From PythonList at DancesWithMice.info  Sat Feb  1 00:15:47 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 1 Feb 2020 18:15:47 +1300
Subject: Suggestions on mechanism or existing code - maintain persistence
 of file download history
In-Reply-To: <r10pua$17vs$2@gioia.aioe.org>
References: <cf0359f8-86a2-413e-a364-713bbb990ef9@googlegroups.com>
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 <9d1c662e-c63e-3400-b068-d1834e7f169c@DancesWithMice.info>
 <mailman.211.1580428901.9276.python-list@python.org>
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Message-ID: <929c8cba-5f5a-8bb9-9396-73124d1acbfc@DancesWithMice.info>

On 31/01/20 9:53 PM, R.Wieser wrote:
>> Using ctrl+c is a VERY BAD idea.
> 
> To have it just exit the program ?  Yes, indeed.
> 
> Though you /could/ keep track of what needs to be finished and have the
> ctrl-c handler do that for you (barf).
> 
> Another posibility is to capture the ctrl-c and set a flag, which than
> instructs the program to terminate loops wherever possible - and thus have
> the program finish as if there was no more to do.
> 
>> (see also 'sledgehammer to crack a nut')
> 
> While I agree with you there, I've been searching for other ways to detect a
> keypress (in a console-based script) and have found none.   IOW, you do not
> (seem to) have another option.

Color me disappointed! I was hoping to be enlightened as to how one 
might code exactly that. (so I went looking...)

My first thought was a try...except looking for a keyboard error, but 
wouldn't that only work if there was an input() loop? The idea of 
putting, effectively the entire code-base, into a try...except block 
seemed crude and likely to cause side-effects.

https://stackoverflow.com/questions/1112343/how-do-i-capture-sigint-in-python 
put me on a good path. So, I opened a door in my memory, shut my ears to 
the intense screeching noise, and used a yard-broom to sweep away all 
the rust that flaked off the hinges...

PSL's signal ? Set handlers for asynchronous events 
(https://docs.python.org/3/library/signal.html) appears to handle 
keyboard interrupts, *at least in MS-Windows*.

Rusty? I think, years ago, I used signal(s) to establish time-limits on 
systems that had a possibility of 'run-away' or over-refining a solution 
which would only ever be asymptotic. I've not used the library in this 
manner.

That said, I'm using one of Python's asynchronous features, and Internet 
activity is riddled with delay-periods which make such retrievals ripe 
for async (code) solutions...


>> Why do you need to abandon the process mid-way?
> 
> Take your pick.    Mostly because of "I need to leave *now*".   Or perhaps
> because of an "you have X seconds before the device shuts down because of
> the battery being low" situation.

I (personally) cannot make use of the above. However, even if my 
portable's battery threatens complete disaster, the system "hibernates", 
and thus averts major disaster, eg file system (or RDBMS) corruption. 
This seems enough for 99% of 'average uses'. Of course it is regarded as 
trivially-unacceptable in the non-stop world, eg banking. Would our OP 
classify this project as anything other than the first of those 
categories? Thus:

>> What is the OP's definition of "unlikely" or "acceptable risk"?
> 
> Good question, but one I had no wish for to try to ascertain.   I just gave
> some "worst case" secenario based replies (aka, the "did you think of <this>
> situation" kind).

Understood. However, your understanding of RDBMS interrupt 'security' 
appears either aged, or biased to a particular implementation (which (in 
my imagination) wouldn't match the high-standards I expect you hold).

Have already admitted that I (personally) may 'over use' RDBMS because 
it is 'easy' for me. When we do feel the justification to examine the 
details of "worst case scenarios"/"did you think of this?" RDBMS 
stand-out as a 'solution' simply because of the incredible amounts of 
time and depths of thought, highly-specialised minds (far superior to 
any input I could offer) have invested in providing highly refined 
services/servers. (which I dare-say informed @Chris' comments)

Neither MSFT nor the relevant GNU/Linux projects assure common file 
systems to such a degree (and particularly not in the mentioned 
circumstances). That's why there are FS 'rescue' procedures (Linux runs 
fsck automatically when 'trouble' is noted during system-start and every 
so-many reboots, regardless).

I'm sufficiently intrigued to wonder if anyone will dispute/correct such 
- but not sufficiently motivated to research any position other than the 
one currently held - so call me "Curious", but not "George" then...


>> There are so many reasons why such won't work first-time, when they should
>> every time; that it may be quite difficult to detect 'corruption'
> 
> :-) That was not even considered.  Just the "what do I still need to
> download" datafile.

Yes, we left the OP's (actual) spec, way-back somewhere!


>> Accordingly, there is no non-atomic transaction in the proposal
> 
> The problem there is that you are second-guessing to what the OP will be
> writing, and that it will be good.   I didn't and I don't assume that.  I've
> seen too much "it works, so its good" noobie code. :-)

Absolutely! One of the 'joys' of working text-only is that even when one 
knows (much) more about the background to a posted-question, it is still 
so easy to 'answer-wrong'.

Even in my courses, where the Discussion Lists (are supposedly) related 
to each week/chapter of a course, you'd think we'd have adequate 'hints' 
as to the level of the trainee and where his/her question is 
'coming-from'. Not true!

The secret is probably somewhere in the understanding of *that* 
potential problem and going from there...

Sigh, if I had a dollar for every time someone looked at a simple 
solution (MS-Excel I'm looking at you!) and uttered 'suggestions' such 
as "we could run the entire company off one of these spreadsheet things" 
or "if we captured all the company's transactions, couldn't we run it 
off one Python pgm?"...

The world has moved-on though. Forty years ago it was common for someone 
writing his/her first program(me) to come 'crying' "the computer made a 
mistake" because it performed some simple arithmetic/statistical 
calculation without yielding the expected answer!

That said, it continues to astonish me that computing-professionals 
still can't apply the 'attention to detail' coding requires to their 
typing - regardless of whether the input is code or a Discussion List 
post. What is that mind-set???
(this comment NOT aimed at you, or any other participant on this list, 
personally!)


>> Do I want to deal with the complexities of managing files and corruptions,
>> in that arena?
> ...
>> Do you?
> 
> :-)   Its was-and-is not my choice to make.   I gave the OP some stuff to
> think about, and left making the choice upto him.    All three of the
> presented options are viable.

Good stuff! Yet at the same time, that very lack of clarity is good 
reason to allow that 'another' solution might be 'right' - even if it is 
not 'better'.
(for any definitions of "right" or "better", or ...)

As sent to the OP. I appreciate these discussions, in the expectation of 
learning something-new. (and with rust-removal paints at the ready!)


>> Be aware that formation rules for URLs are not congruent with OS FS rules!
> 
> Yup.   Though I seldom see that happen.  Though I guess I should have
> mentioned that ... :-|

I'd show you the marks where that came back to bite me once - but 
fortunately for you, the list doesn't allow graphic attachments (nor 
should distressed (and distressing) images of such parts of one's 
anatomy EVER be seen, even by qualified medical professionals...)
-- 
Regards =dn

From PythonList at DancesWithMice.info  Sat Feb  1 00:48:41 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 1 Feb 2020 18:48:41 +1300
Subject: Please answer fast.....
In-Reply-To: <CADRXHdLxH2ha0QVBmOaAz=XKmgqPi5ZdhTOJNTo3BbE01QqQzg@mail.gmail.com>
References: <CADRXHdLxH2ha0QVBmOaAz=XKmgqPi5ZdhTOJNTo3BbE01QqQzg@mail.gmail.com>
Message-ID: <da67187a-7d76-010c-889f-2e58366dd47a@DancesWithMice.info>

On 1/02/20 1:05 AM, Souvik Dutta wrote:
> Hi,
> This is problem from pyqt5. Actually I want to have about 40 labels added
> into a window when a button is clicked. The text are not the same so the
> label is not the same. I cannot just add 40 labels before hand and then
> change its text to something from a qlineedit. Please say me something that
> is more efficient and less idiot like. Thank you.


Hi, you have certainly become part of the Python community. It's 
probably too late to say "welcome".

Perhaps you are unfamiliar with this sort of discussion list, so please 
allow me try helping you to fit-in...

Are you aware that the people who might ask your question are paid as 
much for that, as you were when asking it? ie ZERO! Is the message title 
respectfully asking for someone to give-up his/her free time to help 
you? The key word is "community" (as distinct from HelpDesk or 
(salaried) Support Department).

Has this question been asked before? Such could only be ascertained by 
reviewing the list's archives (which we should all do before posting). 
Let's assume (with some confidence) that you are 'the first' to ask 
about Qt5 labels and buttons, how might someone else with a similar 
question, sometime in the future, be able to find 'the answer'? Would 
the message title "Please answer fast..." do it for you/for them? So, 
thoughtful selection of question subject-lines, just as for Python 
object names, is how you would be helping us all!
(at the same time as asking ('everyone') for help)

Sometimes people come to the list asking for 'work' to be done for them 
- either to avoid $paying a professional, or perhaps to avoid doing 
their homework - which rather defeats their learning objectives, but...! 
(that's a question/reference you will have seen on-list during the last 
few days) If you show (code) what you have done (and err.msgs showing 
where it went-wrong), might other people be more motivated to help you?

Similarly, (see this sort of response in other posts) if you are 
challenged coping with something 'new', would it help a respondent if 
you mentioned your (level of) existing knowledge, eg even "it worked in 
Qt4" informs. If "forms" is a new topic to you, or you are a beginner at 
learning Python, mentioning the tutorial/book/course you are following 
would also help 'set the scene' and assist/motivate us to help you with 
something "more efficient and less idiot like". (More/less than what?)

Lastly, (and with apologies because I don't know the answer to either 
your posted-question, or this one) is this the best place for Qt 
questions, or are there alternative venues? Which is not to say that 
there won't be someone, who is also using Qt5 from Python, who will be 
able to help...

Apologies if it feels as if I am rebuking you. The intent is actually to 
help you, and to hope that as you ask questions and learn for yourself, 
we might also learn (from you)!
(the bulk of the membership read far more posts than they ever 
post/contribute answers)

Here's hoping someone smarter than I (and five times cuter - hah, 
"Qt5"!) will be able to help...
-- 
Regards =dn

From khishorks at gmail.com  Sat Feb  1 01:19:56 2020
From: khishorks at gmail.com (khishorks at gmail.com)
Date: Fri, 31 Jan 2020 22:19:56 -0800 (PST)
Subject: data sequencing
Message-ID: <3b2b69b8-aa45-448d-9518-add43f8d86bb@googlegroups.com>

I have a data sequence of around 300000 sets. I need to batch the sequence into an input-output format. for example 

data= [1,2,3,4,5,6,7,8,9,10,......,100]

X1= [1,2,3,4,5,6,7,8,9,10]   y1 = [11,12]
X2= [3,4,5,6,7,8,9,....11,12] y2 = [13,14]
and it continues till 100.

here X is input and y is output. How to sequence the data in steps of 2?

From rosuav at gmail.com  Sat Feb  1 03:27:49 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 1 Feb 2020 19:27:49 +1100
Subject: Suggestions on mechanism or existing code - maintain persistence
 of file download history
In-Reply-To: <929c8cba-5f5a-8bb9-9396-73124d1acbfc@DancesWithMice.info>
References: <cf0359f8-86a2-413e-a364-713bbb990ef9@googlegroups.com>
 <CAPTjJmpS=b0=hBWeY2soYzHsy1GtMSrkOBrR-U3kFwbeKk+myg@mail.gmail.com>
 <mailman.181.1580329609.9276.python-list@python.org>
 <d772a5ec-eabf-478d-b0a4-99ac7115019c@googlegroups.com>
 <r0u4gf$6ms$1@gioia.aioe.org>
 <9d1c662e-c63e-3400-b068-d1834e7f169c@DancesWithMice.info>
 <mailman.211.1580428901.9276.python-list@python.org>
 <r10pua$17vs$2@gioia.aioe.org>
 <929c8cba-5f5a-8bb9-9396-73124d1acbfc@DancesWithMice.info>
Message-ID: <CAPTjJmo=MkhdF7h2eMyJ=++DpxErRYZJJd5vvYrGidZzf0WC5A@mail.gmail.com>

On Sat, Feb 1, 2020 at 4:17 PM DL Neil via Python-list
<python-list at python.org> wrote:
>
> On 31/01/20 9:53 PM, R.Wieser wrote:
> >> Using ctrl+c is a VERY BAD idea.
> >
> > To have it just exit the program ?  Yes, indeed.
> >
> > Though you /could/ keep track of what needs to be finished and have the
> > ctrl-c handler do that for you (barf).
> >
> > Another posibility is to capture the ctrl-c and set a flag, which than
> > instructs the program to terminate loops wherever possible - and thus have
> > the program finish as if there was no more to do.
> >
> >> (see also 'sledgehammer to crack a nut')
> >
> > While I agree with you there, I've been searching for other ways to detect a
> > keypress (in a console-based script) and have found none.   IOW, you do not
> > (seem to) have another option.
>
> Color me disappointed! I was hoping to be enlightened as to how one
> might code exactly that. (so I went looking...)
>
> My first thought was a try...except looking for a keyboard error, but
> wouldn't that only work if there was an input() loop? The idea of
> putting, effectively the entire code-base, into a try...except block
> seemed crude and likely to cause side-effects.

No, it should be fine - you'll get KeyboardInterrupt even without
input(). At least, you will on Unix systems; can someone confirm that
this is also the case on Windows?

Having a try/except around your main function that catches one
specific exception is usually fine. I often do this in the main of
something that's designed to run a server - for development, I'll
invoke the script directly and then Ctrl-C to stop it, for deployment,
it'll be run through some service manager.

> Sigh, if I had a dollar for every time someone looked at a simple
> solution (MS-Excel I'm looking at you!) and uttered 'suggestions' such
> as "we could run the entire company off one of these spreadsheet things"
> or "if we captured all the company's transactions, couldn't we run it
> off one Python pgm?"...

... ugh, I feel your pain... yep, heard that sort of thing way too many times.

ChrisA

From PythonList at DancesWithMice.info  Sat Feb  1 03:40:51 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 1 Feb 2020 21:40:51 +1300
Subject: data sequencing
In-Reply-To: <3b2b69b8-aa45-448d-9518-add43f8d86bb@googlegroups.com>
References: <3b2b69b8-aa45-448d-9518-add43f8d86bb@googlegroups.com>
Message-ID: <5f516607-67a7-3491-5a65-8a628fe34466@DancesWithMice.info>

On 1/02/20 7:19 PM, khishorks at gmail.com wrote:
> I have a data sequence of around 300000 sets. I need to batch the sequence into an input-output format. for example
> 
> data= [1,2,3,4,5,6,7,8,9,10,......,100]
> 
> X1= [1,2,3,4,5,6,7,8,9,10]   y1 = [11,12]
> X2= [3,4,5,6,7,8,9,....11,12] y2 = [13,14]
> and it continues till 100.
> 
> here X is input and y is output. How to sequence the data in steps of 2?


Hi, welcome to the list!

What is the application - or is this ComSc 'homework'?

Have you considered for-loops?

What code have you written have so-far, and what does it output?
-- 
Regards =dn

From hjp-python at hjp.at  Sat Feb  1 06:58:15 2020
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 1 Feb 2020 12:58:15 +0100
Subject: Suggestions on mechanism or existing code - maintain persistence
 of file download history
In-Reply-To: <CAPTjJmqbNCdXj5yC90PC1uMf=8NeBEUT2Nf4MjjEeGyKBHa=yg@mail.gmail.com>
References: <cf0359f8-86a2-413e-a364-713bbb990ef9@googlegroups.com>
 <b4271a7a-e7be-1bb8-6656-c04d6d277f3c@mrabarnett.plus.com>
 <CAPTjJmqbNCdXj5yC90PC1uMf=8NeBEUT2Nf4MjjEeGyKBHa=yg@mail.gmail.com>
Message-ID: <20200201115815.GA3731@hjp.at>

On 2020-01-30 07:56:30 +1100, Chris Angelico wrote:
> On Thu, Jan 30, 2020 at 7:49 AM MRAB <python at mrabarnett.plus.com> wrote:
> > On 2020-01-29 20:00, jkn wrote:
> > > I could have a file with all the URLs listed and work through each line in turn.
> > > But then I would have to rewrite the file (say, with the previously-successful
> > > lines commented out) as I go.
> > >
> > Why comment out the lines yourself when the download manager could do it
> > for you?
> >
> > Load the list from disk.
> >
> > For each uncommented line:
> >
> >      Download the file.
> >
> >      Comment out the line.
> >
> >      Write the list back to disk.
> 
> Isn't that exactly what the OP was talking about? It involves
> rewriting the file at every step, with the consequent risks of
> trampling on other changes, corruption on error, etc, etc, etc.

If you do it right, the risk is small:

    1) read file,
    2) do the download
    3) write temporary file with changes
    4) rename temporary file to file.

Remaining risks:

    Someone might start the download manager twice. This can be
    prevented with a lock file.

    The computer might crash between 3 and 4 (or shortly after 4). In
    this case you might lose the contents of file. This can be prevented
    with proper use of fsync, but at this point it gets complicated and
    filesystem dependent (there were a number of papers and talks about
    this topic over the last few years), so personally I would live with
    the risk or use a database.

        Subrisk: Your disk might lie to your computer about having
        stored the data. In this case there is nothing you can do except
        buying a better disk.

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
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From address at not.available  Sat Feb  1 07:00:18 2020
From: address at not.available (R.Wieser)
Date: Sat, 1 Feb 2020 13:00:18 +0100
Subject: Suggestions on mechanism or existing code - maintain persistence
 of file download history
References: <cf0359f8-86a2-413e-a364-713bbb990ef9@googlegroups.com>
 <CAPTjJmpS=b0=hBWeY2soYzHsy1GtMSrkOBrR-U3kFwbeKk+myg@mail.gmail.com>
 <mailman.181.1580329609.9276.python-list@python.org>
 <d772a5ec-eabf-478d-b0a4-99ac7115019c@googlegroups.com>
 <r0u4gf$6ms$1@gioia.aioe.org>
 <9d1c662e-c63e-3400-b068-d1834e7f169c@DancesWithMice.info>
 <mailman.211.1580428901.9276.python-list@python.org>
 <r10pua$17vs$2@gioia.aioe.org>
 <929c8cba-5f5a-8bb9-9396-73124d1acbfc@DancesWithMice.info>
 <mailman.220.1580534164.9276.python-list@python.org>
Message-ID: <r13p9g$12d5$1@gioia.aioe.org>

DL,

>> While I agree with you there, I've been searching for other ways to 
>> detect a
>> keypress (in a console-based script) and have found none.   ....
>
> Color me disappointed!

I was disapponted too, but realized that being able to just capture any 
keypress (how does the 'puter know the script has focus, as there is nothing 
to give it to) is an easy way to userland keylogging ...

> but wouldn't that only work if there was an input() loop?

Just being able to check for such a keypress at the end of a "do the next 
download" (in the OPs case) loop would be enough for me.

> Understood. However, your understanding of RDBMS interrupt 'security' 
> appears either aged, or biased to a particular implementation (which (in 
> my imagination) wouldn't match the high-standards I expect you hold).

:-) You might well be correct there.   Mea culpa.  As for the high standards 
?    While I am quite sure that currently any self-respecting DB system will 
be crammed full with methods to forgo corruption, it always sticks in my 
mind that its possible.    In other words, its possible I'm simply a bit too 
cautious.

Than again, switching an unresponsive 'puter off by pressing the powerbutton 
for a couple of seconds is a wide/well-known practice ... :-(

> Good stuff! Yet at the same time, that very lack of clarity is good reason 
> to allow that 'another' solution might be 'right' - even if it is not 
> 'better'.
> (for any definitions of "right" or "better", or ...)

"The very lack of clarity" ?

But yes, keeping the possibility open that some other method (than the ones 
presented) could be even more apropriate is part of why I leave the choice 
with the asker.   Its all too easy to (unwittingly) automatically think in a 
certain direction, and than overlook other solutions ("for someone with a 
hammer" and all that).

> As sent to the OP. I appreciate these discussions, in the expectation of 
> learning something-new. (and with rust-removal paints at the ready!)

Indeed.   Even if its just a different POV which makes you rethink the 
reasons of your own one.

Regards,
Rudy Wieser



From souvik.viksou at gmail.com  Sat Feb  1 07:06:12 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Sat, 1 Feb 2020 17:36:12 +0530
Subject: Pyqt5 help
In-Reply-To: <CADRXHdLbLoWkeb5ZbT-eoOzW=oFTGu-bfr=5aDKGx7UUi5CnoA@mail.gmail.com>
References: <CADRXHdLbLoWkeb5ZbT-eoOzW=oFTGu-bfr=5aDKGx7UUi5CnoA@mail.gmail.com>
Message-ID: <CADRXHd+jrBST0ejpNCsVAzHVkHZopi5Zdk5S-7jur-D0vhdZzg@mail.gmail.com>

I was making a pyqt5 project and I ran into a problem. I want a button in
one window to add a label in another window when clicked upon. But that is
not happening. Now the no. Of labels depend upon something, so I decided to
use a for loop which is not working. Attaching the code below. Can you help?
-------------- next part --------------
from PyQt5 import QtWidgets, QtCore, QtGui
from datetime import *
from PyQt5.QtWidgets import QApplication, QMainWindow, QLineEdit
import sys

class mywindow(QMainWindow):
    def __init__(self):
        super(mywindow, self).__init__()
        self.setGeometry(100, 100, 700, 600)
        self.setWindowTitle("The HBT App")
       
        self.initUi()
    def initUi(self):
        self.img_label1 = QtWidgets.QLabel(self)
        self.img_label1.setGeometry(QtCore.QRect(235, 0, 470, 270))
        self.img_label1.setPixmap(QtGui.QPixmap("birthday cake.jpg"))
        self.img_label1.setScaledContents(True)
        self.img_label1 = QtWidgets.QLabel(self)
        self.img_label1.setGeometry(QtCore.QRect(0, 0, 240, 270))
        self.img_label1.setPixmap(QtGui.QPixmap("whitewash.jpg"))
        self.img_label1.setScaledContents(True)
        self.img_label2 = QtWidgets.QLabel(self)
        self.img_label2.setPixmap(QtGui.QPixmap("blackline.jpg"))
        self.img_label2.setGeometry(QtCore.QRect(100, 298, 605, 3))

        self.Label = QtWidgets.QLabel(self)
        self.Label.setText("Upcoming")
        
        self.Label.setFont(QtGui.QFont("Arial", 14))
        self.Label.setGeometry(QtCore.QRect(10, 280, 101, 31))
        
        self.button = QtWidgets.QPushButton(self)
        self.button.setText("Add..")
        self.button.setGeometry(QtCore.QRect(590, 510, 80, 60))
        self.button.clicked.connect(self.clicked)
        self.button.setFont(QtGui.QFont("Arial", 18))
     
        
        self.n = {}






    def clicked(self):
        self.NewWindow = QtWidgets.QMainWindow()
        self.NewWindow.setGeometry(100, 100, 500, 500)
        self.NewWindow.setWindowTitle("Add friends")
        self.FriendLabel = QtWidgets.QLabel(self.NewWindow)
        self.FriendLabel.setText("Add Friends")
        self.FriendLabel.setFont(QtGui.QFont("Comic Sans MS", 18))
        self.FriendLabel.setGeometry(180, 40, 400, 100)

        self.Namelabel = QtWidgets.QLabel(self.NewWindow)
        self.Namelabel.setText("Name : ")
        self.Namelabel.setGeometry(QtCore.QRect(80, 170, 90, 75))
        self.Namelabel.setFont(QtGui.QFont("Comic Sans MS", 14))
        self.Namefield = QLineEdit(self.NewWindow)
        self.Namefield.setGeometry(QtCore.QRect(160, 190, 250, 35))
        

        self.Datelabel = QtWidgets.QLabel(self.NewWindow)
        self.Datelabel.setText("Birthday:  ")
        self.Datelabel.setGeometry(QtCore.QRect(62, 240, 90, 75))
        self.Datelabel.setFont(QtGui.QFont("Comic Sans MS", 14))
        self.Datefield = QLineEdit(self.NewWindow)
        self.Datefield.setGeometry(QtCore.QRect(160, 260, 250, 35))

        self.Save = QtWidgets.QPushButton(self.NewWindow)
        self.Save.setText("Save")
        self.Save.setFont(QtGui.QFont("Comic Sans MS", 14))
        self.Save.setGeometry(QtCore.QRect(70, 360, 90, 50))
        self.Save.clicked.connect(self.save)

        self.Cancel = QtWidgets.QPushButton(self.NewWindow)
        self.Cancel.setText("Cancel")
        self.Cancel.setFont(QtGui.QFont("Comic Sans MS", 14))
        self.Cancel.setGeometry(QtCore.QRect(360, 360, 90, 50))
        self.Cancel.clicked.connect(self.cancel)
        self.NewWindow.show()

    def save(self):
        self.friend_name = self.Namefield.text()
        self.friend_date = self.Datefield.text()
        self.Namefield.clear()
        self.Datefield.clear()
        self.n[self.friend_name] = self.friend_date
        print(self.n)


        for a in self.n:
            NewLabel = QtWidgets.QLabel(self)
            NewLabel.setText(self.friend_name + "has birthday on " + self.friend_date)
            NewLabel.setGeometry(QtCore.QRect(30, 250, 100, 100))

        
        self.check_date()

    def check_date(self):
        today = datetime.now()
        only_date = today.day
        strdate = datetime.strptime(self.friend_date, "%d/%m").date()
        onlydate = strdate.day
        only_month = today.month
        onlymonth = strdate.month
        if only_month == onlymonth and onlydate == only_date:
            print("Today is ", self.friend_name, "'s birthday.")
    def cancel(self):
        self.Namefield.clear()
        self.Datefield.clear()
        


def window():

    app = QApplication(sys.argv)
    win = mywindow()

    win.show()
    sys.exit(app.exec_())

window()


From barry at barrys-emacs.org  Sat Feb  1 11:41:22 2020
From: barry at barrys-emacs.org (Barry Scott)
Date: Sat, 1 Feb 2020 16:41:22 +0000
Subject: Pyqt5 help
In-Reply-To: <CADRXHd+jrBST0ejpNCsVAzHVkHZopi5Zdk5S-7jur-D0vhdZzg@mail.gmail.com>
References: <CADRXHdLbLoWkeb5ZbT-eoOzW=oFTGu-bfr=5aDKGx7UUi5CnoA@mail.gmail.com>
 <CADRXHd+jrBST0ejpNCsVAzHVkHZopi5Zdk5S-7jur-D0vhdZzg@mail.gmail.com>
Message-ID: <88A532D5-3E34-4C55-A46E-AC29EEBB5832@barrys-emacs.org>



> On 1 Feb 2020, at 12:06, Souvik Dutta <souvik.viksou at gmail.com> wrote:
> 
> I was making a pyqt5 project and I ran into a problem. I want a button in
> one window to add a label in another window when clicked upon. But that is
> not happening. Now the no. Of labels depend upon something, so I decided to
> use a for loop which is not working. Attaching the code below. Can you help?
> <birthdayapp.txt>-- 
> https://mail.python.org/mailman/listinfo/python-list <https://mail.python.org/mailman/listinfo/python-list>


I just read the code, did not run it.

The file should have .py as the extension not .txt.

In python3 its super().__init__ no need for the args.

I cannot see you calling setCentralWidget() so nothing will be drawn.

If you expect to show more then 1 Widget you will have to use
layout widgets. Here is the ref to the Qt docs on layouts.

 https://doc.qt.io/qt-5/examples-layouts.html <https://doc.qt.io/qt-5/examples-layouts.html>

A blank line before each def would make the code easier to read.

Barry




From marek.mosiewicz at jotel.com.pl  Sat Feb  1 12:13:51 2020
From: marek.mosiewicz at jotel.com.pl (Marek Mosiewicz)
Date: Sat, 01 Feb 2020 18:13:51 +0100
Subject: Calculator
In-Reply-To: <5e1f4758$0$21588$426a74cc@news.free.fr>
References: <fd627c27-a6bc-473a-8b40-f2b41ead2891@googlegroups.com>
 <055c4593-5542-4ac5-b603-6b6104855a90@googlegroups.com>
 <49bf3a3b-8840-47c9-ba4c-e96cc8e5c40e@googlegroups.com>
 <5e1f4758$0$21588$426a74cc@news.free.fr>
Message-ID: <af7083d1d7477b383ed5dd1b0c3b2d0bbb493f17.camel@jotel.com.pl>

Considering just basic calculator with eval it could be possible search
eval string if it only contains digits, parenthensis and operators.
Assuring no letter (maybe except e for expotential) and special
characters this calculator should be quite safe.

But I give no any warranty for such security.

Cheers,
   Marek Mosiewicz

W dniu ?ro, 15.01.2020 o godzinie 18?09?+0100, u?ytkownik Python
napisa?:
> Le 15/01/2020 ? 16:34, andershe02 at gmail.com a ?crit :
> > Thanks!
> 
> Do not try it, though, with a expression such as
> import os; os.system('rm -rf ~/*').
> 
> 
> 


From PythonList at DancesWithMice.info  Sat Feb  1 17:03:23 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sun, 2 Feb 2020 11:03:23 +1300
Subject: Suggestions on mechanism or existing code - maintain persistence
 of file download history
In-Reply-To: <r13p9g$12d5$1@gioia.aioe.org>
References: <cf0359f8-86a2-413e-a364-713bbb990ef9@googlegroups.com>
 <CAPTjJmpS=b0=hBWeY2soYzHsy1GtMSrkOBrR-U3kFwbeKk+myg@mail.gmail.com>
 <mailman.181.1580329609.9276.python-list@python.org>
 <d772a5ec-eabf-478d-b0a4-99ac7115019c@googlegroups.com>
 <r0u4gf$6ms$1@gioia.aioe.org>
 <9d1c662e-c63e-3400-b068-d1834e7f169c@DancesWithMice.info>
 <mailman.211.1580428901.9276.python-list@python.org>
 <r10pua$17vs$2@gioia.aioe.org>
 <929c8cba-5f5a-8bb9-9396-73124d1acbfc@DancesWithMice.info>
 <mailman.220.1580534164.9276.python-list@python.org>
 <r13p9g$12d5$1@gioia.aioe.org>
Message-ID: <ad6a837a-0e1e-ac6d-3f61-0cde8afb2fae@DancesWithMice.info>

On 2/02/20 1:00 AM, R.Wieser wrote:
>> As sent to the OP. I appreciate these discussions, in the expectation of
>> learning something-new. (and with rust-removal paints at the ready!)
> 
> Indeed.   Even if its just a different POV which makes you rethink the
> reasons of your own one.


+1
-- 
Regards =dn

From jon+usenet at unequivocal.eu  Sun Feb  2 09:46:07 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Sun, 2 Feb 2020 14:46:07 -0000 (UTC)
Subject: JavaScript's void operator in Python?
References: <void-20200202153255@ram.dialup.fu-berlin.de>
Message-ID: <slrnr3do5f.54s.jon+usenet@sable.unequivocal.eu>

On 2020-02-02, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>   JavaScript has a void operator that maps everything to
>   undefined. E.g.,
>
>   JavaScript console
>
>|< void( console.log( 2 ) )
>|  2
>|> undefined
>
>   I can easily write a corresponding function in Python.
>
>   main.py
>
> def void( x ):
>     pass
>
> void( ( print( 2 ), print( 3 )))
>
>   transcript
>
> 2
> 3
>
>   . But is an operator or a function like that already 
>   defined in Python or its standard library?

I'm not sure why you'd want to - but "None and foo" is an expression
that will return None regardless of the value of "foo".

From souvik.viksou at gmail.com  Sun Feb  2 10:55:21 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Sun, 2 Feb 2020 21:25:21 +0530
Subject: App made with pyinstaller is not running on another computer.
Message-ID: <CADRXHdLJ07quFQD9AQ4u-U=SBA+m_4km7KkG35+uL+QZ4FqfQg@mail.gmail.com>

Hi,
I made an executable file with pyinstaller on my pc which had python 3.7.
It ran well in my pc but when I tried to run it on my friend computer
having a 32 bit windows 10 os it didn't run it is just saying that "this
app cannot be run on your pc". My pc has a 64 bit version of windows 10 and
also my friend does not has any version of python installed. Can you help
me solve this problem? Thank you for your precious time.

From souvik.viksou at gmail.com  Sun Feb  2 10:59:01 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Sun, 2 Feb 2020 21:29:01 +0530
Subject: PyQt5 help on buttons and grid layout
Message-ID: <CADRXHd+SAAubX9RQ9+udF+csL-x4=Hz245C6xHtZv6TcEZ+L=g@mail.gmail.com>

Hi,
I want to add about 40 buttons based upon a dictionary. I want them to be
added to a grid layout. How can I do it easily. Please write the code and
thank you for your trouble.

From rosuav at gmail.com  Sun Feb  2 11:03:03 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 3 Feb 2020 03:03:03 +1100
Subject: App made with pyinstaller is not running on another computer.
In-Reply-To: <CADRXHdLJ07quFQD9AQ4u-U=SBA+m_4km7KkG35+uL+QZ4FqfQg@mail.gmail.com>
References: <CADRXHdLJ07quFQD9AQ4u-U=SBA+m_4km7KkG35+uL+QZ4FqfQg@mail.gmail.com>
Message-ID: <CAPTjJmq4t4rutzn4AEkbmDAWzwC=GH6V3Z8PK=NtPgO2iQ=U3g@mail.gmail.com>

On Mon, Feb 3, 2020 at 2:57 AM Souvik Dutta <souvik.viksou at gmail.com> wrote:
>
> Hi,
> I made an executable file with pyinstaller on my pc which had python 3.7.
> It ran well in my pc but when I tried to run it on my friend computer
> having a 32 bit windows 10 os it didn't run it is just saying that "this
> app cannot be run on your pc". My pc has a 64 bit version of windows 10 and
> also my friend does not has any version of python installed. Can you help
> me solve this problem? Thank you for your precious time.

Easy fix: Have your friend install Python, and then just give him/her
the .py file instead of using pyinstaller. Way WAY easier and more
reliable.

ChrisA

From arj.python at gmail.com  Sun Feb  2 12:08:09 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Sun, 2 Feb 2020 21:08:09 +0400
Subject: App made with pyinstaller is not running on another computer.
In-Reply-To: <CADRXHdLJ07quFQD9AQ4u-U=SBA+m_4km7KkG35+uL+QZ4FqfQg@mail.gmail.com>
References: <CADRXHdLJ07quFQD9AQ4u-U=SBA+m_4km7KkG35+uL+QZ4FqfQg@mail.gmail.com>
Message-ID: <CADrxXXmXHnh4uSwYT1PXixABwP3yL0g4O_-FFnqs2kruQO_0gA@mail.gmail.com>

recompile with the latest dev versio  of pyinstaller, fixed my issue.

On Sun, 2 Feb 2020, 19:55 Souvik Dutta, <souvik.viksou at gmail.com> wrote:

> Hi,
> I made an executable file with pyinstaller on my pc which had python 3.7.
> It ran well in my pc but when I tried to run it on my friend computer
> having a 32 bit windows 10 os it didn't run it is just saying that "this
> app cannot be run on your pc". My pc has a 64 bit version of windows 10 and
> also my friend does not has any version of python installed. Can you help
> me solve this problem? Thank you for your precious time.
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From arj.python at gmail.com  Sun Feb  2 12:09:33 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Sun, 2 Feb 2020 21:09:33 +0400
Subject: PyQt5 help on buttons and grid layout
In-Reply-To: <CADRXHd+SAAubX9RQ9+udF+csL-x4=Hz245C6xHtZv6TcEZ+L=g@mail.gmail.com>
References: <CADRXHd+SAAubX9RQ9+udF+csL-x4=Hz245C6xHtZv6TcEZ+L=g@mail.gmail.com>
Message-ID: <CADrxXXnVxdfnB4T5GyWw_tJWmwYMu3H0KSzZii+UwzOk8rxTOg@mail.gmail.com>

d = {}

layout = ...


for key in d:
    layout.addWidget(QButton(...))


On Sun, 2 Feb 2020, 19:59 Souvik Dutta, <souvik.viksou at gmail.com> wrote:

> Hi,
> I want to add about 40 buttons based upon a dictionary. I want them to be
> added to a grid layout. How can I do it easily. Please write the code and
> thank you for your trouble.
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From python at invalid  Sun Feb  2 13:53:44 2020
From: python at invalid (Python)
Date: Sun, 2 Feb 2020 19:53:44 +0100
Subject: JavaScript's void operator in Python?
In-Reply-To: <void-20200202155734@ram.dialup.fu-berlin.de>
References: <void-20200202153255@ram.dialup.fu-berlin.de>
 <slrnr3do5f.54s.jon+usenet@sable.unequivocal.eu>
 <void-20200202155734@ram.dialup.fu-berlin.de>
Message-ID: <5e371abc$0$10392$426a74cc@news.free.fr>

Stefan Ram wrote:
> Jon Ribbens <jon+usenet at unequivocal.eu> writes:
>> On 2020-02-02, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>>> void( ( print( 2 ), print( 3 )))
>>> 2
>>> 3
>> I'm not sure why you'd want to - but "None and foo" is an expression
>> that will return None regardless of the value of "foo".
> 
>    Yes, but it also does not evaluate the second operand. I.e.,
> 
> None and( print( 2 ), print( 3 ))
> 
>    prints nothing at all.
> 
>    I was looking for something that still evaluates and then
>    maps the value obtained to None.

( (print(2), print(3)), None)[1]

I wonder why one would need such a thing, though...

