234.1577283764.11485.python-list@python.org>
References: <c6629df4-46e7-4263-a982-68417dc5211a@googlegroups.com>
 <CAPTjJmrmPdddXz6wHmX-oXcrbrUCWxSWy3whvnLhnjaYL-xQyQ@mail.gmail.com>
 <mailman.234.1577283764.11485.python-list@python.org>
Message-ID: <58fde3ea-ff62-47eb-bbe9-3ad9f6df9ada@googlegroups.com>

On Wednesday, December 25, 2019 at 9:22:56 AM UTC-5, Chris Angelico wrote:
> On Thu, Dec 26, 2019 at 1:16 AM Jeff Gitlin <jeff.gitlin at gmail.com> wrote:
> >
> > With the new operator := in Python 3.8
> > that allows you to do things like
> >
> > if ( x := f() ) == 1:
> >
> > Is there any reason to use just the assignment operator?
> 
> I don't understand the question. Are you asking why the normal "="
> operator should be used? For starters, "=" is far more flexible than
> ":=" in terms of what it can assign to.
> 
> ChrisA

Chris,
Can you give me a few examples of what you can do with? = and not do with the new := ?? ?
Thanks
? ? Jeff

From rosuav at gmail.com  Wed Dec 25 12:51:44 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 26 Dec 2019 04:51:44 +1100
Subject: Python 3.8 and :=
In-Reply-To: <58fde3ea-ff62-47eb-bbe9-3ad9f6df9ada@googlegroups.com>
References: <c6629df4-46e7-4263-a982-68417dc5211a@googlegroups.com>
 <CAPTjJmrmPdddXz6wHmX-oXcrbrUCWxSWy3whvnLhnjaYL-xQyQ@mail.gmail.com>
 <mailman.234.1577283764.11485.python-list@python.org>
 <58fde3ea-ff62-47eb-bbe9-3ad9f6df9ada@googlegroups.com>
Message-ID: <CAPTjJmqcNeC9dEo=0M6LX3T9CSM=A16ZSQcuoZOQ4905gMFGMw@mail.gmail.com>

On Thu, Dec 26, 2019 at 4:21 AM Jeff Gitlin <jeff.gitlin at gmail.com> wrote:
>
> On Wednesday, December 25, 2019 at 9:22:56 AM UTC-5, Chris Angelico wrote:
> > On Thu, Dec 26, 2019 at 1:16 AM Jeff Gitlin <jeff.gitlin at gmail.com> wrote:
> > >
> > > With the new operator := in Python 3.8
> > > that allows you to do things like
> > >
> > > if ( x := f() ) == 1:
> > >
> > > Is there any reason to use just the assignment operator?
> >
> > I don't understand the question. Are you asking why the normal "="
> > operator should be used? For starters, "=" is far more flexible than
> > ":=" in terms of what it can assign to.
> >
> > ChrisA
>
> Chris,
> Can you give me a few examples of what you can do with  = and not do with the new :=    ?

https://www.python.org/dev/peps/pep-0572/#differences-between-assignment-expressions-and-assignment-statements

ChrisA

From jeff.gitlin at gmail.com  Wed Dec 25 13:02:21 2019
From: jeff.gitlin at gmail.com (Jeff Gitlin)
Date: Wed, 25 Dec 2019 10:02:21 -0800 (PST)
Subject: Python 3.8 and :=
In-Reply-To: <c6629df4-46e7-4263-a982-68417dc5211a@googlegroups.com>
References: <c6629df4-46e7-4263-a982-68417dc5211a@googlegroups.com>
Message-ID: <759d915f-d3fd-4a34-a919-b72ecaa5e648@googlegroups.com>

On Wednesday, December 25, 2019 at 9:13:09 AM UTC-5, Jeff Gitlin wrote:
> With the new operator := in Python 3.8
> that allows you to do things like
> 
> if ( x := f() ) == 1:
> 
> Is there any reason to use just the assignment operator?

???????..
Thanks. That web page is exactly what I was looking for!

From soyeomul at doraji.xyz  Thu Dec 26 06:11:17 2019
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Thu, 26 Dec 2019 20:11:17 +0900
Subject: [Q] __init__ in class
Message-ID: <yw87vqhgh2.fsf@vul6.birch.chromebook>

in making class, why we should set "__init__"? so non-init class is
useless? actually i did fail to understand __init__'s meaning. what is
role of __init__ in class.

sincerely, from python beginner.

-- 
^????? _????_ ?????_^))//

From PythonList at DancesWithMice.info  Thu Dec 26 13:23:12 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Fri, 27 Dec 2019 07:23:12 +1300
Subject: [Q] __init__ in class
In-Reply-To: <yw87vqhgh2.fsf@vul6.birch.chromebook>
References: <yw87vqhgh2.fsf@vul6.birch.chromebook>
Message-ID: <48230401-ef4e-3457-cb71-945ca596def5@DancesWithMice.info>

On 27/12/19 12:11 AM, ??? wrote:
> in making class, why we should set "__init__"? so non-init class is
> useless? actually i did fail to understand __init__'s meaning. what is
> role of __init__ in class.
> 
> sincerely, from python beginner.


Please be aware that there is a Python Tutor Discussion List.

If you are a beginner in Object-Oriented Programming, Wikipedia offers a 
multi-language, if dense introduction. This is complemented by their 
Class (computer programming) page.

If you are new to Python's implementation then don't go past the Python 
Tutorial (in particular Section 9).

There are plenty of web-tutorials discussion Python classes. 
HackerEarth's aligns nicely with the Wikipedia definitions (or the 
abstract terminology introduced in many ComSc texts and courses).


WebRefs:
Python Tutor: https://mail.python.org/mailman/listinfo/tutor
Object-oriented programming: 
https://en.wikipedia.org/wiki/Object-oriented_programming
Class (computer programming): 
https://en.wikipedia.org/wiki/Class_(computer_programming)
The Python Tutorial: https://docs.python.org/3/tutorial/index.html
HackerEarth: 
https://www.hackerearth.com/practice/python/object-oriented-programming/classes-and-objects-i/tutorial/
-- 
Regards =dn

From Irv at furrypants.com  Thu Dec 26 16:58:32 2019
From: Irv at furrypants.com (Irv Kalb)
Date: Thu, 26 Dec 2019 13:58:32 -0800
Subject: [Q] __init__ in class
In-Reply-To: <yw87vqhgh2.fsf@vul6.birch.chromebook>
References: <yw87vqhgh2.fsf@vul6.birch.chromebook>
Message-ID: <0A6BE303-2690-455C-8B71-964896E35A2A@furrypants.com>

> On Dec 26, 2019, at 3:11 AM, ??? <soyeomul at doraji.xyz> wrote:
> 
> in making class, why we should set "__init__"? so non-init class is
> useless? actually i did fail to understand __init__'s meaning. what is
> role of __init__ in class.
> 
> sincerely, from python beginner.
> 
> -- 
> ^????? _????_ ?????_^))//
> -- 
> https://mail.python.org/mailman/listinfo/python-list

Whenever you create object from a class, you use the name of the class in a statement like this:

myObject = MyClass()   #  "MyClass" would be the name of a class in your code

When you run a line like the one above, Python looks to see if that class has a method named __init__().  If it does, then Python calls that method of the newly created object.  In that method you typically put the initialization of any instance variables that you want to use in other methods, and include any additional code that you only want to run when an object is created from the class.  While it is not required to have an __init__() method in a  class, it is generally considered good practice to have one.  

As an example, let's say that you create a point class, where the Point has both an x and a yY value.  Your class might look like this:

class Point:
    def __init__(self, x, y):   # When you create a Point object, you must pass in a value for x and y
        self.x = x
        self.y = y

    #Then you would probably have other methods like:

    def getX(self):
        return self.x

     def getY(self):
         return self.y

     def show(self):
          print('The values of this point are:', self.x, self.y)

etc.

Given a class like that, when you create an object from the Point class, you pass in values for x and y.  The code in the __init__() method saves away those values into instance variables.  Those instance variables can be used by other methods.  In this example class, getX, getY, and show.

Here is some sample code to create two Point objects, then ask them to show their contents:

pointA = Point(10, 15)
pointB = Point(-3, 38)
pointA.show()  
printB.show()

When run, this will print:

The values of this point are: 10, 15
The values of this point are: -3, 38

Hope that gives you a start in the world of OOP.

Irv


From PythonList at DancesWithMice.info  Thu Dec 26 19:56:04 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Fri, 27 Dec 2019 13:56:04 +1300
Subject: [Q] __init__ in class
In-Reply-To: <0A6BE303-2690-455C-8B71-964896E35A2A@furrypants.com>
References: <yw87vqhgh2.fsf@vul6.birch.chromebook>
 <0A6BE303-2690-455C-8B71-964896E35A2A@furrypants.com>
Message-ID: <d20aa4c7-8f1d-d381-261c-6ea8a11458e2@DancesWithMice.info>

On 27/12/19 10:58 AM, Irv Kalb wrote:
>> On Dec 26, 2019, at 3:11 AM, ??? <soyeomul at doraji.xyz> wrote:
>> in making class, why we should set "__init__"? so non-init class is
>> useless? actually i did fail to understand __init__'s meaning. what is
>> role of __init__ in class.

...

> As an example, let's say that you create a point class, where the Point has both an x and a yY value.  Your class might look like this:
> 
> class Point:
>      def __init__(self, x, y):   # When you create a Point object, you must pass in a value for x and y
>          self.x = x
>          self.y = y
> 
>      #Then you would probably have other methods like:
> 
>      def getX(self):
>          return self.x
> 
>       def getY(self):
>           return self.y
> 
>       def show(self):
>            print('The values of this point are:', self.x, self.y)
> 
> etc.
> 
> Given a class like that, when you create an object from the Point class, you pass in values for x and y.  The code in the __init__() method saves away those values into instance variables.  Those instance variables can be used by other methods.  In this example class, getX, getY, and show.
> 
> Here is some sample code to create two Point objects, then ask them to show their contents:
> 
> pointA = Point(10, 15)
> pointB = Point(-3, 38)
> pointA.show()
> printB.show()


Is this a/the pythonic way to access attributes?

It appears Java-like, or some other language transliterated into Python. 
Further, the naming convention suffers similar heritage.


What was not shown is that in order to access the values of Point()'s x 
and y attribute, the following is needed:

x_value = pointA.getX()

which in and of itself is not too bad, if wordy and ugly; but what 
happens when we perform a vector addition?

point_a_plus_b = Point( pointA.getX() + pointB.getX(),
			pointA.getY() + pointB.getY()
			)

Which is still not too shocking, but imagine a more complicated 
calculation, eg widen to include z- and w- dimensions or consider 
n-dimensional matrices...
(there are optimised tools for such, but continuing with the post-er's 
example)


Rather than a 'closed' view of objects ("encapsulation") Python 
maintains a more 'open' approach. "Getter" and "Setter" functions are 
put-aside in favor of direct-access:

value = instance.attribute	# 'getter'
instance.attribute = value  	# 'setter'
del instance.attribute		# 'destructor'


Now, imagine a class with ten attributes (for example) in Java (and 
similar). Before use, we would have to write ten getter-functions, ten 
setter-functions, and maybe (just to be 'complete') ten 
destructor-functions. Whereas in Python, nothing!

Whatever you do, don't mention this to such coder-colleagues! We are 
able to code so much faster than they, and are considerably less 
restricted by our choice of language, thus promoting numerous efficacies!


There are times when we can't allow 'just any value' to be applied to an 
attribute. For example, should a person's birth-date be recorded as 
ten-years from now? So, when we need to check or 'massage' data before 
use/recording, we might turn the attribute into a "property". This does 
give us the Python (and pythonic) version of getters-and-setters.

Similarly, there are tactics which do enable data-hiding (or strict 
"encapsulation") for those occasions when it is needed...but now we're 
likely way beyond the OP's needs!


WebRefs: (additional to those previously-posted in this thread)
https://www.python-course.eu/python3_properties.php
https://www.python.org/dev/peps/pep-0008/
-- 
Regards =dn

From soyeomul at doraji.xyz  Thu Dec 26 21:53:41 2019
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Fri, 27 Dec 2019 11:53:41 +0900
Subject: [Q] __init__ in class
References: <yw87vqhgh2.fsf@vul6.birch.chromebook>
 <class-definition-20191226132818@ram.dialup.fu-berlin.de>
Message-ID: <yw87uiqayj.fsf@vukm.birch.chromebook>

Hellow Stefan^^^

>   The class definition depends on the requirement
>   specification for the class.
>
>   ??? ??? ???? ?? ?? ??? ?? ????.

Now i got it, understood, thanks a lot^^^

Sincerely,

-- 
^????? _????_ ?????_^))//

From soyeomul at doraji.xyz  Thu Dec 26 21:56:19 2019
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Fri, 27 Dec 2019 11:56:19 +0900
Subject: [Q] __init__ in class
References: <yw87vqhgh2.fsf@vul6.birch.chromebook>
 <48230401-ef4e-3457-cb71-945ca596def5@DancesWithMice.info>
 <mailman.238.1577384613.11485.python-list@python.org>
Message-ID: <yw87uikhpt.fsf@vulk.birch.chromebook>

Hellow DL^^^

> Please be aware that there is a Python Tutor Discussion List.

Thanks for advice^^^

Sincerely,

-- 
^????? _????_ ?????_^))//

From soyeomul at doraji.xyz  Thu Dec 26 21:59:33 2019
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Fri, 27 Dec 2019 11:59:33 +0900
Subject: [Q] __init__ in class
References: <yw87vqhgh2.fsf@vul6.birch.chromebook>
 <0A6BE303-2690-455C-8B71-964896E35A2A@furrypants.com>
 <mailman.239.1577397659.11485.python-list@python.org>
Message-ID: <yw87uigikm.fsf@vukm.birch.chromebook>

Irv Kalb <Irv at furrypants.com> writes:

> myObject = MyClass()   #  "MyClass" would be the name of a class in your code
>
> When you run a line like the one above, Python looks to see if that
> class has a method named __init__().  If it does, then Python calls
> that method of the newly created object.

Very clean comments, thank you Irv^^^ INDEED.

Sincerely,

-- 
^????? _????_ ?????_^))//

From vid_tech at yahoo.com  Fri Dec 27 01:29:39 2019
From: vid_tech at yahoo.com (Kishor Soni)
Date: Fri, 27 Dec 2019 06:29:39 +0000 (UTC)
Subject: Error in python installation
References: <66413736.2558666.1577428179364.ref@mail.yahoo.com>
Message-ID: <66413736.2558666.1577428179364@mail.yahoo.com>

Hello
I have Intel DH61 series mother board, with Windows7 64bit + SP1 + some debugging components ( as shown in microsoft website, as service pack for W7)
however when I try to install current version of python, it displays error.
See the screenshot attached herewith.
(board configuration displays in background window)

Kishor Soni,
Vid Technology,
Rajkot - Gujarat.
URL: www.vidtech.co.in,
Landline: 0281-2225527
Cell: 093757 25527

From auriocus at gmx.de  Fri Dec 27 15:59:48 2019
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Fri, 27 Dec 2019 21:59:48 +0100
Subject: scrollable Frame object
In-Reply-To: <dca222df-1722-4de6-b566-88a1417665e5@googlegroups.com>
References: <66620145-f0ec-4752-8d69-eae3474481f8@googlegroups.com>
 <qtqo67$nei$1@tota-refugium.de>
 <dca222df-1722-4de6-b566-88a1417665e5@googlegroups.com>
Message-ID: <qu5rc5$2r3$1@dont-email.me>

Hi David,

Am 24.12.19 um 13:48 schrieb david.isal2 at gmail.com:

> thank you for your answer. I downloaded and had a look at your library, it is a great solution to use a canvas-free scrollable frame. but it is in pure tcl, how do I use this with python tkinter ?

Yes, because you asked this in the Tcl/Tk newsgroup. We use Tcl directly 
here, not via Python Tkinter.

> Although my initial request is that the frame object is not scrollable by default.
> so My request for the tcl/tk developers would be, why not make the object frame scrollbale by default, in order to attach a scrollbar to it?
> I believe it is a typical need.

This may well be. For that, the developers of Tkinter (distinct from the 
developers of Tk and Tcl) have to include a scrollable frame into 
Tkinter. There is unfortunately a number of extension packages which 
exist for Tk, but which are not wrapped by a standard installatino of 
Tkinter for Python, despite them being extremely useful / not even 
possible otherwise. Among those are:

* Tablelist - a great tree and multi-column widget. Much more versatile 
then the built-in treeview
* TkDnD - native drag'n'drop support, works on all 3 OSes
* tkPath - a canvas replacement with "modern" 2D features 
(anti-aliasing, image scaling/rotation, alpha blending)
* pdf4tcl, generate PDF images from a canvas drawing
* tkTable, spreadsheet-like widget
* tktreectrl, yet another extremely powerful treeview / explorer like widget

Building support for these packages would not be that hard, but it must 
be done by the Python community.

Christian

(X-post & Fup to clp)

From jfong at ms4.hinet.net  Fri Dec 27 22:20:44 2019
From: jfong at ms4.hinet.net (jfong at ms4.hinet.net)
Date: Fri, 27 Dec 2019 19:20:44 -0800 (PST)
Subject: Does the argparse generate a wrong help message?
Message-ID: <ce3fde7a-97a5-4e16-a5c0-9d3bf03e0cb4@googlegroups.com>

The codes in test.py are:
---------
import argparse
parser = argparse.ArgumentParser()
parser.add_argument('--foo', nargs='?', help='foo help')
parser.add_argument('--goo', nargs=1, help='goo help')  
args = parser.parse_args()
print(args.foo, args.goo)
---------

But I get the following result:
---------
D:\Works\Python>py test.py -h
usage: test.py [-h] [--foo [FOO]] [--goo GOO]

optional arguments:
  -h, --help   show this help message and exit
  --foo [FOO]  foo help
  --goo GOO    goo help

D:\Works\Python>py test.py --foo 1 --goo 2
1 ['2']
---------

It seems to me that the help message should be:
usage: test.py [-h] [--foo FOO] [--goo [GOO]]

Do I had missed something?

--Jach

From rosuav at gmail.com  Fri Dec 27 22:30:22 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 28 Dec 2019 14:30:22 +1100
Subject: Does the argparse generate a wrong help message?
In-Reply-To: <ce3fde7a-97a5-4e16-a5c0-9d3bf03e0cb4@googlegroups.com>
References: <ce3fde7a-97a5-4e16-a5c0-9d3bf03e0cb4@googlegroups.com>
Message-ID: <CAPTjJmoxMhAhB7Kxe3eUkv3PBLmn+cjP+e9+Q+RbJ9AvOYuz-A@mail.gmail.com>

On Sat, Dec 28, 2019 at 2:26 PM <jfong at ms4.hinet.net> wrote:
>
> The codes in test.py are:
> ---------
> import argparse
> parser = argparse.ArgumentParser()
> parser.add_argument('--foo', nargs='?', help='foo help')
> parser.add_argument('--goo', nargs=1, help='goo help')
> args = parser.parse_args()
> print(args.foo, args.goo)
> ---------
>
> But I get the following result:
> ---------
> D:\Works\Python>py test.py -h
> usage: test.py [-h] [--foo [FOO]] [--goo GOO]
>
> optional arguments:
>   -h, --help   show this help message and exit
>   --foo [FOO]  foo help
>   --goo GOO    goo help
>
> D:\Works\Python>py test.py --foo 1 --goo 2
> 1 ['2']
> ---------
>
> It seems to me that the help message should be:
> usage: test.py [-h] [--foo FOO] [--goo [GOO]]
>
> Do I had missed something?
>

Can you elaborate on why you expect this? You've declared one of them
to have a single mandatory argument, and the other a single optional
argument. This corresponds to what I'm seeing.