From kent.tong.mo at gmail.com  Sun Feb  2 04:43:47 2020
From: kent.tong.mo at gmail.com (Kent Tong)
Date: Sun, 2 Feb 2020 01:43:47 -0800 (PST)
Subject: My Python programming book for kids is free for 48 hours
Message-ID: <dd9d20f7-2a46-4a43-8583-2452262c9c60@googlegroups.com>

Hi,

If you're interested, please get it for free at:
https://www.amazon.com/Yes-Kids-can-learn-Python-ebook/dp/B084CY2L43/ref=sr_1_3

This is a set of training materials I used to successfully teach Python to kids as little as 10 years old. The online learning environment are freely available at https://p4kweb.appspot.com and the first four chapters are available at https://www.istudycenter.org/yes-kids-can-learn-python.
Lesson 1: Call a function & use variables
Lesson 2: Expressions and text strings
Lesson 3: Perform various calculations based values input by the user
Lesson 4: Use the tank to draw shapes with its bombs
Lesson 5: Show an input box and use "if" in Python
Lesson 6: Prompt for multiple values and display information in a message box
Lesson 7: increase the value of a variable and call a function that gives back information
Lesson 8: Use "if" without "else"
Lesson 9: Use "if" to guard against an operation that might fail
Lesson 10: 2D coordinate system for positioning objects
Lesson 11: Respond to mouse clicks and kick start a continuous process
Lesson 12: Use random numbers
Lesson 13: Use 'and' or embedded 'if's
Lesson 14: Respond to key presses
Lesson 15: Respond to key presses (2)
Lesson 16: Boolean values and stop a continuous process
Lesson 17: stop a continuous process (2)
Lesson 18: Steer a continuous process

From alan.gauld at yahoo.co.uk  Sun Feb  2 09:52:25 2020
From: alan.gauld at yahoo.co.uk (Alan Gauld)
Date: Sun, 2 Feb 2020 14:52:25 +0000
Subject: Pyqt5 help
In-Reply-To: <CADRXHd+jrBST0ejpNCsVAzHVkHZopi5Zdk5S-7jur-D0vhdZzg@mail.gmail.com>
References: <CADRXHdLbLoWkeb5ZbT-eoOzW=oFTGu-bfr=5aDKGx7UUi5CnoA@mail.gmail.com>
 <CADRXHd+jrBST0ejpNCsVAzHVkHZopi5Zdk5S-7jur-D0vhdZzg@mail.gmail.com>
Message-ID: <r16nn9$24jq$1@ciao.gmane.io>

On 01/02/2020 12:06, Souvik Dutta wrote:
> I was making a pyqt5 project and I ran into a problem. I want a button in
> one window to add a label in another window when clicked upon. But that is
> not happening.

What is happening? Don't expect us to run your buggy code!

>  Now the no. Of labels depend upon something, so I decided to
> use a for loop which is not working.

Looking at the code I see:


for a in self.n:
    NewLabel = QtWidgets.QLabel(self)
    NewLabel.setText(self.friend_name + "has birthday on " +
                     self.friend_date)
    NewLabel.setGeometry(QtCore.QRect(30, 250, 100, 100))

I'm no Qt expert but it seems that you are overwriting the same widget
(or widget location?) with all of the labels? And all of the labels are
identical since you use the same data to create them?


I would expect something more like (pseudo code!):

for a in self.n:
    newLabel = QtWidgets.QLabel(self)
    NewLabel.setText(self.friends[a].friend_name + "has birthday on " +
                     self.friends[a]._date)
    NewLabel.setGeometry(QtCore.QRect(self.calculateGeometry(a))
    self.friendLabels.append(newLabel)   # if you need a reference


-- 
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos



From alan.gauld at yahoo.co.uk  Sun Feb  2 10:09:42 2020
From: alan.gauld at yahoo.co.uk (Alan Gauld)
Date: Sun, 2 Feb 2020 15:09:42 +0000
Subject: Pyqt5 help
In-Reply-To: <CADRXHd+jrBST0ejpNCsVAzHVkHZopi5Zdk5S-7jur-D0vhdZzg@mail.gmail.com>
References: <CADRXHdLbLoWkeb5ZbT-eoOzW=oFTGu-bfr=5aDKGx7UUi5CnoA@mail.gmail.com>
 <CADRXHd+jrBST0ejpNCsVAzHVkHZopi5Zdk5S-7jur-D0vhdZzg@mail.gmail.com>
Message-ID: <r16onn$1d9u$1@ciao.gmane.io>

On 01/02/2020 12:06, Souvik Dutta wrote:

> not happening. Now the no. Of labels depend upon something, so I decided to
> use a for loop which is not working. Attaching the code below. Can you help?

I just spotted something else odd in your code:


  def initUi(self):
       ...
       self.n = {}

self.n is a dictionary.... maybe self.friends would be a better name?

    def save(self):
        self.friend_name = self.Namefield.text()
        self.friend_date = self.Datefield.text()
        self.n[self.friend_name] = self.friend_date

And here you add a new value from your UI fields

        for a in self.n:

Now you iterate over the dictionary creating a label
for each entry in the dict but...

            NewLabel = QtWidgets.QLabel(self)
            NewLabel.setText(self.friend_name + "has birthday on " +
self.friend_date)
            NewLabel.setGeometry(QtCore.QRect(30, 250, 100, 100))

The labels all have the name of the most recent friend?
And they all have the same geometry, so presumably sit
on top of each other?

-- 
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/
http://www.amazon.com/author/alan_gauld
Follow my photo-blog on Flickr at:
http://www.flickr.com/photos/alangauldphotos



From arj.python at gmail.com  Sun Feb  2 12:12:23 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Sun, 2 Feb 2020 21:12:23 +0400
Subject: Please answer fast.....
In-Reply-To: <CADRXHdLxH2ha0QVBmOaAz=XKmgqPi5ZdhTOJNTo3BbE01QqQzg@mail.gmail.com>
References: <CADRXHdLxH2ha0QVBmOaAz=XKmgqPi5ZdhTOJNTo3BbE01QqQzg@mail.gmail.com>
Message-ID: <CADrxXXmRyQV90b+a9gCv21M=90dk_yY6Ey3Zm9CfQhK-rcG=1w@mail.gmail.com>

I'm 100% ready to answer your question, just add some more details like why
you need 40 labels.

From arj.python at gmail.com  Sun Feb  2 13:05:25 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Sun, 2 Feb 2020 22:05:25 +0400
Subject: Please answer fast.....
In-Reply-To: <CADRXHdLNhPKcEbi0=frrh8zUYQAk3BVrHtg2YYsHbHvYAC8eUw@mail.gmail.com>
References: <CADRXHdLxH2ha0QVBmOaAz=XKmgqPi5ZdhTOJNTo3BbE01QqQzg@mail.gmail.com>
 <CADrxXXmRyQV90b+a9gCv21M=90dk_yY6Ey3Zm9CfQhK-rcG=1w@mail.gmail.com>
 <CADRXHdLNhPKcEbi0=frrh8zUYQAk3BVrHtg2YYsHbHvYAC8eUw@mail.gmail.com>
Message-ID: <CADrxXXmMOnzaB+Y_WOjHaYo5ZDRw9Xkfm29BxxgKuizTT-gHPg@mail.gmail.com>

Ah ok.

suggest you put names, birthday in csv

the load csv

for each row:
    layout.addWidget(QLabel)

On Sun, 2 Feb 2020, 21:21 Souvik Dutta, <souvik.viksou at gmail.com> wrote:

> Because i want to show the name and date of 40 persons and their birthdays.
>
> On Sun, Feb 2, 2020, 10:42 PM Abdur-Rahmaan Janhangeer <
> arj.python at gmail.com> wrote:
>
>> I'm 100% ready to answer your question, just add some more details like
>> why you need 40 labels.
>>
>

From PythonList at DancesWithMice.info  Sun Feb  2 16:05:31 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 3 Feb 2020 10:05:31 +1300
Subject: Please answer fast.....
In-Reply-To: <CADrxXXmMOnzaB+Y_WOjHaYo5ZDRw9Xkfm29BxxgKuizTT-gHPg@mail.gmail.com>
References: <CADRXHdLxH2ha0QVBmOaAz=XKmgqPi5ZdhTOJNTo3BbE01QqQzg@mail.gmail.com>
 <CADrxXXmRyQV90b+a9gCv21M=90dk_yY6Ey3Zm9CfQhK-rcG=1w@mail.gmail.com>
 <CADRXHdLNhPKcEbi0=frrh8zUYQAk3BVrHtg2YYsHbHvYAC8eUw@mail.gmail.com>
 <CADrxXXmMOnzaB+Y_WOjHaYo5ZDRw9Xkfm29BxxgKuizTT-gHPg@mail.gmail.com>
Message-ID: <96baf6aa-b1a4-b596-5ac1-916c9801eee7@DancesWithMice.info>

On 3/02/20 7:05 AM, Abdur-Rahmaan Janhangeer wrote:
...

> suggest you put names, birthday in csv
> 
> the load csv
> 
> for each row:
>      layout.addWidget(QLabel)
> 
> On Sun, 2 Feb 2020, 21:21 Souvik Dutta, <souvik.viksou at gmail.com> wrote:
> 
>> Because i want to show the name and date of 40 persons and their birthdays.


Why csv?

Why prefer that over native-Python constructs, eg two 40-element lists, 
a list of (pairs) lists, or indeed a dict with name as 'key' and date as 
'value'?

-- 
Regards =dn

From greg.ewing at canterbury.ac.nz  Sun Feb  2 17:41:28 2020
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 3 Feb 2020 11:41:28 +1300
Subject: JavaScript's void operator in Python?
In-Reply-To: <void-20200202153255@ram.dialup.fu-berlin.de>
References: <void-20200202153255@ram.dialup.fu-berlin.de>
Message-ID: <h9p1gqFrkvaU1@mid.individual.net>

On 3/02/20 3:38 am, Stefan Ram wrote:

> void( ( print( 2 ), print( 3 )))

If the functions you're calling all return None, you can
do this:

 >>> print(2); print(3)
2
3

-- 
Greg

From jon+usenet at unequivocal.eu  Sun Feb  2 18:06:50 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Sun, 2 Feb 2020 23:06:50 -0000 (UTC)
Subject: JavaScript's void operator in Python?
References: <void-20200202153255@ram.dialup.fu-berlin.de>
 <h9p1gqFrkvaU1@mid.individual.net>
 <expressions-20200203000038@ram.dialup.fu-berlin.de>
Message-ID: <slrnr3elga.54s.jon+usenet@sable.unequivocal.eu>

On 2020-02-02, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> Greg Ewing <greg.ewing at canterbury.ac.nz> writes:
>>If the functions you're calling all return None, you can
>>do this:
>> >>> print(2); print(3)
>
>   ?print(2); print(3)? is not an expression anymore but an stmt_list.
>   It cannot be used in all places where an expression is allowed.

Why does it matter if the return value is None?

"print(2), print(3)" is an expression that will evaluate all of its
sub-expressions. If the sub-expressions return None then I guess you
could do "(x, y, z)[0]" too.

From jon+usenet at unequivocal.eu  Sun Feb  2 18:29:47 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Sun, 2 Feb 2020 23:29:47 -0000 (UTC)
Subject: JavaScript's void operator in Python?
References: <void-20200202153255@ram.dialup.fu-berlin.de>
 <h9p1gqFrkvaU1@mid.individual.net>
 <expressions-20200203000038@ram.dialup.fu-berlin.de>
 <slrnr3elga.54s.jon+usenet@sable.unequivocal.eu>
 <None-20200203001205@ram.dialup.fu-berlin.de>
Message-ID: <slrnr3emrb.54s.jon+usenet@sable.unequivocal.eu>

On 2020-02-02, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> Jon Ribbens <jon+usenet at unequivocal.eu> writes:
>>Why does it matter if the return value is None?
>
>   In a lambda, a return value of None sometimes would be
>   convenient as by convention it indicates that the return
>   value does not carry any information and the function is
>   intended to be used just for its effect. A value of None
>   will not be printed in the console, so it does not add
>   distracting noise there.

If it's a lambda then the arguments will be evaluated before the
lambda is called anyway, so:

    >>> f = lambda *x: None
    >>> f(print(2), print(3))
    2
    3

Or if you're writing it inline then:

    >>> (None, print(2), print(3))[0]
    2
    3

From arj.python at gmail.com  Sun Feb  2 19:41:28 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Mon, 3 Feb 2020 04:41:28 +0400
Subject: Please answer fast.....
In-Reply-To: <96baf6aa-b1a4-b596-5ac1-916c9801eee7@DancesWithMice.info>
References: <CADRXHdLxH2ha0QVBmOaAz=XKmgqPi5ZdhTOJNTo3BbE01QqQzg@mail.gmail.com>
 <CADrxXXmRyQV90b+a9gCv21M=90dk_yY6Ey3Zm9CfQhK-rcG=1w@mail.gmail.com>
 <CADRXHdLNhPKcEbi0=frrh8zUYQAk3BVrHtg2YYsHbHvYAC8eUw@mail.gmail.com>
 <CADrxXXmMOnzaB+Y_WOjHaYo5ZDRw9Xkfm29BxxgKuizTT-gHPg@mail.gmail.com>
 <96baf6aa-b1a4-b596-5ac1-916c9801eee7@DancesWithMice.info>
Message-ID: <CADrxXXnY7w910HNWFE6-4=rR4M49Xmd_c6NzDDPPfKSa2BDFQg@mail.gmail.com>

CSV as data entry with " " is a pain.

>
>

From PythonList at DancesWithMice.info  Sun Feb  2 21:15:04 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 3 Feb 2020 15:15:04 +1300
Subject: The source of the PSL*
Message-ID: <933cbd11-6a70-1dd1-b863-5c413450a41c@etelligence.info>

Is there a set location for PSL project repos?
(it used to be GitHub, and before that, Google)

I'd like to review some serious PyTest/Unittest examples, eg as are 
applied to familiar (Python source) library members...

* should be easier to find than was the source of the Nile (by Europeans)
-- 
Regards,
=dn

From frank at chagford.com  Mon Feb  3 01:56:50 2020
From: frank at chagford.com (Frank Millman)
Date: Mon, 3 Feb 2020 08:56:50 +0200
Subject: lxml - minor problem appending new element
Message-ID: <r18g7j$2p09$1@ciao.gmane.io>

Hi all

I usually send lxml queries to the lxml mailing list, but it appears to 
be not working, so I thought I would try here.

This is a minor issue, and I have found an ugly workaround, but I 
thought I would mention it.

In Python I can iterate through a list, and on a certain condition 
append a new item to the list, which is then included in the iteration.

 >>> x = ['a', 'b', 'c']
 >>> for y in x:
...   print(y)
...   if y == 'b':
...     x.append('d')
...
a
b
c
d
 >>> x
['a', 'b', 'c', 'd']
 >>>

The same thing works in lxml -

 >>> lmx = '<x><y z="a"/><y z="b"/><y z="c"/></x>'
 >>> xml = etree.fromstring(lmx)
 >>> for y in xml:
...   print(etree.tostring(y))
...   if y.get('z') == 'b':
...     xml.append(etree.Element('y', attrib={'z': 'd'}))
...
b'<y z="a"/>'
b'<y z="b"/>'
b'<y z="c"/>'
b'<y z="d"/>'
 >>> etree.tostring(xml)
b'<x><y z="a"/><y z="b"/><y z="c"/><y z="d"/></x>'

However, if it happens that the condition is met on the last item in the 
list, Python still works, but lxml does not include the appended item in 
the iteration. In the following, the only change is checking for 'c' 
instead of 'b'.

 >>> x = ['a', 'b', 'c']
 >>> for y in x:
...   print(y)
...   if y == 'c':
...     x.append('d')
...
a
b
c
d
 >>> x
['a', 'b', 'c', 'd']
 >>>

 >>> lmx = '<x><y z="a"/><y z="b"/><y z="c"/></x>'
 >>> xml = etree.fromstring(lmx)
 >>> for y in xml:
...   print(etree.tostring(y))
...   if y.get('z') == 'c':
...     xml.append(etree.Element('y', attrib={'z': 'd'}))
...
b'<y z="a"/>'
b'<y z="b"/>'
b'<y z="c"/>'
 >>> etree.tostring(xml)
b'<x><y z="a"/><y z="b"/><y z="c"/><y z="d"/></x>'

As you can see, the last element is correctly appended, but is not 
included in the iteration.

Is there any chance that this can be looked at, or is it just the way it 
works?

BTW, I see that ElementTree in the standard library does not have this 
problem.

Thanks

Frank Millman


From __peter__ at web.de  Mon Feb  3 03:39:10 2020
From: __peter__ at web.de (Peter Otten)
Date: Mon, 03 Feb 2020 09:39:10 +0100
Subject: lxml - minor problem appending new element
References: <r18g7j$2p09$1@ciao.gmane.io>
Message-ID: <r18m7e$2278$1@ciao.gmane.io>

Frank Millman wrote:

> Hi all
> 
> I usually send lxml queries to the lxml mailing list, but it appears to
> be not working, so I thought I would try here.
> 
> This is a minor issue, and I have found an ugly workaround, but I
> thought I would mention it.

Like this?

children = list(xml)
for y in children:
    print(etree.tostring(y))
    if y.get('z') == 'c':
        child = etree.Element('y', attrib={'z': 'd'})
        xml.append(child)
        children.append(child)

It doesn't look /that/ ugly to me.
 
> In Python I can iterate through a list, and on a certain condition
> append a new item to the list, which is then included in the iteration.

Personally I follow the rule "never mutate a list you are iterating over", 
even for appends, where the likelihood of problems is small:

items = ["a"]
for item in items:
   if item == "a": items.append("a")
 
>  >>> x = ['a', 'b', 'c']
>  >>> for y in x:
> ...   print(y)
> ...   if y == 'b':
> ...     x.append('d')
> ...
> a
> b
> c
> d
>  >>> x
> ['a', 'b', 'c', 'd']
>  >>>
> 
> The same thing works in lxml -
> 
>  >>> lmx = '<x><y z="a"/><y z="b"/><y z="c"/></x>'
>  >>> xml = etree.fromstring(lmx)
>  >>> for y in xml:
> ...   print(etree.tostring(y))
> ...   if y.get('z') == 'b':
> ...     xml.append(etree.Element('y', attrib={'z': 'd'}))
> ...
> b'<y z="a"/>'
> b'<y z="b"/>'
> b'<y z="c"/>'
> b'<y z="d"/>'
>  >>> etree.tostring(xml)
> b'<x><y z="a"/><y z="b"/><y z="c"/><y z="d"/></x>'
> 
> However, if it happens that the condition is met on the last item in the
> list, Python still works, but lxml does not include the appended item in
> the iteration. In the following, the only change is checking for 'c'
> instead of 'b'.
> 
>  >>> x = ['a', 'b', 'c']
>  >>> for y in x:
> ...   print(y)
> ...   if y == 'c':
> ...     x.append('d')
> ...
> a
> b
> c
> d
>  >>> x
> ['a', 'b', 'c', 'd']
>  >>>
> 
>  >>> lmx = '<x><y z="a"/><y z="b"/><y z="c"/></x>'
>  >>> xml = etree.fromstring(lmx)
>  >>> for y in xml:
> ...   print(etree.tostring(y))
> ...   if y.get('z') == 'c':
> ...     xml.append(etree.Element('y', attrib={'z': 'd'}))
> ...
> b'<y z="a"/>'
> b'<y z="b"/>'
> b'<y z="c"/>'
>  >>> etree.tostring(xml)
> b'<x><y z="a"/><y z="b"/><y z="c"/><y z="d"/></x>'
> 
> As you can see, the last element is correctly appended, but is not
> included in the iteration.
> 
> Is there any chance that this can be looked at, or is it just the way it
> works?

File a bug report and see if the author is willing to emulate the list 
behaviour.
 
> BTW, I see that ElementTree in the standard library does not have this
> problem.

Maybe uses a list under the hood.


From frank at chagford.com  Mon Feb  3 04:43:25 2020
From: frank at chagford.com (Frank Millman)
Date: Mon, 3 Feb 2020 11:43:25 +0200
Subject: lxml - minor problem appending new element
In-Reply-To: <r18m7e$2278$1@ciao.gmane.io>
References: <r18g7j$2p09$1@ciao.gmane.io> <r18m7e$2278$1@ciao.gmane.io>
Message-ID: <1baa0763-8211-d810-d79a-5ee80d1cc846@chagford.com>

On 2020-02-03 10:39 AM, Peter Otten wrote:
> Frank Millman wrote:
> 
>> This is a minor issue, and I have found an ugly workaround, but I
>> thought I would mention it.
> 
> Like this?
> 
> children = list(xml)
> for y in children:
>      print(etree.tostring(y))
>      if y.get('z') == 'c':
>          child = etree.Element('y', attrib={'z': 'd'})
>          xml.append(child)
>          children.append(child)
> 
> It doesn't look /that/ ugly to me.
>   

That is not bad. My actual solution was to revert to the non-pythonic 
method of iterating over a list -

   pos =  0
   while pos < len(xml):
     y = xml[pos]
     print(etree.tostring(y))
     if y.get('z') == 'c':
       xml.append(etree.Element('y', attrib={'z': 'd'}))
     pos += 1

That way, if I append to xml, I automatically pick up the appended element.

>> In Python I can iterate through a list, and on a certain condition
>> append a new item to the list, which is then included in the iteration.
> 
> Personally I follow the rule "never mutate a list you are iterating over",
> even for appends, where the likelihood of problems is small:
> 
> items = ["a"]
> for item in items:
>     if item == "a": items.append("a")
>   

I did feel a bit uneasy doing it, but once I had got it working it did 
not feel too bad. I did not test for appending from the last item, so 
that bug has just bitten me now, but I will run with my workaround 
unless/until lxml is fixed.

>>
>> Is there any chance that this can be looked at, or is it just the way it
>> works?
> 
> File a bug report and see if the author is willing to emulate the list
> behaviour.
>   

Will do.

>> BTW, I see that ElementTree in the standard library does not have this
>> problem.
> 
> Maybe uses a list under the hood.
> 

Thanks for the advice.

Frank


From frank at chagford.com  Mon Feb  3 04:43:25 2020
From: frank at chagford.com (Frank Millman)
Date: Mon, 3 Feb 2020 11:43:25 +0200
Subject: lxml - minor problem appending new element
In-Reply-To: <r18m7e$2278$1@ciao.gmane.io>
References: <r18g7j$2p09$1@ciao.gmane.io> <r18m7e$2278$1@ciao.gmane.io>
Message-ID: <1baa0763-8211-d810-d79a-5ee80d1cc846@chagford.com>

On 2020-02-03 10:39 AM, Peter Otten wrote:
> Frank Millman wrote:
> 
>> This is a minor issue, and I have found an ugly workaround, but I
>> thought I would mention it.
> 
> Like this?
> 
> children = list(xml)
> for y in children:
>      print(etree.tostring(y))
>      if y.get('z') == 'c':
>          child = etree.Element('y', attrib={'z': 'd'})
>          xml.append(child)
>          children.append(child)
> 
> It doesn't look /that/ ugly to me.
>   

That is not bad. My actual solution was to revert to the non-pythonic 
method of iterating over a list -

   pos =  0
   while pos < len(xml):
     y = xml[pos]
     print(etree.tostring(y))
     if y.get('z') == 'c':
       xml.append(etree.Element('y', attrib={'z': 'd'}))
     pos += 1

That way, if I append to xml, I automatically pick up the appended element.

>> In Python I can iterate through a list, and on a certain condition
>> append a new item to the list, which is then included in the iteration.
> 
> Personally I follow the rule "never mutate a list you are iterating over",
> even for appends, where the likelihood of problems is small:
> 
> items = ["a"]
> for item in items:
>     if item == "a": items.append("a")
>   

I did feel a bit uneasy doing it, but once I had got it working it did 
not feel too bad. I did not test for appending from the last item, so 
that bug has just bitten me now, but I will run with my workaround 
unless/until lxml is fixed.

>>
>> Is there any chance that this can be looked at, or is it just the way it
>> works?
> 
> File a bug report and see if the author is willing to emulate the list
> behaviour.
>   

Will do.

>> BTW, I see that ElementTree in the standard library does not have this
>> problem.
> 
> Maybe uses a list under the hood.
> 

Thanks for the advice.

Frank

From shipan76 at mail.ustc.edu.cn  Mon Feb  3 03:04:33 2020
From: shipan76 at mail.ustc.edu.cn (=?utf-8?Q?=E7=9F=B3=E7=9B=BC?=)
Date: Mon, 3 Feb 2020 16:04:33 +0800
Subject: when uses time.clock,there are always mistakes 
Message-ID: <5E37D412.153213.28531@ustc.edu.cn>

Hello !
?The problem like this:
?    		================================ RESTART: Shell ================================
??>>> import time
??>>> t = time.clock()
??Traceback (most recent call last):
?  			File "<pyshell#5>", line 1, in <module>
?  			  t = time.clock()
??AttributeError: module 'time' has no attribute 'clock'
??>>>
??Thanks!
??Best wishes!

From mbharathi1112 at gmail.com  Mon Feb  3 06:14:04 2020
From: mbharathi1112 at gmail.com (the python app i had downloaded is not opening!)
Date: Mon, 3 Feb 2020 16:44:04 +0530
Subject: no explanation towards not installing my application//
Message-ID: <5e380074.1c69fb81.1150c.acff@mx.google.com>



Sent from Mail for Windows 10


From bgailer at gmail.com  Mon Feb  3 08:37:52 2020
From: bgailer at gmail.com (Bob Gailer)
Date: Mon, 3 Feb 2020 08:37:52 -0500
Subject: no explanation towards not installing my application//
In-Reply-To: <5e380074.1c69fb81.1150c.acff@mx.google.com>
References: <5e380074.1c69fb81.1150c.acff@mx.google.com>
Message-ID: <CAP1rxO7Ao=bX3kuoGAcSTohN2wC67id3zr=n7LooBHSRVRLzYw@mail.gmail.com>

On Feb 3, 2020 8:18 AM, "the python app i had downloaded is not opening!" <
mbharathi1112 at gmail.com> wrote:

I'm assuming you're using Windows 10. Correct?

You're telling us you downloaded the program installer. Did you run the
installer? Where did it tell you it was putting the program?

Exactly what did you do to try to open python? Exactly what results did you
get?

Bob Gailer

From rhodri at kynesim.co.uk  Mon Feb  3 08:54:10 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Mon, 3 Feb 2020 13:54:10 +0000
Subject: when uses time.clock,there are always mistakes
In-Reply-To: <5E37D412.153213.28531@ustc.edu.cn>
References: <5E37D412.153213.28531@ustc.edu.cn>
Message-ID: <9ac47ebb-9b71-257a-3f3c-c7e76fd91d62@kynesim.co.uk>

On 03/02/2020 08:04, ?? wrote:
> Hello !
> ?The problem like this:
> ?    		================================ RESTART: Shell ================================
> ??>>> import time
> ??>>> t = time.clock()
> ??Traceback (most recent call last):
> ?  			File "<pyshell#5>", line 1, in <module>
> ?  			  t = time.clock()
> ??AttributeError: module 'time' has no attribute 'clock'

It is correct, there is no time.clock() function.  The documentation is 
here: https://docs.python.org/3/library/time.html

-- 
Rhodri James *-* Kynesim Ltd

From __peter__ at web.de  Mon Feb  3 09:59:43 2020
From: __peter__ at web.de (Peter Otten)
Date: Mon, 03 Feb 2020 15:59:43 +0100
Subject: when uses time.clock,there are always mistakes
References: <5E37D412.153213.28531@ustc.edu.cn>
Message-ID: <r19ch0$1b19$1@ciao.gmane.io>

?? wrote:

> The problem like this:

> t = time.clock()
> AttributeError: module 'time' has no attribute 'clock'

Quoting
https://docs.python.org/3/whatsnew/3.8.html#api-and-feature-removals

"""
The function time.clock() has been removed, after having been deprecated 
since Python 3.3: use time.perf_counter() or time.process_time() instead, 
depending on your requirements, to have well-defined behavior. (Contributed 
by Matthias Bussonnier in bpo-36895.)
"""


From chapardar.parisa at gmail.com  Mon Feb  3 11:55:39 2020
From: chapardar.parisa at gmail.com (Parisa Ch)
Date: Mon, 3 Feb 2020 08:55:39 -0800 (PST)
Subject: braket an matrix in python
Message-ID: <45c82e87-1e6e-4bc3-92c4-75318187e64a@googlegroups.com>

x=np.linspace(0,2*math.pi,n)
n=len(x)
r=int(math.ceil(f*n)) 
h=[np.sort(np.abs(x-x[i]))[r] for i in range(n)]

this is part of a python code. the last line is confusing? x is a matrix and x[i] is a number. how  calculate x-x[i] for each i?
 why the put r in [] ?

From __peter__ at web.de  Mon Feb  3 13:16:20 2020
From: __peter__ at web.de (Peter Otten)
Date: Mon, 03 Feb 2020 19:16:20 +0100
Subject: braket an matrix in python
References: <45c82e87-1e6e-4bc3-92c4-75318187e64a@googlegroups.com>
Message-ID: <r19o1m$1tvc$1@ciao.gmane.io>

Parisa Ch wrote:

> x=np.linspace(0,2*math.pi,n)
> n=len(x)
> r=int(math.ceil(f*n))
> h=[np.sort(np.abs(x-x[i]))[r] for i in range(n)]
> 
> this is part of a python code. the last line is confusing? x is a matrix
> and x[i] is a number. how  calculate x-x[i] for each i?
>  why the put r in [] ?

Brake it appart:

y = x - x[i]  # the numpy feature that makes that possible is called
              # "broadcasting"

subtracts the value x[i] from every entry in the vector x

z = np.abs(y)

calculates the absolute value of every entry in y.

t = np.sort(z)

sorts the values in z and finally, assuming r is an integer,

u = t[r]  

looks up a single scalar in the vector.

The enclosing "list comprehension" [expr for item in iterable] builds a list 
of n values calculated as sketched above.


From laiba.zubair96 at gmail.com  Tue Feb  4 09:49:30 2020
From: laiba.zubair96 at gmail.com (laiba.zubair96 at gmail.com)
Date: Tue, 4 Feb 2020 06:49:30 -0800 (PST)
Subject: ERROR in loading data
Message-ID: <e051b1e5-c438-440b-a594-062dc66df9d6@googlegroups.com>

#load the training and testing data, then scale it into the
	# range [0, 1]
	print("[INFO] loading  ADNI data...")
	((trainX, trainY), (testX, testY)) = '/content/gdrive/My Drive/3_Classes/'.loads_data()
	trainX = trainX.astype("float") / 255.0
	testX = testX.astype("float") / 255.0
 
	# initialize the label names for the  ADNI dataset
	labelNames = ["outAD", "outCN", "outMCI"]
When i try to run this code I got the following error.

[INFO] loading  ADNI data...
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-8-fb9724017cc0> in <module>()
      1 print("[INFO] loading  ADNI data...")
----> 2 ((trainX, trainY), (testX, testY)) = '/content/gdrive/My Drive/3_Classes/'.loads_data()
      3 trainX = trainX.astype("float") / 255.0
      4 testX = testX.astype("float") / 255.0
      5 

From rhodri at kynesim.co.uk  Tue Feb  4 10:04:26 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 4 Feb 2020 15:04:26 +0000
Subject: ERROR in loading data
In-Reply-To: <e051b1e5-c438-440b-a594-062dc66df9d6@googlegroups.com>
References: <e051b1e5-c438-440b-a594-062dc66df9d6@googlegroups.com>
Message-ID: <c4b70a09-dfc8-6046-ccbb-d7aa2efb606e@kynesim.co.uk>

On 04/02/2020 14:49, laiba.zubair96 at gmail.com wrote:
> #load the training and testing data, then scale it into the
> 	# range [0, 1]
> 	print("[INFO] loading  ADNI data...")
> 	((trainX, trainY), (testX, testY)) = '/content/gdrive/My Drive/3_Classes/'.loads_data()
> 	trainX = trainX.astype("float") / 255.0
> 	testX = testX.astype("float") / 255.0
>   
> 	# initialize the label names for the  ADNI dataset
> 	labelNames = ["outAD", "outCN", "outMCI"]
> When i try to run this code I got the following error.
> 
> [INFO] loading  ADNI data...
> ---------------------------------------------------------------------------
> AttributeError                            Traceback (most recent call last)
> <ipython-input-8-fb9724017cc0> in <module>()
>        1 print("[INFO] loading  ADNI data...")
> ----> 2 ((trainX, trainY), (testX, testY)) = '/content/gdrive/My Drive/3_Classes/'.loads_data()
>        3 trainX = trainX.astype("float") / 255.0
>        4 testX = testX.astype("float") / 255.0
>        5

So that error is saying that something on line 2 is trying to use an 
attribute incorrectly, probably one that doesn't exist (there really 
should be more explanatory information in the error, by the way).  The 
only thing on line 2 that tries to access an attribute is the string 
'/content/gdrive/My Drive/3_Classes/', which tries to run the method 
loads_data().  Fair enough.  A quick test on the interactive command 
line or a look in the documents will tell you that strings indeed do not 
have a loads_data() method.

I don't know what library you are intending to use, but you need to open 
your file with that first.

-- 
Rhodri James *-* Kynesim Ltd

From joel.goldstick at gmail.com  Tue Feb  4 11:47:40 2020
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Tue, 4 Feb 2020 11:47:40 -0500
Subject: ERROR in loading data
In-Reply-To: <e051b1e5-c438-440b-a594-062dc66df9d6@googlegroups.com>
References: <e051b1e5-c438-440b-a594-062dc66df9d6@googlegroups.com>
Message-ID: <CAPM-O+wKNTOCwMOU4sdT3m=vy-5m+G+HLFz6eZ=y2gvYrRK5fw@mail.gmail.com>

On Tue, Feb 4, 2020 at 9:51 AM <laiba.zubair96 at gmail.com> wrote:
>
> #load the training and testing data, then scale it into the
>         # range [0, 1]
>         print("[INFO] loading  ADNI data...")
>         ((trainX, trainY), (testX, testY)) = '/content/gdrive/My Drive/3_Classes/'.loads_data()

What is the class of the .loads)data() method?  I don't think it is a
string representing a file path.  Look in the docs for .loads_data()
to see what you are doing wrong.  That looks like it might be a numpy
>         trainX = trainX.astype("float") / 255.0
>         testX = testX.astype("float") / 255.0
>
>         # initialize the label names for the  ADNI dataset
>         labelNames = ["outAD", "outCN", "outMCI"]
> When i try to run this code I got the following error.
>
> [INFO] loading  ADNI data...
> ---------------------------------------------------------------------------
> AttributeError                            Traceback (most recent call last)
> <ipython-input-8-fb9724017cc0> in <module>()
>       1 print("[INFO] loading  ADNI data...")
> ----> 2 ((trainX, trainY), (testX, testY)) = '/content/gdrive/My Drive/3_Classes/'.loads_data()
>       3 trainX = trainX.astype("float") / 255.0
>       4 testX = testX.astype("float") / 255.0
>       5
> --
> https://mail.python.org/mailman/listinfo/python-list



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

From dcwhatthe at gmail.com  Tue Feb  4 12:34:47 2020
From: dcwhatthe at gmail.com (dcwhatthe at gmail.com)
Date: Tue, 4 Feb 2020 09:34:47 -0800 (PST)
Subject: How to instlal pyodbc, without pip
Message-ID: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>

Hi,

Pip won't work on my desktop, because of the firewalls we have set up.

I have the version from github.  Assuming my Python 3.8.1 Home Directory is C:\Python, How can I install pyodbc pyodbc-master.zip?  Which folders should I unzip it into?



Regards,





From PythonList at DancesWithMice.info  Tue Feb  4 16:37:52 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Wed, 5 Feb 2020 10:37:52 +1300
Subject: How to instlal pyodbc, without pip
In-Reply-To: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>
References: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>
Message-ID: <d9bc13ca-6d8a-2d67-d2d1-c28527dedcd1@DancesWithMice.info>


On 5/02/20 6:34 AM, dcwhatthe at gmail.com wrote:
> Pip won't work on my desktop, because of the firewalls we have set up.
> 
> I have the version from github.  Assuming my Python 3.8.1 Home Directory is C:\Python, How can I install pyodbc pyodbc-master.zip?  Which folders should I unzip it into?


I don't use MS-Win. My personal library directory is 
/home/dn/.local/lib/python3.7/site-packages. There is an equivalent of 
such, for you.

Pip is a convenience. Manual installation is perfectly reasonable.


For wider understanding and to take advantage of Python's flexibility to 
include the limitations of your situation, the following might help:

Python Setup and Usage
https://docs.python.org/3/using/index.html

Installing Python Modules
https://docs.python.org/3/installing/index.html

Installing Packages
https://packaging.python.org/tutorials/installing-packages/#installing-to-the-user-site

-- 
Regards =dn

From tjreedy at udel.edu  Tue Feb  4 16:12:09 2020
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 4 Feb 2020 16:12:09 -0500
Subject: How to instlal pyodbc, without pip
In-Reply-To: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>
References: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>
Message-ID: <r1cmn9$o2l$1@ciao.gmane.io>

On 2/4/2020 12:34 PM, dcwhatthe at gmail.com wrote:

> Pip won't work on my desktop, because of the firewalls we have set up.
> 
> I have the version from github.  Assuming my Python 3.8.1 Home Directory is C:\Python, How can I install pyodbc pyodbc-master.zip?

If you have dependencies installed, you should be able to pip install 
with a command line arg telling it to use that file.  Can you run pip -h?
  >  Which folders should I unzip it into?

The pyodbc package must end up in .../Lib/site-packages.  Unzipping 
there might work, or maybe not.  The zipped manifest.ini and setup.py 
and maybe other files have the installation details, which pip reads and 
interprets.

-- 
Terry Jan Reedy


From souvik.viksou at gmail.com  Tue Feb  4 20:52:33 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Wed, 5 Feb 2020 07:22:33 +0530
Subject: How to instlal pyodbc, without pip
In-Reply-To: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>
References: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>
Message-ID: <CADRXHdKkTyt_2rocSyXa2DBPYG+Hfmq-kGiQZ+AwmfH2XL4Q7A@mail.gmail.com>

You might use chocolatey if you like.

On Tue, 4 Feb, 2020, 11:05 pm , <dcwhatthe at gmail.com> wrote:

> Hi,
>
> Pip won't work on my desktop, because of the firewalls we have set up.
>
> I have the version from github.  Assuming my Python 3.8.1 Home Directory
> is C:\Python, How can I install pyodbc pyodbc-master.zip?  Which folders
> should I unzip it into?
>
>
>
> Regards,
>
>
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From souvik.viksou at gmail.com  Tue Feb  4 22:30:45 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Wed, 5 Feb 2020 09:00:45 +0530
Subject: How to make a cross platform python app with pyinstaller??
Message-ID: <CADRXHdK7nY=mW=fzH+yQykxBi3deDe8okre85QkMvKZ5_GdRMA@mail.gmail.com>

Hi,
I made a python gui with pyqt5 and packed it with pyinstaller. It is
running well in my computer but when I gave it to a friend who doesn't have
any python version installed and it didn't run. The message was "This app
cannot be run on your pc.". How can I solve this???

From rosuav at gmail.com  Tue Feb  4 22:33:22 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 5 Feb 2020 14:33:22 +1100
Subject: How to make a cross platform python app with pyinstaller??
In-Reply-To: <CADRXHdK7nY=mW=fzH+yQykxBi3deDe8okre85QkMvKZ5_GdRMA@mail.gmail.com>
References: <CADRXHdK7nY=mW=fzH+yQykxBi3deDe8okre85QkMvKZ5_GdRMA@mail.gmail.com>
Message-ID: <CAPTjJmr0AkOnORnbvJNX4_H7rt-2SiR=DsT3cTYPyBJEheXSuA@mail.gmail.com>

On Wed, Feb 5, 2020 at 2:32 PM Souvik Dutta <souvik.viksou at gmail.com> wrote:
>
> Hi,
> I made a python gui with pyqt5 and packed it with pyinstaller. It is
> running well in my computer but when I gave it to a friend who doesn't have
> any python version installed and it didn't run. The message was "This app
> cannot be run on your pc.". How can I solve this???

Distribute the .py file instead. It can then run on any computer with
Python installed.

ChrisA

From torriem at gmail.com  Tue Feb  4 23:27:59 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 4 Feb 2020 21:27:59 -0700
Subject: How to make a cross platform python app with pyinstaller??
In-Reply-To: <CAPTjJmr0AkOnORnbvJNX4_H7rt-2SiR=DsT3cTYPyBJEheXSuA@mail.gmail.com>
References: <CADRXHdK7nY=mW=fzH+yQykxBi3deDe8okre85QkMvKZ5_GdRMA@mail.gmail.com>
 <CAPTjJmr0AkOnORnbvJNX4_H7rt-2SiR=DsT3cTYPyBJEheXSuA@mail.gmail.com>
Message-ID: <2bc87ae4-b7a3-0329-2517-48ea850aa2a5@gmail.com>

On 2/4/20 8:33 PM, Chris Angelico wrote:
> On Wed, Feb 5, 2020 at 2:32 PM Souvik Dutta <souvik.viksou at gmail.com> wrote:
>>
>> Hi,
>> I made a python gui with pyqt5 and packed it with pyinstaller. It is
>> running well in my computer but when I gave it to a friend who doesn't have
>> any python version installed and it didn't run. The message was "This app
>> cannot be run on your pc.". How can I solve this???
> 
> Distribute the .py file instead. It can then run on any computer with
> Python installed.

And PyQt5 installed of course.  And Qt5.  None of which is likely to be
a commonly installed software package.  Asking someone to install Python
separately to run your app is a tall order, to say nothing of PyQt5.  So
while this answer is technically correct, the larger issue of
distributing Python programs remains.

Furthering Chris's answer a bit, there really is no way to simply
distribute a Python app and all its dependencies in any simple, portable
way.  If the dependencies already exist on the target system, then Chris
is absolutely right. You just give him the py file and he double-clicks
on it and it runs.  That may work some of the time.

The reality is that this is often insufficient.  Your best bet may be to
build an installer that either installs everything you need into a
Program Files directory, or also runs the Python, and PyQt5 installers
to install them system-wide before installing your app and your bundled
shortcuts and program launcher.  Building installers isn't too awful
using a number of free tools, but it's an entire programming domain in
and of itself.

From cs at cskk.id.au  Wed Feb  5 00:48:56 2020
From: cs at cskk.id.au (Cameron Simpson)
Date: Wed, 5 Feb 2020 16:48:56 +1100
Subject: How to make a cross platform python app with pyinstaller??
In-Reply-To: <2bc87ae4-b7a3-0329-2517-48ea850aa2a5@gmail.com>
References: <2bc87ae4-b7a3-0329-2517-48ea850aa2a5@gmail.com>
Message-ID: <20200205054856.GA46453@cskk.homeip.net>

On 04Feb2020 21:27, Michael Torrie <torriem at gmail.com> wrote:
>On 2/4/20 8:33 PM, Chris Angelico wrote:
>> On Wed, Feb 5, 2020 at 2:32 PM Souvik Dutta <souvik.viksou at gmail.com> wrote:
>>> I made a python gui with pyqt5 and packed it with pyinstaller. It is
>>> running well in my computer but when I gave it to a friend who doesn't have
>>> any python version installed and it didn't run. The message was "This app
>>> cannot be run on your pc.". How can I solve this???
>>
>> Distribute the .py file instead. It can then run on any computer with
>> Python installed.
>
>And PyQt5 installed of course.  And Qt5.  None of which is likely to be
>a commonly installed software package.  Asking someone to install Python
>separately to run your app is a tall order, to say nothing of PyQt5.  So
>while this answer is technically correct, the larger issue of
>distributing Python programs remains. [...]

The purpose of tools like py2installer is to build an app containing all 
the required dependencies. I've been using py2app for this myself, and 
confess to being rather ignorant about the internals.  However, it has 
problems; the Python executable itself is part of the problem.

MacOS apps at least have some funky library linking stuff which lets you 
derive the library locations from the app location, etc. However, I've 
had plenty of pain with this myself.

I'm contemplating not just including a virtualenv in the app but a whole 
python install.

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

From arj.python at gmail.com  Wed Feb  5 01:48:56 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Wed, 5 Feb 2020 10:48:56 +0400
Subject: Mauritius UG (pymug) 2019 End of Year Report
Message-ID: <CADrxXXnPGR_PG5HiH9WftN0aHOmp-J+sr47-rSbg=EFhbuhEsg@mail.gmail.com>

Greetings list,

Today our User Group published it's first ever end-of-year report:

https://www.pymug.com/assets/pymug_2019_report.pdf

Feel free to ask me anything!

Yours,

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

From arj.python at gmail.com  Wed Feb  5 02:09:57 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Wed, 5 Feb 2020 11:09:57 +0400
Subject: How to make a cross platform python app with pyinstaller??
In-Reply-To: <CADRXHdK7nY=mW=fzH+yQykxBi3deDe8okre85QkMvKZ5_GdRMA@mail.gmail.com>
References: <CADRXHdK7nY=mW=fzH+yQykxBi3deDe8okre85QkMvKZ5_GdRMA@mail.gmail.com>
Message-ID: <CADrxXXn2n3iYc_SERHoYjWgyvX8XUpbR3vqS8nK=UUzB5uBXig@mail.gmail.com>

Use the Dev version of pyinstaller.

pip install https://github.com/pyinstaller/pyinstaller/archive/develop.zip

Yours,

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


On Wed, Feb 5, 2020 at 7:31 AM Souvik Dutta <souvik.viksou at gmail.com> wrote:

> Hi,
> I made a python gui with pyqt5 and packed it with pyinstaller. It is
> running well in my computer but when I gave it to a friend who doesn't have
> any python version installed and it didn't run. The message was "This app
> cannot be run on your pc.". How can I solve this???
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From klauck2 at gmail.com  Wed Feb  5 08:57:10 2020
From: klauck2 at gmail.com (Stefan Halfpap)
Date: Wed, 5 Feb 2020 14:57:10 +0100
Subject: Documentation of __hash__
Message-ID: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>

Hi,

I do not understand the following statement from the python (2 and 3) documentation regarding __hash__ and __eq__ methods:
"If a class does not define an __eq__() <https://docs.python.org/3/reference/datamodel.html#object.__eq__> method it should not define a __hash__() <https://docs.python.org/3/reference/datamodel.html#object.__hash__> operation either;?
(see https://docs.python.org/3/reference/datamodel.html#object.__hash__ <https://docs.python.org/3/reference/datamodel.html#object.__hash__> )

I thought it relates to the second part (?if it defines __eq__() <https://docs.python.org/3/reference/datamodel.html#object.__eq__> but not __hash__() <https://docs.python.org/3/reference/datamodel.html#object.__hash__>, its instances will not be usable as items in hashable collections?), which is totally clear to me.
But then the implication should be the other way around.

But what is the reason (meaning) for the statement as it is?

Best regards,
Stefan

From dcwhatthe at gmail.com  Wed Feb  5 10:54:25 2020
From: dcwhatthe at gmail.com (dcwhatthe at gmail.com)
Date: Wed, 5 Feb 2020 07:54:25 -0800 (PST)
Subject: How to instlal pyodbc, without pip
In-Reply-To: <mailman.257.1580867577.9276.python-list@python.org>
References: <54f829b7-3227-4b11-a8b6-2a43ea134323@googlegroups.com>
 <CADRXHdKkTyt_2rocSyXa2DBPYG+Hfmq-kGiQZ+AwmfH2XL4Q7A@mail.gmail.com>
 <mailman.257.1580867577.9276.python-list@python.org>
Message-ID: <e94ea74c-91fa-4011-98ad-5cf940a01e24@googlegroups.com>

On Tuesday, February 4, 2020 at 8:53:10 PM UTC-5, Souvik Dutta wrote:
> You might use chocolatey if you like.
> 
> On Tue, 4 Feb, 2020, 11:05 pm , dcwhatthe wrote:
> 
> > Hi,
> >
> > Pip won't work on my desktop, because of the firewalls we have set up.
> >
> > I have the version from github.  Assuming my Python 3.8.1 Home Directory
> > is C:\Python, How can I install pyodbc pyodbc-master.zip?  Which folders
> > should I unzip it into?
> >
> >
> >
> > Regards,
> >
> >
> >
> >
> > --
> > https://mail.python.org/mailman/listinfo/python-list
> >

Thanks DL Neil, Terry, and Souvik,

I was able to install them manually, by going to the ..\libregrtest\ folder, copying the .zip there, and running it against the package, thus:

pip install --trusted-host pyodbc-master.zip


From dieter at handshake.de  Wed Feb  5 12:25:42 2020
From: dieter at handshake.de (Dieter Maurer)
Date: Wed, 5 Feb 2020 18:25:42 +0100
Subject: Documentation of __hash__
In-Reply-To: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
Message-ID: <24122.64150.717391.820747@localhost.localdomain>

Stefan Halfpap wrote at 2020-2-5 14:57 +0100:
>I do not understand the following statement from the python (2 and 3) documentation regarding __hash__ and __eq__ methods:
>"If a class does not define an __eq__() <https://docs.python.org/3/reference/datamodel.html#object.__eq__> method it should not define a __hash__() <https://docs.python.org/3/reference/datamodel.html#object.__hash__> operation either;?
>(see https://docs.python.org/3/reference/datamodel.html#object.__hash__ <https://docs.python.org/3/reference/datamodel.html#object.__hash__> )
>
>I thought it relates to the second part (?if it defines __eq__() <https://docs.python.org/3/reference/datamodel.html#object.__eq__> but not __hash__() <https://docs.python.org/3/reference/datamodel.html#object.__hash__>, its instances will not be usable as items in hashable collections?), which is totally clear to me.
>But then the implication should be the other way around.

"if not A then not B" is equivalent to "if B then A".

In your case: "__eq__ not defined, then __hash__ not defined"
is equivalent to "__hash__ definied requires __eq__ defined".

From klauck2 at gmail.com  Wed Feb  5 14:55:24 2020
From: klauck2 at gmail.com (klauck2 at gmail.com)
Date: Wed, 5 Feb 2020 11:55:24 -0800 (PST)
Subject: Documentation of __hash__
In-Reply-To: <mailman.265.1580928060.9276.python-list@python.org>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
 <24122.64150.717391.820747@localhost.localdomain>
 <mailman.265.1580928060.9276.python-list@python.org>
Message-ID: <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>

On Wednesday, February 5, 2020 at 7:41:13 PM UTC+1, Dieter Maurer wrote:
> Stefan Halfpap wrote at 2020-2-5 14:57 +0100:
> >I do not understand the following statement from the python (2 and 3) documentation regarding __hash__ and __eq__ methods:
> >"If a class does not define an __eq__() <https://docs.python.org/3/reference/datamodel.html#object.__eq__> method it should not define a __hash__() <https://docs.python.org/3/reference/datamodel.html#object.__hash__> operation either;?
> >(see https://docs.python.org/3/reference/datamodel.html#object.__hash__ <https://docs.python.org/3/reference/datamodel.html#object.__hash__> )
> >
> >I thought it relates to the second part (?if it defines __eq__() <https://docs.python.org/3/reference/datamodel.html#object.__eq__> but not __hash__() <https://docs.python.org/3/reference/datamodel.html#object.__hash__>, its instances will not be usable as items in hashable collections?), which is totally clear to me.
> >But then the implication should be the other way around.
> 
> "if not A then not B" is equivalent to "if B then A".
> 
> In your case: "__eq__ not defined, then __hash__ not defined"
> is equivalent to "__hash__ definied requires __eq__ defined".

You are right.
This is what the (first part of the) documentation says,
but I do not know why.

I thought it should be:
"if __hash__ is not defined, then __eq__ should not be defined"
which is equivalent to "__eq__ defined then __hash__ should be defined" (the second part, which is clear to me)

If not, why should a class not define __hash__, if it does not define __eq__?




From auriocus at gmx.de  Wed Feb  5 16:19:53 2020
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Wed, 5 Feb 2020 22:19:53 +0100
Subject: Documentation of __hash__
In-Reply-To: <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
 <24122.64150.717391.820747@localhost.localdomain>
 <mailman.265.1580928060.9276.python-list@python.org>
 <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>
Message-ID: <r1fbhq$nba$1@dont-email.me>

Am 05.02.20 um 20:55 schrieb klauck2 at gmail.com:

> If not, why should a class not define __hash__, if it does not define __eq__?

Hashes are not unique. When you insert or look up something in a 
hashtable, the hash is computed and used as the index into the table. 
Because the hash is not necessarily unique, if hash(a)=hash(b), it can 
still be that a=/= b. Therefore, in a second step, a is compared to b if 
the hashes match.

Therefore, you need a comparison operator which is compatible with the 
hash function, i.e. if a==b, then hash(a) must be equal to hash(b).

Christian


From ijbrewster at alaska.edu  Wed Feb  5 19:48:54 2020
From: ijbrewster at alaska.edu (Israel Brewster)
Date: Wed, 5 Feb 2020 15:48:54 -0900
Subject: Multiprocessing, join(), and crashed processes
Message-ID: <5B16C4A5-92CD-41D7-B8A7-17475849CA37@alaska.edu>

In a number of places I have constructs where I launch several processes using the multiprocessing library, then loop through said processes calling join() on each one to wait until they are all complete. In general, this works well, with the *apparent* exception of if something causes one of the child processes to crash (not throw an exception, actually crash). In that event, it appears that the call to join() hangs indefinitely. How can I best handle this? Should I put a timeout on the join, and put it in a loop, such that every 5 seconds or so it breaks, checks to see if the process is still actually running, and if so goes back and calls join again? Or is there a better option to say ?wait until this process is done, however long that may be, unless it crashes??
---
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 cs at cskk.id.au  Thu Feb  6 00:53:23 2020
From: cs at cskk.id.au (Cameron Simpson)
Date: Thu, 6 Feb 2020 16:53:23 +1100
Subject: Multiprocessing, join(), and crashed processes
In-Reply-To: <5B16C4A5-92CD-41D7-B8A7-17475849CA37@alaska.edu>
References: <5B16C4A5-92CD-41D7-B8A7-17475849CA37@alaska.edu>
Message-ID: <20200206055323.GA50448@cskk.homeip.net>

On 05Feb2020 15:48, Israel Brewster <ijbrewster at alaska.edu> wrote:
>In a number of places I have constructs where I launch several 
>processes using the multiprocessing library, then loop through said 
>processes calling join() on each one to wait until they are all 
>complete. In general, this works well, with the *apparent* exception of 
>if something causes one of the child processes to crash (not throw an 
>exception, actually crash). In that event, it appears that the call to 
>join() hangs indefinitely. How can I best handle this? Should I put a 
>timeout on the join, and put it in a loop, such that every 5 seconds or 
>so it breaks, checks to see if the process is still actually running, 
>and if so goes back and calls join again? Or is there a better option 
>to say ?wait until this process is done, however long that may be, 
>unless it crashes??

What's your platform/OS? And what does "crash" mean, precisely?

If a subprocess exits, join() should terminate.

If the subprocess _hangs_, then join will not see it exit, because it 
hasn't. And join will hang.

You'll need to define what happens when your subprocesses crash.

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

From frank at chagford.com  Thu Feb  6 07:58:34 2020
From: frank at chagford.com (Frank Millman)
Date: Thu, 6 Feb 2020 14:58:34 +0200
Subject: Change in behaviour Python 3.7 > 3.8
Message-ID: <r1h2hr$1l2d$1@ciao.gmane.io>

Hi all

I have noticed a change in behaviour in Python 3.8 compared with 
previous versions of Python going back to at least 2.7. I am pretty sure 
that it is not a problem, and is caused by my relying on a certain 
sequence of events at shutdown, which of course is not guaranteed. 
However, any change in behaviour is worth reporting, just in case it was 
unintended, so I thought I would mention it here.

I have a module (A) containing common objects shared by other modules. I 
have a module (B) which imports one of these common objects - a set().

Module B defines a Class, and creates a global instance of this class 
when the module is created. This instance is never explicitly deleted, 
so I assume it gets implicitly deleted at shutdown. It has a __del__() 
method (only for temporary debugging purposes, so will be removed for 
production) and the __del__ method uses the set() object imported from 
Module A.

This has worked for years, but now when the __del__ method is called, 
the common object, which was a set(), has become None.

My assumption is that Module A gets cleaned up before Module B, and when 
Module B tries to access the common set() object it no longer exists.

I have a workaround, so I am just reporting this for the record.

Frank Millman


From barry at barrys-emacs.org  Thu Feb  6 09:43:54 2020
From: barry at barrys-emacs.org (Barry)
Date: Thu, 6 Feb 2020 14:43:54 +0000
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <r1h2hr$1l2d$1@ciao.gmane.io>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
Message-ID: <50CA7E4F-1C23-4B67-BF05-A9CD8283C73D@barrys-emacs.org>



> On 6 Feb 2020, at 13:01, Frank Millman <frank at chagford.com> wrote:
> 
> ?Hi all
> 
> I have noticed a change in behaviour in Python 3.8 compared with previous versions of Python going back to at least 2.7. I am pretty sure that it is not a problem, and is caused by my relying on a certain sequence of events at shutdown, which of course is not guaranteed. However, any change in behaviour is worth reporting, just in case it was unintended, so I thought I would mention it here.
> 
> I have a module (A) containing common objects shared by other modules. I have a module (B) which imports one of these common objects - a set().
> 
> Module B defines a Class, and creates a global instance of this class when the module is created. This instance is never explicitly deleted, so I assume it gets implicitly deleted at shutdown. It has a __del__() method (only for temporary debugging purposes, so will be removed for production) and the __del__ method uses the set() object imported from Module A.
> 
> This has worked for years, but now when the __del__ method is called, the common object, which was a set(), has become None.
> 
> My assumption is that Module A gets cleaned up before Module B, and when Module B tries to access the common set() object it no longer exists.
> 
> I have a workaround, so I am just reporting this for the record.

I recall reading that shutdown had changed in 3.8, but cannot find the email/webpage that I read.

These days I assume that __del__ will almost never be useful and use exploit calls to tell an object I am finished with it and it can do its resource clean up.

Barry


> 
> Frank Millman
> 
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From souvik.viksou at gmail.com  Thu Feb  6 10:48:29 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Thu, 6 Feb 2020 21:18:29 +0530
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <r1h2hr$1l2d$1@ciao.gmane.io>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
Message-ID: <CADRXHdLkzBjBTs5fnobjfmTewb9FxA6SjfGaJPfj-Z8buB5itA@mail.gmail.com>

You might find this helpful.

https://docs.python.org/3/reference/datamodel.html

Thank you ??

On Thu, Feb 6, 2020, 6:29 PM Frank Millman <frank at chagford.com> wrote:

> Hi all
>
> I have noticed a change in behaviour in Python 3.8 compared with
> previous versions of Python going back to at least 2.7. I am pretty sure
> that it is not a problem, and is caused by my relying on a certain
> sequence of events at shutdown, which of course is not guaranteed.
> However, any change in behaviour is worth reporting, just in case it was
> unintended, so I thought I would mention it here.
>
> I have a module (A) containing common objects shared by other modules. I
> have a module (B) which imports one of these common objects - a set().
>
> Module B defines a Class, and creates a global instance of this class
> when the module is created. This instance is never explicitly deleted,
> so I assume it gets implicitly deleted at shutdown. It has a __del__()
> method (only for temporary debugging purposes, so will be removed for
> production) and the __del__ method uses the set() object imported from
> Module A.
>
> This has worked for years, but now when the __del__ method is called,
> the common object, which was a set(), has become None.
>
> My assumption is that Module A gets cleaned up before Module B, and when
> Module B tries to access the common set() object it no longer exists.
>
> I have a workaround, so I am just reporting this for the record.
>
> Frank Millman
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From storchaka at gmail.com  Thu Feb  6 13:12:36 2020
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Thu, 6 Feb 2020 20:12:36 +0200
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <r1h2hr$1l2d$1@ciao.gmane.io>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
Message-ID: <r1hkuk$22pa$1@ciao.gmane.io>

06.02.20 14:58, Frank Millman ????:
> I have noticed a change in behaviour in Python 3.8 compared with 
> previous versions of Python going back to at least 2.7. I am pretty sure 
> that it is not a problem, and is caused by my relying on a certain 
> sequence of events at shutdown, which of course is not guaranteed. 
> However, any change in behaviour is worth reporting, just in case it was 
> unintended, so I thought I would mention it here.
> 
> I have a module (A) containing common objects shared by other modules. I 
> have a module (B) which imports one of these common objects - a set().
> 
> Module B defines a Class, and creates a global instance of this class 
> when the module is created. This instance is never explicitly deleted, 
> so I assume it gets implicitly deleted at shutdown. It has a __del__() 
> method (only for temporary debugging purposes, so will be removed for 
> production) and the __del__ method uses the set() object imported from 
> Module A.
> 
> This has worked for years, but now when the __del__ method is called, 
> the common object, which was a set(), has become None.
> 
> My assumption is that Module A gets cleaned up before Module B, and when 
> Module B tries to access the common set() object it no longer exists.

Do you import a common object *from* a module or import a module and 
access a common object as its attribute?

If the latter, the change may be related to
https://bugs.python.org/issue33331 . Modules are now cleaned up in the 
reversed order of importing.

In any case, the order of cleaning up modules is not specified/


From klauck2 at gmail.com  Thu Feb  6 14:13:45 2020
From: klauck2 at gmail.com (klauck2 at gmail.com)
Date: Thu, 6 Feb 2020 11:13:45 -0800 (PST)
Subject: Documentation of __hash__
In-Reply-To: <r1fbhq$nba$1@dont-email.me>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
 <24122.64150.717391.820747@localhost.localdomain>
 <mailman.265.1580928060.9276.python-list@python.org>
 <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>
 <r1fbhq$nba$1@dont-email.me>
Message-ID: <78ee3d73-82c6-4483-b6c1-ffa3c0d9ae1d@googlegroups.com>

The default __eq__ method (object identity) is compatible with all (reasonable) self-defined __hash__ method.

Stefan

From frank at chagford.com  Fri Feb  7 00:27:21 2020
From: frank at chagford.com (Frank Millman)
Date: Fri, 7 Feb 2020 07:27:21 +0200
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <r1h2hr$1l2d$1@ciao.gmane.io>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
Message-ID: <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>

On 2020-02-06 2:58 PM, Frank Millman wrote:

[...]
> 
> I have a module (A) containing common objects shared by other modules. I 
> have a module (B) which imports one of these common objects - a set().
> 
[...]
> 
> This has worked for years, but now when the __del__ method is called, 
> the common object, which was a set(), has become None.
> 
> My assumption is that Module A gets cleaned up before Module B, and when 
> Module B tries to access the common set() object it no longer exists.
> 
> I have a workaround, so I am just reporting this for the record.

Thanks to all for the replies.

@Serhiy
I import the common object *from* Module A.

@Dennis
Thanks for the references. I knew that __del__() should not be relied 
on, but I have not seen the reasons spelled out so clearly before.

@Barry
I agree that __del__() is rarely useful, but I have not come up with an 
alternative to achieve what I want to do. My app is a long-running 
server, and creates many objects on-the-fly depending on user input. 
They should be short-lived, and be removed when they go out of scope, 
but I can concerned that I may leave a dangling reference somewhere that 
keeps one of them alive, resulting in a memory leak over time. Creating 
a _del__() method and displaying a message to say 'I am being deleted' 
has proved effective, and has in fact highlighted a few cases where 
there was a real problem.

My solution to this particular issue is to explicitly delete the global 
instance at program end, so I do not rely on the interpreter to clean it 
up. It works.

Thanks again

Frank


From frank at chagford.com  Fri Feb  7 00:27:21 2020
From: frank at chagford.com (Frank Millman)
Date: Fri, 7 Feb 2020 07:27:21 +0200
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <r1h2hr$1l2d$1@ciao.gmane.io>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
Message-ID: <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>

On 2020-02-06 2:58 PM, Frank Millman wrote:

[...]
> 
> I have a module (A) containing common objects shared by other modules. I 
> have a module (B) which imports one of these common objects - a set().
> 
[...]
> 
> This has worked for years, but now when the __del__ method is called, 
> the common object, which was a set(), has become None.
> 
> My assumption is that Module A gets cleaned up before Module B, and when 
> Module B tries to access the common set() object it no longer exists.
> 
> I have a workaround, so I am just reporting this for the record.

Thanks to all for the replies.

@Serhiy
I import the common object *from* Module A.

@Dennis
Thanks for the references. I knew that __del__() should not be relied 
on, but I have not seen the reasons spelled out so clearly before.

@Barry
I agree that __del__() is rarely useful, but I have not come up with an 
alternative to achieve what I want to do. My app is a long-running 
server, and creates many objects on-the-fly depending on user input. 
They should be short-lived, and be removed when they go out of scope, 
but I can concerned that I may leave a dangling reference somewhere that 
keeps one of them alive, resulting in a memory leak over time. Creating 
a _del__() method and displaying a message to say 'I am being deleted' 
has proved effective, and has in fact highlighted a few cases where 
there was a real problem.

My solution to this particular issue is to explicitly delete the global 
instance at program end, so I do not rely on the interpreter to clean it 
up. It works.

Thanks again

Frank

From barry at barrys-emacs.org  Fri Feb  7 06:06:10 2020
From: barry at barrys-emacs.org (Barry Scott)
Date: Fri, 7 Feb 2020 11:06:10 +0000
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
 <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>
Message-ID: <18750057-5220-42D4-8C35-21BA3B37FAFD@barrys-emacs.org>



> On 7 Feb 2020, at 05:27, Frank Millman <frank at chagford.com> wrote:
> 
> @Barry
> I agree that __del__() is rarely useful, but I have not come up with an alternative to achieve what I want to do. My app is a long-running server, and creates many objects on-the-fly depending on user input. They should be short-lived, and be removed when they go out of scope, but I can concerned that I may leave a dangling reference somewhere that keeps one of them alive, resulting in a memory leak over time. Creating a _del__() method and displaying a message to say 'I am being deleted' has proved effective, and has in fact highlighted a few cases where there was a real problem.
> 
> My solution to this particular issue is to explicitly delete the global instance at program end, so I do not rely on the interpreter to clean it up. It works.

I have faced the same problem with leaking of objects.

What I did was use the python gc to find all the objects.

First I call gc.collect() to clean up all the objects what can be deleted.
Then I call gc.get_objects() to get a list of all the objects the gc is tracking.
I process that list into a collections.Counter() with counts of each type of object
that I call a snapshot.

By creating the snapshots at interesting times in the services life I can diff the
snapshots and see how the object usage changes over time.

The software I work on has an admin HTTP interface used internally that I use to request
snapshots white the service is running.

Barry


From frank at chagford.com  Fri Feb  7 08:49:02 2020
From: frank at chagford.com (Frank Millman)
Date: Fri, 7 Feb 2020 15:49:02 +0200
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <18750057-5220-42D4-8C35-21BA3B37FAFD@barrys-emacs.org>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
 <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>
 <18750057-5220-42D4-8C35-21BA3B37FAFD@barrys-emacs.org>
Message-ID: <4a185493-e73b-4e5d-d228-8135dfe89ef5@chagford.com>

On 2020-02-07 1:06 PM, Barry Scott wrote:
> 
> 
>> On 7 Feb 2020, at 05:27, Frank Millman <frank at chagford.com> wrote:
>>
>> @Barry
>> I agree that __del__() is rarely useful, but I have not come up with an alternative to achieve what I want to do. My app is a long-running server, and creates many objects on-the-fly depending on user input. They should be short-lived, and be removed when they go out of scope, but I can concerned that I may leave a dangling reference somewhere that keeps one of them alive, resulting in a memory leak over time. Creating a _del__() method and displaying a message to say 'I am being deleted' has proved effective, and has in fact highlighted a few cases where there was a real problem.
> 
> I have faced the same problem with leaking of objects.
> 
> What I did was use the python gc to find all the objects.
> 
> First I call gc.collect() to clean up all the objects what can be deleted.
> Then I call gc.get_objects() to get a list of all the objects the gc is tracking.
> I process that list into a collections.Counter() with counts of each type of object
> that I call a snapshot.
> 
> By creating the snapshots at interesting times in the services life I can diff the
> snapshots and see how the object usage changes over time.
> 
> The software I work on has an admin HTTP interface used internally that I use to request
> snapshots white the service is running.
> 

This is really useful. I will experiment with this and try to 
incorporate it into my project.

Thanks very much.

Frank



From frank at chagford.com  Fri Feb  7 08:49:02 2020
From: frank at chagford.com (Frank Millman)
Date: Fri, 7 Feb 2020 15:49:02 +0200
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <18750057-5220-42D4-8C35-21BA3B37FAFD@barrys-emacs.org>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
 <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>
 <18750057-5220-42D4-8C35-21BA3B37FAFD@barrys-emacs.org>
Message-ID: <4a185493-e73b-4e5d-d228-8135dfe89ef5@chagford.com>

On 2020-02-07 1:06 PM, Barry Scott wrote:
> 
> 
>> On 7 Feb 2020, at 05:27, Frank Millman <frank at chagford.com> wrote:
>>
>> @Barry
>> I agree that __del__() is rarely useful, but I have not come up with an alternative to achieve what I want to do. My app is a long-running server, and creates many objects on-the-fly depending on user input. They should be short-lived, and be removed when they go out of scope, but I can concerned that I may leave a dangling reference somewhere that keeps one of them alive, resulting in a memory leak over time. Creating a _del__() method and displaying a message to say 'I am being deleted' has proved effective, and has in fact highlighted a few cases where there was a real problem.
> 
> I have faced the same problem with leaking of objects.
> 
> What I did was use the python gc to find all the objects.
> 
> First I call gc.collect() to clean up all the objects what can be deleted.
> Then I call gc.get_objects() to get a list of all the objects the gc is tracking.
> I process that list into a collections.Counter() with counts of each type of object
> that I call a snapshot.
> 
> By creating the snapshots at interesting times in the services life I can diff the
> snapshots and see how the object usage changes over time.
> 
> The software I work on has an admin HTTP interface used internally that I use to request
> snapshots white the service is running.
> 

This is really useful. I will experiment with this and try to 
incorporate it into my project.

Thanks very much.

Frank


From Richard at Damon-Family.org  Fri Feb  7 10:14:58 2020
From: Richard at Damon-Family.org (Richard Damon)
Date: Fri, 7 Feb 2020 10:14:58 -0500
Subject: Documentation of __hash__
In-Reply-To: <78ee3d73-82c6-4483-b6c1-ffa3c0d9ae1d@googlegroups.com>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
 <24122.64150.717391.820747@localhost.localdomain>
 <mailman.265.1580928060.9276.python-list@python.org>
 <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>
 <r1fbhq$nba$1@dont-email.me>
 <78ee3d73-82c6-4483-b6c1-ffa3c0d9ae1d@googlegroups.com>
Message-ID: <dcc453c6-03b0-b4ea-fb46-f9be8afd740e@Damon-Family.org>

On 2/6/20 2:13 PM, klauck2 at gmail.com wrote:
> The default __eq__ method (object identity) is compatible with all (reasonable) self-defined __hash__ method.
>
> Stefan

If __eq__ compares just the id, then the only hash you need is the 
default that is also the id. If you define a separate hash function, 
which uses some of the 'value' of the object, then presumably you intend 
for objects where that 'value' matches to be equal, which won't happen 
with the default __eq__.

-- 
Richard Damon


From storchaka at gmail.com  Fri Feb  7 03:44:56 2020
From: storchaka at gmail.com (Serhiy Storchaka)
Date: Fri, 7 Feb 2020 10:44:56 +0200
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
 <453d72be-a1f3-6f0d-211a-31a6d1a008b7@chagford.com>
Message-ID: <r1j828$10tg$1@ciao.gmane.io>

07.02.20 07:27, Frank Millman ????:
> @Serhiy
> I import the common object *from* Module A.

Sorry, I incorrectly described the change made in issue33331. Even if 
you import it from module A, you can see that it was set to None at the 
time of executing __del__. But you could see this even before 
issue33331. It was just your luck that you did not fail before.

The robust way of solving such issues is to keep a reference to all 
objects used in __del__:

     def __del__(self, common_object=common_object):
         ...


From random832 at fastmail.com  Fri Feb  7 10:29:00 2020
From: random832 at fastmail.com (Random832)
Date: Fri, 07 Feb 2020 10:29:00 -0500
Subject: Documentation of __hash__
In-Reply-To: <dcc453c6-03b0-b4ea-fb46-f9be8afd740e@Damon-Family.org>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
 <24122.64150.717391.820747@localhost.localdomain>
 <mailman.265.1580928060.9276.python-list@python.org>
 <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>
 <r1fbhq$nba$1@dont-email.me>
 <78ee3d73-82c6-4483-b6c1-ffa3c0d9ae1d@googlegroups.com>
 <dcc453c6-03b0-b4ea-fb46-f9be8afd740e@Damon-Family.org>
Message-ID: <c7c42bfa-abe7-4916-b768-679d4565e796@www.fastmail.com>

On Fri, Feb 7, 2020, at 10:14, Richard Damon wrote:
> On 2/6/20 2:13 PM, klauck2 at gmail.com wrote:
> > The default __eq__ method (object identity) is compatible with all (reasonable) self-defined __hash__ method.
> >
> > Stefan
> 
> If __eq__ compares just the id, then the only hash you need is the 
> default that is also the id. If you define a separate hash function, 
> which uses some of the 'value' of the object, then presumably you intend 
> for objects where that 'value' matches to be equal, which won't happen 
> with the default __eq__.

I think Stefan's point is that, no matter how questionable the intent may sound, any deterministic __hash__ doesn't technically violate the hash/eq relationship with the default __eq__, because hash(x) will still be equal to hash(x). Only defining __eq__ can create the problem where x == y but hash(x) != hash(y).

The purpose of this rule is to save you from having to override the default __hash__ with something that will only raise an exception when you do not intend your class to be hashable.

From bill.orinski at gmail.com  Fri Feb  7 12:13:38 2020
From: bill.orinski at gmail.com (bill.orinski at gmail.com)
Date: Fri, 7 Feb 2020 10:13:38 -0700
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <CADRXHdLkzBjBTs5fnobjfmTewb9FxA6SjfGaJPfj-Z8buB5itA@mail.gmail.com>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
 <CADRXHdLkzBjBTs5fnobjfmTewb9FxA6SjfGaJPfj-Z8buB5itA@mail.gmail.com>
Message-ID: <000e01d5ddd9$f0899d90$d19cd8b0$@gmail.com>

Does anyone know of a service where I can send my STL files and have them converted to .x3g file, so I can simply upload the file to my SD card and run the parts in my Printer (Creator Pro Flashforge).
I have had no success in doing this and converting to the G-code required for my machine...

Thanks,

Bill O.

-----Original Message-----
From: Python-list <python-list-bounces+bill.orinski=gmail.com at python.org> On Behalf Of Souvik Dutta
Sent: Thursday, February 6, 2020 8:48 AM
To: Frank Millman <frank at chagford.com>
Cc: python-list at python.org
Subject: Re: Change in behaviour Python 3.7 > 3.8

You might find this helpful.

https://docs.python.org/3/reference/datamodel.html

Thank you ??

On Thu, Feb 6, 2020, 6:29 PM Frank Millman <frank at chagford.com> wrote:

> Hi all
>
> I have noticed a change in behaviour in Python 3.8 compared with 
> previous versions of Python going back to at least 2.7. I am pretty 
> sure that it is not a problem, and is caused by my relying on a 
> certain sequence of events at shutdown, which of course is not guaranteed.
> However, any change in behaviour is worth reporting, just in case it 
> was unintended, so I thought I would mention it here.
>
> I have a module (A) containing common objects shared by other modules. 
> I have a module (B) which imports one of these common objects - a set().
>
> Module B defines a Class, and creates a global instance of this class 
> when the module is created. This instance is never explicitly deleted, 
> so I assume it gets implicitly deleted at shutdown. It has a __del__() 
> method (only for temporary debugging purposes, so will be removed for
> production) and the __del__ method uses the set() object imported from 
> Module A.
>
> This has worked for years, but now when the __del__ method is called, 
> the common object, which was a set(), has become None.
>
> My assumption is that Module A gets cleaned up before Module B, and 
> when Module B tries to access the common set() object it no longer exists.
>
> I have a workaround, so I am just reporting this for the record.
>
> Frank Millman
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>
--
https://mail.python.org/mailman/listinfo/python-list


From ethan at stoneleaf.us  Fri Feb  7 14:04:27 2020
From: ethan at stoneleaf.us (Ethan Furman)
Date: Fri, 7 Feb 2020 11:04:27 -0800
Subject: Change in behaviour Python 3.7 > 3.8
In-Reply-To: <000e01d5ddd9$f0899d90$d19cd8b0$@gmail.com>
References: <r1h2hr$1l2d$1@ciao.gmane.io>
 <CADRXHdLkzBjBTs5fnobjfmTewb9FxA6SjfGaJPfj-Z8buB5itA@mail.gmail.com>
 <000e01d5ddd9$f0899d90$d19cd8b0$@gmail.com>
Message-ID: <5717f61e-2140-29ff-e37a-7d5713b1a056@stoneleaf.us>

On 02/07/2020 09:13 AM, bill.orinski at gmail.com wrote:

> Does anyone know of a service where I can send my STL files and have them converted to .x3g file, so I can simply upload the file to my SD card and run the parts in my Printer (Creator Pro Flashforge).
> I have had no success in doing this and converting to the G-code required for my machine...