ChrisA

From jfong at ms4.hinet.net  Fri Dec 27 23:08:16 2019
From: jfong at ms4.hinet.net (jfong at ms4.hinet.net)
Date: Fri, 27 Dec 2019 20:08:16 -0800 (PST)
Subject: Does the argparse generate a wrong help message?
In-Reply-To: <mailman.243.1577503835.11485.python-list@python.org>
References: <ce3fde7a-97a5-4e16-a5c0-9d3bf03e0cb4@googlegroups.com>
 <CAPTjJmoxMhAhB7Kxe3eUkv3PBLmn+cjP+e9+Q+RbJ9AvOYuz-A@mail.gmail.com>
 <mailman.243.1577503835.11485.python-list@python.org>
Message-ID: <63c01a3b-6e47-48e7-9405-d144371b54d6@googlegroups.com>

Chris Angelico? 2019?12?28???? UTC+8??11?30?47????
> On Sat, Dec 28, 2019 at 2:26 PM <jfong at ms4.hinet.net> wrote:
> >
> > The codes in test.py are:
> > ---------
> > import argparse
> > parser = argparse.ArgumentParser()
> > parser.add_argument('--foo', nargs='?', help='foo help')
> > parser.add_argument('--goo', nargs=1, help='goo help')
> > args = parser.parse_args()
> > print(args.foo, args.goo)
> > ---------
> >
> > But I get the following result:
> > ---------
> > D:\Works\Python>py test.py -h
> > usage: test.py [-h] [--foo [FOO]] [--goo GOO]
> >
> > optional arguments:
> >   -h, --help   show this help message and exit
> >   --foo [FOO]  foo help
> >   --goo GOO    goo help
> >
> > D:\Works\Python>py test.py --foo 1 --goo 2
> > 1 ['2']
> > ---------
> >
> > It seems to me that the help message should be:
> > usage: test.py [-h] [--foo FOO] [--goo [GOO]]
> >
> > Do I had missed something?
> >
> 
> Can you elaborate on why you expect this? You've declared one of them
> to have a single mandatory argument, and the other a single optional
> argument. This corresponds to what I'm seeing.
> 
> ChrisA

So the square bracket means optional, not list? My misunderstanding:-(

--Jach

From Richard at Damon-Family.org  Fri Dec 27 23:18:28 2019
From: Richard at Damon-Family.org (Richard Damon)
Date: Fri, 27 Dec 2019 23:18:28 -0500
Subject: Does the argparse generate a wrong help message?
In-Reply-To: <63c01a3b-6e47-48e7-9405-d144371b54d6@googlegroups.com>
References: <ce3fde7a-97a5-4e16-a5c0-9d3bf03e0cb4@googlegroups.com>
 <CAPTjJmoxMhAhB7Kxe3eUkv3PBLmn+cjP+e9+Q+RbJ9AvOYuz-A@mail.gmail.com>
 <mailman.243.1577503835.11485.python-list@python.org>
 <63c01a3b-6e47-48e7-9405-d144371b54d6@googlegroups.com>
Message-ID: <dd9db310-96e0-4842-ef4f-972ba8d589b4@Damon-Family.org>

On 12/27/19 11:08 PM, jfong at ms4.hinet.net wrote:
> Chris Angelico? 2019?12?28???? UTC+8??11?30?47????
>> On Sat, Dec 28, 2019 at 2:26 PM <jfong at ms4.hinet.net> wrote:
>>> The codes in test.py are:
>>> ---------
>>> import argparse
>>> parser = argparse.ArgumentParser()
>>> parser.add_argument('--foo', nargs='?', help='foo help')
>>> parser.add_argument('--goo', nargs=1, help='goo help')
>>> args = parser.parse_args()
>>> print(args.foo, args.goo)
>>> ---------
>>>
>>> But I get the following result:
>>> ---------
>>> D:\Works\Python>py test.py -h
>>> usage: test.py [-h] [--foo [FOO]] [--goo GOO]
>>>
>>> optional arguments:
>>>    -h, --help   show this help message and exit
>>>    --foo [FOO]  foo help
>>>    --goo GOO    goo help
>>>
>>> D:\Works\Python>py test.py --foo 1 --goo 2
>>> 1 ['2']
>>> ---------
>>>
>>> It seems to me that the help message should be:
>>> usage: test.py [-h] [--foo FOO] [--goo [GOO]]
>>>
>>> Do I had missed something?
>>>
>> Can you elaborate on why you expect this? You've declared one of them
>> to have a single mandatory argument, and the other a single optional
>> argument. This corresponds to what I'm seeing.
>>
>> ChrisA
> So the square bracket means optional, not list? My misunderstanding:-(
>
> --Jach

Yes, the normal notation is [x] indicates that x is optionial

-- 
Richard Damon


From nt_mahmood at yahoo.com  Sat Dec 28 00:29:53 2019
From: nt_mahmood at yahoo.com (Mahmood Naderan)
Date: Sat, 28 Dec 2019 08:59:53 +0330
Subject: Grepping words for match in a file
Message-ID: <47lC1y0nHDznXmY@mail.python.org>

Hi
I have some lines in a text file like
ADD R1, R2
ADD3 R4, R5, R6
ADD.MOV R1, R2, [0x10]
If I grep words with this code
for line in fp:
    if my_word in line:
Then if my_word is "ADD", I get 3 matches. However, if I grep word with this code
for line in fp:
    for word in line.split():    
        if my_word == word:
Then I get only one match which is ADD R1. R2.
Actually I want to get 2 matches. ADD R1, R2 and ADD.MOV R1, R2, [0x10] because these two lines are actually "ADD" instructions. However, "ADD3" is something else.
How can I fix the code for that purpose?
--
Regards,
Mahmood

From smitla at yandex.com  Sat Dec 28 05:52:54 2019
From: smitla at yandex.com (L A Smit)
Date: Sat, 28 Dec 2019 12:52:54 +0200
Subject: Front end
Message-ID: <fff45e00-c1c7-ad61-52e8-0fc9fb5b04a1@yandex.com>

Hi

Don't know if this is the correct subject but i want a program like an 
invoice, You make an invoice and save it and the next one is ready to 
use. I am completely new to programming and want this program for myself.


I want to use python to do it. Have already build the program but don't 
know how to put it in usable format. I hope you understand what i mean.

Ex: Input.

Quote Nr:

Client:

Product:

Then there will be costs and in the end a cost per product.

In the end a save button to save quote with input from line 1 and 2.

Then the template is ready for next input.

I understand that there is probably hundreds of these programs but to 
teach myself i want to wright my own program and then i can update it 
when needed.



Thx


L Smit


From jsf80238 at gmail.com  Sat Dec 28 11:05:33 2019
From: jsf80238 at gmail.com (Jason Friedman)
Date: Sat, 28 Dec 2019 09:05:33 -0700
Subject: Grepping words for match in a file
In-Reply-To: <47lC1y0nHDznXmY@mail.python.org>
References: <47lC1y0nHDznXmY@mail.python.org>
Message-ID: <CANy1k1hVkBCbt9EpqO55e5K-4ACgHnBVoGps-MfUYxXycCEc3g@mail.gmail.com>

>
>
> I have some lines in a text file like
> ADD R1, R2
> ADD3 R4, R5, R6
> ADD.MOV R1, R2, [0x10]
> ....

Actually I want to get 2 matches. ADD R1, R2 and ADD.MOV R1, R2, [0x10]
> because these two lines are actually "ADD" instructions. However, "ADD3" is
> something else.
>

>>> s = """ADD R1, R2
... ADD3 R4, R5, R6
... ADD.MOV R1, R2, [0x10]"""
>>> import re
>>> pattern = re.compile(r"^ADD\b.+")
>>> for line in s.splitlines():
...     if re.search(pattern, line):
...         print(line)
...
ADD R1, R2
ADD.MOV R1, R2, [0x10]

From 2QdxY4RzWzUUiLuE at potatochowder.com  Sat Dec 28 11:05:57 2019
From: 2QdxY4RzWzUUiLuE at potatochowder.com (Dan Sommers)
Date: Sat, 28 Dec 2019 11:05:57 -0500
Subject: Grepping words for match in a file
In-Reply-To: <47lC1y0nHDznXmY@mail.python.org>
References: <47lC1y0nHDznXmY@mail.python.org>
Message-ID: <64a7f92e-3899-aa9e-ec5a-068c0f196994@potatochowder.com>

On 12/28/19 12:29 AM, Mahmood Naderan via Python-list wrote:
> Hi
> I have some lines in a text file like
> ADD R1, R2
> ADD3 R4, R5, R6
> ADD.MOV R1, R2, [0x10]
> If I grep words with this code
> for line in fp:
>      if my_word in line:
> Then if my_word is "ADD", I get 3 matches. However, if I grep word with this code
> for line in fp:
>      for word in line.split():
>          if my_word == word:
> Then I get only one match which is ADD R1. R2.
> Actually I want to get 2 matches. ADD R1, R2 and ADD.MOV R1, R2, [0x10] because these two lines are actually "ADD" instructions. However, "ADD3" is something else.
> How can I fix the code for that purpose?