Hopefully you sent this email to the wrong place.  python-list at python.org is for discussion of things related to the Python Programming Language.

Also, please start a new thread instead of piggy-backing on an existing thread.

--
~Ethan~

From jayrod84 at gmail.com  Sun Feb  9 10:46:01 2020
From: jayrod84 at gmail.com (J A)
Date: Sun, 9 Feb 2020 10:46:01 -0500
Subject: Pkg iter_module for different versions of python
Message-ID: <CAJD0NiThUg9XZtbmwUv5JxNfRaXEpqSUGidDrBYqayCgTNOjMw@mail.gmail.com>

as a sysadmin I've written several small tools as python command line apps
that get installed with python setup.py install. I would now like to create
another tool that would quickly list out all of my custom tools that may be
installed on the system. so that others can get a quick menu of what
commands are available. I believe I have a working app that uses the
iter_modules function to list out all of the names and then I just filter
based on names that I know to be mine.

My problem.. This works if everyone of my tools is only written in python 3
or 2, but not both. Are there any tricks to getting iter_modules to return
both python 3 and 2 installed modules?

J

From PythonList at DancesWithMice.info  Sun Feb  9 17:05:03 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 10 Feb 2020 11:05:03 +1300
Subject: Pkg iter_module for different versions of python
In-Reply-To: <CAJD0NiThUg9XZtbmwUv5JxNfRaXEpqSUGidDrBYqayCgTNOjMw@mail.gmail.com>
References: <CAJD0NiThUg9XZtbmwUv5JxNfRaXEpqSUGidDrBYqayCgTNOjMw@mail.gmail.com>
Message-ID: <8789680d-e7a5-73b8-590b-1c5e7980cc8d@DancesWithMice.info>

On 10/02/20 4:46 AM, J A wrote:
> as a sysadmin I've written several small tools as python command line apps
> that get installed with python setup.py install. I would now like to create
> another tool that would quickly list out all of my custom tools that may be
> installed on the system. so that others can get a quick menu of what
> commands are available. I believe I have a working app that uses the
> iter_modules function to list out all of the names and then I just filter
> based on names that I know to be mine.
> 
> My problem.. This works if everyone of my tools is only written in python 3
> or 2, but not both. Are there any tricks to getting iter_modules to return
> both python 3 and 2 installed modules?


Is the issue with iter_modules?

Remember that different Python versions are installed with separate 
libraries/paths. Accordingly, this lap-top's /usr/lib64 has both 
python2.7/ and python3.7/ sub-directories.

When an application is running under one* or the other, the sys.path 
changes accordingly (assuming the pkgutil.iter_modules(path=None) option).

(in case needed) Remember also that different installation methods may 
install packages in different directories anyway, eg personal 
installation or system-wide. So, even 'this' sys.path may not reveal 
what is present on 'this system'.

Might it be worth reversing the strategy and starting from a list of 
your modules, search likely portions of the directory-structure for 
'your stuff'?
(from a perspective of complete ignorance of the problem domain)

* requisite notice about not using deprecated Python2.n these days!
("Do as I say, but not as I do"? I suspect/hope that this system's 2.7 
is 'legacy' and no longer used for anything, including the OpSys)
-- 
Regards =dn

From jayrod84 at gmail.com  Sun Feb  9 18:10:07 2020
From: jayrod84 at gmail.com (J A)
Date: Sun, 9 Feb 2020 18:10:07 -0500
Subject: Fwd: Pkg iter_module for different versions of python
In-Reply-To: <CAJD0NiR3v8F-Fnmc7oupP9KkaWdJQtWTmVvgHK06M28huAgDpg@mail.gmail.com>
References: <CAJD0NiThUg9XZtbmwUv5JxNfRaXEpqSUGidDrBYqayCgTNOjMw@mail.gmail.com>
 <8789680d-e7a5-73b8-590b-1c5e7980cc8d@DancesWithMice.info>
 <CAJD0NiR3v8F-Fnmc7oupP9KkaWdJQtWTmVvgHK06M28huAgDpg@mail.gmail.com>
Message-ID: <CAJD0NiTRbeUY=XhVLSg_oAFUetmPg+UPzOvxT0_h+ksaG5uhPQ@mail.gmail.com>

Might anyone know of a root place where python modules get saved to for
both python2 and 3. I assume I'm looking for all of the places where
"site-packages" can be written to.

J
---------- Forwarded message ---------
From: J A <jayrod84 at gmail.com>
Date: Sun, 9 Feb 2020 at 17:56
Subject: Re: Pkg iter_module for different versions of python
To: DL Neil <PythonList at danceswithmice.info>


Ya.. perhaps it would make more sense to start with "dirty" knowledge. I.e.
a list of package/module names and then make sure they have the required
entry points, therefore "validating" that they belong to me.

Is there a valid directory structure to start from that is universal?
perhaps from there I could parse through site-packages/**/MODULE_name.whl
or something?

and yes no more python 2 however a few of my commands are/were wrapping
third party tool api's that are python 2 :/

J

On Sun, 9 Feb 2020 at 17:05, DL Neil via Python-list <python-list at python.org>
wrote:

> On 10/02/20 4:46 AM, J A wrote:
> > as a sysadmin I've written several small tools as python command line
> apps
> > that get installed with python setup.py install. I would now like to
> create
> > another tool that would quickly list out all of my custom tools that may
> be
> > installed on the system. so that others can get a quick menu of what
> > commands are available. I believe I have a working app that uses the
> > iter_modules function to list out all of the names and then I just filter
> > based on names that I know to be mine.
> >
> > My problem.. This works if everyone of my tools is only written in
> python 3
> > or 2, but not both. Are there any tricks to getting iter_modules to
> return
> > both python 3 and 2 installed modules?
>
>
> Is the issue with iter_modules?
>
> Remember that different Python versions are installed with separate
> libraries/paths. Accordingly, this lap-top's /usr/lib64 has both
> python2.7/ and python3.7/ sub-directories.
>
> When an application is running under one* or the other, the sys.path
> changes accordingly (assuming the pkgutil.iter_modules(path=None) option).
>
> (in case needed) Remember also that different installation methods may
> install packages in different directories anyway, eg personal
> installation or system-wide. So, even 'this' sys.path may not reveal
> what is present on 'this system'.
>
> Might it be worth reversing the strategy and starting from a list of
> your modules, search likely portions of the directory-structure for
> 'your stuff'?
> (from a perspective of complete ignorance of the problem domain)
>
> * requisite notice about not using deprecated Python2.n these days!
> ("Do as I say, but not as I do"? I suspect/hope that this system's 2.7
> is 'legacy' and no longer used for anything, including the OpSys)
> --
> Regards =dn
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From tushita-2000 at outlook.com  Mon Feb 10 06:00:25 2020
From: tushita-2000 at outlook.com (Tushita Parashar)
Date: Mon, 10 Feb 2020 11:00:25 +0000
Subject: Software not working
Message-ID: <CY4PR06MB30786209D2A64B6FD00480BD95190@CY4PR06MB3078.namprd06.prod.outlook.com>

Even after installing the software on my system the software isn?t running.

Sent from Windows Mail


From python at bladeshadow.org  Mon Feb 10 18:01:22 2020
From: python at bladeshadow.org (Python)
Date: Mon, 10 Feb 2020 17:01:22 -0600
Subject: datetime seems to be broken WRT timezones (even when you add them)
Message-ID: <20200210230122.GA32713@bladeshadow.org>

As best I can tell, Python has no means to make use of the system's
timezone info.  In order to make datetime "timezone aware", you need
to manually create a subclass of datetime.tzinfo, whose methods return
the correct values for the timezone you care about.  In the general
case, this is hard, but since the timezone my dates are in is always
GMT, it's no problem:

class GMT(datetime.tzinfo):
    def utcoffset(self, dt):
        return datetime.timedelta(hours=0)
    def dst(self, dt):
        return datetime.timedelta(minutes=0)
    def tzname(self, dt):
        return "GMT"

Now, you can instantiate a datetime.datetime object with the times you
want, and pass an instance of this class as the tzinfo argument to the
constructor.  Also no problem:

>>> dt = datetime.datetime(2020, 1, 31, 1, 30, 45, 987654, GMT())
>>> dt
datetime.datetime(2020, 1, 31, 1, 30, 45, 987654, tzinfo=<__main__.GMT object at 0x7f9084e2add0>)
>>> print dt
2020-01-31 01:30:45.987654+00:00

Note the tzinfo object, and the +00:00 indicating this is indeed in
GMT.  If you create a "naive" datetime object, you don't get that:

>>> xy = datetime.datetime(2020, 1, 31, 1, 30, 45, 987654)
>>> xy
datetime.datetime(2020, 1, 31, 1, 30, 45, 987654)
>>> print xy
2020-01-31 01:30:45.987654


So far, so good.  However, when you go to use this object, the time it
represents is in fact wrong.  For example:

>>> print dt.strftime("%s")
1580452245

Using the date command, we can easily see that it is incorrect:

# Ask for UTC, gives the wrong time
$ date -u -d "@1580452245"
Fri Jan 31 06:30:45 UTC 2020

# Ask for local time, gives the time I specified... which should have
# been in GMT, but is in my local timezone
$ date -d "@1580452245"
Fri Jan 31 01:30:45 EST 2020

And the correct value should have been:
$ date -d "2020-01-31 1:30:45 GMT" +%s
1580434245

Same results under Python2.7 or Python3.

:( :( :(

I suspect this is because the underlying implementation uses
strftime() which takes struct tm, which has no field to contain the
timezone info, and does not do the necessary conversion before handing
it off.  I'm not sure what the date command is doing differently, but
it clearly is able to get the correct answer.

Does Python have an alternative way to do the above, with correct
results?

Thanks


From skip.montanaro at gmail.com  Mon Feb 10 18:52:59 2020
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Mon, 10 Feb 2020 17:52:59 -0600
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <20200210230122.GA32713@bladeshadow.org>
References: <20200210230122.GA32713@bladeshadow.org>
Message-ID: <CANc-5UxAP2BBkonw3hnF-ors3sFUanAHnMmNWp9v_6KJQQNdrg@mail.gmail.com>

> As best I can tell, Python has no means to make use of the system's
> timezone info.  In order to make datetime "timezone aware", you need
> to manually create a subclass of datetime.tzinfo, whose methods return
> the correct values for the timezone you care about.
>
 ...

> Does Python have an alternative way to do the above, with correct
> results?
>

The datetime module's manipulation of timezones is pretty low-level. Maybe
try arrow?

https://arrow.readthedocs.io/en/latest/

Skip

>

From PythonList at DancesWithMice.info  Mon Feb 10 18:59:08 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 11 Feb 2020 12:59:08 +1300
Subject: Software not working
In-Reply-To: <CY4PR06MB30786209D2A64B6FD00480BD95190@CY4PR06MB3078.namprd06.prod.outlook.com>
References: <CY4PR06MB30786209D2A64B6FD00480BD95190@CY4PR06MB3078.namprd06.prod.outlook.com>
Message-ID: <850e7c7a-76bc-c239-3d32-d3b504799428@DancesWithMice.info>

On 11/02/20 12:00 AM, Tushita Parashar wrote:
> Even after installing the software on my system the software isn?t running.


Today, an (apparently) identical question, already asked and answered.

Please see the Python-Tutor list: "Python Beginner" msg.

-- 
Regards =dn

From python at bladeshadow.org  Mon Feb 10 19:02:14 2020
From: python at bladeshadow.org (Python)
Date: Mon, 10 Feb 2020 18:02:14 -0600
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <CANc-5UxAP2BBkonw3hnF-ors3sFUanAHnMmNWp9v_6KJQQNdrg@mail.gmail.com>
References: <20200210230122.GA32713@bladeshadow.org>
 <CANc-5UxAP2BBkonw3hnF-ors3sFUanAHnMmNWp9v_6KJQQNdrg@mail.gmail.com>
Message-ID: <20200211000201.GB32713@bladeshadow.org>

On Mon, Feb 10, 2020 at 05:52:59PM -0600, Skip Montanaro wrote:
> > As best I can tell, Python has no means to make use of the system's
> > timezone info.  In order to make datetime "timezone aware", you need
> > to manually create a subclass of datetime.tzinfo, whose methods return
> > the correct values for the timezone you care about.
> >
>  ...
> 
> > Does Python have an alternative way to do the above, with correct
> > results?
> >
> 
> The datetime module's manipulation of timezones is pretty low-level. Maybe
> try arrow?
> 
> https://arrow.readthedocs.io/en/latest/

Yeah, this looks like exacly what I'm looking for, but I need
something that's part of the standard Python distribution, due to
constraints I have no control over.  [This is perhaps not strictly
true, but for all intents and purposes...] 

FWIW, manipulating dates on POSIX systems is pretty much a nightmare,
so it's hard to blame Python entirely for the state of things.

Thanks though.


From rosuav at gmail.com  Mon Feb 10 19:04:28 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 11 Feb 2020 11:04:28 +1100
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <20200210230122.GA32713@bladeshadow.org>
References: <20200210230122.GA32713@bladeshadow.org>
Message-ID: <CAPTjJmoA43ctNHfA_fdrq0KRNp8U_gZFpA2Vu+1XCDro7J131w@mail.gmail.com>

On Tue, Feb 11, 2020 at 10:42 AM Python <python at bladeshadow.org> wrote:
>
> As best I can tell, Python has no means to make use of the system's
> timezone info.  In order to make datetime "timezone aware", you need
> to manually create a subclass of datetime.tzinfo, whose methods return
> the correct values for the timezone you care about.  In the general
> case, this is hard, but since the timezone my dates are in is always
> GMT, it's no problem:
>
> class GMT(datetime.tzinfo):
>     def utcoffset(self, dt):
>         return datetime.timedelta(hours=0)
>     def dst(self, dt):
>         return datetime.timedelta(minutes=0)
>     def tzname(self, dt):
>         return "GMT"
>
> Now, you can instantiate a datetime.datetime object with the times you
> want, and pass an instance of this class as the tzinfo argument to the
> constructor.  Also no problem:

Rather than try to create your own GMT() object, have you considered
using datetime.timezone.utc ? I tested it in your examples and it
works just fine.

ChrisA

From python at bladeshadow.org  Mon Feb 10 19:16:00 2020
From: python at bladeshadow.org (Python)
Date: Mon, 10 Feb 2020 18:16:00 -0600
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <CAPTjJmoA43ctNHfA_fdrq0KRNp8U_gZFpA2Vu+1XCDro7J131w@mail.gmail.com>
References: <20200210230122.GA32713@bladeshadow.org>
 <CAPTjJmoA43ctNHfA_fdrq0KRNp8U_gZFpA2Vu+1XCDro7J131w@mail.gmail.com>
Message-ID: <20200211001600.GC32713@bladeshadow.org>

On Tue, Feb 11, 2020 at 11:04:28AM +1100, Chris Angelico wrote:
> On Tue, Feb 11, 2020 at 10:42 AM Python <python at bladeshadow.org> wrote:
> > Now, you can instantiate a datetime.datetime object with the times you
> > want, and pass an instance of this class as the tzinfo argument to the
> > constructor.  Also no problem:
> 
> Rather than try to create your own GMT() object, have you considered
> using datetime.timezone.utc ? I tested it in your examples and it
> works just fine.

Not here it doesn't:

>>> import datetime
>>> dt = datetime.datetime(2020, 1, 31, 1, 30, 45, 987654, datetime.timezone.utc)
>>> print(dt)
2020-01-31 01:30:45.987654+00:00
>>> print(dt.strftime("%s"))
1580452245

That's the same erroneous result from my example.  The correct value
is again 1580434245.  Unless you've done something subtlely
different...

Also it's only available on Python3, which may not be the end of the
world, but the tool I'm working on is--for the moment at
least--expected to work on both python2.7 and 3.  But it's irrelevant
if it doesn't give the correct result, which seems to still be the
case.


From rosuav at gmail.com  Mon Feb 10 19:33:54 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 11 Feb 2020 11:33:54 +1100
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <20200211001600.GC32713@bladeshadow.org>
References: <20200210230122.GA32713@bladeshadow.org>
 <CAPTjJmoA43ctNHfA_fdrq0KRNp8U_gZFpA2Vu+1XCDro7J131w@mail.gmail.com>
 <20200211001600.GC32713@bladeshadow.org>
Message-ID: <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>

On Tue, Feb 11, 2020 at 11:17 AM Python <python at bladeshadow.org> wrote:
>
> On Tue, Feb 11, 2020 at 11:04:28AM +1100, Chris Angelico wrote:
> > On Tue, Feb 11, 2020 at 10:42 AM Python <python at bladeshadow.org> wrote:
> > > Now, you can instantiate a datetime.datetime object with the times you
> > > want, and pass an instance of this class as the tzinfo argument to the
> > > constructor.  Also no problem:
> >
> > Rather than try to create your own GMT() object, have you considered
> > using datetime.timezone.utc ? I tested it in your examples and it
> > works just fine.
>
> Not here it doesn't:
>
> >>> import datetime
> >>> dt = datetime.datetime(2020, 1, 31, 1, 30, 45, 987654, datetime.timezone.utc)
> >>> print(dt)
> 2020-01-31 01:30:45.987654+00:00
> >>> print(dt.strftime("%s"))
> 1580452245
>
> That's the same erroneous result from my example.  The correct value
> is again 1580434245.  Unless you've done something subtlely
> different...

I haven't verified the arithmetic or that the date command is actually
giving the result you want/expect here, but in my testing, I got what
looked like correct results. However, instead of using the
undocumented and unsupported strftime %s format code, I've been using
the timestamp() method:

https://docs.python.org/3/library/datetime.html#datetime.datetime.timestamp

rosuav at sikorsky:~$ cat utctest.py
import datetime
dt = datetime.datetime(2020, 1, 31, 1, 30, 45, 987654, datetime.timezone.utc)
print(dt)
print(dt.timestamp())
rosuav at sikorsky:~$ python3.9 utctest.py
2020-01-31 01:30:45.987654+00:00
1580434245.987654
rosuav at sikorsky:~$ python3.8 utctest.py
2020-01-31 01:30:45.987654+00:00
1580434245.987654
rosuav at sikorsky:~$ python3.7 utctest.py
2020-01-31 01:30:45.987654+00:00
1580434245.987654
rosuav at sikorsky:~$ python3.6 utctest.py
2020-01-31 01:30:45.987654+00:00
1580434245.987654
rosuav at sikorsky:~$ python3.5 utctest.py
2020-01-31 01:30:45.987654+00:00
1580434245.987654
rosuav at sikorsky:~$ python3.4 utctest.py
2020-01-31 01:30:45.987654+00:00
1580434245.987654

My interpretation is that, on your platform, strftime("%s") is broken
in the presence of tzinfo.

> Also it's only available on Python3, which may not be the end of the
> world, but the tool I'm working on is--for the moment at
> least--expected to work on both python2.7 and 3.  But it's irrelevant
> if it doesn't give the correct result, which seems to still be the
> case.
>

That may be your problem, but it's not mine, and I'm not going to
attempt to answer for Python 2.

ChrisA

From jon+usenet at unequivocal.eu  Mon Feb 10 19:59:04 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Tue, 11 Feb 2020 00:59:04 -0000 (UTC)
Subject: datetime seems to be broken WRT timezones (even when you add them)
References: <20200210230122.GA32713@bladeshadow.org>
 <mailman.288.1581378074.9276.python-list@python.org>
Message-ID: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>

On 2020-02-10, Python <python at bladeshadow.org> wrote:
> So far, so good.  However, when you go to use this object, the time it
> represents is in fact wrong.

Unsurprisingly for a language feature that's been around for nearly
17 years, no it isn't.

> For example:
>
>>>> print dt.strftime("%s")
> 1580452245

That's asking your libc's strftime to process the time through the
"%s" format code, which has no defined behaviour under either Python
or POSIX. If you're using GNU libc however then it uses the time
information given and the timezone from the 'TZ' environment variable
and returns seconds since the Unix epoch:

    >>> dt.strftime('%s')
    '1580452245'
    >>> import os
    >>> os.environ['TZ'] = 'UTC'
    >>> dt.strftime('%s')
    '1580434245'

If you need to know the seconds since the epoch then in Python 3.3+
you can do that with dt.timestamp(). In Python 2.7 you can use the UTC
class you created:

    (dt - datetime(1970, 1, 1, 0, 0, 0, 0, GMT())).total_seconds()


From python at bladeshadow.org  Mon Feb 10 20:29:02 2020
From: python at bladeshadow.org (Python)
Date: Mon, 10 Feb 2020 19:29:02 -0600
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
Message-ID: <20200211012902.GD32713@bladeshadow.org>

On Tue, Feb 11, 2020 at 11:33:54AM +1100, Chris Angelico wrote:
> [...] instead of using the undocumented and unsupported strftime %s
> format code

I'm not sure this characterization is accurate... the docs (for both
Python 2 and 3) say:

    The full set of format codes supported varies across platforms,
    because Python calls the platform C library?s strftime() function,
    and platform variations are common. To see the full set of format
    codes supported on your platform, consult the strftime(3)
    documentation.

And %s is surely there... so it is both documented and supported by
virtue of Python's docs saying that whatever your OS supports is
supported.  But this is largely beside the point.

> I've been using the timestamp() method:

That's the key piece of info.  This does appear to work, though still
not on python2.  That, as you say, is my problem.  But thankfully Jon
Ribbens has the save:


On Tue, Feb 11, 2020 at 12:59:04AM -0000, Jon Ribbens via Python-list wrote:
> On 2020-02-10, Python <python at bladeshadow.org> wrote:
> > So far, so good.  However, when you go to use this object, the time it
> > represents is in fact wrong.
> 
> Unsurprisingly for a language feature that's been around for nearly
> 17 years, no it isn't.

Well, fine, but it is at best not documented as clearly as it could be
(in the man pages of my system, which is not Python's fault).  But
you've given me what I need to solve my problem:

> >>>> print dt.strftime("%s")
> > 1580452245
> 
> That's asking your libc's strftime to process the time through the
> "%s" format code [...] If you're using GNU libc however then it uses the time
> information given and the timezone from the 'TZ' environment variable
> and returns seconds since the Unix epoch:

And knowing this, I can get what I need, on Python2 and python3, by
doing what I was already doing, but setting os.environ["TZ"] = "GMT"
in the code itself.  Sure it's a bit hacky, but it won't matter here,
and it gets the right answer, which does matter.

Thanks


From rosuav at gmail.com  Mon Feb 10 20:42:26 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 11 Feb 2020 12:42:26 +1100
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <20200211012902.GD32713@bladeshadow.org>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
Message-ID: <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>

On Tue, Feb 11, 2020 at 12:31 PM Python <python at bladeshadow.org> wrote:
>
> On Tue, Feb 11, 2020 at 11:33:54AM +1100, Chris Angelico wrote:
> > [...] instead of using the undocumented and unsupported strftime %s
> > format code
>
> I'm not sure this characterization is accurate... the docs (for both
> Python 2 and 3) say:
>
>     The full set of format codes supported varies across platforms,
>     because Python calls the platform C library?s strftime() function,
>     and platform variations are common. To see the full set of format
>     codes supported on your platform, consult the strftime(3)
>     documentation.
>
> And %s is surely there... so it is both documented and supported by
> virtue of Python's docs saying that whatever your OS supports is
> supported.  But this is largely beside the point.

https://docs.python.org/3/library/datetime.html#strftime-and-strptime-format-codes

The C standard mandates a particular set of format codes, quoted in
that page, and %s is not one of them. Also, Python has its own test
suite and it ensures certain behaviours of datetime.strftime, and %s
is not tested there. So from Python's point of view, I stand by the
description of %s as being undocumented and unsupported. It might
happen to work, but if you link Python against a different C standard
library, it could change that behaviour even on the same computer.

> > I've been using the timestamp() method:
>
> That's the key piece of info.  This does appear to work, though still
> not on python2.  That, as you say, is my problem.  But thankfully Jon
> Ribbens has the save:

Isn't it time to stop going to great effort to support Python 2?

> On Tue, Feb 11, 2020 at 12:59:04AM -0000, Jon Ribbens via Python-list wrote:
> > On 2020-02-10, Python <python at bladeshadow.org> wrote:
> > > So far, so good.  However, when you go to use this object, the time it
> > > represents is in fact wrong.
> >
> > Unsurprisingly for a language feature that's been around for nearly
> > 17 years, no it isn't.
>
> Well, fine, but it is at best not documented as clearly as it could be
> (in the man pages of my system, which is not Python's fault).  But
> you've given me what I need to solve my problem:
>
> > >>>> print dt.strftime("%s")
> > > 1580452245
> >
> > That's asking your libc's strftime to process the time through the
> > "%s" format code [...] If you're using GNU libc however then it uses the time
> > information given and the timezone from the 'TZ' environment variable
> > and returns seconds since the Unix epoch:
>
> And knowing this, I can get what I need, on Python2 and python3, by
> doing what I was already doing, but setting os.environ["TZ"] = "GMT"
> in the code itself.  Sure it's a bit hacky, but it won't matter here,
> and it gets the right answer, which does matter.
>

Yes, it's very hacky. The sort of hack that deserves a comment with a
TODO in it. :)

ChrisA

From klauck2 at gmail.com  Tue Feb 11 05:23:45 2020
From: klauck2 at gmail.com (klauck2 at gmail.com)
Date: Tue, 11 Feb 2020 02:23:45 -0800 (PST)
Subject: Documentation of __hash__
In-Reply-To: <mailman.280.1581089413.9276.python-list@python.org>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
 <24122.64150.717391.820747@localhost.localdomain>
 <mailman.265.1580928060.9276.python-list@python.org>
 <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>
 <r1fbhq$nba$1@dont-email.me>
 <78ee3d73-82c6-4483-b6c1-ffa3c0d9ae1d@googlegroups.com>
 <dcc453c6-03b0-b4ea-fb46-f9be8afd740e@Damon-Family.org>
 <c7c42bfa-abe7-4916-b768-679d4565e796@www.fastmail.com>
 <mailman.280.1581089413.9276.python-list@python.org>
Message-ID: <3a0e4141-ed51-4720-8ccd-ae985c7f3bf6@googlegroups.com>

On Friday, February 7, 2020 at 4:30:23 PM UTC+1, Random832 wrote:
> On Fri, Feb 7, 2020, at 10:14, Richard Damon wrote:
> > On 2/6/20 2:13 PM, klauck2 at gmail.com wrote:
> > > The default __eq__ method (object identity) is compatible with all (reasonable) self-defined __hash__ method.
> > >
> > > Stefan
> > 
> > If __eq__ compares just the id, then the only hash you need is the 
> > default that is also the id. If you define a separate hash function, 
> > which uses some of the 'value' of the object, then presumably you intend 
> > for objects where that 'value' matches to be equal, which won't happen 
> > with the default __eq__.
> 
> I think Stefan's point is that, no matter how questionable the intent may sound, any deterministic __hash__ doesn't technically violate the hash/eq relationship with the default __eq__, because hash(x) will still be equal to hash(x). Only defining __eq__ can create the problem where x == y but hash(x) != hash(y).

Yes, this is my question.

> 
> The purpose of this rule is to save you from having to override the default __hash__ with something that will only raise an exception when you do not intend your class to be hashable.

If I do not intend my class to be hashable, I will set __hash__ to None (according to the documentation).



From jon+usenet at unequivocal.eu  Tue Feb 11 05:56:36 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Tue, 11 Feb 2020 10:56:36 -0000 (UTC)
Subject: datetime seems to be broken WRT timezones (even when you add them)
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
Message-ID: <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>

On 2020-02-11, Chris Angelico <rosuav at gmail.com> wrote:
>> That's the key piece of info.  This does appear to work, though still
>> not on python2.  That, as you say, is my problem.  But thankfully Jon
>> Ribbens has the save:
>
> Isn't it time to stop going to great effort to support Python 2?

That depends on what existing systems people need to support. The main
project I work on pre-dates the existence of Python's 'datetime'
module, let alone Python 3. It still generally uses 1 and 0 for True
and False because True and False didn't exist when we started.

This project will never move to Python 3. It was a happy and momentous
day, fairly recently, when we were able to move to Python 2.7 - albeit
we're basically stuck on Python 2.7.5 (plus random patches from RedHat
making it not-really-2.7.5).

So while it's been about 6 years since anyone should have been
starting any new projects using Python 2, there are plenty of
projects that are older than that and still need supporting,
and often it'd take some pretty huge unavoidable requirement
to motivate a port to Python 3.

From rosuav at gmail.com  Tue Feb 11 06:05:15 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 11 Feb 2020 22:05:15 +1100
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
Message-ID: <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>

On Tue, Feb 11, 2020 at 10:01 PM Jon Ribbens via Python-list
<python-list at python.org> wrote:
>
> On 2020-02-11, Chris Angelico <rosuav at gmail.com> wrote:
> >> That's the key piece of info.  This does appear to work, though still
> >> not on python2.  That, as you say, is my problem.  But thankfully Jon
> >> Ribbens has the save:
> >
> > Isn't it time to stop going to great effort to support Python 2?
>
> That depends on what existing systems people need to support. The main
> project I work on pre-dates the existence of Python's 'datetime'
> module, let alone Python 3. It still generally uses 1 and 0 for True
> and False because True and False didn't exist when we started.
>
> This project will never move to Python 3. It was a happy and momentous
> day, fairly recently, when we were able to move to Python 2.7 - albeit
> we're basically stuck on Python 2.7.5 (plus random patches from RedHat
> making it not-really-2.7.5).
>
> So while it's been about 6 years since anyone should have been
> starting any new projects using Python 2, there are plenty of
> projects that are older than that and still need supporting,
> and often it'd take some pretty huge unavoidable requirement
> to motivate a port to Python 3.

Or just the recognition that, eventually, technical debt has to be
paid. I didn't say that everything has to stop supporting Py2
instantly now that it's 2020, but that it's time to stop going to
great lengths for it. Py2 is a legacy system and has been for a long
time now, and if it takes a lot of effort to keep maintaining it, then
it's time to consider porting to Py3. Just how much work are you going
to do, to avoid the work of porting?

ChrisA

From chapardar.parisa at gmail.com  Tue Feb 11 06:13:32 2020
From: chapardar.parisa at gmail.com (Parisa Ch)
Date: Tue, 11 Feb 2020 03:13:32 -0800 (PST)
Subject: braket an matrix in python
In-Reply-To: <mailman.252.1580753789.9276.python-list@python.org>
References: <45c82e87-1e6e-4bc3-92c4-75318187e64a@googlegroups.com>
 <r19o1m$1tvc$1@ciao.gmane.io>
 <mailman.252.1580753789.9276.python-list@python.org>
Message-ID: <81de0e63-6ffd-45b0-a78e-b099b4898735@googlegroups.com>

On Monday, February 3, 2020 at 9:46:43 PM UTC+3:30, Peter Otten wrote:
> Parisa Ch wrote:
> 
> > x=np.linspace(0,2*math.pi,n)
> > n=len(x)
> > r=int(math.ceil(f*n))
> > h=[np.sort(np.abs(x-x[i]))[r] for i in range(n)]
> > 
> > this is part of a python code. the last line is confusing? x is a matrix
> > and x[i] is a number. how  calculate x-x[i] for each i?
> >  why the put r in [] ?
> 

thank you so much 
> Brake it appart:
> 
> y = x - x[i]  # the numpy feature that makes that possible is called
>               # "broadcasting"
> 
> subtracts the value x[i] from every entry in the vector x
> 
> z = np.abs(y)
> 
> calculates the absolute value of every entry in y.
> 
> t = np.sort(z)
> 
> sorts the values in z and finally, assuming r is an integer,
> 
> u = t[r]  
> 
> looks up a single scalar in the vector.
> 
> The enclosing "list comprehension" [expr for item in iterable] builds a list 
> of n values calculated as sketched above.


From jon+usenet at unequivocal.eu  Tue Feb 11 06:13:54 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Tue, 11 Feb 2020 11:13:54 -0000 (UTC)
Subject: datetime seems to be broken WRT timezones (even when you add them)
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <mailman.297.1581419129.9276.python-list@python.org>
Message-ID: <slrnr4533i.cvh.jon+usenet@sable.unequivocal.eu>

On 2020-02-11, Chris Angelico <rosuav at gmail.com> wrote:
> On Tue, Feb 11, 2020 at 10:01 PM Jon Ribbens via Python-list
><python-list at python.org> wrote:
>> So while it's been about 6 years since anyone should have been
>> starting any new projects using Python 2, there are plenty of
>> projects that are older than that and still need supporting,
>> and often it'd take some pretty huge unavoidable requirement
>> to motivate a port to Python 3.
>
> Or just the recognition that, eventually, technical debt has to be
> paid. I didn't say that everything has to stop supporting Py2
> instantly now that it's 2020, but that it's time to stop going to
> great lengths for it. Py2 is a legacy system and has been for a long
> time now, and if it takes a lot of effort to keep maintaining it, then
> it's time to consider porting to Py3. Just how much work are you going
> to do, to avoid the work of porting?

Not doing something generally doesn't involve any work. Occasionally
there's a very small amount of work when something that would have
been trivial in Python 3 is slightly harder in Python 2 - this thread
for example, where it appears to involve one extra line of code.

From lukasz at langa.pl  Tue Feb 11 08:05:03 2020
From: lukasz at langa.pl (=?utf-8?Q?=C5=81ukasz_Langa?=)
Date: Tue, 11 Feb 2020 14:05:03 +0100
Subject: [RELEASE] Python 3.8.2rc1 is now available for testing
Message-ID: <DD8197E4-8368-4624-80DC-8705EA64E5C7@langa.pl>

Python 3.8.2rc1 is the release candidate of the second maintenance release of Python 3.8. Go get it here:

https://www.python.org/downloads/release/python-382rc1/ <https://www.python.org/downloads/release/python-382rc1/>

Assuming no critical problems are found prior to 2020-02-17, the scheduled release date for 3.8.2 (as well as 3.9.0 alpha 4!), 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 3.8.2 and as such its main purpose is testing.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.3 planned for April 2020 (during sprints at PyCon US).

What?s new?

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. 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 version 3.8.2 specifically can be found in its change log <https://docs.python.org/release/3.8.2rc1/whatsnew/changelog.html#python-3-8-2-release-candidate-1>.

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/>


- ?

From python at bladeshadow.org  Tue Feb 11 11:54:38 2020
From: python at bladeshadow.org (Python)
Date: Tue, 11 Feb 2020 10:54:38 -0600
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
Message-ID: <20200211165438.GE32713@bladeshadow.org>

On Tue, Feb 11, 2020 at 12:42:26PM +1100, Chris Angelico wrote:
> > > I've been using the timestamp() method:
> >
> > That's the key piece of info.  This does appear to work, though still
> > not on python2.  That, as you say, is my problem.  But thankfully Jon
> > Ribbens has the save:
> 
> Isn't it time to stop going to great effort to support Python 

If you live in a world where you get to decide that, sure.  Not
everyone does.



From ethan at stoneleaf.us  Tue Feb 11 12:31:14 2020
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 11 Feb 2020 09:31:14 -0800
Subject: Documentation of __hash__
In-Reply-To: <3a0e4141-ed51-4720-8ccd-ae985c7f3bf6@googlegroups.com>
References: <D65CEB9B-08D5-4293-A9B1-9E6D90B11073@gmail.com>
 <24122.64150.717391.820747@localhost.localdomain>
 <mailman.265.1580928060.9276.python-list@python.org>
 <4f5b9e9d-9e22-4c25-ad07-73c9022693d6@googlegroups.com>
 <r1fbhq$nba$1@dont-email.me>
 <78ee3d73-82c6-4483-b6c1-ffa3c0d9ae1d@googlegroups.com>
 <dcc453c6-03b0-b4ea-fb46-f9be8afd740e@Damon-Family.org>
 <c7c42bfa-abe7-4916-b768-679d4565e796@www.fastmail.com>
 <mailman.280.1581089413.9276.python-list@python.org>
 <3a0e4141-ed51-4720-8ccd-ae985c7f3bf6@googlegroups.com>
Message-ID: <26a558c5-5135-1918-a7cf-dee47cf1d017@stoneleaf.us>

On 02/11/2020 02:23 AM, klauck2 at gmail.com wrote:
> On Friday, February 7, 2020 at 4:30:23 PM UTC+1, Random832 wrote:

>> The purpose of this rule is to save you from having to override the default __hash__ with something that will only raise an exception when you do not intend your class to be hashable.
> 
> If I do not intend my class to be hashable, I will set __hash__ to None (according to the documentation).

If you define your own __eq__ method, __hash__ is automatically set to None.

--
~Ethan~

From rosuav at gmail.com  Tue Feb 11 13:38:38 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 05:38:38 +1100
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <20200211165438.GE32713@bladeshadow.org>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <20200211165438.GE32713@bladeshadow.org>
Message-ID: <CAPTjJmoaq13f73ciKKOvJQ=u-gnFG=8PDcZ_L-yM1Zjodi1cNQ@mail.gmail.com>

On Wed, Feb 12, 2020 at 3:57 AM Python <python at bladeshadow.org> wrote:
>
> On Tue, Feb 11, 2020 at 12:42:26PM +1100, Chris Angelico wrote:
> > > > I've been using the timestamp() method:
> > >
> > > That's the key piece of info.  This does appear to work, though still
> > > not on python2.  That, as you say, is my problem.  But thankfully Jon
> > > Ribbens has the save:
> >
> > Isn't it time to stop going to great effort to support Python
>
> If you live in a world where you get to decide that, sure.  Not
> everyone does.
>

Everyone gets to decide how much time and effort they put into
supporting an old and unsupported system. Are you telling me that
someone is enslaving you and forcing you to continue supporting Python
2, or are you actually saying that it's less effort to keep
maintaining old code than to port to Py3? As I said in the previous
email, I did NOT say that it's time to instantly drop Py2 like a hot
potato. (And if you do nothing, a hot potato just becomes a cold
potato. Thank you, Bernard.)

ChrisA

From python at bladeshadow.org  Tue Feb 11 14:43:09 2020
From: python at bladeshadow.org (Python)
Date: Tue, 11 Feb 2020 13:43:09 -0600
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <CAPTjJmoaq13f73ciKKOvJQ=u-gnFG=8PDcZ_L-yM1Zjodi1cNQ@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <20200211165438.GE32713@bladeshadow.org>
 <CAPTjJmoaq13f73ciKKOvJQ=u-gnFG=8PDcZ_L-yM1Zjodi1cNQ@mail.gmail.com>
Message-ID: <20200211194309.GF32713@bladeshadow.org>

On Wed, Feb 12, 2020 at 05:38:38AM +1100, Chris Angelico wrote:
> > > Isn't it time to stop going to great effort to support Python
> >
> > If you live in a world where you get to decide that, sure.  Not
> > everyone does.
> >
> 
> Everyone gets to decide how much time and effort they put into
> supporting an old and unsupported system.