Grep's "words" are different from what line.split() returns:

     >>> 'ADD.MOV R1, R2, [0x10]'.split()
     ['ADD.MOV', 'R1,', 'R2,', '[0x10]']

If you want to match "ADD" instructions, you'll have to use
word.startswith or some other method to separate the "ADD"
from the ".MOV."

Dan

From 2QdxY4RzWzUUiLuE at potatochowder.com  Sat Dec 28 11:14:14 2019
From: 2QdxY4RzWzUUiLuE at potatochowder.com (Dan Sommers)
Date: Sat, 28 Dec 2019 11:14:14 -0500
Subject: Grepping words for match in a file
In-Reply-To: <47lC1y0nHDznXmY@mail.python.org>
References: <47lC1y0nHDznXmY@mail.python.org>
Message-ID: <cef1dd99-898f-5aff-eba2-391509c3be45@potatochowder.com>

On 12/28/19 12:29 AM, Mahmood Naderan via Python-list wrote:
> Hi
> I have some lines in a text file like
> ADD R1, R2
> ADD3 R4, R5, R6
> ADD.MOV R1, R2, [0x10]
> If I grep words with this code
> for line in fp:
>      if my_word in line:
> Then if my_word is "ADD", I get 3 matches. However, if I grep word with this code
> for line in fp:
>      for word in line.split():
>          if my_word == word:
> Then I get only one match which is ADD R1. R2.
> Actually I want to get 2 matches. ADD R1, R2 and ADD.MOV R1, R2, [0x10] because these two lines are actually "ADD" instructions. However, "ADD3" is something else.
> How can I fix the code for that purpose?
(1) word.startswith() won't solve your problem.  Expliticly
checking the character after the second "D" would.  You'll
have to determine which characters are or aren't part of
the instruction.  A complete solution probably depends on
what else you are or will look for in the future.

(2) That looks like a programming language (88000? POWER?).
Watch out for comments containing the word ADD, too.

From tjreedy at udel.edu  Sat Dec 28 15:48:23 2019
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 28 Dec 2019 15:48:23 -0500
Subject: Front end
In-Reply-To: <fff45e00-c1c7-ad61-52e8-0fc9fb5b04a1@yandex.com>
References: <fff45e00-c1c7-ad61-52e8-0fc9fb5b04a1@yandex.com>
Message-ID: <qu8f2o$56if$1@blaine.gmane.org>

On 12/28/2019 5:52 AM, L A Smit wrote:
> Hi
> 
> Don't know if this is the correct subject but i want a program like an 
> invoice, You make an invoice and save it and the next one is ready to 
> use. I am completely new to programming and want this program for myself.
> 
> 
> I want to use python to do it. Have already build the program but don't 
> know how to put it in usable format. I hope you understand what i mean.
> 
> Ex: Input.
> 
> Quote Nr:
> 
> Client:
> 
> Product:
> 
> Then there will be costs and in the end a cost per product.
> 
> In the end a save button to save quote with input from line 1 and 2.
> 
> Then the template is ready for next input.

Start with the simplest thing that works, which would be something like:

quotenum = input('Quote Nr: ')
client = input('Client: ')
...

invoice =  f"""\
Quote Nr: {quotenum}
Client: {client}
...
"""
with open('quotenum'+'client', mode='w') as f:
     f.write(invoice)

Then do something fancier if you want.
1. GUI form with tkinter.
2. Generate input statements or GUI form from the invoice template string.

-- 
Terry Jan Reedy


From PythonList at DancesWithMice.info  Sat Dec 28 17:35:57 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sun, 29 Dec 2019 11:35:57 +1300
Subject: Friday Finking: Source code organisation
Message-ID: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>

Is it helpful to, and thus, do you have a style/convention for ordering 
the methods within each class in your code?


Python's "honking great idea" of namespaces enables us to gather 
functions/methods under a single name-umbrella, thereby avoiding 
name-clashes/name-space 'pollution'. [Oh yeah!]

Thus, if we collect a bunch of module-functions, we refer to them 
collectively by module-name/import-name, eg

	import collected_functions_module as cfm
	...
	cfm.make_it_happen()
	cfm.make_it_better()

Similarly, methods within a class may be accessed either as 
class-methods, or through instances (as required).
[am assuming no code example necessary]

A major difference however, is that if our mythical collection of 
module-functions has an internal-reference, eg b() requires a(), then 
function a() MUST exist, ie be defined, 'before' function b(). Whereas a 
class's methods may be defined in any (complete) sequence.

In the ?good? old days, eg COBOL - or more logically: when source code 
was most-usually viewed as printouts and the prevailing coding-style was 
for largely monolithic program(me)s; we would often number subroutines 
(initially in tens) to better navigate long listings of source-code, and 
more easily locate the subroutine's code from some reference-point. In 
data-terms, we might even create an abbreviation of a record's name and 
use that as an hyphenated-prefix for all of its data-fields' names.

Today, such artifice is unnecessary, given that code-editors (normally) 
offer one-click access from reference to source - even spanning multiple 
Python modules. [another, "oh yeah"!]


So, do you have an orderly method [hah!] for presenting/locating 
class-methods (and module-functions) within your code?

- why bother, the editor does 'the heavy lifting'
- dunders to the fore
- alphanumeric sequence by name
- order of appearance/use in 'mainline code'
- as they sprang to mind during TDD-creation
- most-used first, least-used last
- my code 'at the top', their stuff later...
- names of Monty Python characters by TV appearance date
or,
- some combination of ideas
and,
- how do you vary the above when dependencies intrude?

-- 
Regards,
=dn

From rosuav at gmail.com  Sat Dec 28 17:49:06 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 29 Dec 2019 09:49:06 +1100
Subject: Friday Finking: Source code organisation
In-Reply-To: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
Message-ID: <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>

On Sun, Dec 29, 2019 at 9:37 AM DL Neil via Python-list
<python-list at python.org> wrote:
>
> Is it helpful to, and thus, do you have a style/convention for ordering
> the methods within each class in your code?
>
> A major difference however, is that if our mythical collection of
> module-functions has an internal-reference, eg b() requires a(), then
> function a() MUST exist, ie be defined, 'before' function b(). Whereas a
> class's methods may be defined in any (complete) sequence.
>
> So, do you have an orderly method [hah!] for presenting/locating
> class-methods (and module-functions) within your code?
>
> - why bother, the editor does 'the heavy lifting'
> - dunders to the fore
> - alphanumeric sequence by name
> - order of appearance/use in 'mainline code'
> - as they sprang to mind during TDD-creation
> - most-used first, least-used last
> - my code 'at the top', their stuff later...
> - names of Monty Python characters by TV appearance date
> or,
> - some combination of ideas
> and,
> - how do you vary the above when dependencies intrude?
>

"Define before use" is a broad principle that I try to follow, even
when the code itself doesn't mandate this. This generally means that
"if name is main" is the very last thing in the file, and if there's a
main() function or equivalent, that's usually just before that. Any
metaprogramming goes right at the top; sometimes this is mandated (if
I write a decorator function, it has to be above the functions it's
decorating), but even if it's not, metaprogramming goes before the
mainline.

Other than that, I don't have any consistent logic other than a loose
idea of trying to keep related things together.

ChrisA

From Richard at Damon-Family.org  Sat Dec 28 18:39:42 2019
From: Richard at Damon-Family.org (Richard Damon)
Date: Sat, 28 Dec 2019 18:39:42 -0500
Subject: Friday Finking: Source code organisation
In-Reply-To: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
Message-ID: <3d4e9955-f83e-4641-9f77-1fcab809df4f@Damon-Family.org>

On 12/28/19 5:35 PM, DL Neil via Python-list wrote:
> Is it helpful to, and thus, do you have a style/convention for 
> ordering the methods within each class in your code?
>
>
> Python's "honking great idea" of namespaces enables us to gather 
> functions/methods under a single name-umbrella, thereby avoiding 
> name-clashes/name-space 'pollution'. [Oh yeah!]
>
> Thus, if we collect a bunch of module-functions, we refer to them 
> collectively by module-name/import-name, eg
>
> ????import collected_functions_module as cfm
> ????...
> ????cfm.make_it_happen()
> ????cfm.make_it_better()
>
> Similarly, methods within a class may be accessed either as 
> class-methods, or through instances (as required).
> [am assuming no code example necessary]
>
> A major difference however, is that if our mythical collection of 
> module-functions has an internal-reference, eg b() requires a(), then 
> function a() MUST exist, ie be defined, 'before' function b(). Whereas 
> a class's methods may be defined in any (complete) sequence. 

If module function b calls function a in the same module, then a has to 
exist when b is CALLED, not before it is defined. Thus it is very 
possible to get a multi-function recursion where b() calls a() which 
then calls b(). (The existence of items mentioned within a function are 
looked up until that statement as actually executed)

as an example, in a module:

def b():

 ? a()

def a():

 ? pass

is perfectly valid.

Modules are a bit different, if module b needs resources from module a, 
it needs to import module a before it can use them. If module a also 
needs resources from module b, and imports it, then stuff from b might 
not be available while doing the running of module a that is defining 
the items in a.

-- 
Richard Damon


From greg.ewing at canterbury.ac.nz  Sat Dec 28 18:42:37 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Sun, 29 Dec 2019 12:42:37 +1300
Subject: Friday Finking: Source code organisation
In-Reply-To: <mailman.252.1577572577.11485.python-list@python.org>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <mailman.252.1577572577.11485.python-list@python.org>
Message-ID: <h6q7jgF2sp6U1@mid.individual.net>

On 29/12/19 11:35 am, DL Neil wrote:
> if our mythical collection of 
> module-functions has an internal-reference, eg b() requires a(), then 
> function a() MUST exist, ie be defined, 'before' function b().