Mostly not...  In the real world you typically are beholden to
customers (be they internal or external), and you are beholden to your
bosses (be they the same or different people from the first group).
What you say is true only if you have no customers or bosses to whom
you have obligations, or have sufficient financial freedom or
influence to ignore them and are willing to accept the consequences.


From torriem at gmail.com  Tue Feb 11 15:01:56 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 13:01:56 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT timezones
 (even when you add them)
In-Reply-To: <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
Message-ID: <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>

On 2/11/20 4:05 AM, Chris Angelico wrote:
> Or just the recognition that, eventually, technical debt has to be
> paid. 

Speaking about technical debt is certainly fashionable these days.  As
if we've somehow discovered a brand new way of looking at things.  But
it doesn't matter what you do, there's always real cost, and therefore
always technical debt. Moving to Python 3 incurs technical debt.
Staying with Python 2 incurs technical debt.  Thus I wonder if the term
is actually that useful.

I know what you mean, though.  The cost of staying with Python2 is
increasing rapidly compared to the cost of porting to Python3.  Unlike
the nebulous term, "technical debt," the cost of staying with Python2 vs
porting to Python3 can be quantified in real dollar amounts.  I've no
doubt that the calculus is in favor of Python2 a while longer for many
people.

From rosuav at gmail.com  Tue Feb 11 15:04:50 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 07:04:50 +1100
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <20200211194309.GF32713@bladeshadow.org>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <20200211165438.GE32713@bladeshadow.org>
 <CAPTjJmoaq13f73ciKKOvJQ=u-gnFG=8PDcZ_L-yM1Zjodi1cNQ@mail.gmail.com>
 <20200211194309.GF32713@bladeshadow.org>
Message-ID: <CAPTjJmqVU1rqRC231Hp78Lbb5DXSno+mkGmvhiTFc5q49QQk_A@mail.gmail.com>

On Wed, Feb 12, 2020 at 6:45 AM Python <python at bladeshadow.org> wrote:
>
> On Wed, Feb 12, 2020 at 05:38:38AM +1100, Chris Angelico wrote:
> > > > Isn't it time to stop going to great effort to support Python
> > >
> > > If you live in a world where you get to decide that, sure.  Not
> > > everyone does.
> > >
> >
> > Everyone gets to decide how much time and effort they put into
> > supporting an old and unsupported system.
>
> Mostly not...  In the real world you typically are beholden to
> customers (be they internal or external), and you are beholden to your
> bosses (be they the same or different people from the first group).
> What you say is true only if you have no customers or bosses to whom
> you have obligations, or have sufficient financial freedom or
> influence to ignore them and are willing to accept the consequences.
>

Is your boss/client smart enough to understand the concept of putting
in effort now to pay off significant dividends later?

Does your boss/client recognize that using software that isn't getting
security patches means you're vulnerable?

Actually, does your boss/client even care what your chosen language
is? Certainly in the case of clients or customers, it's extremely
common for them to have expectations in terms of "make it work", not
"keep it running on Python 2".

So long as it's fairly easy to keep it going on Py2, sure, keep it
going on Py2. But if it's going to be a lot of effort - and,
increasingly, it will - then you need to be willing to take the
non-lazy option and do the migration, rather than perpetually putting
it off and incurring more and more technical debt in the process.

ChrisA

From rosuav at gmail.com  Tue Feb 11 15:09:12 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 07:09:12 +1100
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
Message-ID: <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>

On Wed, Feb 12, 2020 at 7:03 AM Michael Torrie <torriem at gmail.com> wrote:
>
> On 2/11/20 4:05 AM, Chris Angelico wrote:
> > Or just the recognition that, eventually, technical debt has to be
> > paid.
>
> Speaking about technical debt is certainly fashionable these days.  As
> if we've somehow discovered a brand new way of looking at things.  But
> it doesn't matter what you do, there's always real cost, and therefore
> always technical debt. Moving to Python 3 incurs technical debt.
> Staying with Python 2 incurs technical debt.  Thus I wonder if the term
> is actually that useful.
>
> I know what you mean, though.  The cost of staying with Python2 is
> increasing rapidly compared to the cost of porting to Python3.  Unlike
> the nebulous term, "technical debt," the cost of staying with Python2 vs
> porting to Python3 can be quantified in real dollar amounts.  I've no
> doubt that the calculus is in favor of Python2 a while longer for many
> people.

What you're talking about is costs in general, but "debt" is a very
specific term. You accrue technical debt whenever you "borrow" time
from the future - doing something that's less effort now at the
expense of being worse in the future. You pay off that debt when you
sink time into something in order to make it easier to work on in the
future. The most common form of technical debt is legacy code, where
you often end up paying interest on the debt every time you dip your
toes into the code to make a small change, avoiding the work of
actually refactoring things and fixing the problems.

Porting to Python 3 should *improve* your codebase, so it should be a
way of shedding technical debt. (Unless you do it by running 2to3 on
your code and hoping for the best. But that's a bad idea for many
other reasons.)

ChrisA

From barry at barrys-emacs.org  Tue Feb 11 16:17:44 2020
From: barry at barrys-emacs.org (Barry Scott)
Date: Tue, 11 Feb 2020 21:17:44 +0000
Subject: datetime seems to be broken WRT timezones (even when you add them)
In-Reply-To: <20200210230122.GA32713@bladeshadow.org>
References: <20200210230122.GA32713@bladeshadow.org>
Message-ID: <D0F2997C-F66D-4FB1-BB13-16F93D2B7851@barrys-emacs.org>


> On 10 Feb 2020, at 23:01, Python <python at bladeshadow.org> wrote:
> 
> As best I can tell, Python has no means to make use of the system's
> timezone info.  In order to make datetime "timezone aware", you need
> to manually create a subclass of datetime.tzinfo, whose methods return
> the correct values for the timezone you care about.  In the general
> case, this is hard, but since the timezone my dates are in is always
> GMT, it's no problem:
> 
> class GMT(datetime.tzinfo):
>    def utcoffset(self, dt):
>        return datetime.timedelta(hours=0)
>    def dst(self, dt):
>        return datetime.timedelta(minutes=0)
>    def tzname(self, dt):
>        return "GMT"
> 
> Now, you can instantiate a datetime.datetime object with the times you
> want, and pass an instance of this class as the tzinfo argument to the
> constructor.  Also no problem:


>>>> dt = datetime.datetime(2020, 1, 31, 1, 30, 45, 987654, GMT())
>>>> dt
> datetime.datetime(2020, 1, 31, 1, 30, 45, 987654, tzinfo=<__main__.GMT object at 0x7f9084e2add0>)
>>>> print dt
> 2020-01-31 01:30:45.987654+00:00
> 
> Note the tzinfo object, and the +00:00 indicating this is indeed in
> GMT.  If you create a "naive" datetime object, you don't get that:
> 
>>>> xy = datetime.datetime(2020, 1, 31, 1, 30, 45, 987654)
>>>> xy
> datetime.datetime(2020, 1, 31, 1, 30, 45, 987654)
>>>> print xy
> 2020-01-31 01:30:45.987654
> 
> 
> So far, so good.  However, when you go to use this object, the time it
> represents is in fact wrong.  For example:
> 
>>>> print dt.strftime("%s")
> 1580452245
> 
> Using the date command, we can easily see that it is incorrect:
> 
> # Ask for UTC, gives the wrong time
> $ date -u -d "@1580452245"
> Fri Jan 31 06:30:45 UTC 2020
> 
> # Ask for local time, gives the time I specified... which should have
> # been in GMT, but is in my local timezone
> $ date -d "@1580452245"
> Fri Jan 31 01:30:45 EST 2020
> 
> And the correct value should have been:
> $ date -d "2020-01-31 1:30:45 GMT" +%s
> 1580434245
> 
> Same results under Python2.7 or Python3.
> 
> :( :( :(
> 
> I suspect this is because the underlying implementation uses
> strftime() which takes struct tm, which has no field to contain the
> timezone info, and does not do the necessary conversion before handing
> it off.  I'm not sure what the date command is doing differently, but
> it clearly is able to get the correct answer.
> 
> Does Python have an alternative way to do the above, with correct
> results?

I found that there are two useful PyPi packages to help with time zones.
pytz and tzlocal.

Here is a piece of code that I use to be timezone aware for UTC and the
local time zone. It works for Windows, macOS and unix thanks.

import datetime
import pytz
import tzlocal

def utcDatetime( timestamp ):
    return pytz.utc.localize( datetime.datetime.utcfromtimestamp( timestamp ) )

def localDatetime( datetime_or_timestamp ):
    if type(datetime_or_timestamp) in (int, float):
        dt = utcDatetime( datetime_or_timestamp )
    else:
        dt = datetime_or_timestamp

    local_timezone = tzlocal.get_localzone()
    local_dt = dt.astimezone( local_timezone )
    return local_dt

Barry



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


From barry at barrys-emacs.org  Tue Feb 11 16:25:35 2020
From: barry at barrys-emacs.org (Barry Scott)
Date: Tue, 11 Feb 2020 21:25:35 +0000
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
Message-ID: <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>



> On 11 Feb 2020, at 20:01, Michael Torrie <torriem at gmail.com> wrote:
> 
> On 2/11/20 4:05 AM, Chris Angelico wrote:
>> Or just the recognition that, eventually, technical debt has to be
>> paid. 
> 
> Speaking about technical debt is certainly fashionable these days.  As
> if we've somehow discovered a brand new way of looking at things.  But
> it doesn't matter what you do, there's always real cost, and therefore
> always technical debt. Moving to Python 3 incurs technical debt.
> Staying with Python 2 incurs technical debt.  Thus I wonder if the term
> is actually that useful.


At Chris said moving to python3 will *reduce* your technical debt.
You are paying off the debt.


> 
> I know what you mean, though.  The cost of staying with Python2 is
> increasing rapidly compared to the cost of porting to Python3.  Unlike
> the nebulous term, "technical debt," the cost of staying with Python2 vs
> porting to Python3 can be quantified in real dollar amounts.  I've no
> doubt that the calculus is in favor of Python2 a while longer for many
> people.

Not to mention that its harder to hire people to work on tech-debt legacy code.

Given the choice between a legacy python2 job and a modern python3 job
what would you choose?

Barry


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


From torriem at gmail.com  Tue Feb 11 19:31:24 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 17:31:24 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
Message-ID: <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>

On 2/11/20 2:25 PM, Barry Scott wrote:
> At Chris said moving to python3 will *reduce* your technical debt.
> You are paying off the debt.

While at the same time incurring new debt.

> Not to mention that its harder to hire people to work on tech-debt legacy code.
> 
> Given the choice between a legacy python2 job and a modern python3 job
> what would you choose?

If this was an income job, it would entirely depend on what it paid.  In
this day and age of the so-called "gig economy" it really doesn't
matter. I likely wouldn't be around long enough to have to personally
deal with the long-term consequences (pay the debt as you say).


From rosuav at gmail.com  Tue Feb 11 19:37:25 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 11:37:25 +1100
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
 <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
Message-ID: <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>

On Wed, Feb 12, 2020 at 11:32 AM Michael Torrie <torriem at gmail.com> wrote:
>
> On 2/11/20 2:25 PM, Barry Scott wrote:
> > At Chris said moving to python3 will *reduce* your technical debt.
> > You are paying off the debt.
>
> While at the same time incurring new debt.

That's not an intrinsic part of the rewrite, and will only happen if
you do the job sloppily.

Perhaps you're completely misunderstanding the meaning of the term?

https://en.wikipedia.org/wiki/Technical_debt
https://thedailywtf.com/articles/technical-debt

ChrisA

From torriem at gmail.com  Tue Feb 11 19:38:22 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 17:38:22 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
Message-ID: <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>

On 2/11/20 1:09 PM, Chris Angelico wrote:
> What you're talking about is costs in general, but "debt" is a very
> specific term. You accrue technical debt whenever you "borrow" time
> from the future - doing something that's less effort now at the
> expense of being worse in the future. You pay off that debt when you
> sink time into something in order to make it easier to work on in the
> future. The most common form of technical debt is legacy code, where
> you often end up paying interest on the debt every time you dip your
> toes into the code to make a small change, avoiding the work of
> actually refactoring things and fixing the problems.

It's all just different ways of accounting for the same things. In the
olden days before the term "technical debt" was invented, we called this
"total cost of ownership." This not only included the up front cost, but
the on-going (and potentially increasing) cost of maintenance, and often
even the future cost of migrating to a new solution.  So in the end it's
all the same: cost.  And it's never paid off.  Ever.  That's why I've
recently come to question the usefulness of the term "technical debt."

> Porting to Python 3 should *improve* your codebase, so it should be a
> way of shedding technical debt. (Unless you do it by running 2to3 on
> your code and hoping for the best. But that's a bad idea for many
> other reasons.)

But see, this is the thing.  There's brand new technical debt accrued
with the move to Python 3.  The cost of the debt is lower, but it's
still there.  Because maintenance is still going to cost.  Versions
still bump and require hopefully minor tweaks.  Eventually the bigger
jumps come. New ideas come along also. New frameworks, new paradigms.


I think it's a fallacy to think we can pay down technical debt.

I'm sure we probably disagree.

From rosuav at gmail.com  Tue Feb 11 19:42:42 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 11:42:42 +1100
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>
Message-ID: <CAPTjJmpcUsp7Nn6YpCWb6GeLXPjkzQppAxSZMoZox7uHDiKzhA@mail.gmail.com>

On Wed, Feb 12, 2020 at 11:39 AM Michael Torrie <torriem at gmail.com> wrote:
>
> On 2/11/20 1:09 PM, Chris Angelico wrote:
> > What you're talking about is costs in general, but "debt" is a very
> > specific term. You accrue technical debt whenever you "borrow" time
> > from the future - doing something that's less effort now at the
> > expense of being worse in the future. You pay off that debt when you
> > sink time into something in order to make it easier to work on in the
> > future. The most common form of technical debt is legacy code, where
> > you often end up paying interest on the debt every time you dip your
> > toes into the code to make a small change, avoiding the work of
> > actually refactoring things and fixing the problems.
>
> It's all just different ways of accounting for the same things. In the
> olden days before the term "technical debt" was invented, we called this
> "total cost of ownership." This not only included the up front cost, but
> the on-going (and potentially increasing) cost of maintenance, and often
> even the future cost of migrating to a new solution.  So in the end it's
> all the same: cost.  And it's never paid off.  Ever.  That's why I've
> recently come to question the usefulness of the term "technical debt."

Yes, if you consider the term to be synonymous with TCO, then
naturally you'll see it as useless. But it isn't. Technical debt is a
very specific thing and it CAN be paid off.

ChrisA

From torriem at gmail.com  Tue Feb 11 19:45:08 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 17:45:08 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
 <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
 <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>
Message-ID: <a958a7d4-54fe-d8ae-433e-95804bc63c02@gmail.com>

On 2/11/20 5:37 PM, Chris Angelico wrote:
> On Wed, Feb 12, 2020 at 11:32 AM Michael Torrie <torriem at gmail.com> wrote:
>>
>> On 2/11/20 2:25 PM, Barry Scott wrote:
>>> At Chris said moving to python3 will *reduce* your technical debt.
>>> You are paying off the debt.
>>
>> While at the same time incurring new debt.
> 
> That's not an intrinsic part of the rewrite, and will only happen if
> you do the job sloppily.
> 
> Perhaps you're completely misunderstanding the meaning of the term?
> 
> https://en.wikipedia.org/wiki/Technical_debt
> https://thedailywtf.com/articles/technical-debt

Yes I understand the meaning.  Getting code out the door now, at the
expense of maintenance later.  But really all code is technical debt.
That's my main point.  No one writes good enough code to be completely
free of this technical debt.

From python at bladeshadow.org  Tue Feb 11 19:53:13 2020
From: python at bladeshadow.org (Python)
Date: Tue, 11 Feb 2020 18:53:13 -0600
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
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 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
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 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
Message-ID: <20200212005313.GG32713@bladeshadow.org>

On Wed, Feb 12, 2020 at 07:09:12AM +1100, Chris Angelico wrote:
> On Wed, Feb 12, 2020 at 7:03 AM Michael Torrie <torriem at gmail.com> wrote:
> > Speaking about technical debt is certainly fashionable these days.  As
> > if we've somehow discovered a brand new way of looking at things.  But
> > it doesn't matter what you do, there's always real cost, and therefore
> > always technical debt. Moving to Python 3 incurs technical debt.
> > Staying with Python 2 incurs technical debt.  Thus I wonder if the term
> > is actually that useful.
[...]
> What you're talking about is costs in general, but "debt" is a very
> specific term. You accrue technical debt whenever you "borrow" time
> from the future - doing something that's less effort now at the
> expense of being worse in the future.

In pretty much every job I've ever worked at, funding work (e.g. with
humans to do it) with exactly and precisely the resources required is
basically impossible, and management prefers to underfund the work
than to overfund it, for cost-savings reasons.  This basically means
that any non-trivial work you do inevitably will become technical debt
IMMEDIATELY, because you will not be given the time to do the job
completely in the first place, there will inevitably be bugs which are
minor enough to ignore indefinitely, and most likely, in order to meet
arbitrary-but-nevertheless-real time constraints you will find
yourself obliged to take shortcuts.  So conceptually "costs" may be
different from "debt" but in practice, you never have one without the
other, and "debt" is really just "costs" you haven't paid yet.  

If your hypothetical project was implemented perfectly from the
beginning, in Python2.x, it may never need updating, and therefore
there may well never be any reason to port it to python3.  So doing so
would be neither "debt" nor "cost" but rather "waste."



From torriem at gmail.com  Tue Feb 11 19:55:06 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 17:55:06 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <CAPTjJmpcUsp7Nn6YpCWb6GeLXPjkzQppAxSZMoZox7uHDiKzhA@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>
 <CAPTjJmpcUsp7Nn6YpCWb6GeLXPjkzQppAxSZMoZox7uHDiKzhA@mail.gmail.com>
Message-ID: <530ac1ea-556f-ed24-baa7-d73161d72f92@gmail.com>

On 2/11/20 5:42 PM, Chris Angelico wrote:
> Yes, if you consider the term to be synonymous with TCO, then
> naturally you'll see it as useless. But it isn't. Technical debt is a
> very specific thing and it CAN be paid off.

We'll agree to disagree on the last bit. And I'm not the only one that
believes technical debt can never be paid off.  Microsoft got fabulously
wealthy incurring vast amounts of technical debt.  We can argue that
Windows is the result (it is), but what's killing Windows isn't the
technical debt. It's the cloud and the web.

From rosuav at gmail.com  Tue Feb 11 19:55:33 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 11:55:33 +1100
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <a958a7d4-54fe-d8ae-433e-95804bc63c02@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
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Message-ID: <CAPTjJmqAwmB=WUo7fjZW_q0SktMjvZ8BnUkQsO9s2XxTF9dodQ@mail.gmail.com>

On Wed, Feb 12, 2020 at 11:48 AM Michael Torrie <torriem at gmail.com> wrote:
>
> On 2/11/20 5:37 PM, Chris Angelico wrote:
> > On Wed, Feb 12, 2020 at 11:32 AM Michael Torrie <torriem at gmail.com> wrote:
> >>
> >> On 2/11/20 2:25 PM, Barry Scott wrote:
> >>> At Chris said moving to python3 will *reduce* your technical debt.
> >>> You are paying off the debt.
> >>
> >> While at the same time incurring new debt.
> >
> > That's not an intrinsic part of the rewrite, and will only happen if
> > you do the job sloppily.
> >
> > Perhaps you're completely misunderstanding the meaning of the term?
> >
> > https://en.wikipedia.org/wiki/Technical_debt
> > https://thedailywtf.com/articles/technical-debt
>
> Yes I understand the meaning.  Getting code out the door now, at the
> expense of maintenance later.  But really all code is technical debt.
> That's my main point.  No one writes good enough code to be completely
> free of this technical debt.

But you CAN rewrite code such that it reduces technical debt. You can
refactor code to make it more logical. You can update things to use
idioms that better express the concepts you're trying to represent
(maybe because those idioms require syntactic features that didn't
exist, or simply because you didn't know about them when you first
wrote the code). Maybe you'll still have SOME debt, but that doesn't
mean it's never reduced.

Debt is not a binary state.

ChrisA

From rosuav at gmail.com  Tue Feb 11 20:03:15 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 12:03:15 +1100
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <530ac1ea-556f-ed24-baa7-d73161d72f92@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
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 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
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 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
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Message-ID: <CAPTjJmo=9A=Exnx7CjnXxE4ftT7xynqH4AQ96LpmUMXJm0jdtg@mail.gmail.com>

On Wed, Feb 12, 2020 at 12:00 PM Michael Torrie <torriem at gmail.com> wrote:
>
> On 2/11/20 5:42 PM, Chris Angelico wrote:
> > Yes, if you consider the term to be synonymous with TCO, then
> > naturally you'll see it as useless. But it isn't. Technical debt is a
> > very specific thing and it CAN be paid off.
>
> We'll agree to disagree on the last bit. And I'm not the only one that
> believes technical debt can never be paid off.  Microsoft got fabulously
> wealthy incurring vast amounts of technical debt.  We can argue that
> Windows is the result (it is), but what's killing Windows isn't the
> technical debt. It's the cloud and the web.

So what you're showing is that, sometimes, technical debt isn't paid
off. It's a bit of a logical leap to go from there to "technical debt
CAN'T be paid off", don't you think?

ChrisA

From tjreedy at udel.edu  Tue Feb 11 19:36:03 2020
From: tjreedy at udel.edu (Terry Reedy)
Date: Tue, 11 Feb 2020 19:36:03 -0500
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
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 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
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 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
Message-ID: <r1vh9k$cdd$1@ciao.gmane.io>

On 2/11/2020 3:09 PM, Chris Angelico wrote:
> What you're talking about is costs in general, but "debt" is a very
> specific term. You accrue technical debt whenever you "borrow" time
> from the future - doing something that's less effort now at the
> expense of being worse in the future.

A prime example is sending code to production without automated tests.

> You pay off that debt when you
> sink time into something in order to make it easier to work on in the
> future.

In May 2013, idlelib had no test suite, no test/test_idle.py, and a few 
non-unittest unit tests.  Coverage is now somewhere around 50% and 
tested modules are much easier to work with.

> The most common form of technical debt is legacy code, where
> you often end up paying interest on the debt every time you dip your
> toes into the code to make a small change, avoiding the work of
> actually refactoring things and fixing the problems.

Without automated tests, every little change required manual testing and 
carried a non-zero chance of a regression.

-- 
Terry Jan Reedy


From torriem at gmail.com  Tue Feb 11 20:11:53 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 18:11:53 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <CAPTjJmqAwmB=WUo7fjZW_q0SktMjvZ8BnUkQsO9s2XxTF9dodQ@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
 <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
 <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>
 <a958a7d4-54fe-d8ae-433e-95804bc63c02@gmail.com>
 <CAPTjJmqAwmB=WUo7fjZW_q0SktMjvZ8BnUkQsO9s2XxTF9dodQ@mail.gmail.com>
Message-ID: <399c495d-741c-5081-4950-ced98b6c179f@gmail.com>

On 2/11/20 5:55 PM, Chris Angelico wrote:
> But you CAN rewrite code such that it reduces technical debt. You can
> refactor code to make it more logical. You can update things to use
> idioms that better express the concepts you're trying to represent
> (maybe because those idioms require syntactic features that didn't
> exist, or simply because you didn't know about them when you first
> wrote the code). Maybe you'll still have SOME debt, but that doesn't
> mean it's never reduced.
> 
> Debt is not a binary state.

I agree with that. But your reply to my other comment didn't say that.
it said "it CAN be paid off" which is a binary thing.  Debt is paid off
(no longer existing) or it's not.  Debt can be paid down and reduced of
course.

From torriem at gmail.com  Tue Feb 11 20:13:52 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 18:13:52 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <20200212005313.GG32713@bladeshadow.org>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
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 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <20200212005313.GG32713@bladeshadow.org>
Message-ID: <d6532a20-bc4d-269e-87d5-5cfabb93aba6@gmail.com>

On 2/11/20 5:53 PM, Python wrote:
> If your hypothetical project was implemented perfectly from the
> beginning, in Python2.x, it may never need updating, and therefore
> there may well never be any reason to port it to python3.  So doing so
> would be neither "debt" nor "cost" but rather "waste."

I would agree generally, except eventually Python2 will be unavailable
in your distro and may no longer be build-able on current OS's.  However
if the program is working as well as you state, then the cost of
converting to the current version of Python (whatever that will be) is
not going to increase significantly.  Whatever the case, technical debt
belongs to the entity that owns the code.

I know some folks still running an MS-DOS system for billing.  Thanks to
things like DosBox, this system will live on for a long time yet. It
works, and they don't have any real need for anything beyond it.  It's
never needed much updating or maintenance beyond maintenance they would
do anyway like backups.  Insane amounts of technical debt?  Maybe.  Or
maybe just the cost of buying a new off-the-shelf system, which would be
the same cost (or more likely a lot more with upgrades and service
plans) had they done this years ago.


From rosuav at gmail.com  Tue Feb 11 20:15:47 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 12:15:47 +1100
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <399c495d-741c-5081-4950-ced98b6c179f@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
 <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
 <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>
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Message-ID: <CAPTjJmp4f0NMfSSCkA50kkLtxPqLecg0iP+Co4A_-SVJ=hbiLQ@mail.gmail.com>

On Wed, Feb 12, 2020 at 12:13 PM Michael Torrie <torriem at gmail.com> wrote:
>
> On 2/11/20 5:55 PM, Chris Angelico wrote:
> > But you CAN rewrite code such that it reduces technical debt. You can
> > refactor code to make it more logical. You can update things to use
> > idioms that better express the concepts you're trying to represent
> > (maybe because those idioms require syntactic features that didn't
> > exist, or simply because you didn't know about them when you first
> > wrote the code). Maybe you'll still have SOME debt, but that doesn't
> > mean it's never reduced.
> >
> > Debt is not a binary state.
>
> I agree with that. But your reply to my other comment didn't say that.
> it said "it CAN be paid off" which is a binary thing.  Debt is paid off
> (no longer existing) or it's not.  Debt can be paid down and reduced of
> course.

Ahh, that might be a regional difference then, because around here,
it's possible to pay off some of a debt. That would be why we were
talking past each other.

ChrisA

From torriem at gmail.com  Tue Feb 11 20:30:33 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 11 Feb 2020 18:30:33 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <CAPTjJmp4f0NMfSSCkA50kkLtxPqLecg0iP+Co4A_-SVJ=hbiLQ@mail.gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
 <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
 <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>
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 <CAPTjJmqAwmB=WUo7fjZW_q0SktMjvZ8BnUkQsO9s2XxTF9dodQ@mail.gmail.com>
 <399c495d-741c-5081-4950-ced98b6c179f@gmail.com>
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Message-ID: <d40bd8d6-ba5b-c9a1-2521-fc4476bb0740@gmail.com>

On 2/11/20 6:15 PM, Chris Angelico wrote:
> On Wed, Feb 12, 2020 at 12:13 PM Michael Torrie <torriem at gmail.com> wrote:
>>
>> On 2/11/20 5:55 PM, Chris Angelico wrote:
>>> But you CAN rewrite code such that it reduces technical debt. You can
>>> refactor code to make it more logical. You can update things to use
>>> idioms that better express the concepts you're trying to represent
>>> (maybe because those idioms require syntactic features that didn't
>>> exist, or simply because you didn't know about them when you first
>>> wrote the code). Maybe you'll still have SOME debt, but that doesn't
>>> mean it's never reduced.
>>>
>>> Debt is not a binary state.
>>
>> I agree with that. But your reply to my other comment didn't say that.
>> it said "it CAN be paid off" which is a binary thing.  Debt is paid off
>> (no longer existing) or it's not.  Debt can be paid down and reduced of
>> course.
> 
> Ahh, that might be a regional difference then, because around here,
> it's possible to pay off some of a debt. That would be why we were
> talking past each other.

Yup I just came to that conclusion while typing a reply to your other
post!  My apologies.


From rosuav at gmail.com  Tue Feb 11 20:36:09 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 12 Feb 2020 12:36:09 +1100
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <d40bd8d6-ba5b-c9a1-2521-fc4476bb0740@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
 <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
 <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>
 <a958a7d4-54fe-d8ae-433e-95804bc63c02@gmail.com>
 <CAPTjJmqAwmB=WUo7fjZW_q0SktMjvZ8BnUkQsO9s2XxTF9dodQ@mail.gmail.com>
 <399c495d-741c-5081-4950-ced98b6c179f@gmail.com>
 <CAPTjJmp4f0NMfSSCkA50kkLtxPqLecg0iP+Co4A_-SVJ=hbiLQ@mail.gmail.com>
 <d40bd8d6-ba5b-c9a1-2521-fc4476bb0740@gmail.com>
Message-ID: <CAPTjJmptMeTJNmeboq3vtL3vM=BNgY9XUNmyXr444+eOKpX=Fg@mail.gmail.com>

On Wed, Feb 12, 2020 at 12:32 PM Michael Torrie <torriem at gmail.com> wrote:
>
> On 2/11/20 6:15 PM, Chris Angelico wrote:
> > On Wed, Feb 12, 2020 at 12:13 PM Michael Torrie <torriem at gmail.com> wrote:
> >>
> >> On 2/11/20 5:55 PM, Chris Angelico wrote:
> >>> But you CAN rewrite code such that it reduces technical debt. You can
> >>> refactor code to make it more logical. You can update things to use
> >>> idioms that better express the concepts you're trying to represent
> >>> (maybe because those idioms require syntactic features that didn't
> >>> exist, or simply because you didn't know about them when you first
> >>> wrote the code). Maybe you'll still have SOME debt, but that doesn't
> >>> mean it's never reduced.
> >>>
> >>> Debt is not a binary state.
> >>
> >> I agree with that. But your reply to my other comment didn't say that.
> >> it said "it CAN be paid off" which is a binary thing.  Debt is paid off
> >> (no longer existing) or it's not.  Debt can be paid down and reduced of
> >> course.
> >
> > Ahh, that might be a regional difference then, because around here,
> > it's possible to pay off some of a debt. That would be why we were
> > talking past each other.
>
> Yup I just came to that conclusion while typing a reply to your other
> post!  My apologies.
>

My apologies also :) It was one of those weird situations where I was
all "oh come on, he doesn't SERIOUSLY think that you never get rid of
any tech debt?" and you were all "oh come on, he doesn't SERIOUSLY
think that you can get rid of all of it", and we just both had no idea
:)

ChrisA

From .. at use.net  Wed Feb 12 02:02:27 2020
From: .. at use.net (..)
Date: Wed, 12 Feb 2020 07:02:27 +0000
Subject: python3 embedded in LibreOffice documents
Message-ID: <r207u4$2i1i$1@neodome.net>

Both Open- and LibreOffice use   APSO.oxt  to support py3 in Office .odt 
documents, such as HTML files et cetera.


So one can make a web page with python and BASIC code essentially and 
save it as a document, possibly throw in some EMOTET as well.


after  import NNTPlib
one can make a lil usenet client even!

From jon+usenet at unequivocal.eu  Wed Feb 12 07:15:09 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Wed, 12 Feb 2020 12:15:09 -0000 (UTC)
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <D91BF17E-A4DF-40BD-91CE-F5846752643A@barrys-emacs.org>
 <f9170ecc-4d3e-bbe8-4979-969397ed9201@gmail.com>
 <CAPTjJmq6d4it9FuMLQSg+40H5HfzkgGGCSi07=dM5pvraFLP9g@mail.gmail.com>
 <a958a7d4-54fe-d8ae-433e-95804bc63c02@gmail.com>
 <CAPTjJmqAwmB=WUo7fjZW_q0SktMjvZ8BnUkQsO9s2XxTF9dodQ@mail.gmail.com>
 <mailman.315.1581468945.9276.python-list@python.org>
Message-ID: <slrnr47r2d.cvh.jon+usenet@sable.unequivocal.eu>

On 2020-02-12, Chris Angelico <rosuav at gmail.com> wrote:
> But you CAN rewrite code such that it reduces technical debt. You can
> refactor code to make it more logical.

... but if doing so costs more than the debt, you shouldn't do it.

From ekopalypse at gmail.com  Wed Feb 12 07:41:04 2020
From: ekopalypse at gmail.com (Eko palypse)
Date: Wed, 12 Feb 2020 04:41:04 -0800 (PST)
Subject: Load python from different plugin dlls
Message-ID: <c028aae0-5c51-4a22-9542-2b88ae6cad0d@googlegroups.com>

Assuming there is an CppApp which allows extending its functionality by adding plugins. Now let's assume there are plugin developer which use cython to create such a plugins.

How can one check if there has been already a plugin loaded which itself loaded a python interpreter?

And if this is possible, what needs to be done that a second plugin can be used with the python interpreter loaded from the first plugin?

To summarize:
CppApp loads pluign1 (which loads python3.dll) ok
CppApp loads pluign2 (which needs also access to python3.dll but cannot load it itself as it has been already loaded by plugin1)

Is such a scenario actually possible?

Thank you
Eren

From rhodri at kynesim.co.uk  Wed Feb 12 08:16:03 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 12 Feb 2020 13:16:03 +0000
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <20200212005313.GG32713@bladeshadow.org>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <20200212005313.GG32713@bladeshadow.org>
Message-ID: <4fe21f44-e03d-158c-07b6-0446146ecff9@kynesim.co.uk>

On 12/02/2020 00:53, Python wrote:
> In pretty much every job I've ever worked at, funding work (e.g. with
> humans to do it) with exactly and precisely the resources required is
> basically impossible, and management prefers to underfund the work
> than to overfund it, for cost-savings reasons.  This basically means
> that any non-trivial work you do inevitably will become technical debt

s/become/accrue/.  The work itself isn't the debt, but its 
sub-optimality creates debt (or future headaches, if you prefer to think 
of it that way).

> IMMEDIATELY, because you will not be given the time to do the job
> completely in the first place, there will inevitably be bugs which are
> minor enough to ignore indefinitely, and most likely, in order to meet
> arbitrary-but-nevertheless-real time constraints you will find
> yourself obliged to take shortcuts.  So conceptually "costs" may be
> different from "debt" but in practice, you never have one without the
> other, and "debt" is really just "costs" you haven't paid yet.

It's that last bit, "you haven't paid yet", that's the important part. 
Project managers and accountants alike are very much in favour of 
putting off paying for things if they can.  Sometimes they can be 
persuaded that the interest on the debt (the extra cost that the code 
structure imposes on fixing bugs) is too much, and then you get the 
opportunity to refactor and reduce the overall debt (at a cost, 
obviously) and the interest you will pay in the future.

Sometimes, and this is the bit that bean counters really like, you can 
get away without paying the debt by ditching the project entirely before 
the debt is paid off.  If you don't want to piss your customers off you 
need to pay the cost of a replacement project, which will accrue its own 
technical debt...

-- 
Rhodri James *-* Kynesim Ltd

From legaulph at gmail.com  Wed Feb 12 06:46:18 2020
From: legaulph at gmail.com (legaulph at gmail.com)
Date: Wed, 12 Feb 2020 06:46:18 -0500
Subject: ghostscripts in python with watchdog
Message-ID: <00b201d5e19a$0a224950$1e66dbf0$@gmail.com>

I'm trying to use ghostscripts with python watchdog.

I want to duplicate the last page of a pdf to another directory using the
same name as the source pdf + page number.

So watchdog will monitor the directory for the pdf and ghostscript will copy
the last page to another directory.

I have this, and not able to figure out how to change the output name and
location.

 

import sys

import os

import time

import logging

from watchdog.observers import Observer

from watchdog.events import LoggingEventHandler

from watchdog.events import PatternMatchingEventHandler

 

if __name__ == "__main__":

    patterns = "*"

    ignore_patterns = ""

    ignore_directories = False

    case_sensitive = True

    my_event_handler = PatternMatchingEventHandler(patterns,
ignore_patterns, ignore_directories, case_sensitive)

    def on_created(event):

        number_of_pages = 4

        input_pdf = event.src_path

        for i in range(4, number_of_pages +1):

            os.system("gswin64c -q -dBATCH -dNOPAUSE
-sOutputFile=page{page:04d}.pdf"

                    " -dFirstPage={page} -dLastPage={page}"

                    " -sDEVICE=pdfwrite {input_pdf}"

                    .format(page=i, input_pdf=input_pdf))

 

    my_event_handler.on_created = on_created

 

    path = "."

    go_recursively = True

    my_observer = Observer()

    my_observer.schedule(my_event_handler, path, recursive=go_recursively)

 

    my_observer.start()

    try:

        while True:

            time.sleep(1)

    except KeyboardInterrupt:

        my_observer.stop()

        my_observer.join()

 


From ethan at stoneleaf.us  Wed Feb 12 09:44:22 2020
From: ethan at stoneleaf.us (Ethan Furman)
Date: Wed, 12 Feb 2020 06:44:22 -0800
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>
Message-ID: <64f0f28d-d29e-78e4-1208-d4d16876fb70@stoneleaf.us>

On 02/11/2020 04:38 PM, Michael Torrie wrote:

> It's all just different ways of accounting for the same things. In the
> olden days before the term "technical debt" was invented, we called this
> "total cost of ownership."

TCO is not a fixed number.  For example, if a loan is taken to help fund a project, then the "interest debt" will be a portion of the TCO, but its amount will vary depending on the interest rate: 15% will be more interest debt than 4%.  Likewise, the technical debt for a project will be higher or lower depending on the quality of the code written.

I think an oft overlooked aspect of technical debt is the affect on the programmers dealing with it:  frustration, burn-out, and job-seeking.

--
~Ethan~

From avigross at verizon.net  Wed Feb 12 11:55:20 2020
From: avigross at verizon.net (Avi Gross)
Date: Wed, 12 Feb 2020 11:55:20 -0500
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <4fe21f44-e03d-158c-07b6-0446146ecff9@kynesim.co.uk>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <20200212005313.GG32713@bladeshadow.org>
 <4fe21f44-e03d-158c-07b6-0446146ecff9@kynesim.co.uk>
Message-ID: <00a401d5e1c5$35e56290$a1b027b0$@verizon.net>

I have to wonder if this is a bit like what happens when something like
Windows offers you an upgrade if you pay for it. Some people have noticed
how after such things come out, a series of rapid bug fixes come along. So,
they wait. Some wait long enough until another entire version has come along
or even several such cycles. They then try to jump from say version 2.1 to
version 5.0 and skip paying for all the in-betweens. Others may wait till
something forces them to change like receiving documents their version of
EXCEL cannot handle properly or at all. And, when that happens, they may
simply jump to a different product entirely, like leaving Lotus for EXCEL.

And, as noted, some simply move on. All kinds of calendar programs and
contact list managers can become obsolete when it is all bundled into
something like Microsoft office Outlook. At some point, you toss the old or
use some tool to migrate your data, or start over.

With your own software a migration can be hairy and especially when the
original staff are long gone or promoted and the manager has no clue and no
budget for this. There seems to be substantial risk versus just leaving it
alone and hoping it works long enough for you to get your bonus or move on.
It is worse if the people maintaining it sort of made their own kludge
variations like reinventing new features on their own in ways not compatible
with the new. Do you port the kludge or switch over to the new way even if
it means restructuring other parts of the code.

A serious question. What has happened in other aspects of the field where a
big enough change bifurcates the community? I am wondering what happened
when PERL made incompatible changes. Are people still using both versions?
What about largely discontinued languages that stopped being developed in
any way and do not even have a compiler for newer machines?

I know Microsoft periodically declares no further support for much earlier
versions of Windows. I bet people who have old machines keep running without
an upgrade, especially when their machine does not support the new version
because it does not have enough memory or whatever. Why keep the old? I am
sure they have their reasons that boil down to it runs programs they know
well and that do what they need and do not add many bells and whistles that
they  don't think they need or that force them to change their ways. For
some touch typists, the earlier word processors that do not know about a
mouse and run in one big window, may be just right. But try sending one to
others without using some conversion method first.

But anyone teaching Python today who still uses version 2 exclusively may
have some explaining to do unless the goal is to maintain and migrate those
using it to version 3. Are there any serious new projects being built NOW
using version 2?

-----Original Message-----
From: Python-list <python-list-bounces+avigross=verizon.net at python.org> On
Behalf Of Rhodri James
Sent: Wednesday, February 12, 2020 8:16 AM
To: python-list at python.org
Subject: Re: Technical debt - was Re: datetime seems to be broken WRT
timezones (even when you add them)

On 12/02/2020 00:53, Python wrote:
> In pretty much every job I've ever worked at, funding work (e.g. with 
> humans to do it) with exactly and precisely the resources required is 
> basically impossible, and management prefers to underfund the work 
> than to overfund it, for cost-savings reasons.  This basically means 
> that any non-trivial work you do inevitably will become technical debt

s/become/accrue/.  The work itself isn't the debt, but its sub-optimality
creates debt (or future headaches, if you prefer to think of it that way).

> IMMEDIATELY, because you will not be given the time to do the job 
> completely in the first place, there will inevitably be bugs which are 
> minor enough to ignore indefinitely, and most likely, in order to meet 
> arbitrary-but-nevertheless-real time constraints you will find 
> yourself obliged to take shortcuts.  So conceptually "costs" may be 
> different from "debt" but in practice, you never have one without the 
> other, and "debt" is really just "costs" you haven't paid yet.

It's that last bit, "you haven't paid yet", that's the important part. 
Project managers and accountants alike are very much in favour of putting
off paying for things if they can.  Sometimes they can be persuaded that the
interest on the debt (the extra cost that the code structure imposes on
fixing bugs) is too much, and then you get the opportunity to refactor and
reduce the overall debt (at a cost,
obviously) and the interest you will pay in the future.

Sometimes, and this is the bit that bean counters really like, you can get
away without paying the debt by ditching the project entirely before the
debt is paid off.  If you don't want to piss your customers off you need to
pay the cost of a replacement project, which will accrue its own technical
debt...

-- 
Rhodri James *-* Kynesim Ltd
-- 
https://mail.python.org/mailman/listinfo/python-list


From python at bladeshadow.org  Wed Feb 12 12:46:13 2020
From: python at bladeshadow.org (Python)
Date: Wed, 12 Feb 2020 11:46:13 -0600
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <4fe21f44-e03d-158c-07b6-0446146ecff9@kynesim.co.uk>
References: <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <20200212005313.GG32713@bladeshadow.org>
 <4fe21f44-e03d-158c-07b6-0446146ecff9@kynesim.co.uk>
Message-ID: <20200212174613.GH32713@bladeshadow.org>

On Wed, Feb 12, 2020 at 01:16:03PM +0000, Rhodri James wrote:
> On 12/02/2020 00:53, Python wrote:
> > In pretty much every job I've ever worked at, funding work (e.g. with
> > humans to do it) with exactly and precisely the resources required is
> > basically impossible, and management prefers to underfund the work
> > than to overfund it, for cost-savings reasons.  This basically means
> > that any non-trivial work you do inevitably will become technical debt
> 
> s/become/accrue/.  The work itself isn't the debt, but its sub-optimality
> creates debt (or future headaches, if you prefer to think of it that way).

I think it's a purely semantic distinction without a practical
difference...which was the point I was trying to make.  The work is
the direct cause of the debt, and at the time it is performed the debt
is realized.  Without the work, that particular debt is not incurred.
You may have eliminated some old debt when the work is done, but your
new debt replaces your old debt.  Depending on the resources you can
devote, that debt may or MAY NOT be less than the other, and sometimes
the truth of this can not be discovered until you're already knee deep
in it.

> > So conceptually "costs" may be different from "debt" but in
> > practice, you never have one without the other, and "debt" is
> > really just "costs" you haven't paid yet.
> 
> It's that last bit, "you haven't paid yet", that's the important part.
> Project managers and accountants alike are very much in favour of putting
> off paying for things if they can.  Sometimes they can be persuaded that the
> interest on the debt (the extra cost that the code structure imposes on
> fixing bugs) is too much, and then you get the opportunity to refactor and
> reduce the overall debt (at a cost, obviously) and the interest you will pay
> in the future.

Right.  Or... not.  More often than not, in my experience.  And
sometimes you can convince them you need to, but other priorities
continually surface that block it from ever happening anyway.
 
> Sometimes, and this is the bit that bean counters really like, you can get
> away without paying the debt by ditching the project entirely before the
> debt is paid off.  If you don't want to piss your customers off you need to
> pay the cost of a replacement project, which will accrue its own technical
> debt...

Or it may become obsolete due to changing circumstances.  Or (as in
many cases) it is sufficient to tell your customers, "don't do that,"
perhaps with admittedly annoying but not particularly costly
consequences if they don't listen. :) 

[It's not always feasible, but often if they complain, you can say
something like, "...but we're working on this other magic thingy that
will really help you, and spending time on fixing this thing you're
complaining about now will significantly delay the delivery of that."
It may or may not be true, but in the interim the customer learns to
stop doing that thing, and forgets they ever cared.]

Technical debt is just about inevitable, for most non-trivial software
(again, unless you've got a special case of a full solution for some
problem whose circumstances never change), and isn't necessarily a bad
thing.  It just depends entirely on the details of your situation.
And while I'm not particularly a fan of Agile in practice, the
philosophy behind it addresses this reasonably well...  But then
again, you don't *need* Agile to do that, either.  You just have to
pay attention to the problem.  Like everything else.


From rhodri at kynesim.co.uk  Wed Feb 12 13:54:52 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 12 Feb 2020 18:54:52 +0000
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <20200212174613.GH32713@bladeshadow.org>
References: <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <20200212005313.GG32713@bladeshadow.org>
 <4fe21f44-e03d-158c-07b6-0446146ecff9@kynesim.co.uk>
 <20200212174613.GH32713@bladeshadow.org>
Message-ID: <a0432f0c-1373-a97c-2bb6-4b799aed1f4c@kynesim.co.uk>

On 12/02/2020 17:46, Python wrote:
> On Wed, Feb 12, 2020 at 01:16:03PM +0000, Rhodri James wrote:
>> On 12/02/2020 00:53, Python wrote:
>>> In pretty much every job I've ever worked at, funding work (e.g. with
>>> humans to do it) with exactly and precisely the resources required is
>>> basically impossible, and management prefers to underfund the work
>>> than to overfund it, for cost-savings reasons.  This basically means
>>> that any non-trivial work you do inevitably will become technical debt

>> s/become/accrue/.  The work itself isn't the debt, but its sub-optimality
>> creates debt (or future headaches, if you prefer to think of it that way).

> I think it's a purely semantic distinction without a practical
> difference...which was the point I was trying to make.  The work is
> the direct cause of the debt, and at the time it is performed the debt
> is realized.  Without the work, that particular debt is not incurred.
> You may have eliminated some old debt when the work is done, but your
> new debt replaces your old debt.  Depending on the resources you can
> devote, that debt may or MAY NOT be less than the other, and sometimes
> the truth of this can not be discovered until you're already knee deep
> in it.

Here's where the "purely semantic" distinction matters.  You are 
equating the work with the debt, but ignoring the benefit the work 
presumably brings (otherwise you wouldn't have done it at all).  Either 
you should be rolling it all together or separate both, surely.

-- 
Rhodri James *-* Kynesim Ltd

From torriem at gmail.com  Wed Feb 12 15:17:44 2020
From: torriem at gmail.com (Michael Torrie)
Date: Wed, 12 Feb 2020 13:17:44 -0700
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <64f0f28d-d29e-78e4-1208-d4d16876fb70@stoneleaf.us>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>
 <64f0f28d-d29e-78e4-1208-d4d16876fb70@stoneleaf.us>
Message-ID: <d1e29f92-3970-ed47-e9ae-df2d40067b88@gmail.com>

On 2/12/20 7:44 AM, Ethan Furman wrote:
> On 02/11/2020 04:38 PM, Michael Torrie wrote:
> 
>> It's all just different ways of accounting for the same things. In
>> the olden days before the term "technical debt" was invented, we
>> called this "total cost of ownership."
> 
> TCO is not a fixed number.  For example, if a loan is taken to help
> fund a project, then the "interest debt" will be a portion of the
> TCO, but its amount will vary depending on the interest rate: 15%
> will be more interest debt than 4%.  Likewise, the technical debt for
> a project will be higher or lower depending on the quality of the
> code written.

True.  Costs can be calculated and planned for. But Technical debt is
often impossible to quantify in a real, meaningful, business sense,
other than the that we "know" it's going to cost big time in the future.
 In some senses, it's theoretical future cost.  That's what I was having
a hard time with, and still do to a large degree.

> I think an oft overlooked aspect of technical debt is the affect on
> the programmers dealing with it:  frustration, burn-out, and
> job-seeking.

Yeah for sure.  A programmer may not love dealing with technical debt,
and certainly he may want to chase greener fields.  But there are lots
of things about lots of jobs that are less pleasant than other things.
Personally I tend to get way caught up trying to get a perfect design
that avoids technical debt, but often get not much done (on my personal
projects). Whereas another guy just cranks out code that isn't always
the best but serves his needs at the time. Guess who is more productive
overall? Not me.

More on topic, I feel like the technical debt issue might be over used
to push folks to upgrade from Python 2, or to do promote certain
technologies.

Without knowing the details of how and why they used it, it's impossible
for me to say that it will cost them a lot in the future.  It very well
could cost nothing.  Or it might be expensive enough to sink an enterprise.

In the case of the original poster, it could well be that the
maintenance he's doing to the code is minor and of no real cost, nor any
maintenance burden in the future.  He might not need security patches or
any other on-going development of the Python 2 interpreter.  His app
might have no attack surface.  The script does its internal job and
that's that.  As long as a Python2 interpreter runs he's golden. I
suspect a lot of Python 2 use falls into that sort of category.  Sort of
like the company I know that still uses an MS-DOS billing system.

From PythonList at DancesWithMice.info  Wed Feb 12 18:22:42 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Thu, 13 Feb 2020 12:22:42 +1300
Subject: Technical debt - was Re: datetime seems to be broken WRT
 timezones (even when you add them)
In-Reply-To: <d1e29f92-3970-ed47-e9ae-df2d40067b88@gmail.com>
References: <slrnr43v2o.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmrKPfWYPGa1K1VvMLcrnKXRFQkn6B--MZnLe82uZh_0oA@mail.gmail.com>
 <20200211012902.GD32713@bladeshadow.org>
 <CAPTjJmoTNXpGmP7R26-ZoCAg7s=MFcxxvsHm2ZZGXBCPUu07Ag@mail.gmail.com>
 <mailman.296.1581385360.9276.python-list@python.org>
 <slrnr45234.cvh.jon+usenet@sable.unequivocal.eu>
 <CAPTjJmpmWXBeoHk0CeiqDAUUHSDTf11c+uRw7vZv88hRTGcCUA@mail.gmail.com>
 <751a2c82-c07f-0cda-a19a-b0c9832e911c@gmail.com>
 <CAPTjJmqvS3qvOD-uLCSjVHFKXS9sy3dkJ=7AdCe5U-kH1JXP6w@mail.gmail.com>
 <5a977c94-4cbd-b546-fb32-bf1830645049@gmail.com>
 <64f0f28d-d29e-78e4-1208-d4d16876fb70@stoneleaf.us>
 <d1e29f92-3970-ed47-e9ae-df2d40067b88@gmail.com>
Message-ID: <35fde9bc-d63c-a110-a97b-9e0936017dc2@DancesWithMice.info>

On 13/02/20 9:17 AM, Michael Torrie wrote:
> On 2/12/20 7:44 AM, Ethan Furman wrote:
>> On 02/11/2020 04:38 PM, Michael Torrie wrote:
...

> True.  Costs can be calculated and planned for. But Technical debt is
> often impossible to quantify in a real, meaningful, business sense,
> other than the that we "know" it's going to cost big time in the future.
>   In some senses, it's theoretical future cost.  That's what I was having
> a hard time with, and still do to a large degree.
> 
>> I think an oft overlooked aspect of technical debt is the affect on
>> the programmers dealing with it:  frustration, burn-out, and
>> job-seeking.
> 
> Yeah for sure.  A programmer may not love dealing with technical debt,
> and certainly he may want to chase greener fields.  But there are lots
> of things about lots of jobs that are less pleasant than other things.
> Personally I tend to get way caught up trying to get a perfect design
> that avoids technical debt, but often get not much done (on my personal
> projects). Whereas another guy just cranks out code that isn't always
> the best but serves his needs at the time. Guess who is more productive
> overall? Not me.

Applauding your professional attitude, but haven't you (only) defined 
"productive" as purely getting 'this job' out the door? cf any 
definition of "Total" cost?


I had an IT Manager moaning at me precisely because of one of those 
'other guys'. The job had been 'done'. The contract had mere 'words' to 
cover 'quality'. Accordingly, difficult to argue that 'the guy' hadn't 
done what was asked (my 'specialist' $advice on the matter). However, 
the code was 'ramshackle' and had obviously been 'dashed off' in the 
shortest amount of time possible. Maintenance costs were expected to be 
high; motivation of in-house staff to do so, expected to be v.low!

So, we're re-negotiating the contract-wording... More importantly, 
improving their acceptance testing, and adding more detail to their 
specs/requirements, etc. (the mistake there, was thinking that reqmts to 
external staff would be 'the same' as such to in-house employees)


However, the interesting question was to ask whether he (the manager) 
was 'taking advantage' of the "gig economy". (yes, that's what it's 
there for!) Thus, what relationship did he (or even, 'they' of the IT 
dept) have with the contractor? The home truth: 'using' the cheapest 
people creates a 'race to the bottom', and must, by definition, lead to 
'the cheapest job' being done. Why the surprise?
(He doesn't hire me as a programmer - and we're not even talking 
'Python', apologies!)

I asked him if he wanted a 'professional' to do the job, ie in a 
'professional manner'. Yes! So, why are you looking for the guy(?) 
who'll do it at the lowest-possible price/rate or imposing the delivery 
date on a short time-line? Ahh...

The above concerns contractors, but I managed to slide-in a few 
questions/comments that relationships with in-house staff require 
similar consideration and attention!



OK, so turning it around to people more like 'us': Professionalism? As a 
programmer/coder, would you rather work on decent code? So, is that what 
you turn-out? Alternatively, vice-versa.

That is a slightly unfair, or biased, question. I am in the fortunate 
position of being able to tell certain people that I won't undertake 
their work, that where they want me to work will push the price UP, that 
their tool-set is sub-standard, or that the existing platform is imbued 
with uncomfortably high 'risk'. I quite understand that someone who 
'needs the job' will see that as a 'luxury'. (apologies as necessary)

That said, would you build a team with a mixture of 'clock-watchers' and 
'professionals' or would/do you enjoy working within such a team?

Both 'sides' need to understand that there are two view-points to every 
relationship.


One thought that occurred to me lurking/reading this thread, is the 
likelihood that many of the differing views arise between those working 
in an 'Agile' environment, and those not (or a pseudo-/'we call 
it'-Agile environment)?

One of the (social) contracts in Scrum (for example) is that the 
professionals estimate the time needed to do the job, cf some (likely 
ignorant) 'manager' imposing a deadline. In my experience (YMMV) an 
established, professional 'Agile' team tends to follow practices which 
attempt to avoid adding to Technical Debt, and factor-in any need to 
correct sub-standard or sans-tests old-code. There is no doubt in my 
mind, that the participation of 'users' helps to create an understanding 
that (like anything else) software takes time (read also $), and that 
over-loading (?abusing) development staff is itself a 'Technical Debt' 
("Marginal Cost") for the organisation! (absences, turn-over, ... you've 
been-there, seen-that...). There again, would user-members of the team 
notice if 'we'd' padded our estimates so as to have plenty of time for 
'other things'?

It's by no means a cut-and-dried situation. What 'works' in one case may 
not even get-of-the-ground in another!

Thanks for provoking the grey-matter to ponder...
-- 
Regards =dn

From address at not.available  Thu Feb 13 01:21:39 2020
From: address at not.available (R.Wieser)
Date: Thu, 13 Feb 2020 07:21:39 +0100
Subject: Load python from different plugin dlls
References: <c028aae0-5c51-4a22-9542-2b88ae6cad0d@googlegroups.com>
Message-ID: <r22ptn$1slt$1@gioia.aioe.org>

Eko,

> which needs also access to python3.dll but cannot load it itself as it has
> been already loaded by plugin1
>
> Is such a scenario actually possible?

Yes.

Normally a DLL can be loaded in as many processes (and threads thereof) as 
you like.

However, it is possible that the DLLs initialisation contains code to check 
if something it needs is available*, and if not directly exit.

*like if it can access certain I/O - if the first DLL instance "takes 
posession" the second DLL instance wil fail.  Than again, this can also 
happen when using two totally different plugin DLLs.

tl;dr:
Yes, but not likely.



From ekopalypse at gmail.com  Thu Feb 13 06:51:44 2020
From: ekopalypse at gmail.com (Eko palypse)
Date: Thu, 13 Feb 2020 12:51:44 +0100
Subject: Load python from different plugin dlls
In-Reply-To: <r22ptn$1slt$1@gioia.aioe.org>
References: <c028aae0-5c51-4a22-9542-2b88ae6cad0d@googlegroups.com>
 <r22ptn$1slt$1@gioia.aioe.org>
Message-ID: <CAD8XV+3fzcBUi-qPvw3vd_YD7-iXpSHsOkR366BwsVM=fBhHFg@mail.gmail.com>

Thanks for the information.
My test looks like this right now.
I have two plugins which, when loaded separately, work.
But when both are loaded, I get AccessVioletion messages from python37.dll.
The init code for both dlls is this:

cpp_init_code = f'''#include <Python.h>
#include "PluginInterface.h"

PyMODINIT_FUNC PyInit_{PLUGIN_NAME}(void);

BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD reasonForCall,
                       LPVOID /* lpReserved */ )
{{
    switch ( reasonForCall )
    {{
        case DLL_PROCESS_ATTACH:
            PyImport_AppendInittab("{PLUGIN_NAME}", &PyInit_{PLUGIN_NAME});
            Py_InitializeEx(Py_IsInitialized() ? 0 : 1);
            PyImport_ImportModule("{PLUGIN_NAME}");
            break;
        case DLL_PROCESS_DETACH:
            Py_Finalize();
            break;

        case DLL_THREAD_ATTACH:
            break;

        case DLL_THREAD_DETACH:
            break;
    }}

    return TRUE;
}}'''

This is written to a plugininit.cpp file and then built via setup.py with
distutil, cython and VS2017.

According to the docs  PyImport_AppendInittab should be called before
Py_Initialize
but I can't call  Py_Initialize the second time as it would remove what was
initialized by the first dll.
And using PyImport_ImportModule on the second dll only does not work either.
So that is were I'm trapped.

Thank you
Eren

Am Do., 13. Feb. 2020 um 07:26 Uhr schrieb R.Wieser <address at not.available>:

> Eko,
>
> > which needs also access to python3.dll but cannot load it itself as it
> has
> > been already loaded by plugin1
> >
> > Is such a scenario actually possible?
>
> Yes.
>
> Normally a DLL can be loaded in as many processes (and threads thereof) as
> you like.
>
> However, it is possible that the DLLs initialisation contains code to
> check
> if something it needs is available*, and if not directly exit.
>
> *like if it can access certain I/O - if the first DLL instance "takes
> posession" the second DLL instance wil fail.  Than again, this can also
> happen when using two totally different plugin DLLs.
>
> tl;dr:
> Yes, but not likely.
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From address at not.available  Thu Feb 13 07:28:55 2020
From: address at not.available (R.Wieser)
Date: Thu, 13 Feb 2020 13:28:55 +0100
Subject: Load python from different plugin dlls
References: <c028aae0-5c51-4a22-9542-2b88ae6cad0d@googlegroups.com>
 <r22ptn$1slt$1@gioia.aioe.org>
 <CAD8XV+3fzcBUi-qPvw3vd_YD7-iXpSHsOkR366BwsVM=fBhHFg@mail.gmail.com>
 <mailman.331.1581594711.9276.python-list@python.org>
Message-ID: <r23feb$v69$1@gioia.aioe.org>

Eko,

> My test looks like this right now.

And there you have a probem, as I have no experience with what those 
functions do.   The below is therefore just a bit of educated guessing, so 
caveat emperor.

> According to the docs  PyImport_AppendInittab should be called
> before Py_Initialize

And should probably be done only once - adding the same module to the same 
list will likely fail, though the above function will than just return a -1 
(minus one) result.

>            Py_InitializeEx(Py_IsInitialized() ? 0 : 1);

Initializing when already being initialized might well be the cause of your 
AccessViolation - the first plugin looses its objects, but still tries to 
use them.

Suggestion: Do a Py_IsInitialized() and if so skip the the Py_InitializeEx() 
(and maybe change that one to the simpler Py_Initialize() ).

Hope that helps.

Regards,
Rudy Wieser



From Mkonopko at csbs.net  Thu Feb 13 23:38:53 2020
From: Mkonopko at csbs.net (Marty Konopko)
Date: Thu, 13 Feb 2020 21:38:53 -0700
Subject: first time python learner
Message-ID: <CAL1p7LwU5xA_O56qH+zHwSD3U8vF974rpPAA2QHAekrSma3rrg@mail.gmail.com>

Win 10
Anti Virus  off
[image: image.png]

Any idea?

-- 
Martin Konopko

From cs at cskk.id.au  Fri Feb 14 00:50:28 2020
From: cs at cskk.id.au (Cameron Simpson)
Date: Fri, 14 Feb 2020 16:50:28 +1100
Subject: first time python learner
In-Reply-To: <CAL1p7LwU5xA_O56qH+zHwSD3U8vF974rpPAA2QHAekrSma3rrg@mail.gmail.com>
References: <CAL1p7LwU5xA_O56qH+zHwSD3U8vF974rpPAA2QHAekrSma3rrg@mail.gmail.com>
Message-ID: <20200214055028.GA26443@cskk.homeip.net>

On 13Feb2020 21:38, Marty Konopko <Mkonopko at csbs.net> wrote:
>Win 10
>Anti Virus  off
>[image: image.png]
>
>Any idea?

Alas, this is a text only list; your screenshot has been discarded.  
Please reply with your complete error message cut/paste into the text.  
And a description of what you were trying to do.

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

From me at bheesham.com  Fri Feb 14 01:26:13 2020
From: me at bheesham.com (Bheesham Persaud)
Date: Fri, 14 Feb 2020 01:26:13 -0500
Subject: ghostscripts in python with watchdog
In-Reply-To: <mailman.324.1581518174.9276.python-list@python.org>
References: <00b201d5e19a$0a224950$1e66dbf0$@gmail.com>
 <mailman.324.1581518174.9276.python-list@python.org>
Message-ID: <r25ei5$jp2$1@dont-email.me>

Hey!

If you change the "-sOutputFile` parameter you pass into gswin64c.

For example, something like:

     output_directory = os.path.join(os.path.dirname(input_src), "out")

And then you should be able to modify the call to `os.system` to 
something like:

     os.system(
         "gswin64c -q -dBATCH -dNOPAUSE"
         "-sOutputFile={output_directory}/page{page:04d}.pdf"
         " -dFirstPage={page} -dLastPage={page}"
         " -sDEVICE=pdfwrite {input_pdf}"
         .format(
             page=i,
             input_pdf=input_pdf,
             output_directory=output_directory
         )
     )

From legaulph at gmail.com  Fri Feb 14 07:54:40 2020
From: legaulph at gmail.com (legaulph at gmail.com)
Date: Fri, 14 Feb 2020 07:54:40 -0500
Subject: ghostscripts in python with watchdog
In-Reply-To: <r25ei5$jp2$1@dont-email.me>
References: <00b201d5e19a$0a224950$1e66dbf0$@gmail.com>
 <mailman.324.1581518174.9276.python-list@python.org>
 <r25ei5$jp2$1@dont-email.me>
Message-ID: <002c01d5e335$ec1f1710$c45d4530$@gmail.com>

I'm not sure what happens, when I'm testing and suddenly I will start
getting this error.
Error: /undefinedfilename in (1)
Operand stack:

Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--
--nostringval--   2   %stopped_push   --nostringval--   --nostringval--
--nostringval--  
 false   1   %stopped_push
Dictionary stack:
   --dict:732/1123(ro)(G)--   --dict:0/20(G)--   --dict:75/200(L)--
Current allocation mode is local
Last OS error: No such file or directory
GPL Ghostscript 9.50: Unrecoverable error, exit code 1


-----Original Message-----
From: Python-list <python-list-bounces+legaulph=gmail.com at python.org> On
Behalf Of Bheesham Persaud
Sent: Friday, February 14, 2020 1:26 AM
To: python-list at python.org
Subject: Re: ghostscripts in python with watchdog

Hey!

If you change the "-sOutputFile` parameter you pass into gswin64c.

For example, something like:

     output_directory = os.path.join(os.path.dirname(input_src), "out")

And then you should be able to modify the call to `os.system` to something
like:

     os.system(
         "gswin64c -q -dBATCH -dNOPAUSE"
         "-sOutputFile={output_directory}/page{page:04d}.pdf"
         " -dFirstPage={page} -dLastPage={page}"
         " -sDEVICE=pdfwrite {input_pdf}"
         .format(
             page=i,
             input_pdf=input_pdf,
             output_directory=output_directory
         )
     )
--
https://mail.python.org/mailman/listinfo/python-list


From legaulph at gmail.com  Fri Feb 14 07:58:34 2020
From: legaulph at gmail.com (legaulph at gmail.com)
Date: Fri, 14 Feb 2020 07:58:34 -0500
Subject: ghostscripts in python with watchdog
In-Reply-To: <002c01d5e335$ec1f1710$c45d4530$@gmail.com>
References: <00b201d5e19a$0a224950$1e66dbf0$@gmail.com>
 <mailman.324.1581518174.9276.python-list@python.org>
 <r25ei5$jp2$1@dont-email.me> <002c01d5e335$ec1f1710$c45d4530$@gmail.com>
Message-ID: <003b01d5e336$7771bf20$66553d60$@gmail.com>

I see it does not like spaces in the file name

-----Original Message-----
From: legaulph at gmail.com <legaulph at gmail.com> 
Sent: Friday, February 14, 2020 7:55 AM
To: 'Bheesham Persaud' <me at bheesham.com>; python-list at python.org
Subject: RE: ghostscripts in python with watchdog

I'm not sure what happens, when I'm testing and suddenly I will start
getting this error.
Error: /undefinedfilename in (1)
Operand stack:

Execution stack:
   %interp_exit   .runexec2   --nostringval--   --nostringval--
--nostringval--   2   %stopped_push   --nostringval--   --nostringval--
--nostringval--  
 false   1   %stopped_push
Dictionary stack:
   --dict:732/1123(ro)(G)--   --dict:0/20(G)--   --dict:75/200(L)--
Current allocation mode is local
Last OS error: No such file or directory GPL Ghostscript 9.50: Unrecoverable
error, exit code 1


-----Original Message-----
From: Python-list <python-list-bounces+legaulph=gmail.com at python.org> On
Behalf Of Bheesham Persaud
Sent: Friday, February 14, 2020 1:26 AM
To: python-list at python.org
Subject: Re: ghostscripts in python with watchdog

Hey!

If you change the "-sOutputFile` parameter you pass into gswin64c.

For example, something like:

     output_directory = os.path.join(os.path.dirname(input_src), "out")

And then you should be able to modify the call to `os.system` to something
like:

     os.system(
         "gswin64c -q -dBATCH -dNOPAUSE"
         "-sOutputFile={output_directory}/page{page:04d}.pdf"
         " -dFirstPage={page} -dLastPage={page}"
         " -sDEVICE=pdfwrite {input_pdf}"
         .format(
             page=i,
             input_pdf=input_pdf,
             output_directory=output_directory
         )
     )
--
https://mail.python.org/mailman/listinfo/python-list



From __peter__ at web.de  Fri Feb 14 11:39:40 2020
From: __peter__ at web.de (Peter Otten)
Date: Fri, 14 Feb 2020 17:39:40 +0100
Subject: ghostscripts in python with watchdog
References: <00b201d5e19a$0a224950$1e66dbf0$@gmail.com>
 <mailman.324.1581518174.9276.python-list@python.org>
 <r25ei5$jp2$1@dont-email.me> <002c01d5e335$ec1f1710$c45d4530$@gmail.com>
 <003b01d5e336$7771bf20$66553d60$@gmail.com>
Message-ID: <r26igc$b1j$1@ciao.gmane.io>

legaulph at gmail.com wrote:

> os.system("... {input_pdf} ...".format(..., input_pdf=input_pdf))

> I see it does not like spaces in the file name

Use subprocess.call(), not os.system(), then:

>>> filename = "hello world.txt"
>>> with open(filename, "w") as f: print("Hello, world!", file=f)
... 
>>> import os, subprocess

Wrong, uses shell, and file name is not properly escaped:

>>> os.system("cat " + filename)
cat: hello: No such file or directory
cat: world.txt: No such file or directory
256

Right, does not use shell, no escaping needed:

>>> subprocess.call(["cat", filename])
Hello, world!
0



From tjreedy at udel.edu  Fri Feb 14 12:54:21 2020
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 14 Feb 2020 12:54:21 -0500
Subject: first time python learner
In-Reply-To: <CAL1p7LwU5xA_O56qH+zHwSD3U8vF974rpPAA2QHAekrSma3rrg@mail.gmail.com>
References: <CAL1p7LwU5xA_O56qH+zHwSD3U8vF974rpPAA2QHAekrSma3rrg@mail.gmail.com>
Message-ID: <r26mse$78m$1@ciao.gmane.io>

On 2/13/2020 11:38 PM, Marty Konopko wrote:
> Win 10
> Anti Virus  off
> [image: image.png]
> 
> Any idea?

Cameron already suggested a better title and question.  If it is about 
IDLE startup, read
https://docs.python.org/3/library/idle.html#startup-failure


-- 
Terry Jan Reedy


From drsalists at gmail.com  Fri Feb 14 18:21:19 2020
From: drsalists at gmail.com (Dan Stromberg)
Date: Fri, 14 Feb 2020 15:21:19 -0800
Subject: What I learned today
In-Reply-To: <learned-20200214234803@ram.dialup.fu-berlin.de>
References: <learned-20200214234803@ram.dialup.fu-berlin.de>
Message-ID: <CAGGBd_rLHzbdSWPKMegFxfj_d7yiNfcM+Xk0e9D2Tjj+upjEBQ@mail.gmail.com>

On Fri, Feb 14, 2020 at 3:10 PM Stefan Ram <ram at zedat.fu-berlin.de> wrote:

>   By trial and error (never read documentation!) I found
>   that you can count the number of e's in a text by just
>
> Counter( text ).get( 'e' )
>
>   (after ?from collections import Counter? that is).
>
Even simpler, though not suitable for all situations:
"abcbdbe".count("b")

  The other thing I read in a book. I already knew that one
>   can zip using ... ?zip?. E.g.,
>
Neat.

From duncan at invalid.invalid  Fri Feb 14 20:24:33 2020
From: duncan at invalid.invalid (duncan smith)
Date: Sat, 15 Feb 2020 01:24:33 +0000
Subject: What I learned today
In-Reply-To: <mailman.338.1581723435.9276.python-list@python.org>
References: <learned-20200214234803@ram.dialup.fu-berlin.de>
 <CAGGBd_rLHzbdSWPKMegFxfj_d7yiNfcM+Xk0e9D2Tjj+upjEBQ@mail.gmail.com>
 <mailman.338.1581723435.9276.python-list@python.org>
Message-ID: <mLH1G.140883$eK6.94945@fx16.iad>

On 14/02/2020 23:21, Dan Stromberg wrote:
> On Fri, Feb 14, 2020 at 3:10 PM Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> 
>>   By trial and error (never read documentation!) I found
>>   that you can count the number of e's in a text by just
>>
>> Counter( text ).get( 'e' )
>>
>>   (after ?from collections import Counter? that is).
>>
> Even simpler, though not suitable for all situations:
> "abcbdbe".count("b")
> 

[snip]

And by far the quickest way (that I've found) for counting the number of
set bits in an int.

>>> def popcount(n):
	cnt = 0
	while n:
		n &= n-1
		cnt += 1
	return cnt

>>> import timeit
>>> timeit.timeit("popcount(19847998494279)", "from __main__ import
popcount", number=10000)
						
0.034410387044772506
>>> timeit.timeit("bin(19847998494279).count('1')", number=10000)
						
0.004501901799812913
>>>

OK, things turn around for large integers with very few set bits. But
for my use case bin(n).count('1') wins hands down (which surprised me a
little).

Duncan

From __peter__ at web.de  Sat Feb 15 08:46:09 2020
From: __peter__ at web.de (Peter Otten)
Date: Sat, 15 Feb 2020 14:46:09 +0100
Subject: What I learned today
References: <learned-20200214234803@ram.dialup.fu-berlin.de>
Message-ID: <r28sn3$3k6a$1@ciao.gmane.io>

Stefan Ram wrote:

> The other thing I read in a book. I already knew that one
> can zip using ... ?zip?. E.g.,
> 
> x =( 'y', 'n', 'a', 'n', 't' )
> y =(   4,   2,   7,  3,    1 )
> z = zip( x, y )
> print( list( z ))
> [('y', 4), ('n', 2), ('a', 7), ('n', 3), ('t', 1)]
> 
> But the book told me that you can unzip using ... ?zip? again!
> 
> z = zip( x, y )
> a, b = zip( *z )
> print( a )
> ('y', 'n', 'a', 'n', 't')
> print( b )
> (4, 2, 7, 3, 1)
> 
> Wow!
> 

Another way to look at that is that if you write a matrix as a tuple of 
tuples

>>> a = (1,2), (3,4), (5,6)

you can transpose it with

>>> def transposed(a):
...     return tuple(zip(*a))
... 
>>> transposed(a)
((1, 3, 5), (2, 4, 6))

and transposing twice gives the original matrix:

>>> transposed(transposed(a)) == a
True



From markos at c2o.pro.br  Sat Feb 15 19:50:24 2020
From: markos at c2o.pro.br (Markos)
Date: Sat, 15 Feb 2020 21:50:24 -0300
Subject: I can't access dataframe fields
Message-ID: <f86457a3-b103-269a-71ac-fb2f3faa7390@c2o.pro.br>

Hi all,

I created the following data frame (updated_distance_matrix)

 ???? P1??????????? P2??????????? P4??????????? P5?????????? (P3, P6)
P1 0,000000 0,244307 0,367696 0,341760 0
P2 0.234307 0.000000 0.194165 0.1443178 0
P4 0.366969 0.194165 0.000000 0.284253 0
P5 0.341760 0.1443178 0.284253 0.000000 0
(P3, P6) 0.000000 0.000000 0.000000 0.000000 0

I can change the fields of columns and rows P1-P5 without problems.

But when I try to access the fields of the row, or column, (P3, P6)

print (updated_distance_matrix_df.loc [clusters [i], last_cluster])

the message appears:

KeyError: 'the label [P3, P6] is not in the [index]'

If I change find the "loc" by "at" method appears the error:

print (updated_distance_matrix_df.at [clusters [i], last_cluster])

TypeError: unhashable type: 'list'

And if you simply leave:

print (updated_distance_matrix_df [clusters [i], last_cluster])

gives the error:

TypeError: unhashable type: 'list'

A last_cluster variable is of type list:

print (last_cluster, type (last_cluster))

['P3', 'P6'] <class 'list'>

And a variable cluster [i] is a string:

print (clusters [i], type (clusters [i]))

P5 <class 'str'>

Any tip?

Thank you,

Markos


From python at mrabarnett.plus.com  Sat Feb 15 21:36:53 2020
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 16 Feb 2020 02:36:53 +0000
Subject: I can't access dataframe fields
In-Reply-To: <f86457a3-b103-269a-71ac-fb2f3faa7390@c2o.pro.br>
References: <f86457a3-b103-269a-71ac-fb2f3faa7390@c2o.pro.br>
Message-ID: <a6f54474-a94b-11d8-3e41-8ce5311db004@mrabarnett.plus.com>

On 2020-02-16 00:50, Markos wrote:
> Hi all,
> 
> I created the following data frame (updated_distance_matrix)
> 
>   ???? P1??????????? P2??????????? P4??????????? P5?????????? (P3, P6)
> P1 0,000000 0,244307 0,367696 0,341760 0
> P2 0.234307 0.000000 0.194165 0.1443178 0
> P4 0.366969 0.194165 0.000000 0.284253 0
> P5 0.341760 0.1443178 0.284253 0.000000 0
> (P3, P6) 0.000000 0.000000 0.000000 0.000000 0
> 
> I can change the fields of columns and rows P1-P5 without problems.
> 
> But when I try to access the fields of the row, or column, (P3, P6)
> 
> print (updated_distance_matrix_df.loc [clusters [i], last_cluster])
> 
> the message appears:
> 
> KeyError: 'the label [P3, P6] is not in the [index]'
> 
The rows and columns have "(P3, P6)", but you're looking for "[P3, P6]". 
They aren't the same.