Not true in Python -- a() must exist by the time b() is run,
but they can be written in the file in either order,

-- 
Greg

From greg.ewing at canterbury.ac.nz  Sat Dec 28 18:52:54 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Sun, 29 Dec 2019 12:52:54 +1300
Subject: Friday Finking: Source code organisation
In-Reply-To: <mailman.253.1577573395.11485.python-list@python.org>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <mailman.253.1577573395.11485.python-list@python.org>
Message-ID: <h6q86pF3064U1@mid.individual.net>

On 29/12/19 11:49 am, Chris Angelico wrote:
> "Define before use" is a broad principle that I try to follow, even
> when the code itself doesn't mandate this.

I tend to do this too, although it's probably just a habit
carried over from languages such as Pascal and C where you
have to go out of your way to get things in a different
order.

But strangely, I tend to do the opposite for methods of
a class. I don't really know why. My instinctive idea of
the "right" ordering just seems to flip over somehow
between modules and classes.

-- 
Greg

From rosuav at gmail.com  Sat Dec 28 20:12:19 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 29 Dec 2019 12:12:19 +1100
Subject: Friday Finking: Source code organisation
In-Reply-To: <h6q86pF3064U1@mid.individual.net>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <mailman.253.1577573395.11485.python-list@python.org>
 <h6q86pF3064U1@mid.individual.net>
Message-ID: <CAPTjJmqmO0gGu=FnTPRYvi3p5+0YDZUoqq6nJ+Wyttfn67Fpew@mail.gmail.com>

On Sun, Dec 29, 2019 at 10:56 AM Greg Ewing <greg.ewing at canterbury.ac.nz> wrote:
>
> On 29/12/19 11:49 am, Chris Angelico wrote:
> > "Define before use" is a broad principle that I try to follow, even
> > when the code itself doesn't mandate this.
>
> I tend to do this too, although it's probably just a habit
> carried over from languages such as Pascal and C where you
> have to go out of your way to get things in a different
> order.

IMO it makes the code easier to navigate even when it's not strictly
necessary. As others have said, Python mandates that the functions be
defined before they're CALLED, but I find that it's worth being
stricter. As a general rule, any global name in my code (that includes
constants, module-level functions, etc, etc) will have its definition
as the textually-first instance of that name. Or, at worst, the first
instance will be a comment immediately above the definition.

> But strangely, I tend to do the opposite for methods of
> a class. I don't really know why. My instinctive idea of
> the "right" ordering just seems to flip over somehow
> between modules and classes.

That's curious. I have a similar sort of inversion in that __init__ is
usually going to be up the top (even though main() would be at the
bottom), although not a complete inversion: anything that __init__
calls will still go above it.

ChrisA

From 2QdxY4RzWzUUiLuE at potatochowder.com  Sat Dec 28 20:13:27 2019
From: 2QdxY4RzWzUUiLuE at potatochowder.com (Dan Sommers)
Date: Sat, 28 Dec 2019 20:13:27 -0500
Subject: Friday Finking: Source code organisation
In-Reply-To: <h6q86pF3064U1@mid.individual.net>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <mailman.253.1577573395.11485.python-list@python.org>
 <h6q86pF3064U1@mid.individual.net>
Message-ID: <62196530-433e-5414-7262-1398c72465e8@potatochowder.com>

On 12/28/19 6:52 PM, Greg Ewing wrote:

 > On 29/12/19 11:49 am, Chris Angelico wrote:

 >> "Define before use" is a broad principle that I try to follow, even
 >> when the code itself doesn't mandate this.

 > But strangely, I tend to do the opposite for methods of a class. I
 > don't really know why. My instinctive idea of the "right" ordering
 > just seems to flip over somehow between modules and classes.

Me, too.  :-/  Could be one of two reasons:

(1) putting the public API at the top and pushing the internal/helper
functions towards the bottom (whether program, library, or class); or

(2) writing too much FORTRAN and/or BASIC early on, where execution
begins at the top, whether you want it to or not

Who puts a class's __init__ function anywhere except the very top of a
class definition (doc strings and class attributes that aren't "def"ed
notwithstanding), even when it calls some other method in the class?

Dan

From python.list at tim.thechases.com  Sat Dec 28 20:19:04 2019
From: python.list at tim.thechases.com (Tim Chase)
Date: Sat, 28 Dec 2019 19:19:04 -0600
Subject: Friday Finking: Source code organisation
In-Reply-To: <h6q86pF3064U1@mid.individual.net>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <mailman.253.1577573395.11485.python-list@python.org>
 <h6q86pF3064U1@mid.individual.net>
Message-ID: <20191228191904.5327f8c5@bigbox.attlocal.net>

On 2019-12-29 12:52, Greg Ewing wrote:
> On 29/12/19 11:49 am, Chris Angelico wrote:
> > "Define before use" is a broad principle that I try to follow,
> > even when the code itself doesn't mandate this.  
> 
> I tend to do this too, although it's probably just a habit
> carried over from languages such as Pascal and C where you
> have to go out of your way to get things in a different
> order.

Apparently I'm not alone in my Pascal/C-derived habits of
define-before-use.

Inside a class, I tend to roughly follow

  __new__ (if present)
  __init__
  other dunder methods
  subsequent methods alphabetically

-tkc




From PythonList at DancesWithMice.info  Sat Dec 28 21:32:18 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sun, 29 Dec 2019 15:32:18 +1300
Subject: Friday Finking: Source code organisation
In-Reply-To: <CAPTjJmqmO0gGu=FnTPRYvi3p5+0YDZUoqq6nJ+Wyttfn67Fpew@mail.gmail.com>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <mailman.253.1577573395.11485.python-list@python.org>
 <h6q86pF3064U1@mid.individual.net>
 <CAPTjJmqmO0gGu=FnTPRYvi3p5+0YDZUoqq6nJ+Wyttfn67Fpew@mail.gmail.com>
Message-ID: <88ce9ccc-cb4f-b081-d536-649745b6b2a3@DancesWithMice.info>

>>> "Define before use" is a broad principle that I try to follow, even
>>> when the code itself doesn't mandate this.
> 
> IMO it makes the code easier to navigate even when it's not strictly
> necessary. As others have said, Python mandates that the functions be
> defined before they're CALLED, but I find that it's worth being
> stricter. As a general rule, any global name in my code (that includes
> constants, module-level functions, etc, etc) will have its definition
> as the textually-first instance of that name. Or, at worst, the first
> instance will be a comment immediately above the definition.

('Anonymised' because this is not 'aimed' at any particular individual)


I was somewhat amused at being 'corrected' in the "defined" cf "called" 
discussion. The 'corrections' are more precise. However such 
distinctions are machine-related, ie how does the Python interpreter behave?


The central topic of this (ideally, thought-provoking) discussion, is on 
the person (not the machine). Yes, the author. Although, if you 
subscribe to the philosophy that program(me)s should be written with 
human-readers in-mind, then the likes of "beauty is in the eye of the 
beholder" and "readability counts", apply!

Various 'gurus', probably even before the Agile/Gang-of-Four/OOP, have 
talked of code craftsmanship having a number of characteristics. One of 
which is that *my* code should appear pretty-much as *you* expect the 
solution. When we were asked to discuss this, over-the-teacups (on 
Friday, hence the "FF" moniker) the young fellow's question was phrased 
"what do you guys expect [from me]".
(yes, he was quoting/abstracting from 'Uncle Bob' and "Clean Code" 
[Prentice-Hall, 2009]).

We have a number of 'what do you expect'-s in Python. For example, there 
is no "law" saying that we must use "self" within classes. Other 
languages use similar but alternate terminology, eg "this". I could 
decide to use "dn_was_here" and the interpreter will be perfectly happy 
- but because you don't expect it and would be made to (unnecessarily) 
comprehend, I doubt it would promote our friendship/mutual-respect!

So, do you hold any 'expectation' relating to the organisation of class 
methods?
-- 
Regards =dn

From PythonList at DancesWithMice.info  Sat Dec 28 21:43:46 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sun, 29 Dec 2019 15:43:46 +1300
Subject: Friday Finking: Source code organisation
In-Reply-To: <20191228191904.5327f8c5@bigbox.attlocal.net>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <mailman.253.1577573395.11485.python-list@python.org>
 <h6q86pF3064U1@mid.individual.net>
 <20191228191904.5327f8c5@bigbox.attlocal.net>
Message-ID: <9d3049aa-0308-30d6-6aa1-648b50ab640c@DancesWithMice.info>

On 29/12/19 2:19 PM, Tim Chase wrote:
> On 2019-12-29 12:52, Greg Ewing wrote:
>> I tend to do this too, although it's probably just a habit
>> carried over from languages such as Pascal and C where you
>> have to go out of your way to get things in a different
>> order.
> 
> Apparently I'm not alone in my Pascal/C-derived habits of
> define-before-use.

I didn't expect to be the only one who would bring 'prior experience' 
into it...