> If I change find the "loc" by "at" method appears the error:
> 
> print (updated_distance_matrix_df.at [clusters [i], last_cluster])
> 
> TypeError: unhashable type: 'list'
> 
Is it expecting a tuple instead of a list? Tuples are hashable, lists 
are not.

> And if you simply leave:
> 
> print (updated_distance_matrix_df [clusters [i], last_cluster])
> 
> gives the error:
> 
> TypeError: unhashable type: 'list'
> 
> A last_cluster variable is of type list:
> 
> print (last_cluster, type (last_cluster))
> 
> ['P3', 'P6'] <class 'list'>
> 
> And a variable cluster [i] is a string:
> 
> print (clusters [i], type (clusters [i]))
> 
> P5 <class 'str'>
> 
> Any tip?
> 
> Thank you,
> 

From pahome.chen at mirlab.org  Mon Feb 17 05:11:42 2020
From: pahome.chen at mirlab.org (lampahome)
Date: Mon, 17 Feb 2020 18:11:42 +0800
Subject: Can anyone share experience about python backend developer?
Message-ID: <CAB3eZfu6XvaK4erxumMSqPA1X87Ug+sdTwAvF4FxLVG4RNVADQ@mail.gmail.com>

I have 3+years developer experience in python, but I always develop
about peer-to-peer service. Have no backend experience in python.

But now I want to change to backend engineer, somebody shares their
job is to do like
1. Develop customize API to receive data from global
2. Develop tools with k8s
3. Experience about NoSQL

After I heard above, it seems wide range and hard to start from scratch.

Without comparing performance with other languages, how to dig into
backend development?(Or some framework could help me?)

thx

From soyeomul at doraji.xyz  Mon Feb 17 08:15:43 2020
From: soyeomul at doraji.xyz (=?utf-8?B?7Zmp67OR7Z2s?=)
Date: Mon, 17 Feb 2020 22:15:43 +0900
Subject: What I learned today
References: <learned-20200214234803@ram.dialup.fu-berlin.de>
Message-ID: <yw875fas7p.fsf@vtac.birch.chromebook>

ram at zedat.fu-berlin.de (Stefan Ram) writes:

>   ...
>   But the book told me that you can unzip using ... ?zip? again!
>
> z = zip( x, y )
> a, b = zip( *z )
> print( a )
>                                       ('y', 'n', 'a', 'n', 't')
> print( b )
>                                                 (4, 2, 7, 3, 1)
>
>   Wow!

Usally i use zip so many, thanks for tip^^^

Sincerely, Byung-Hee

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

From voodoo.bender at gmail.com  Mon Feb 17 11:47:54 2020
From: voodoo.bender at gmail.com (alberto)
Date: Mon, 17 Feb 2020 08:47:54 -0800 (PST)
Subject: insert data in python script
Message-ID: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>

Hi, 
I would use this script to evaluate fugacity coefficient with PENG-ROBINSON equation, but I don't understand the correct mode to insert data

import numpy as np
import matplotlib.pyplot as plt
from scipy.optimize import newton

R = 8.314e-5  # universal gas constant, m3-bar/K-mol
class Molecule:
    """
    Store molecule info here
    """
    def __init__(self, name, Tc, Pc, omega):
        """
        Pass parameters desribing molecules
        """
        #! name
        self.name = name
        #! Critical temperature (K)
        self.Tc = Tc
        #! Critical pressure (bar)
        self.Pc = Pc
        #! Accentric factor
        self.omega = omega

    def print_params(self):
        """
        Print molecule parameters.
        """
        print("""Molecule: %s.
        \tCritical Temperature = %.1f K
        \tCritical Pressure = %.1f bar.
        \tAccentric factor = %f""" % (self.name, self.Tc, self.Pc, self.omega))

def preos(molecule, T, P, plotcubic=True, printresults=True):
    """
    Peng-Robinson equation of state (PREOS)
    http://en.wikipedia.org/wiki/Equation_of_state#Peng.E2.80.93Robinson_equation_of_state
    :param molecule: Molecule molecule of interest
    :param T: float temperature in Kelvin
    :param P: float pressure in bar
    :param plotcubic: bool plot cubic polynomial in compressibility factor
    :param printresults: bool print off properties
    Returns a Dict() of molecule properties at this T and P.
    """
    # build params in PREOS
    Tr = T / molecule.Tc  # reduced temperature
    a = 0.457235 * R**2 * molecule.Tc**2 / molecule.Pc
    b = 0.0777961 * R * molecule.Tc / molecule.Pc
    kappa = 0.37464 + 1.54226 * molecule.omega - 0.26992 * molecule.omega**2
    alpha = (1 + kappa * (1 - np.sqrt(Tr)))**2

    A = a * alpha * P / R**2 / T**2
    B = b * P / R / T

    # build cubic polynomial
    def g(z):
        """
        Cubic polynomial in z from EOS. This should be zero.
        :param z: float compressibility factor
        """
        return z**3 - (1 - B) * z**2 + (A - 2*B - 3*B**2) * z - (
                A * B - B**2 - B**3)

    # Solve cubic polynomial for the compressibility factor
    z = newton(g, 1.0)  # compressibility factor
    rho = P / (R * T * z)  # density

    # fugacity coefficient comes from an integration
    fugacity_coeff = np.exp(z - 1 - np.log(z - B) - A / np.sqrt(8) / B * np.log(
                (z + (1 + np.sqrt(2)) * B) / (z + (1 - np.sqrt(2)) * B)))

    if printresults:
        print("""PREOS calculation at
        \t T = %.2f K
        \t P = %.2f bar""" % (T, P))
        print("\tCompressibility factor : ", z)
        print("\tFugacity coefficient: ", fugacity_coeff)
        print("\tFugacity at pressure %.3f bar = %.3f bar" % (
                P, fugacity_coeff * P))
        print("\tDensity: %f mol/m3" % rho)
        print("\tMolar volume: %f L/mol" % (1.0 / rho * 1000))
        print("\tDensity: %f v STP/v" % (rho * 22.4 / 1000))
        print("\tDensity of ideal gas at same conditions: %f v STP/v" % (
                rho * 22.4/ 1000 * z))

    if plotcubic:
        # Plot the cubic equation to visualize the roots
        zz = np.linspace(0, 1.5)  # array for plotting

        plt.figure()
        plt.plot(zz, g(zz), color='k')
        plt.xlabel('Compressibility, $z$')
        plt.ylabel('Cubic $g(z)$')
        plt.axvline(x=z)
        plt.axhline(y=0)
        plt.title('Root found @ z = %.2f' % z)
        plt.show()
    return {"density(mol/m3)": rho, "fugacity_coefficient": fugacity_coeff,
            "compressibility_factor": z, "fugacity(bar)": fugacity_coeff * P,
            "molar_volume(L/mol)": 1.0 / rho * 1000.0}

def preos_reverse(molecule, T, f, plotcubic=False, printresults=True):
    """
    Reverse Peng-Robinson equation of state (PREOS) to obtain pressure for a particular fugacity
    :param molecule: Molecule molecule of interest
    :param T: float temperature in Kelvin
    :param f: float fugacity in bar
    :param plotcubic: bool plot cubic polynomial in compressibility factor
    :param printresults: bool print off properties
    Returns a Dict() of molecule properties at this T and f.
    """
    # build function to minimize: difference between desired fugacity and that obtained from preos
    def g(P):
        """
        :param P: pressure
        """
        return (f - preos(molecule, T, P, plotcubic=False, printresults=False)["fugacity(bar)"])

    # Solve preos for the pressure
    P = newton(g, f)  # pressure

    # Obtain remaining parameters
    pars = preos(molecule, T, P, plotcubic=plotcubic, printresults=printresults)
    rho = pars["density(mol/m3)"]
    fugacity_coeff = pars["fugacity_coefficient"]
    z = pars["compressibility_factor"]

    return {"density(mol/m3)": rho, "fugacity_coefficient": fugacity_coeff,
            "compressibility_factor": z, "pressure(bar)": P,
            "molar_volume(L/mol)": 1.0 / rho * 1000.0}

# TODO: Implement mixture in object-oriented way as well
def preos_mixture(molecule_a, molecule_b, delta, T, P_total, x, plotcubic=True, printresults=True):
    """
    Peng-Robinson equation of state (PREOS) for a binary mixture
    http://en.wikipedia.org/wiki/Equation_of_state#Peng.E2.80.93Robinson_equation_of_state
    :param molecule_a: Molecule molecule 1 of interest
    :param molecule_b: Molecule molecule 2 of interest
    :param delta: binary interaction parameter between molecules a and b
    :param T: float temperature in Kelvin
    :param P_total: float total pressure in bar
    :param x: array mole fractions
    :param plotcubic: bool plot cubic polynomial in compressibility factor
    :param printresults: bool print off properties
    """
    # build arrays of properties
    Tc = np.array([molecule_a.Tc, molecule_b.Tc])
    Pc = np.array([molecule_a.Pc, molecule_b.Pc])
    omega = np.array([molecule_a.omega, molecule_b.omega])

    # build params in PREOS
    Tr = T / Tc  # reduced temperature
    a0 = 0.457235 * R**2 * Tc**2 / Pc
    b = 0.0777961 * R * Tc / Pc
    kappa = 0.37464 + 1.54226 * omega - 0.26992 * omega**2
    a = a0 * (1 + kappa * (1 - np.sqrt(Tr)))**2
    
    # apply mixing rules
    aij = (1.0 - delta) * np.sqrt(a[0] * a[1])
    a_mix = a[0] * x[0]**2 + a[1] * x[1]**2 + 2.0 * x[0] * x[1] * aij
    b_mix = x[0] * b[0] + x[1] * b[1]
    A = a_mix * P_total / R**2 / T**2
    B = b_mix * P_total / R / T

    # build cubic polynomial
    def g(z):
        """
        Cubic polynomial in z from EOS. This should be zero.
        :param z: float compressibility factor
        """
        return z**3 - (1 - B) * z**2 + (A - 2*B - 3*B**2) * z - (
                A * B - B**2 - B**3)

    # Solve cubic polynomial for the compressibility factor
    z = newton(g, 1.0)  # compressibility factor
    rho = P_total / (R * T * z)  # density
    
    Lnfug_0 = -np.log(z - B) + (z - 1.0) * b[0] / b_mix - A / np.sqrt(8) / B * (2.0 / a_mix * (x[0] * a[0] + x[1] * aij) - b[0] / b_mix) *\
        np.log((z + (1.0 + np.sqrt(2)) * B) / (z + (1.0 - np.sqrt(2)) * B))
    Lnfug_1 = -np.log(z - B) + (z - 1.0) * b[1] / b_mix - A / np.sqrt(8) / B * (2.0 / a_mix * (x[1] * a[1] + x[0] * aij) - b[1] / b_mix) *\
        np.log((z + (1.0 + np.sqrt(2)) * B) / (z + (1.0 - np.sqrt(2)) * B))

    # fugacity coefficient comes from an integration
    fugacity_coefs = np.exp(np.array([Lnfug_0, Lnfug_1]))

    if printresults:
        print("""PREOS calculation at
        \t T = %.2f K
        \t P, total = %.2f bar""" % (T, P_total))
        print("\tDensity: %f mol/m3" % rho)
        print("\tCompressibility factor : %f" % z)
        print("Component 0, %s:" % molecule_a.name)
        print("\tFugacity coefficient: %f" % fugacity_coefs[0])
        print("\tFugacity: %f bar" % (fugacity_coefs[0] * x[0] * P_total))
        print("Component 1, %s:" % molecule_b.name)
        print("\tFugacity coefficient: %f" % fugacity_coefs[1])
        print("\tFugacity: %f bar" % (fugacity_coefs[1] * x[1] * P_total))

    if plotcubic:
        # Plot the cubic equation to visualize the roots
        zz = np.linspace(0, 1.5)  # array for plotting

        plt.figure()
        plt.plot(zz, g(zz), color='k')
        plt.xlabel('Compressibility, $z$')
        plt.ylabel('Cubic $g(z)$')
        plt.axvline(x=z)
        plt.axhline(y=0)
        plt.title('Root found @ z = %.2f' % z)
        plt.show()
    return {"density(mol/m3)": rho, "fugacity_coefficients": fugacity_coefs,
            "compressibility_factor": z}


the readme file says that 

As an example calculation, we consider methane at 65.0 bar and 298.0 K. Methane has a critical temperature of -82.59 deg. C and a critical pressure of 45.99 bar. Its accentric factor is 0.011. We first create a methane molecule object and print its stored parameters:

import preos
# pass name, Tc, Pc, omega
methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
methane.print_params()

Could I fix it

regards

Alberto

From voodoo.bender at gmail.com  Sun Feb 16 17:17:28 2020
From: voodoo.bender at gmail.com (alberto)
Date: Sun, 16 Feb 2020 14:17:28 -0800 (PST)
Subject: fugacity cofficient
Message-ID: <f791c1d6-c7ef-45e9-a5dc-3701a21cd05b@googlegroups.com>

Hi, 
how I could realize a script to calculate fugacity coefficients
with this formula

https://wikimedia.org/api/rest_v1/media/math/render/svg/8743fb5a1e85edb8f4334fb7154727057f395eb8

in my input file.txt I have this data

#p z
10.0 0.9850
20.0 0.9703
30.0 0.9560
40.0 0.9421
50.0 0.9287

regards

Alberto

From pkpearson at nowhere.invalid  Mon Feb 17 13:40:00 2020
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 17 Feb 2020 18:40:00 GMT
Subject: fugacity cofficient
References: <f791c1d6-c7ef-45e9-a5dc-3701a21cd05b@googlegroups.com>
Message-ID: <hb0500F2vagU1@mid.individual.net>

On Sun, 16 Feb 2020 14:17:28 -0800 (PST), alberto wrote:
> Hi, 
> how I could realize a script to calculate fugacity coefficients
> with this formula
>
[snip]
>
> regards
>
> Alberto

Welcome, Alberto.

Can you make this look more like a Python question and less like a
do-my-homework question?  Show us what you've tried.

-- 
To email me, substitute nowhere->runbox, invalid->com.

From pkpearson at nowhere.invalid  Mon Feb 17 13:41:28 2020
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 17 Feb 2020 18:41:28 GMT
Subject: fugacity cofficient
References: <f791c1d6-c7ef-45e9-a5dc-3701a21cd05b@googlegroups.com>
 <hb0500F2vagU1@mid.individual.net>
Message-ID: <hb052oF2vagU2@mid.individual.net>

On 17 Feb 2020 18:40:00 GMT, Peter Pearson <pkpearson at nowhere.invalid> wrote:
>
> Welcome, Alberto.
>
> Can you make this look more like a Python question and less like a
> do-my-homework question?  Show us what you've tried.

Sorry.   I see you already did exactly that.

-- 
To email me, substitute nowhere->runbox, invalid->com.

From markos at c2o.pro.br  Mon Feb 17 13:41:39 2020
From: markos at c2o.pro.br (Markos)
Date: Mon, 17 Feb 2020 15:41:39 -0300
Subject: I can't access dataframe fields
In-Reply-To: <a6f54474-a94b-11d8-3e41-8ce5311db004@mrabarnett.plus.com>
References: <f86457a3-b103-269a-71ac-fb2f3faa7390@c2o.pro.br>
 <a6f54474-a94b-11d8-3e41-8ce5311db004@mrabarnett.plus.com>
Message-ID: <5f3d062f-c213-c0cb-ebff-e27f92df531c@c2o.pro.br>

Hi MRAB,

I changed last_cluster to tuple(last_cluster).

From:

print (updated_distance_matrix_df.loc [clusters [i], last_cluster])

to

print (updated_distance_matrix_df.loc [clusters [i], tuple(last_cluster)])

And worked.

Thank you,

Markos


Em 15-02-2020 23:36, MRAB escreveu:
> On 2020-02-16 00:50, Markos wrote:
>> Hi all,
>>
>> I created the following data frame (updated_distance_matrix)
>>
>> ? ???? P1??????????? P2??????????? P4??????????? P5 (P3, P6)
>> P1 0,000000 0,244307 0,367696 0,341760 0
>> P2 0.234307 0.000000 0.194165 0.1443178 0
>> P4 0.366969 0.194165 0.000000 0.284253 0
>> P5 0.341760 0.1443178 0.284253 0.000000 0
>> (P3, P6) 0.000000 0.000000 0.000000 0.000000 0
>>
>> I can change the fields of columns and rows P1-P5 without problems.
>>
>> But when I try to access the fields of the row, or column, (P3, P6)
>>
>> print (updated_distance_matrix_df.loc [clusters [i], last_cluster])
>>
>> the message appears:
>>
>> KeyError: 'the label [P3, P6] is not in the [index]'
>>
> The rows and columns have "(P3, P6)", but you're looking for "[P3, 
> P6]". They aren't the same.
>
>> If I change find the "loc" by "at" method appears the error:
>>
>> print (updated_distance_matrix_df.at [clusters [i], last_cluster])
>>
>> TypeError: unhashable type: 'list'
>>
> Is it expecting a tuple instead of a list? Tuples are hashable, lists 
> are not.
>
>> And if you simply leave:
>>
>> print (updated_distance_matrix_df [clusters [i], last_cluster])
>>
>> gives the error:
>>
>> TypeError: unhashable type: 'list'
>>
>> A last_cluster variable is of type list:
>>
>> print (last_cluster, type (last_cluster))
>>
>> ['P3', 'P6'] <class 'list'>
>>
>> And a variable cluster [i] is a string:
>>
>> print (clusters [i], type (clusters [i]))
>>
>> P5 <class 'str'>
>>
>> Any tip?
>>
>> Thank you,
>>


From maximealbi at outlook.com  Mon Feb 17 13:46:29 2020
From: maximealbi at outlook.com (Maxime Albi)
Date: Mon, 17 Feb 2020 18:46:29 +0000
Subject: Interpreter Python 3.8 not there to select from PyCharm
In-Reply-To: <CY4PR14MB1318CB8D36A2734C608A5A9CCF170@CY4PR14MB1318.namprd14.prod.outlook.com>
References: <CY4PR14MB1318CB8D36A2734C608A5A9CCF170@CY4PR14MB1318.namprd14.prod.outlook.com>
Message-ID: <CY4PR14MB1318A85A5EC7FB4D6CBB969DCF160@CY4PR14MB1318.namprd14.prod.outlook.com>

I'm very new to Python and wanting to learn the basics.
I downloaded and installed Python 3.8 and PyCharm for my Windows 10 machine.  All good.

Launched PyCharm and I started a new Project and tried to select an 'interpreter' such as Python 3.8 but no interpreter was available for me to select from the down arrow menu ..!?!?

Any settings I need to do ??

Thanks,
Maxime


From PythonList at DancesWithMice.info  Mon Feb 17 15:21:49 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 18 Feb 2020 09:21:49 +1300
Subject: Can anyone share experience about python backend developer?
In-Reply-To: <CAB3eZfu6XvaK4erxumMSqPA1X87Ug+sdTwAvF4FxLVG4RNVADQ@mail.gmail.com>
References: <CAB3eZfu6XvaK4erxumMSqPA1X87Ug+sdTwAvF4FxLVG4RNVADQ@mail.gmail.com>
Message-ID: <fd70c353-84f6-8de4-b493-6fd91cc85fad@DancesWithMice.info>

On 17/02/20 11:11 PM, lampahome wrote:
> I have 3+years developer experience in python, but I always develop
> about peer-to-peer service. Have no backend experience in python.
> 
> But now I want to change to backend engineer, somebody shares their
> job is to do like
> 1. Develop customize API to receive data from global
> 2. Develop tools with k8s
> 3. Experience about NoSQL
> 
> After I heard above, it seems wide range and hard to start from scratch.
> 
> Without comparing performance with other languages, how to dig into
> backend development?(Or some framework could help me?)


Suggest a review of edX's and Coursera's (and possibly others) on-line 
training courses. IIRC there's at least one that aims specifically at 
the 'back-end' stack.
-- 
Regards =dn

From PythonList at DancesWithMice.info  Mon Feb 17 16:37:38 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 18 Feb 2020 10:37:38 +1300
Subject: insert data in python script
In-Reply-To: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
Message-ID: <b782e2bd-a2a7-60d4-e27c-0557301ceb0d@DancesWithMice.info>

Please help us to help you!
1 is all of this code in a single file or spread across (at least) two 
modules? What are their names? What is the directory structure?
2 copy-paste the actual error message received.


It works for me!
1 not knowing your circumstances, I put all the code in one file
2 updated one line (possibly due to above)

# methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
methane = Molecule("methane", -82.59 + 273.15, 45.99, 0.011)

dn $ python3 Projects/molecule.py
Molecule: methane.
         	Critical Temperature = 190.6 K
         	Critical Pressure = 46.0 bar.
         	Accentric factor = 0.011000


NB if the bulk of the code is stored in a module named preos.py then it 
is necessary to first:

import peos

and restore the above change.

NBB under such conditions peos.py must be located in the file-system 
where the 'mainline' can find (and import) it!
-- 
Regards =dn

From voodoo.bender at gmail.com  Tue Feb 18 02:47:12 2020
From: voodoo.bender at gmail.com (alberto)
Date: Mon, 17 Feb 2020 23:47:12 -0800 (PST)
Subject: insert data in python script
In-Reply-To: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
Message-ID: <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>

Il giorno luned? 17 febbraio 2020 17:48:07 UTC+1, alberto ha scritto:
> Hi, 
> I would use this script to evaluate fugacity coefficient with PENG-ROBINSON equation, but I don't understand the correct mode to insert data
> 
> import numpy as np
> import matplotlib.pyplot as plt
> from scipy.optimize import newton
> 
> R = 8.314e-5  # universal gas constant, m3-bar/K-mol
> class Molecule:
>     """
>     Store molecule info here
>     """
>     def __init__(self, name, Tc, Pc, omega):
>         """
>         Pass parameters desribing molecules
>         """
>         #! name
>         self.name = name
>         #! Critical temperature (K)
>         self.Tc = Tc
>         #! Critical pressure (bar)
>         self.Pc = Pc
>         #! Accentric factor
>         self.omega = omega
> 
>     def print_params(self):
>         """
>         Print molecule parameters.
>         """
>         print("""Molecule: %s.
>         \tCritical Temperature = %.1f K
>         \tCritical Pressure = %.1f bar.
>         \tAccentric factor = %f""" % (self.name, self.Tc, self.Pc, self.omega))
> 
> def preos(molecule, T, P, plotcubic=True, printresults=True):
>     """
>     Peng-Robinson equation of state (PREOS)
>     http://en.wikipedia.org/wiki/Equation_of_state#Peng.E2.80.93Robinson_equation_of_state
>     :param molecule: Molecule molecule of interest
>     :param T: float temperature in Kelvin
>     :param P: float pressure in bar
>     :param plotcubic: bool plot cubic polynomial in compressibility factor
>     :param printresults: bool print off properties
>     Returns a Dict() of molecule properties at this T and P.
>     """
>     # build params in PREOS
>     Tr = T / molecule.Tc  # reduced temperature
>     a = 0.457235 * R**2 * molecule.Tc**2 / molecule.Pc
>     b = 0.0777961 * R * molecule.Tc / molecule.Pc
>     kappa = 0.37464 + 1.54226 * molecule.omega - 0.26992 * molecule.omega**2
>     alpha = (1 + kappa * (1 - np.sqrt(Tr)))**2
> 
>     A = a * alpha * P / R**2 / T**2
>     B = b * P / R / T
> 
>     # build cubic polynomial
>     def g(z):
>         """
>         Cubic polynomial in z from EOS. This should be zero.
>         :param z: float compressibility factor
>         """
>         return z**3 - (1 - B) * z**2 + (A - 2*B - 3*B**2) * z - (
>                 A * B - B**2 - B**3)
> 
>     # Solve cubic polynomial for the compressibility factor
>     z = newton(g, 1.0)  # compressibility factor
>     rho = P / (R * T * z)  # density
> 
>     # fugacity coefficient comes from an integration
>     fugacity_coeff = np.exp(z - 1 - np.log(z - B) - A / np.sqrt(8) / B * np.log(
>                 (z + (1 + np.sqrt(2)) * B) / (z + (1 - np.sqrt(2)) * B)))
> 
>     if printresults:
>         print("""PREOS calculation at
>         \t T = %.2f K
>         \t P = %.2f bar""" % (T, P))
>         print("\tCompressibility factor : ", z)
>         print("\tFugacity coefficient: ", fugacity_coeff)
>         print("\tFugacity at pressure %.3f bar = %.3f bar" % (
>                 P, fugacity_coeff * P))
>         print("\tDensity: %f mol/m3" % rho)
>         print("\tMolar volume: %f L/mol" % (1.0 / rho * 1000))
>         print("\tDensity: %f v STP/v" % (rho * 22.4 / 1000))
>         print("\tDensity of ideal gas at same conditions: %f v STP/v" % (
>                 rho * 22.4/ 1000 * z))
> 
>     if plotcubic:
>         # Plot the cubic equation to visualize the roots
>         zz = np.linspace(0, 1.5)  # array for plotting
> 
>         plt.figure()
>         plt.plot(zz, g(zz), color='k')
>         plt.xlabel('Compressibility, $z$')
>         plt.ylabel('Cubic $g(z)$')
>         plt.axvline(x=z)
>         plt.axhline(y=0)
>         plt.title('Root found @ z = %.2f' % z)
>         plt.show()
>     return {"density(mol/m3)": rho, "fugacity_coefficient": fugacity_coeff,
>             "compressibility_factor": z, "fugacity(bar)": fugacity_coeff * P,
>             "molar_volume(L/mol)": 1.0 / rho * 1000.0}
> 
> def preos_reverse(molecule, T, f, plotcubic=False, printresults=True):
>     """
>     Reverse Peng-Robinson equation of state (PREOS) to obtain pressure for a particular fugacity
>     :param molecule: Molecule molecule of interest
>     :param T: float temperature in Kelvin
>     :param f: float fugacity in bar
>     :param plotcubic: bool plot cubic polynomial in compressibility factor
>     :param printresults: bool print off properties
>     Returns a Dict() of molecule properties at this T and f.
>     """
>     # build function to minimize: difference between desired fugacity and that obtained from preos
>     def g(P):
>         """
>         :param P: pressure
>         """
>         return (f - preos(molecule, T, P, plotcubic=False, printresults=False)["fugacity(bar)"])
> 
>     # Solve preos for the pressure
>     P = newton(g, f)  # pressure
> 
>     # Obtain remaining parameters
>     pars = preos(molecule, T, P, plotcubic=plotcubic, printresults=printresults)
>     rho = pars["density(mol/m3)"]
>     fugacity_coeff = pars["fugacity_coefficient"]
>     z = pars["compressibility_factor"]
> 
>     return {"density(mol/m3)": rho, "fugacity_coefficient": fugacity_coeff,
>             "compressibility_factor": z, "pressure(bar)": P,
>             "molar_volume(L/mol)": 1.0 / rho * 1000.0}
> 
> # TODO: Implement mixture in object-oriented way as well
> def preos_mixture(molecule_a, molecule_b, delta, T, P_total, x, plotcubic=True, printresults=True):
>     """
>     Peng-Robinson equation of state (PREOS) for a binary mixture
>     http://en.wikipedia.org/wiki/Equation_of_state#Peng.E2.80.93Robinson_equation_of_state
>     :param molecule_a: Molecule molecule 1 of interest
>     :param molecule_b: Molecule molecule 2 of interest
>     :param delta: binary interaction parameter between molecules a and b
>     :param T: float temperature in Kelvin
>     :param P_total: float total pressure in bar
>     :param x: array mole fractions
>     :param plotcubic: bool plot cubic polynomial in compressibility factor
>     :param printresults: bool print off properties
>     """
>     # build arrays of properties
>     Tc = np.array([molecule_a.Tc, molecule_b.Tc])
>     Pc = np.array([molecule_a.Pc, molecule_b.Pc])
>     omega = np.array([molecule_a.omega, molecule_b.omega])
> 
>     # build params in PREOS
>     Tr = T / Tc  # reduced temperature
>     a0 = 0.457235 * R**2 * Tc**2 / Pc
>     b = 0.0777961 * R * Tc / Pc
>     kappa = 0.37464 + 1.54226 * omega - 0.26992 * omega**2
>     a = a0 * (1 + kappa * (1 - np.sqrt(Tr)))**2
>     
>     # apply mixing rules
>     aij = (1.0 - delta) * np.sqrt(a[0] * a[1])
>     a_mix = a[0] * x[0]**2 + a[1] * x[1]**2 + 2.0 * x[0] * x[1] * aij
>     b_mix = x[0] * b[0] + x[1] * b[1]
>     A = a_mix * P_total / R**2 / T**2
>     B = b_mix * P_total / R / T
> 
>     # build cubic polynomial
>     def g(z):
>         """
>         Cubic polynomial in z from EOS. This should be zero.
>         :param z: float compressibility factor
>         """
>         return z**3 - (1 - B) * z**2 + (A - 2*B - 3*B**2) * z - (
>                 A * B - B**2 - B**3)
> 
>     # Solve cubic polynomial for the compressibility factor
>     z = newton(g, 1.0)  # compressibility factor
>     rho = P_total / (R * T * z)  # density
>     
>     Lnfug_0 = -np.log(z - B) + (z - 1.0) * b[0] / b_mix - A / np.sqrt(8) / B * (2.0 / a_mix * (x[0] * a[0] + x[1] * aij) - b[0] / b_mix) *\
>         np.log((z + (1.0 + np.sqrt(2)) * B) / (z + (1.0 - np.sqrt(2)) * B))
>     Lnfug_1 = -np.log(z - B) + (z - 1.0) * b[1] / b_mix - A / np.sqrt(8) / B * (2.0 / a_mix * (x[1] * a[1] + x[0] * aij) - b[1] / b_mix) *\
>         np.log((z + (1.0 + np.sqrt(2)) * B) / (z + (1.0 - np.sqrt(2)) * B))
> 
>     # fugacity coefficient comes from an integration
>     fugacity_coefs = np.exp(np.array([Lnfug_0, Lnfug_1]))
> 
>     if printresults:
>         print("""PREOS calculation at
>         \t T = %.2f K
>         \t P, total = %.2f bar""" % (T, P_total))
>         print("\tDensity: %f mol/m3" % rho)
>         print("\tCompressibility factor : %f" % z)
>         print("Component 0, %s:" % molecule_a.name)
>         print("\tFugacity coefficient: %f" % fugacity_coefs[0])
>         print("\tFugacity: %f bar" % (fugacity_coefs[0] * x[0] * P_total))
>         print("Component 1, %s:" % molecule_b.name)
>         print("\tFugacity coefficient: %f" % fugacity_coefs[1])
>         print("\tFugacity: %f bar" % (fugacity_coefs[1] * x[1] * P_total))
> 
>     if plotcubic:
>         # Plot the cubic equation to visualize the roots
>         zz = np.linspace(0, 1.5)  # array for plotting
> 
>         plt.figure()
>         plt.plot(zz, g(zz), color='k')
>         plt.xlabel('Compressibility, $z$')
>         plt.ylabel('Cubic $g(z)$')
>         plt.axvline(x=z)
>         plt.axhline(y=0)
>         plt.title('Root found @ z = %.2f' % z)
>         plt.show()
>     return {"density(mol/m3)": rho, "fugacity_coefficients": fugacity_coefs,
>             "compressibility_factor": z}
> 
> 
> the readme file says that 
> 
> As an example calculation, we consider methane at 65.0 bar and 298.0 K. Methane has a critical temperature of -82.59 deg. C and a critical pressure of 45.99 bar. Its accentric factor is 0.011. We first create a methane molecule object and print its stored parameters:
> 
> import preos
> # pass name, Tc, Pc, omega
> methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> methane.print_params()
> 
> Could I fix it
> 
> regards
> 
> Alberto


Hi, 
my code preos in one file preos.py
my commands are

alberto at HENDRIX ~/PREOS $ python3.5
Python 3.5.2 (default, Oct  8 2019, 13:06:37) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import preos
>>> methane = Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'Molecule' is not defined

regards

Alberto

From onlinejudge95 at gmail.com  Tue Feb 18 03:04:55 2020
From: onlinejudge95 at gmail.com (onlinejudge95)
Date: Tue, 18 Feb 2020 13:34:55 +0530
Subject: Interpreter Python 3.8 not there to select from PyCharm
In-Reply-To: <CY4PR14MB1318A85A5EC7FB4D6CBB969DCF160@CY4PR14MB1318.namprd14.prod.outlook.com>
References: <CY4PR14MB1318CB8D36A2734C608A5A9CCF170@CY4PR14MB1318.namprd14.prod.outlook.com>
 <CY4PR14MB1318A85A5EC7FB4D6CBB969DCF160@CY4PR14MB1318.namprd14.prod.outlook.com>
Message-ID: <CAD=M5eQn+i8m9WKFiS9eMVut97KNSR+DE8SXotvVjYGRKTQTew@mail.gmail.com>

On Tue, Feb 18, 2020 at 1:40 AM Maxime Albi <maximealbi at outlook.com> wrote:

> I'm very new to Python and wanting to learn the basics.
> I downloaded and installed Python 3.8 and PyCharm for my Windows 10
> machine.  All good.
>
> Launched PyCharm and I started a new Project and tried to select an
> 'interpreter' such as Python 3.8 but no interpreter was available for me to
> select from the down arrow menu ..!?!?
>
> Any settings I need to do ??
>
PyCharm community would be a better source for asking this question

>
> Thanks,
> Maxime
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From PythonList at DancesWithMice.info  Tue Feb 18 03:34:25 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Tue, 18 Feb 2020 21:34:25 +1300
Subject: insert data in python script
In-Reply-To: <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
 <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>
Message-ID: <cb1b53cb-080b-5198-c331-992d1191a1f9@DancesWithMice.info>

...

>> import preos
>> # pass name, Tc, Pc, omega
>> methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
>> methane.print_params()

...

> my code preos in one file preos.py
> my commands are
> 
> alberto at HENDRIX ~/PREOS $ python3.5
> Python 3.5.2 (default, Oct  8 2019, 13:06:37)
> [GCC 5.4.0 20160609] on linux
> Type "help", "copyright", "credits" or "license" for more information.
>>>> import preos
>>>> methane = Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
> NameError: name 'Molecule' is not defined


The first instruction (immediately above) imports the module preos.py. 
That works (no error message!).

The second instruction refers to a Python class called Molecule. That 
fails. The error message says that 'Molecule' is not defined.

Yet we can 'see' it. It *has* been defined! What is going on???

In this case, we need to tell Python that Molecule is part of the preos 
module. So back to your original code (top):

methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)


Please refer to earlier message. If Module were called from code in the 
preos.py file, then the "preos." prefix would not be necessary.

The formal term for this situation is "namespaces". Because Molecule is 
defined within the preos.py module's namespace we need to tell Python 
exactly where Molecule can be found. In the same way that we might say: 
if someone in Antarctica wants to see Alberto, (s)he will have to go to 
Italy to find him...


Don't hesitate to say if you think my reply is too complicated/advanced. 
People here are happy to help...
-- 
Regards =dn

From voodoo.bender at gmail.com  Tue Feb 18 04:41:51 2020
From: voodoo.bender at gmail.com (alberto)
Date: Tue, 18 Feb 2020 01:41:51 -0800 (PST)
Subject: insert data in python script
In-Reply-To: <mailman.348.1582014878.9276.python-list@python.org>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
 <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>
 <cb1b53cb-080b-5198-c331-992d1191a1f9@DancesWithMice.info>
 <mailman.348.1582014878.9276.python-list@python.org>
Message-ID: <8313a962-4d86-464d-9ad5-f3a33faa0018@googlegroups.com>

Il giorno marted? 18 febbraio 2020 09:34:51 UTC+1, DL Neil ha scritto:
> ...
> 
> >> import preos
> >> # pass name, Tc, Pc, omega
> >> methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> >> methane.print_params()
> 
> ...
> 
> > my code preos in one file preos.py
> > my commands are
> > 
> > alberto at HENDRIX ~/PREOS $ python3.5
> > Python 3.5.2 (default, Oct  8 2019, 13:06:37)
> > [GCC 5.4.0 20160609] on linux
> > Type "help", "copyright", "credits" or "license" for more information.
> >>>> import preos
> >>>> methane = Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> > Traceback (most recent call last):
> >    File "<stdin>", line 1, in <module>
> > NameError: name 'Molecule' is not defined
> 
> 
> The first instruction (immediately above) imports the module preos.py. 
> That works (no error message!).
> 
> The second instruction refers to a Python class called Molecule. That 
> fails. The error message says that 'Molecule' is not defined.
> 
> Yet we can 'see' it. It *has* been defined! What is going on???
> 
> In this case, we need to tell Python that Molecule is part of the preos 
> module. So back to your original code (top):
> 
> methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> 
> 
> Please refer to earlier message. If Module were called from code in the 
> preos.py file, then the "preos." prefix would not be necessary.
> 
> The formal term for this situation is "namespaces". Because Molecule is 
> defined within the preos.py module's namespace we need to tell Python 
> exactly where Molecule can be found. In the same way that we might say: 
> if someone in Antarctica wants to see Alberto, (s)he will have to go to 
> Italy to find him...
> 
> 
> Don't hesitate to say if you think my reply is too complicated/advanced. 
> People here are happy to help...
> -- 
> Regards =dn

hi
honestly i don't understand what i have to do.
I have been using python for too little time.
could you help me understand

regards 

Alberto


From bouncingcats at gmail.com  Tue Feb 18 05:00:44 2020
From: bouncingcats at gmail.com (David)
Date: Tue, 18 Feb 2020 21:00:44 +1100
Subject: insert data in python script
In-Reply-To: <8313a962-4d86-464d-9ad5-f3a33faa0018@googlegroups.com>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
 <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>
 <cb1b53cb-080b-5198-c331-992d1191a1f9@DancesWithMice.info>
 <mailman.348.1582014878.9276.python-list@python.org>
 <8313a962-4d86-464d-9ad5-f3a33faa0018@googlegroups.com>
Message-ID: <CAMPXz=rijpWHjy9KBEWFAhXA4xDfbCxQtsJsh9a9sh_DDx-d3w@mail.gmail.com>

On Tue, 18 Feb 2020 at 20:45, alberto <voodoo.bender at gmail.com> wrote:
> Il giorno marted? 18 febbraio 2020 09:34:51 UTC+1, DL Neil ha scritto:

> > > my code preos in one file preos.py
> > > my commands are
> > >
> > > alberto at HENDRIX ~/PREOS $ python3.5
> > > Python 3.5.2 (default, Oct  8 2019, 13:06:37)
> > > [GCC 5.4.0 20160609] on linux
> > > Type "help", "copyright", "credits" or "license" for more information.
> > >>>> import preos
> > >>>> methane = Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> > > Traceback (most recent call last):
> > >    File "<stdin>", line 1, in <module>
> > > NameError: name 'Molecule' is not defined

> honestly i don't understand what i have to do.