> Inside a class, I tend to roughly follow
>    __new__ (if present)
>    __init__
>    other dunder methods
>    subsequent methods alphabetically

+1

Should __new__() and __init__() break with convention because its/their 
method/function signature is (really) part of the class's signature, and 
thus there's a need for proximity?
(aka is "expected")
-- 
Regards =dn

From PythonList at DancesWithMice.info  Sat Dec 28 21:54:22 2019
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sun, 29 Dec 2019 15:54:22 +1300
Subject: Grepping words for match in a file
In-Reply-To: <cef1dd99-898f-5aff-eba2-391509c3be45@potatochowder.com>
References: <47lC1y0nHDznXmY@mail.python.org>
 <cef1dd99-898f-5aff-eba2-391509c3be45@potatochowder.com>
Message-ID: <68f01e33-ec46-4eb1-7ad5-46847cea5760@DancesWithMice.info>

On 29/12/19 5:14 AM, Dan Sommers wrote:
> On 12/28/19 12:29 AM, Mahmood Naderan via Python-list wrote:
>> Hi
>> I have some lines in a text file like
>> ADD R1, R2
>> ADD3 R4, R5, R6
>> ADD.MOV R1, R2, [0x10]
>> If I grep words with this code
>> for line in fp:
>> ???? if my_word in line:
>> Then if my_word is "ADD", I get 3 matches. However, if I grep word 
>> with this code
>> for line in fp:
>> ???? for word in line.split():
>> ???????? if my_word == word:
>> Then I get only one match which is ADD R1. R2.
>> Actually I want to get 2 matches. ADD R1, R2 and ADD.MOV R1, R2, 
>> [0x10] because these two lines are actually "ADD" instructions. 
>> However, "ADD3" is something else.
>> How can I fix the code for that purpose?
> (1) word.startswith() won't solve your problem.? Expliticly
> checking the character after the second "D" would.? You'll
> have to determine which characters are or aren't part of
> the instruction.? A complete solution probably depends on
> what else you are or will look for in the future.
> 
> (2) That looks like a programming language (88000? POWER?).
> Watch out for comments containing the word ADD, too.


For which reason, and given its finite and limited nature, I'd prefer to 
be explicit:-

Assuming "ADD" is only a sample of the total task, perhaps it will not 
be too impractical to create categories of instruction:

	ADD_CATEGORY = [ "ADD", "ADD.MOV" ]
	etc

Now, you can perform an "in" on the first token:

	if line.split()[ 0 ] in ADD_CATEGORY:
		# this command one of those in the ADD category...

In this way, rather than relying upon (actually *not* being able to rely 
upon) similarities of appearance, you have complete control to limit 
which commands fit into which category/ies...
-- 
Regards =dn

From cs at cskk.id.au  Sat Dec 28 23:49:27 2019
From: cs at cskk.id.au (Cameron Simpson)
Date: Sun, 29 Dec 2019 15:49:27 +1100
Subject: Friday Finking: Source code organisation
In-Reply-To: <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
References: <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
Message-ID: <20191229044927.GA50701@cskk.homeip.net>

On 29Dec2019 09:49, Chris Angelico <rosuav at gmail.com> wrote:
>"Define before use" is a broad principle that I try to follow, even
>when the code itself doesn't mandate this. This generally means that
>"if name is main" is the very last thing in the file, and if there's a
>main() function or equivalent, that's usually just before that. Any
>metaprogramming goes right at the top; sometimes this is mandated (if
>I write a decorator function, it has to be above the functions it's
>decorating), but even if it's not, metaprogramming goes before the
>mainline.

For main, i have the opposite habit. If a module has a main() function 
for command line use I usually want that right up the front:

  #!/usr/bin/env python3
  ....
  import...
  
  def main(argv=None):
    ... main command line ...

  classes, functions, etc

  if __name__ == '__main__':
    sys.exit(main(sys.argv))

My reasoning here is that I want the main programme obvious up front.

But then I loosely follow "define before use" after that.

Cheers,
Cameron Simpson <cs at cskk.id.au>

From cs at cskk.id.au  Sat Dec 28 23:55:31 2019
From: cs at cskk.id.au (Cameron Simpson)
Date: Sun, 29 Dec 2019 15:55:31 +1100
Subject: Friday Finking: Source code organisation
In-Reply-To: <20191228191904.5327f8c5@bigbox.attlocal.net>
References: <20191228191904.5327f8c5@bigbox.attlocal.net>
Message-ID: <20191229045531.GA61883@cskk.homeip.net>

On 28Dec2019 19:19, Tim Chase <python.list at tim.thechases.com> wrote:
>Inside a class, I tend to roughly follow
>
>  __new__ (if present)
>  __init__
>  other dunder methods
>  subsequent methods alphabetically

I put the factory methods up near __init__, ahead of other methods.  But 
after most dunders. Here I mean things like this:

  class Foo:

    def __init__(....):

    @classmethod
    def from_bytes(cls, bs, ...):
      ... parse out of `bs` and then finish with something like ...
      return cls(parsed-stuff)

which calls the "conventional" __init__ as normal.

And I often group methods of similar purpose together, rather than 
alphabetically. For example, if there's a few methods for transribing 
the object, they might land together.

Cheers,
Cameron Simpson <cs at cskk.id.au>

From drsalists at gmail.com  Sun Dec 29 13:19:19 2019
From: drsalists at gmail.com (Dan Stromberg)
Date: Sun, 29 Dec 2019 10:19:19 -0800
Subject: With distutils, "optional" C extension module error is fatal
Message-ID: <CAGGBd_p+KcmvfCe8NuOozHQv36v4yYRSjfQf36cfcYmbxdSD+A@mail.gmail.com>

Hi folks.

I'm putting a little time into getting my treap module (like a dict, but
always sorted by key) working with distutils.

I want it to be able to compile and install the Cython version from an
included .c file, or to fall back on a pure python version if that fails.

I'm currently using:
setup(
    name='treap',
    py_modules=[
        'treap',
        'py_treap',
        'nest',
        ],
    # ext_modules=cythonize("pyx_treap.pyx"),
    ext_modules=[Extension('pyx_treap', ['pyx_treap.c'], optional=True)],
    # setup_requires=[
    #     'Cython'
    # ],
    version=version,
    description='Python implementation of treaps,
)

...plus a few more options to setup that don't seem relevant.

If I run python3.6 setup.py build, I get:
running build
running build_py
creating build
creating build/lib.linux-x86_64-3.6
copying treap.py -> build/lib.linux-x86_64-3.6
copying py_treap.py -> build/lib.linux-x86_64-3.6
copying nest.py -> build/lib.linux-x86_64-3.6
running build_ext
building 'pyx_treap' extension
creating build/temp.linux-x86_64-3.6
x86_64-linux-gnu-gcc -pthread -DNDEBUG -g -fwrapv -O2 -Wall -g
-fstack-protector-strong -Wformat -Werror=format-security -Wdate-time
-D_FORTIFY_SOURCE=2 -fPIC -I/usr/include/python3.6m -c pyx_treap.c -o
build/temp.linux-x86_64-3.6/pyx_treap.o
pyx_treap.c:4:10: fatal error: Python.h: No such file or directory
 #include "Python.h"
          ^~~~~~~~~~
compilation terminated.
error: command 'x86_64-linux-gnu-gcc' failed with exit status 1

So it seems like despite using Extension('pyx_treap', ['pyx_treap.c'],
optional=True), the cython version is not optional.

Am I missing something?  Why doesn't it just continue with the pure python
modules?

I realize I could install python3.6-dev or similar to eliminate the error,
but I don't want to assume the user knows that.

Thanks!

From dfnsonfsduifb at gmx.de  Sun Dec 29 17:02:48 2019
From: dfnsonfsduifb at gmx.de (Johannes Bauer)
Date: Sun, 29 Dec 2019 23:02:48 +0100
Subject: '%Y' in strftime() vs. strptime()
Message-ID: <b7ce2767-3123-3525-2a58-72d6189d262a@gmx.de>

Hi list,

I've just stumbled upon a strange phaenomenon and I'm wondering if it's
a bug. Short and sweet:

Python 3.7.3 (default, Oct  7 2019, 12:56:13)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.

>>> from datetime import datetime as d

>>> x = d(1, 1, 1)

>>> x.strftime("%Y-%m-%d")
'1-01-01'

>>> d.strptime(x.strftime("%Y-%m-%d"), "%Y-%m-%d")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python3.7/_strptime.py", line 577, in _strptime_datetime
    tt, fraction, gmtoff_fraction = _strptime(data_string, format)
  File "/usr/lib/python3.7/_strptime.py", line 359, in _strptime
    (data_string, format))
ValueError: time data '1-01-01' does not match format '%Y-%m-%d'

>>> d.strptime("0001-01-01", "%Y-%m-%d")
datetime.datetime(1, 1, 1, 0, 0)

I.e. for years that are not 4 digits longs, strftime() produces no
leading zeros for the '%Y' replacement, but strptime() requires leading
zeros.

Is this expected behavior? Shouldn't %Y be consistent across both?

All the best,
Johannes

From eryksun at gmail.com  Sun Dec 29 17:28:48 2019
From: eryksun at gmail.com (Eryk Sun)
Date: Sun, 29 Dec 2019 16:28:48 -0600
Subject: '%Y' in strftime() vs. strptime()
In-Reply-To: <b7ce2767-3123-3525-2a58-72d6189d262a@gmx.de>
References: <b7ce2767-3123-3525-2a58-72d6189d262a@gmx.de>
Message-ID: <CACL+1au7YgiV+0E43n3z=LwF7aR6ukni7ziEqFWmi1hoRZQ8tA@mail.gmail.com>

On 12/29/19, Johannes Bauer <dfnsonfsduifb at gmx.de> wrote:
>
>>>> x = d(1, 1, 1)
>
>>>> x.strftime("%Y-%m-%d")
> '1-01-01'

The default padding depends on the platform strftime. POSIX strftime
[1] supports an extension of ISO C that allows specifying the "0" pad
character and minimum field width, e.g. "%04Y-%02m-%02d".

[1] https://pubs.opengroup.org/onlinepubs/9699919799/functions/strftime.html

From safiq713 at gmail.com  Mon Dec 30 00:20:54 2019
From: safiq713 at gmail.com (safiq713 at gmail.com)
Date: Sun, 29 Dec 2019 21:20:54 -0800 (PST)
Subject: name 'sys' is not defined
Message-ID: <1325ad47-5b2d-4ee0-b3cd-1e7da33d9dc4@googlegroups.com>

Deal all,
Could you please help me how can I avoid this problem
my Jupyter Notebook code was 
help pls



# init a treemix analysis object with some param arguments
tmx = ipa.treemix(
    data=data,
    imap=imap,
    minmap=minmap,
    seed=123456,
    root="Petronia_petronia",
    m=2,
)

error

NameError                                 Traceback (most recent call last)
<ipython-input-8-d80ffd5719d7> in <module>
      6     seed=123456,
      7     root="Petronia_petronia",
----> 8     m=2,
      9 )

~/opt/miniconda3/envs/py3/lib/python3.6/site-packages/ipyrad/analysis/treemix.py in __init__(self, data, name, workdir, imap, minmap, seed, quiet, raise_root_error, binary, *args, **kwargs)
    118 
    119         # others
--> 120         self.binary = os.path.join(sys.prefix, "bin", "treemix")
    121         self.binary = (binary if binary else self.binary)
    122         self.raise_root_error = raise_root_error

NameError: name 'sys' is not defined

From frank at chagford.com  Mon Dec 30 00:49:43 2019
From: frank at chagford.com (Frank Millman)
Date: Mon, 30 Dec 2019 07:49:43 +0200
Subject: name 'sys' is not defined
In-Reply-To: <1325ad47-5b2d-4ee0-b3cd-1e7da33d9dc4@googlegroups.com>
References: <1325ad47-5b2d-4ee0-b3cd-1e7da33d9dc4@googlegroups.com>
Message-ID: <eaedf3f0-de89-0053-52bc-0554ea82ee10@chagford.com>

On 2019-12-30 7:20 AM, safiq713 at gmail.com wrote:
> Deal all,
> Could you please help me how can I avoid this problem
> my Jupyter Notebook code was
> help pls
> 
[snip]
> 
> NameError: name 'sys' is not defined
> 

I know nothing about Jupyter Notebook but somewhere, usually at the top, 
you have to add this line -

     import sys

HTH

Frank Millman



From frank at chagford.com  Mon Dec 30 00:49:43 2019
From: frank at chagford.com (Frank Millman)
Date: Mon, 30 Dec 2019 07:49:43 +0200
Subject: name 'sys' is not defined
In-Reply-To: <1325ad47-5b2d-4ee0-b3cd-1e7da33d9dc4@googlegroups.com>
References: <1325ad47-5b2d-4ee0-b3cd-1e7da33d9dc4@googlegroups.com>
Message-ID: <eaedf3f0-de89-0053-52bc-0554ea82ee10@chagford.com>

On 2019-12-30 7:20 AM, safiq713 at gmail.com wrote:
> Deal all,
> Could you please help me how can I avoid this problem
> my Jupyter Notebook code was
> help pls
> 
[snip]
> 
> NameError: name 'sys' is not defined
> 

I know nothing about Jupyter Notebook but somewhere, usually at the top, 
you have to add this line -

     import sys

HTH

Frank Millman


From pieter-l at vanoostrum.org  Mon Dec 30 10:04:46 2019
From: pieter-l at vanoostrum.org (Pieter van Oostrum)
Date: Mon, 30 Dec 2019 16:04:46 +0100
Subject: name 'sys' is not defined
References: <1325ad47-5b2d-4ee0-b3cd-1e7da33d9dc4@googlegroups.com>
Message-ID: <lx1rslrh0x.fsf@cochabamba.vanoostrum.org>

safiq713 at gmail.com writes:

> Deal all,
> Could you please help me how can I avoid this problem
> my Jupyter Notebook code was 
> help pls
>
>
>
> # init a treemix analysis object with some param arguments
> tmx = ipa.treemix(
>     data=data,
>     imap=imap,
>     minmap=minmap,
>     seed=123456,
>     root="Petronia_petronia",
>     m=2,
> )
>
> error
>
> NameError                                 Traceback (most recent call last)
> <ipython-input-8-d80ffd5719d7> in <module>
>       6     seed=123456,
>       7     root="Petronia_petronia",
> ----> 8     m=2,
>       9 )
>
> ~/opt/miniconda3/envs/py3/lib/python3.6/site-packages/ipyrad/analysis/treemix.py in __init__(self, data, name, workdir, imap, minmap, seed, quiet, raise_root_error, binary, *args, **kwargs)
>     118 
>     119         # others
> --> 120         self.binary = os.path.join(sys.prefix, "bin", "treemix")
>     121         self.binary = (binary if binary else self.binary)
>     122         self.raise_root_error = raise_root_error
>
> NameError: name 'sys' is not defined

As the name sys is used in the imported module, that module has to import sys.
Importing it in the calling code doesn't help.
So I would say this is a bug in the module.

You should report the bug to its author. In the meantime you can correct your own copy at
~/opt/miniconda3/envs/py3/lib/python3.6/site-packages/ipyrad/analysis/treemix.py
by adding
import sys
for example around line 10

-- 
Pieter van Oostrum
www: http://pieter.vanoostrum.org/
PGP key: [8DAE142BE17999C4]

From barry at barrys-emacs.org  Mon Dec 30 09:47:41 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Mon, 30 Dec 2019 14:47:41 +0000
Subject: Friday Finking: Source code organisation
In-Reply-To: <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
Message-ID: <D3777E7C-F6C3-4286-BC89-D22D37F29539@barrys-emacs.org>



> On 28 Dec 2019, at 22:49, Chris Angelico <rosuav at gmail.com> wrote:
> 
> On Sun, Dec 29, 2019 at 9:37 AM DL Neil via Python-list
> <python-list at python.org> wrote:
>> 
>> Is it helpful to, and thus, do you have a style/convention for ordering
>> the methods within each class in your code?
>> 
>> A major difference however, is that if our mythical collection of
>> module-functions has an internal-reference, eg b() requires a(), then
>> function a() MUST exist, ie be defined, 'before' function b(). Whereas a
>> class's methods may be defined in any (complete) sequence.
>> 
>> So, do you have an orderly method [hah!] for presenting/locating
>> class-methods (and module-functions) within your code?
>> 
>> - why bother, the editor does 'the heavy lifting'
>> - dunders to the fore
>> - alphanumeric sequence by name
>> - order of appearance/use in 'mainline code'
>> - as they sprang to mind during TDD-creation
>> - most-used first, least-used last
>> - my code 'at the top', their stuff later...
>> - names of Monty Python characters by TV appearance date
>> or,
>> - some combination of ideas
>> and,
>> - how do you vary the above when dependencies intrude?
>> 
> 
> "Define before use" is a broad principle that I try to follow, even
> when the code itself doesn't mandate this. This generally means that
> "if name is main" is the very last thing in the file, and if there's a
> main() function or equivalent, that's usually just before that. Any
> metaprogramming goes right at the top; sometimes this is mandated (if
> I write a decorator function, it has to be above the functions it's
> decorating), but even if it's not, metaprogramming goes before the
> mainline.



"define before use" is basically email top-posting for code isn't it?

It means that the first things that you read in a module are the least interesting.

I prefer to follow the a top-down design approach. Start with what is important
and put what that depends on further down the file/class.

With classes, __init__, __new__ then the public API and last the supporting code.

Barry



> 
> Other than that, I don't have any consistent logic other than a loose
> idea of trying to keep related things together.
> 
> ChrisA
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From rosuav at gmail.com  Mon Dec 30 10:35:16 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 31 Dec 2019 02:35:16 +1100
Subject: Friday Finking: Source code organisation
In-Reply-To: <D3777E7C-F6C3-4286-BC89-D22D37F29539@barrys-emacs.org>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <D3777E7C-F6C3-4286-BC89-D22D37F29539@barrys-emacs.org>
Message-ID: <CAPTjJmoDa3=xO_EFSnE3op1AE=armQgXTHFROBkfZ3tGGVWF1A@mail.gmail.com>

On Tue, Dec 31, 2019 at 1:47 AM Barry Scott <barry at barrys-emacs.org> wrote:
>
>
>
> > On 28 Dec 2019, at 22:49, Chris Angelico <rosuav at gmail.com> wrote:
> >
> > On Sun, Dec 29, 2019 at 9:37 AM DL Neil via Python-list
> > <python-list at python.org> wrote:
> >>
> >> Is it helpful to, and thus, do you have a style/convention for ordering
> >> the methods within each class in your code?
> >>
> >> A major difference however, is that if our mythical collection of
> >> module-functions has an internal-reference, eg b() requires a(), then
> >> function a() MUST exist, ie be defined, 'before' function b(). Whereas a
> >> class's methods may be defined in any (complete) sequence.
> >>
> >> So, do you have an orderly method [hah!] for presenting/locating
> >> class-methods (and module-functions) within your code?
> >>
> >> - why bother, the editor does 'the heavy lifting'
> >> - dunders to the fore
> >> - alphanumeric sequence by name
> >> - order of appearance/use in 'mainline code'
> >> - as they sprang to mind during TDD-creation
> >> - most-used first, least-used last
> >> - my code 'at the top', their stuff later...
> >> - names of Monty Python characters by TV appearance date
> >> or,
> >> - some combination of ideas
> >> and,
> >> - how do you vary the above when dependencies intrude?
> >>
> >
> > "Define before use" is a broad principle that I try to follow, even
> > when the code itself doesn't mandate this. This generally means that
> > "if name is main" is the very last thing in the file, and if there's a
> > main() function or equivalent, that's usually just before that. Any
> > metaprogramming goes right at the top; sometimes this is mandated (if
> > I write a decorator function, it has to be above the functions it's
> > decorating), but even if it's not, metaprogramming goes before the
> > mainline.
>
>
>
> "define before use" is basically email top-posting for code isn't it?

Kinda the opposite - it means that you get the context before you get
something that refers to it.

ChrisA

From rosuav at gmail.com  Mon Dec 30 11:21:53 2019
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 31 Dec 2019 03:21:53 +1100
Subject: Friday Finking: Source code organisation
In-Reply-To: <6F82BBA4-6239-4654-B1A8-139740C3C01C@barrys-emacs.org>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <D3777E7C-F6C3-4286-BC89-D22D37F29539@barrys-emacs.org>
 <CAPTjJmoDa3=xO_EFSnE3op1AE=armQgXTHFROBkfZ3tGGVWF1A@mail.gmail.com>
 <6F82BBA4-6239-4654-B1A8-139740C3C01C@barrys-emacs.org>
Message-ID: <CAPTjJmo8J4VMVZnOiuAJs3zm3TKYnH2JehoMYLp_y521BNGL6A@mail.gmail.com>

On Tue, Dec 31, 2019 at 3:08 AM Barry Scott <barry at barrys-emacs.org> wrote:
>
>
>
> > On 30 Dec 2019, at 15:35, Chris Angelico <rosuav at gmail.com> wrote:
> >
> > On Tue, Dec 31, 2019 at 1:47 AM Barry Scott <barry at barrys-emacs.org> wrote:
> >>
> >>
> >>
> >>> On 28 Dec 2019, at 22:49, Chris Angelico <rosuav at gmail.com> wrote:
> >>>
> >>> On Sun, Dec 29, 2019 at 9:37 AM DL Neil via Python-list
> >>> <python-list at python.org> wrote:
> >>>>
> >>>> Is it helpful to, and thus, do you have a style/convention for ordering
> >>>> the methods within each class in your code?
> >>>>
> >>>> A major difference however, is that if our mythical collection of
> >>>> module-functions has an internal-reference, eg b() requires a(), then
> >>>> function a() MUST exist, ie be defined, 'before' function b(). Whereas a
> >>>> class's methods may be defined in any (complete) sequence.
> >>>>
> >>>> So, do you have an orderly method [hah!] for presenting/locating
> >>>> class-methods (and module-functions) within your code?
> >>>>
> >>>> - why bother, the editor does 'the heavy lifting'
> >>>> - dunders to the fore
> >>>> - alphanumeric sequence by name
> >>>> - order of appearance/use in 'mainline code'
> >>>> - as they sprang to mind during TDD-creation
> >>>> - most-used first, least-used last
> >>>> - my code 'at the top', their stuff later...
> >>>> - names of Monty Python characters by TV appearance date
> >>>> or,
> >>>> - some combination of ideas
> >>>> and,
> >>>> - how do you vary the above when dependencies intrude?
> >>>>
> >>>
> >>> "Define before use" is a broad principle that I try to follow, even
> >>> when the code itself doesn't mandate this. This generally means that
> >>> "if name is main" is the very last thing in the file, and if there's a
> >>> main() function or equivalent, that's usually just before that. Any
> >>> metaprogramming goes right at the top; sometimes this is mandated (if
> >>> I write a decorator function, it has to be above the functions it's
> >>> decorating), but even if it's not, metaprogramming goes before the
> >>> mainline.
> >>
> >>
> >>
> >> "define before use" is basically email top-posting for code isn't it?
> >
> > Kinda the opposite - it means that you get the context before you get
> > something that refers to it.
>
> But its not context its the low level detail that I should be able to ignore
> when trying to understand the goals of the code. I'll only need to know
> about the lower level detail if I have a need to change the code.
>
> Another analogy would ne how a journalist writes a story. You can take
> a well written article and stop reading at any point, but still know what
> the story is about. The more paragraphs you read the more informed
> you are about the story. (Editors exploit this property of a story to shorten
> it if it does not fit on the page).
>

Sure, but that's not what top-posting in emails is like. With a
top-posted reply, truncation means you lack context; with the
journalistic style of "front-load the important info", truncation
means you lack detail. So in coding, I would say the journalistic
style corresponds to a broad notion of "first docstring, then main
function, then support code", which is an absolutely legit way to do
things (but not my preferred way).

ChrisA

From barry at barrys-emacs.org  Mon Dec 30 11:08:15 2019
From: barry at barrys-emacs.org (Barry Scott)
Date: Mon, 30 Dec 2019 16:08:15 +0000
Subject: Friday Finking: Source code organisation
In-Reply-To: <CAPTjJmoDa3=xO_EFSnE3op1AE=armQgXTHFROBkfZ3tGGVWF1A@mail.gmail.com>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <D3777E7C-F6C3-4286-BC89-D22D37F29539@barrys-emacs.org>
 <CAPTjJmoDa3=xO_EFSnE3op1AE=armQgXTHFROBkfZ3tGGVWF1A@mail.gmail.com>
Message-ID: <6F82BBA4-6239-4654-B1A8-139740C3C01C@barrys-emacs.org>



> On 30 Dec 2019, at 15:35, Chris Angelico <rosuav at gmail.com> wrote:
> 
> On Tue, Dec 31, 2019 at 1:47 AM Barry Scott <barry at barrys-emacs.org> wrote:
>> 
>> 
>> 
>>> On 28 Dec 2019, at 22:49, Chris Angelico <rosuav at gmail.com> wrote:
>>> 
>>> On Sun, Dec 29, 2019 at 9:37 AM DL Neil via Python-list
>>> <python-list at python.org> wrote:
>>>> 
>>>> Is it helpful to, and thus, do you have a style/convention for ordering
>>>> the methods within each class in your code?
>>>> 
>>>> A major difference however, is that if our mythical collection of
>>>> module-functions has an internal-reference, eg b() requires a(), then
>>>> function a() MUST exist, ie be defined, 'before' function b(). Whereas a
>>>> class's methods may be defined in any (complete) sequence.
>>>> 
>>>> So, do you have an orderly method [hah!] for presenting/locating
>>>> class-methods (and module-functions) within your code?
>>>> 
>>>> - why bother, the editor does 'the heavy lifting'
>>>> - dunders to the fore
>>>> - alphanumeric sequence by name
>>>> - order of appearance/use in 'mainline code'
>>>> - as they sprang to mind during TDD-creation
>>>> - most-used first, least-used last
>>>> - my code 'at the top', their stuff later...
>>>> - names of Monty Python characters by TV appearance date
>>>> or,
>>>> - some combination of ideas
>>>> and,
>>>> - how do you vary the above when dependencies intrude?
>>>> 
>>> 
>>> "Define before use" is a broad principle that I try to follow, even
>>> when the code itself doesn't mandate this. This generally means that
>>> "if name is main" is the very last thing in the file, and if there's a
>>> main() function or equivalent, that's usually just before that. Any
>>> metaprogramming goes right at the top; sometimes this is mandated (if
>>> I write a decorator function, it has to be above the functions it's
>>> decorating), but even if it's not, metaprogramming goes before the
>>> mainline.
>> 
>> 
>> 
>> "define before use" is basically email top-posting for code isn't it?
> 
> Kinda the opposite - it means that you get the context before you get
> something that refers to it.

But its not context its the low level detail that I should be able to ignore
when trying to understand the goals of the code. I'll only need to know
about the lower level detail if I have a need to change the code.

Another analogy would ne how a journalist writes a story. You can take
a well written article and stop reading at any point, but still know what
the story is about. The more paragraphs you read the more informed
you are about the story. (Editors exploit this property of a story to shorten
it if it does not fit on the page).

Barry

> 
> ChrisA
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From amitsis at gmail.com  Mon Dec 30 18:33:52 2019
From: amitsis at gmail.com (amitsis at gmail.com)
Date: Mon, 30 Dec 2019 15:33:52 -0800 (PST)
Subject: Segmentation violation with python installation under Tumbleweed
Message-ID: <af888708-1d5d-43a2-8a99-e27fb9da56b4@googlegroups.com>

Hello,

My full Python installation doesn't seem to work due to a segmentation violation issue with libc-2.30:

Dec 30 23:54:14 craylinux1 Kernel: Python [8467]: Segfault at 100013483 ip 00007f6594c896b6 sp 00007ffe1570d188 error 4 in libc-2.30.so [7f6594c10000 + 14d000]
30.12. 23:54:14 craylinux1 kernel: Code: 0f 1f 40 00 66 0f ef c0 66 0f ef c9 66 0f ef d2 66 0f ef db 48 89 f8 48 89 f9 48 81 e1 ff 0f 00 00 48 81 f9 cf 0f 00 00 77 6a <f3> 0f 6f 20 66 0f 74 e0 66 0f d7 d4 85 d2 74 04 0f bc c2 c3 48 83

I think this is just a bug of mismatched binaries and libraries in my Python installation.

I want to reinstall the full Python installation including the libraries now, but how can you do it with Zypper to get a clean Python environment again?

Any help with the detailed command lines would be greatly appreciated.

Regards,
Andreas

From greg.ewing at canterbury.ac.nz  Tue Dec 31 00:29:41 2019
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Tue, 31 Dec 2019 18:29:41 +1300
Subject: Friday Finking: Source code organisation
In-Reply-To: <mailman.268.1577718896.11485.python-list@python.org>
References: <e91d0c11-9df4-8c82-8a26-8a24102643e0@etelligence.info>
 <CAPTjJmp94Xqop6BM92ahSyFPfc8aWHQNdRjE+4EYyn=2hSn0Hg@mail.gmail.com>
 <D3777E7C-F6C3-4286-BC89-D22D37F29539@barrys-emacs.org>
 <mailman.268.1577718896.11485.python-list@python.org>
Message-ID: <h704m7F9gbjU1@mid.individual.net>

On 31/12/19 3:47 am, Barry Scott wrote:

> "define before use" is basically email top-posting for code isn't it?
> 
> It means that the first things that you read in a module are the least interesting.

That's not a big problem for top-level code, since you can easily
scroll down to the bottom of the file and work backwards.

But it's not so easy for classes if you have more than one class
in a file. That might be part of the reason I do things the
opposite way in classes.

-- 
Greg