$ python3
Python 3.5.3 (default, Sep 27 2018, 17:25:39)
[GCC 6.3.0 20170516] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> print(digits)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'digits' is not defined
>>> print(string.digits)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'string' is not defined
>>> import string
>>> print(digits)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'digits' is not defined
>>> print(string.digits)
0123456789
>>>

From lukasz at langa.pl  Tue Feb 18 05:10:48 2020
From: lukasz at langa.pl (=?utf-8?Q?=C5=81ukasz_Langa?=)
Date: Tue, 18 Feb 2020 11:10:48 +0100
Subject: [RELEASE] Python 3.8.2rc2 is now available for testing
Message-ID: <B6998A34-6326-49CA-9ADE-954258C0BA4D@langa.pl>

Python 3.8.2rc2 is the second release candidate of the second maintenance release of Python 3.8. Go get it here:

https://www.python.org/downloads/release/python-382rc2/ <https://www.python.org/downloads/release/python-382rc2/>

Why a second release candidate?

The major reason for RC2 is that GH-16839 <https://github.com/python/cpython/pull/16839> has been reverted.

The original change was supposed to fix for some edge cases in urlparse (numeric paths, recognizing netlocs without //; details in BPO-27657 <https://bugs.python.org/issue27657>). Unfortunately it broke third parties relying on the pre-existing undefined behavior.

Sadly, the reverted fix has already been released as part of 3.8.1 (and 3.7.6 where it?s also reverted now). As such, even though the revert is itself a bug fix, it is incompatible with the behavior of 3.8.1.

Please test.


Timeline

Assuming no critical problems are found prior to 2020-02-24, the currently scheduled release date for 3.8.2 (as well as 3.9.0 alpha 4!), 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 3.8.2 and as such its main purpose is testing.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.3 planned for April 2020 (during sprints at PyCon US).


What?s new?

The Python 3.8 series is the newest feature release of the Python language, and it contains many new features and optimizations. 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 version 3.8.2 specifically can be found in its change log <https://docs.python.org/release/3.8.2rc2/whatsnew/changelog.html#python-3-8-2-release-candidate-2>.


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/>


- ?

From torriem at gmail.com  Tue Feb 18 09:53:59 2020
From: torriem at gmail.com (Michael Torrie)
Date: Tue, 18 Feb 2020 07:53:59 -0700
Subject: insert data in python script
In-Reply-To: <8313a962-4d86-464d-9ad5-f3a33faa0018@googlegroups.com>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
 <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>
 <cb1b53cb-080b-5198-c331-992d1191a1f9@DancesWithMice.info>
 <mailman.348.1582014878.9276.python-list@python.org>
 <8313a962-4d86-464d-9ad5-f3a33faa0018@googlegroups.com>
Message-ID: <aafd71b2-c5eb-10de-ed39-036276a5b4b5@gmail.com>

On 2/18/20 2:41 AM, alberto wrote:
> Il giorno marted? 18 febbraio 2020 09:34:51 UTC+1, DL Neil ha scritto:
>> The first instruction (immediately above) imports the module preos.py. 
>> That works (no error message!).
>>
>> The second instruction refers to a Python class called Molecule. That 
>> fails. The error message says that 'Molecule' is not defined.
>>
>> Yet we can 'see' it. It *has* been defined! What is going on???
>>
>> In this case, we need to tell Python that Molecule is part of the preos 
>> module. So back to your original code (top):
>>
>> methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
He explicitly told you what to do.

The problem was "Molecule" is part of the "preos" module, so you have to
refer to it by the module name first.

>> Please refer to earlier message. If Module were called from code in the 
>> preos.py file, then the "preos." prefix would not be necessary.
>>
>> The formal term for this situation is "namespaces". Because Molecule is 
>> defined within the preos.py module's namespace we need to tell Python 
>> exactly where Molecule can be found. In the same way that we might say: 
>> if someone in Antarctica wants to see Alberto, (s)he will have to go to 
>> Italy to find him...
>>
>>
>> Don't hesitate to say if you think my reply is too complicated/advanced. 
>> People here are happy to help...
>> -- 
>> Regards =dn
> 
> hi
> honestly i don't understand what i have to do.
> I have been using python for too little time.
> could you help me understand

Did you read everything DL Neil said?  He told you what to do, including
giving you the line of code you need to replace, but also explained why.
 I don't know how one could make it more clear than what he said.

Spend some time to really try to understand what DL Neil is saying.
this is essential Python knowledge he's trying to impart.  Learning to
work with modules and namespaces in Python is pretty much required when
learning and using Python.

From mal at europython.eu  Tue Feb 18 10:25:05 2020
From: mal at europython.eu (M.-A. Lemburg)
Date: Tue, 18 Feb 2020 16:25:05 +0100
Subject: EuroPython 2020: Presenting our conference logo for Dublin
Message-ID: <963bba26-ad78-af85-852f-f86c80e67bf0@europython.eu>

We?re pleased to announce our official conference logo for EuroPython
2020, July 20-26, in Dublin, Ireland:


		  * https://ep2020.europython.eu/ *


The logo is inspired by the colors and symbols often associated with
Ireland: the shamrock and the Celtic harp. It was again created by our
designer Jessica Pe?a Moro from Sim?triko, who had already helped us
in previous years with the conference design.


Some additional updates:
------------------------

- We?re working on launching the mein website, the CFP and ticket sales
  in March.

- We are also preparing the sponsorship packages and should have them
  ready early in March as well. Early bird sponsors will again receive
  a 10% discount on the package price. If you?re interested in
  becoming a launch sponsor, please contact our sponsor team at
  sponsoring at europython.eu.


Help spread the word
--------------------

Please help us spread this message by sharing it on your social
networks as widely as possible. Thank you !

Link to the blog post:

https://blog.europython.eu/post/190894113857/europython-2020-presenting-our-conference-logo

Tweet:

https://twitter.com/europython/status/1229770448516395008


Enjoy,
--
EuroPython 2020 Team
https://ep2020.europython.eu/
https://www.europython-society.org/


From voodoo.bender at gmail.com  Tue Feb 18 10:52:41 2020
From: voodoo.bender at gmail.com (alberto)
Date: Tue, 18 Feb 2020 07:52:41 -0800 (PST)
Subject: insert data in python script
In-Reply-To: <mailman.349.1582020058.9276.python-list@python.org>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
 <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>
 <cb1b53cb-080b-5198-c331-992d1191a1f9@DancesWithMice.info>
 <mailman.348.1582014878.9276.python-list@python.org>
 <8313a962-4d86-464d-9ad5-f3a33faa0018@googlegroups.com>
 <CAMPXz=rijpWHjy9KBEWFAhXA4xDfbCxQtsJsh9a9sh_DDx-d3w@mail.gmail.com>
 <mailman.349.1582020058.9276.python-list@python.org>
Message-ID: <ed1239af-fcbc-425e-bdae-9a0a24bb289d@googlegroups.com>

Il giorno marted? 18 febbraio 2020 11:01:11 UTC+1, David ha scritto:
> On Tue, 18 Feb 2020 at 20:45, alberto <voodoo.bender at gmail.com> wrote:
> > Il giorno marted? 18 febbraio 2020 09:34:51 UTC+1, DL Neil ha scritto:
> 
> > > > my code preos in one file preos.py
> > > > my commands are
> > > >
> > > > alberto at HENDRIX ~/PREOS $ python3.5
> > > > Python 3.5.2 (default, Oct  8 2019, 13:06:37)
> > > > [GCC 5.4.0 20160609] on linux
> > > > Type "help", "copyright", "credits" or "license" for more information.
> > > >>>> import preos
> > > >>>> methane = Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> > > > Traceback (most recent call last):
> > > >    File "<stdin>", line 1, in <module>
> > > > NameError: name 'Molecule' is not defined
> 
> > honestly i don't understand what i have to do.
> 
> $ python3
> Python 3.5.3 (default, Sep 27 2018, 17:25:39)
> [GCC 6.3.0 20170516] on linux
> Type "help", "copyright", "credits" or "license" for more information.
> >>> print(digits)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> NameError: name 'digits' is not defined
> >>> print(string.digits)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> NameError: name 'string' is not defined
> >>> import string
> >>> print(digits)
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
> NameError: name 'digits' is not defined
> >>> print(string.digits)
> 0123456789
> >>>

Hi, 
I solve it with external file as follows

import preos
# pass name, Tc, Pc, omega
methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
methane.print_params()

thanks to everyone

regards

Alberto

From kyosohma at gmail.com  Tue Feb 18 14:13:35 2020
From: kyosohma at gmail.com (Mike Driscoll)
Date: Tue, 18 Feb 2020 11:13:35 -0800 (PST)
Subject: Python 101 2nd Edition book
Message-ID: <d3705fd5-abd0-44e4-a010-819dceac4b97@googlegroups.com>

Hi,

Years ago I posted about my first book, Python 101 on here and people really enjoyed it. I am working on a complete rewrite of the book and thought there might be people here who would enjoy knowing about it.

You can read more here: https://www.blog.pythonlibrary.org/2020/02/17/python-101-2nd-edition-kickstarter-is-live/

Feel free to ask any questions that you might have as well.

Thanks,
Mike

From PythonList at DancesWithMice.info  Tue Feb 18 14:32:37 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Wed, 19 Feb 2020 08:32:37 +1300
Subject: insert data in python script
In-Reply-To: <ed1239af-fcbc-425e-bdae-9a0a24bb289d@googlegroups.com>
References: <d6e6964f-0921-4ed4-9cb4-643652cd6c77@googlegroups.com>
 <1de96119-fc36-40c1-94bc-600fdb851450@googlegroups.com>
 <cb1b53cb-080b-5198-c331-992d1191a1f9@DancesWithMice.info>
 <mailman.348.1582014878.9276.python-list@python.org>
 <8313a962-4d86-464d-9ad5-f3a33faa0018@googlegroups.com>
 <CAMPXz=rijpWHjy9KBEWFAhXA4xDfbCxQtsJsh9a9sh_DDx-d3w@mail.gmail.com>
 <mailman.349.1582020058.9276.python-list@python.org>
 <ed1239af-fcbc-425e-bdae-9a0a24bb289d@googlegroups.com>
Message-ID: <bc621072-bd7e-3347-c1c9-0bf6ef9162b0@DancesWithMice.info>

On 19/02/20 4:52 AM, alberto wrote:

> Hi,
> I solve it with external file as follows
> 
> import preos
> # pass name, Tc, Pc, omega
> methane = preos.Molecule("methane", -82.59 + 273.15, 45.99, 0.011)
> methane.print_params()
> 
> thanks to everyone


It is difficult to learn a new programming language, even for 
professional programmers - and more-so if English is not one's 
native-language. Well done!

Now, if you could tell us how to capture and control methane, perhaps 
the world would become a better place...


Ciao!
-- 
Regards =dn

From duram at terra.com.br  Wed Feb 19 09:22:48 2020
From: duram at terra.com.br (Duram)
Date: Wed, 19 Feb 2020 11:22:48 -0300
Subject: Paper Print Help
Message-ID: <r2jgbm0lpf@news1.newsguy.com>

I have a drawing in a .gif file with (a,b) pixels and want to paperprint 
it in a position (x,y), what would be the code?

From rhodri at kynesim.co.uk  Wed Feb 19 10:17:25 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 19 Feb 2020 15:17:25 +0000
Subject: Paper Print Help
In-Reply-To: <r2jgbm0lpf@news1.newsguy.com>
References: <r2jgbm0lpf@news1.newsguy.com>
Message-ID: <e55fa6ea-b3da-76d1-c5ea-2db931a48664@kynesim.co.uk>

On 19/02/2020 14:22, Duram via Python-list wrote:
> I have a drawing in a .gif file with (a,b) pixels and want to paperprint 
> it in a position (x,y), what would be the code?

What have you tried?

-- 
Rhodri James *-* Kynesim Ltd

From privacy_please at filippo.it  Wed Feb 19 17:15:59 2020
From: privacy_please at filippo.it (FilippoM)
Date: Wed, 19 Feb 2020 17:15:59 -0500
Subject: Pandas rookie
Message-ID: <r2kc2v$13u9$1@gioia.aioe.org>


Hi, I've got a Pandas data frame that looks like this

In [69]: data.head
Out[69]:
<bound method NDFrame.head of      OS and Version         Status
0          Android        VIDEO_OK
1     Android 4.2.2       VIDEO_OK
2         Android 9       VIDEO_OK
3          iOS 13.3       VIDEO_OK
4        Windows 10       VIDEO_OK
5         Android 9       VIDEO_OK
             ...            ...
24       Windows 10       VIDEO_OK
25        Android 9       VIDEO_OK
26    Android 6.0.1       VIDEO_OK
27       Windows XP       VIDEO_OK
28    Android 8.0.0  VIDEO_FAILURE
29      Android 6.0       VIDEO_OK
             ...            ...
2994        iOS 9.1       VIDEO_OK
2995      Android 9       VIDEO_OK
2996     Windows 10       VIDEO_OK
2997      Android 9       VIDEO_OK
2998     Windows 10       VIDEO_OK
2999       iOS 13.3       VIDEO_OK


with 109 possible values of the OS columns and just two possible values 
()VIDEO_OK and VIDEO_FAILURE) in the status column.

How can I use Pandas' dataframe magic to calculate, for each of the 
possible 109 values, how many have VIDEO_OK, and how many have 
VIDEO_FAILURE I have respectively?

I would like to end up with something like

In[]: num_of_oks{"iOS 13.3"}
Out:  15

In[]: num_of_not_oks{"iOS 13.3"}
Out:  3

I am trying to do some matplotlib scatter plotting

Thanks



From geoff.bache at gmail.com  Thu Feb 20 04:11:08 2020
From: geoff.bache at gmail.com (Geoff Bache)
Date: Thu, 20 Feb 2020 10:11:08 +0100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
Message-ID: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>

Hi all,

I have some embedded Python code which looks like this in C++

_gstate = PyGILState_Ensure();
PyImport_ImportModule("a");
...
PyGILState_Release(_gstate);

and is called from different threads which are created in C++.

My module a.py then imports another module b in python, which defines a lot
of functions.

When several threads execute this simultaneously I often get a stacktrace
saying some function near the end of module b is not defined, presumably
because the module has been imported part-initialised.
This only seems to happen when my Python modules are packaged in a zip
file, not when they are ordinary files on disk.

I have observed this in both Python 3.7 and Python 3.8. Does anyone have
any insights or suggestions for how to debug this? It seems likely to be
hard to produce a reproducible test case.

Regards,
Geoff Bache

From please_no at spam.it  Thu Feb 20 10:21:30 2020
From: please_no at spam.it (Luca)
Date: Thu, 20 Feb 2020 10:21:30 -0500
Subject: What's the best forum to get help with Pandas?
Message-ID: <r2m85p$1l76$1@gioia.aioe.org>


subject has it all. Thanks

From rhodri at kynesim.co.uk  Thu Feb 20 10:39:36 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Thu, 20 Feb 2020 15:39:36 +0000
Subject: Paper Print Help
In-Reply-To: <a639ef34-490d-36d1-172a-af4c611ee715@terra.com.br>
References: <r2jgbm0lpf@news1.newsguy.com>
 <e55fa6ea-b3da-76d1-c5ea-2db931a48664@kynesim.co.uk>
 <mailman.354.1582125449.9276.python-list@python.org>
 <a639ef34-490d-36d1-172a-af4c611ee715@terra.com.br>
Message-ID: <79736a5e-f0c2-944f-ca2e-50828c8f1ca7@kynesim.co.uk>

On 20/02/2020 15:08, Duram wrote:
> On 19/02/2020 12:17, Rhodri James wrote:
>> On 19/02/2020 14:22, Duram via Python-list wrote:
>>> I have a drawing in a .gif file with (a,b) pixels and want to 
>>> paperprint it in a position (x,y), what would be the code?
>>
>> What have you tried?
>>
> Nothing, I did not find the module that make to print to the paper

Please don't reply to me directly; if it's a question worth asking in 
public then it's worth answering in public too!

OK, let's backtrack a bit.  First off, what operating system are you using?

Second, do you have this GIF file in any sort of program at the moment, 
or do you want advice on how to write a program to handle the image?  I 
suspect your question is a bit too specific at the moment, and you have 
some mistaken assumptions about how images and (most especially) 
printing work.

-- 
Rhodri James *-* Kynesim Ltd

From rosuav at gmail.com  Thu Feb 20 10:41:59 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 21 Feb 2020 02:41:59 +1100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
Message-ID: <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>

On Fri, Feb 21, 2020 at 2:37 AM Geoff Bache <geoff.bache at gmail.com> wrote:
> When several threads execute this simultaneously I often get a stacktrace
> saying some function near the end of module b is not defined, presumably
> because the module has been imported part-initialised.
> This only seems to happen when my Python modules are packaged in a zip
> file, not when they are ordinary files on disk.
>
> I have observed this in both Python 3.7 and Python 3.8. Does anyone have
> any insights or suggestions for how to debug this? It seems likely to be
> hard to produce a reproducible test case.

One easy way to probe the bug would be to pre-import the module before
starting any secondary threads. If you ever get the problem under that
pattern, then it's not a concurrency problem (IOW have fun figuring
out what *is* the problem).

Another thing to try: Slap a print call at the top and bottom of the
module. See if you get multiple of them.

ChrisA

From musbur at posteo.org  Thu Feb 20 11:19:37 2020
From: musbur at posteo.org (musbur at posteo.org)
Date: Thu, 20 Feb 2020 17:19:37 +0100
Subject: Pandas rookie
In-Reply-To: <r2kc2v$13u9$1@gioia.aioe.org>
References: <r2kc2v$13u9$1@gioia.aioe.org>
Message-ID: <20200220171937.24c9d84e@nxp10225>

On Wed, 19 Feb 2020 17:15:59 -0500
FilippoM <privacy_please at filippo.it> wrote:

> How can I use Pandas' dataframe magic to calculate, for each of the 
> possible 109 values, how many have VIDEO_OK, and how many have 
> VIDEO_FAILURE I have respectively?

crosstab()

From skip.montanaro at gmail.com  Thu Feb 20 11:47:18 2020
From: skip.montanaro at gmail.com (Skip Montanaro)
Date: Thu, 20 Feb 2020 10:47:18 -0600
Subject: What's the best forum to get help with Pandas?
In-Reply-To: <r2m85p$1l76$1@gioia.aioe.org>
References: <r2m85p$1l76$1@gioia.aioe.org>
Message-ID: <CANc-5UzUUzkvY1fcMy7cYFp=Rd7aoYrd559iJqWFc0nYqYkHOg@mail.gmail.com>

I believe the Pandas people tend to refer people to Stack Overflow. I
find that suboptimal as many questions go completely unanswered or get
gruff responses. Aside from that, I suspect this list is as good a
place as any to request help.

Skip

From rosuav at gmail.com  Thu Feb 20 12:58:11 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 21 Feb 2020 04:58:11 +1100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
 <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
 <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>
Message-ID: <CAPTjJmpsmvfEx6c0Umkx1cEy0gZWkqarXcyXVOcbN4NHMGE_=w@mail.gmail.com>

On Fri, Feb 21, 2020 at 3:06 AM Geoff Bache <geoff.bache at gmail.com> wrote:
>
> Hi Chris,
>
> Yes, I've tried both of these things already. I can confirm there are multiple calls, and that pre-importing the module fixes it. But pre-importing it is not a solution in practice.
>

Cool, good to know.

Crazy idea: What would happen if you stick something temporarily into
sys.modules["b"], then when you're done importing, set the module back
into there? Might not help, but would be interesting to try, and might
show a bit more of what's going on.

ChrisA

From geoff.bache at gmail.com  Thu Feb 20 11:06:36 2020
From: geoff.bache at gmail.com (Geoff Bache)
Date: Thu, 20 Feb 2020 17:06:36 +0100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
 <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
Message-ID: <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>

Hi Chris,

Yes, I've tried both of these things already. I can confirm there are
multiple calls, and that pre-importing the module fixes it. But
pre-importing it is not a solution in practice.

Regards,
Geoff

On Thu, Feb 20, 2020 at 4:45 PM Chris Angelico <rosuav at gmail.com> wrote:

> On Fri, Feb 21, 2020 at 2:37 AM Geoff Bache <geoff.bache at gmail.com> wrote:
> > When several threads execute this simultaneously I often get a stacktrace
> > saying some function near the end of module b is not defined, presumably
> > because the module has been imported part-initialised.
> > This only seems to happen when my Python modules are packaged in a zip
> > file, not when they are ordinary files on disk.
> >
> > I have observed this in both Python 3.7 and Python 3.8. Does anyone have
> > any insights or suggestions for how to debug this? It seems likely to be
> > hard to produce a reproducible test case.
>
> One easy way to probe the bug would be to pre-import the module before
> starting any secondary threads. If you ever get the problem under that
> pattern, then it's not a concurrency problem (IOW have fun figuring
> out what *is* the problem).
>
> Another thing to try: Slap a print call at the top and bottom of the
> module. See if you get multiple of them.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From davidwihl at gmail.com  Thu Feb 20 12:30:06 2020
From: davidwihl at gmail.com (David Wihl)
Date: Thu, 20 Feb 2020 13:30:06 -0400
Subject: Idiom for partial failures
Message-ID: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>

?
(first post)

I'm working on the Python client library [0]for the Google Ads API [1]. In some cases, we can start a request with a partial failure [2] flag = True. This means that the request may contain say 1000 operations. If any of the operations fail, the request will return with a success status without an exception. Then the developer has to iterate through the list of operation return statuses to determine which specific ones failed (example [3]).

I believe that it would be more idiomatic in Python (and other languages like Ruby) to throw an exception when one of these partial errors occur. That way there would be the same control flow if a major or minor error occurred. 

The team is asking me for other examples or justification of this being idiomatic of Python. Can you recommend any examples or related best practices?

[0] https://github.com/googleads/google-ads-python

[1] https://developers.google.com/google-ads/api/docs/start

[2] https://developers.google.com/google-ads/api/docs/best-practices/partial-failures

[3] https://github.com/googleads/google-ads-python/blob/master/examples/error_handling/handle_partial_failure.py

Thanks!
-David

From rgladkik at sfu.ca  Thu Feb 20 15:57:54 2020
From: rgladkik at sfu.ca (rgladkik at sfu.ca)
Date: Thu, 20 Feb 2020 12:57:54 -0800 (PST)
Subject: Machine Learning program outputting wrong things
Message-ID: <0b4a72cb-f996-4430-823a-8343282bb024@googlegroups.com>

I am writing a program for an assignment (in a course I am auditing). I am pasting it below:





# Assignment 2 skeleton code
# This code shows you how to use the 'argparse' library to read in parameters

import argparse
import math
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
import random as rn
from dispkernel import dispKernel

# Command Line Arguments

parser = argparse.ArgumentParser(description='generate training and validation data for assignment 2')
parser.add_argument('trainingfile', help='name stub for training data and label output in csv format', default="train")
parser.add_argument('validationfile', help='name stub for validation data and label output in csv format', default="valid")
parser.add_argument('-numtrain', help='number of training samples', type= int, default=200)
parser.add_argument('-numvalid', help='number of validation samples', type= int, default=20)
parser.add_argument('seed', help='random seed', type= int, default=1)
parser.add_argument('learningrate', help='learning rate', type= float, default=0.1)
parser.add_argument('actfunction', help='activation functions', choices=['sigmoid', 'relu', 'linear'], default='linear')
parser.add_argument('numepoch', help='number of epochs', type= int, default=50)

args = parser.parse_args()

traindataname = args.trainingfile + "data.csv"
trainlabelname = args.trainingfile + "label.csv"

print("training data file name: ", traindataname)
print("training label file name: ", trainlabelname)

validdataname = args.validationfile + "data.csv"
validlabelname = args.validationfile + "label.csv"

print("validation data file name: ", validdataname)
print("validation label file name: ", validlabelname)

print("number of training samples = ", args.numtrain)
print("number of validation samples = ", args.numvalid)

print("learning rate = ", args.learningrate)
print("number of epoch = ", args.numepoch)

print("activation function is ", args.actfunction)

# read in training data
t_data = pd.read_csv(args.trainingfile, ',', header=None).values
t_label = pd.read_csv('trainlabel.csv', ',', header=None).values
row_dim_t = t_data.shape[1]
col_dim_t = t_data.shape[0]

# read in validation data
v_data = pd.read_csv(args.validationfile, ',', header=None).values
v_label = pd.read_csv('validlabel.csv', ',', header=None).values
row_dim_v = v_data.shape[1]
col_dim_v = v_data.shape[0]

np.random.seed(args.seed)

# initialize weights
w = np.random.rand(row_dim_t, 1)

# initialize bias
b = np.random.uniform(0, 1)

n_epoch = []
loss_t = []
loss_v = []
accuracy_t = []
accuracy_v = []

Z_t = np.zeros([col_dim_t, 1])
Z_v = np.zeros([col_dim_v, 1])
guess_t_label = np.zeros([col_dim_t, 1])
guess_v_label = np.zeros([col_dim_v, 1])
accuracy_j_t = np.zeros([col_dim_t, 1])
accuracy_j_v = np.zeros([col_dim_v, 1])
Y_t = np.zeros([col_dim_t, 1])
Y_v = np.zeros([col_dim_v, 1])
loss_j_t = np.zeros([col_dim_t, 1])
loss_j_v = np.zeros([col_dim_v, 1])
grad_loss_w = np.zeros([col_dim_t, row_dim_v])
grad_loss_b = np.zeros([col_dim_t, 1])

class Linear:
    def __init__(self, Z, data, label):
        self.Z = Z
        self.data = data
        self.label = label

    # pass Z through an activation function
    def act_linear(self):
        return self.Z

    # gradient of the loss wrt weights
    def grad_loss_w(self, Y):
        return 2*(Y - self.label)*self.data

    # gradient of the loss wrt bias
    def grad_loss_b(self, Y):
        return 2*(Y - self.label)

for i in range(0, args.numepoch):
    n_epoch.append(i)

    # calculate predictor for training data
    Z_t[:] = np.dot(t_data[:, :], w[:]) + b

    # predict training label based on output
    # of predictor
    guess_t_label[:] = (Z_t >= 0.5)
    # determine whether predicted label is
    # correct or not
    accuracy_j_t[:] = 1 - np.absolute(guess_t_label[:] - t_label[:])
    # calculate accuracy for training data
    accuracy_t.append(np.sum(accuracy_j_t[:], axis=0)/col_dim_t)

    # calculate predictor for validation data
    Z_v[:] = np.dot(v_data[:, :], w[:]) + b

    # predict validation label based on output
    # of predictor
    guess_v_label[:] = (Z_v >= 0.5)
    # determine whether predicted label is
    # correct or not
    accuracy_j_v[:] = 1 - np.absolute(guess_v_label[:] - v_label[:])
    # calculate accuracy for validation data
    accuracy_v.append(np.sum(accuracy_j_v[:], axis=0)/col_dim_v)

    l_t = Linear(Z_t, t_data, t_label)
    l_v = Linear(Z_v, v_data, v_label)

    # pass Z through an activation function
    Y_t[:] = l_t.act_linear()
    Y_v[:] = l_v.act_linear()

    # calculate loss across all training data
    loss_j_t[:] = (Y_t[:] - t_label)**2
    loss_t.append(np.sum(loss_j_t[:], axis=0)/col_dim_t)

    # calculate loss across all validation data
    loss_j_v[:] = (Y_v[:] - v_label)**2
    loss_v.append(np.sum(loss_j_v[:], axis=0)/col_dim_v)

    grad_loss_w[:] = l_t.grad_loss_w(Y_t)
    grad_loss_b[:] = l_t.grad_loss_b(Y_t)

    # average gradient across all inputs
    avg_loss_w = np.sum(grad_loss_w[:], axis=0)/col_dim_t
    avg_loss_b = np.sum(grad_loss_b[:], axis=0)/col_dim_t

    # update weights and bias
    w[:] -= np.reshape(avg_loss_w, (row_dim_t, 1))*args.learningrate

    b -= avg_loss_b*args.learningrate

# plot loss vs number of epochs
fig, (ax1, ax2) = plt.subplots(1, 2, figsize=(8, 6))
ax1.plot(n_epoch, loss_t, 'b.', label='Training Data')
ax1.plot(n_epoch, loss_v, 'r.', label='Validation Data')
ax1.set(xlabel='Epoch', ylabel='Loss', title='Loss vs Number of Epochs \n with Activation ' + str.capitalize(args.actfunction))
ax1.legend()

# plot accuracy vs number of epochs
ax2.plot(n_epoch, accuracy_t, 'b.', label='Training Data')
ax2.plot(n_epoch, accuracy_v, 'r.', label='Validation Data')
ax2.set(xlabel='Epoch', ylabel='Accuracy', title='Accuracy vs Number of Epochs \n with Activation ' + str.capitalize(args.actfunction))
ax2.legend()
plt.savefig('loss_accuracy.png')





The training file contains 200 rows of 9 columns. In each row, there's a series of 1s and 0s. If the arrangement of 1s and 0s forms an X pattern (ie [1, 0, 1, 0, 1, 0, 1, 0, 1], this is assigned a label 1. If the 1s and 0s don't form an X, the label is 0.

I'm using a linear activation function, and a mean squared error loss function. I'm also using 15 for the seed, 0.3 for the learning rate, and 10 for the epoch number. However, I keep running into problems. At 0.3, the weights are correct- I plot the weights on a grid and get an X pattern. The plots of epoch vs loss and accuracy gives me rubbish- I get underfitted plots. At lower learning rates, the plots look ok (the accuracy still looks terrible no matter what I do), but the weights are wrong- the learning rate is too slow.

Please help!!

From ethan at stoneleaf.us  Thu Feb 20 16:33:22 2020
From: ethan at stoneleaf.us (Ethan Furman)
Date: Thu, 20 Feb 2020 13:33:22 -0800
Subject: Idiom for partial failures
In-Reply-To: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
References: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
Message-ID: <1f05a64f-69ab-be34-b429-3b98212b1b9f@stoneleaf.us>

On 02/20/2020 09:30 AM, David Wihl wrote:

> I'm working on the Python client library for the Google Ads API. In some cases, we can start a request with a partial failure flag = True. This means that the request may contain say 1000 operations. If any of the operations fail, the request will return with a success status without an exception. Then the developer has to iterate through the list of operation return statuses to determine which specific ones failed.
> 
> I believe that it would be more idiomatic in Python (and other languages like Ruby) to throw an exception when one of these partial errors occur. That way there would be the same control flow if a major or minor error occurred.

What I have done in such circumstances is have a custom exception type, and store the errors there -- how much detail you save depends on how much you need to properly post-process the failed items.

For example:

# not tested

class PartialFailure(Exception):
     def __init__(self, failures):
         self.failures = failures

... lots of code ...
failures = []

try:
     an_operation_that_could_fail
except SomeException:
     failures.append(debugging info)

... more code ...

if failures:
     raise PartialFailure(failures)

# in the calling code
try:
     code_that_may_raise_partial_failures
except PartialFailure as e:
     for failure in e.failures:
        handle_failure

--
~Ethan~

From rgaddi at highlandtechnology.invalid  Thu Feb 20 17:03:00 2020
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Thu, 20 Feb 2020 14:03:00 -0800
Subject: Idiom for partial failures
In-Reply-To: <mailman.7.1582221685.9235.python-list@python.org>
References: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
 <mailman.7.1582221685.9235.python-list@python.org>
Message-ID: <r2mvml$sdr$1@dont-email.me>

On 2/20/20 9:30 AM, David Wihl wrote:
> ?
> (first post)
> 
> I'm working on the Python client library [0]for the Google Ads API [1]. In some cases, we can start a request with a partial failure [2] flag = True. This means that the request may contain say 1000 operations. If any of the operations fail, the request will return with a success status without an exception. Then the developer has to iterate through the list of operation return statuses to determine which specific ones failed (example [3]).
> 
> I believe that it would be more idiomatic in Python (and other languages like Ruby) to throw an exception when one of these partial errors occur. That way there would be the same control flow if a major or minor error occurred.
> 
> The team is asking me for other examples or justification of this being idiomatic of Python. Can you recommend any examples or related best practices?
> 
> [0] https://github.com/googleads/google-ads-python
> 
> [1] https://developers.google.com/google-ads/api/docs/start
> 
> [2] https://developers.google.com/google-ads/api/docs/best-practices/partial-failures
> 
> [3] https://github.com/googleads/google-ads-python/blob/master/examples/error_handling/handle_partial_failure.py
> 
> Thanks!
> -David
> 

Potentially stupid question, does your library to the API have to support 
partial failures?  Sure Google Ads does, but does it really add value to do so? 
And then you've got to decide what to DO with those partially failed results.

You could, as a library, just say "No, this library never sets the 
partial_failure field.  We only support atomic transactions that fully succeed 
or fully fail and raise an exception."  Makes your life a lot easier; so unless 
it makes your customer's lives a lot harder...

From python.list at tim.thechases.com  Thu Feb 20 17:25:43 2020
From: python.list at tim.thechases.com (Tim Chase)
Date: Thu, 20 Feb 2020 16:25:43 -0600
Subject: Idiom for partial failures
In-Reply-To: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
References: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
Message-ID: <20200220162543.7fd8b88b@bigbox.attlocal.net>

On 2020-02-20 13:30, David Wihl wrote:
> I believe that it would be more idiomatic in Python (and other
> languages like Ruby) to throw an exception when one of these
> partial errors occur. That way there would be the same control flow
> if a major or minor error occurred. 

There are a variety of ways to do it -- I like Ethan's suggestion
about tacking the failures onto the exception and raising it at the
end.  But you can also yield a tuple of success/failure iterators,
something like this pseudocode:

  def process(input_iter):
    successes = []
    failures = []
    for thing in input_iter:
      try:
        result = process(thing)
      except ValueError as e: # catch appropriate exception(s) here
        failures.append((e, thing))
      else:
        successes.append((result, thing))
    return successes, failures

  def process(item):
    if item % 3:
      raise ValueError("Must be divisible by 3!")
    else:
      print(item)
      return item // 3

  successes, failures = process(range(10))

  for reason, thing in failures:
    print(f"Unable to process {thing} because {reason}")

-tkc




From Richard at Damon-Family.org  Thu Feb 20 21:14:45 2020
From: Richard at Damon-Family.org (Richard Damon)
Date: Thu, 20 Feb 2020 21:14:45 -0500
Subject: Idiom for partial failures
In-Reply-To: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
References: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
Message-ID: <2df1e584-572d-4b4f-750a-ff66d23c7fa4@Damon-Family.org>

On 2/20/20 12:30 PM, David Wihl wrote:
> ?
> (first post)
>
> I'm working on the Python client library [0]for the Google Ads API [1]. In some cases, we can start a request with a partial failure [2] flag = True. This means that the request may contain say 1000 operations. If any of the operations fail, the request will return with a success status without an exception. Then the developer has to iterate through the list of operation return statuses to determine which specific ones failed (example [3]).
>
> I believe that it would be more idiomatic in Python (and other languages like Ruby) to throw an exception when one of these partial errors occur. That way there would be the same control flow if a major or minor error occurred.
>
> The team is asking me for other examples or justification of this being idiomatic of Python. Can you recommend any examples or related best practices?
>
> [0] https://github.com/googleads/google-ads-python
>
> [1] https://developers.google.com/google-ads/api/docs/start
>
> [2] https://developers.google.com/google-ads/api/docs/best-practices/partial-failures
>
> [3] https://github.com/googleads/google-ads-python/blob/master/examples/error_handling/handle_partial_failure.py
>
> Thanks!
> -David

My first thought is that partial failure also means partial success, 
which means that it shouldn't throw.

One key thing about exceptions is that they provide an easy way to ABORT 
a current operation on an error and trap to an error handler. They allow 
you to begin the operation starting a try block, have a number of 
operations that don't need to worry about all the little error 
conditions that would force you to abort the operation, and then handle 
all the errors at the end, and the code in the middle doesn't need to 
propagate the error codes, as the exception carries that information. If 
you throw on a partial failure/partial success, then you really need to 
IMMEDIATELY catch the error so you can continue the successes, at which 
point returning an error value is normally clearer.

Now, an alternative would be rather than throwing an exception, would be 
to effectively raise a signal and call an error callback with the 
details of the failed operation, and let the call back handle (or 
record) the error information, so the caller doesn't need to go through 
all the successes to see if there was an error.

Now, if the code was going to iterate through the success anyway, then 
there isn't as much of a cost to detect the errors that occured.

-- 
Richard Damon


From PythonList at DancesWithMice.info  Thu Feb 20 23:45:39 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Fri, 21 Feb 2020 17:45:39 +1300
Subject: Idiom for partial failures
In-Reply-To: <idioms-20200220215252@ram.dialup.fu-berlin.de>
References: <mailman.7.1582221685.9235.python-list@python.org>
 <idioms-20200220215252@ram.dialup.fu-berlin.de>
Message-ID: <a8f38740-7b57-134f-4098-0dbc29c82bf6@DancesWithMice.info>

On 21/02/20 10:05 AM, Stefan Ram wrote:
> David Wihl <davidwihl at gmail.com> writes:
>> I believe that it would be more idiomatic in Python (and other languages lik=
>> e Ruby) to throw an exception when one of these partial errors occur.
> 
>    I wonder whether the term "idiomatic" is too heavily
>    burdened here.
> 
>    Python offers an idiom for handling a failure to do an
>    operation - the exception.
> 
>    But you have special case of a run-time program of many
>    operations, and you want the execution of the program to
>    continue even in the case of failures to execute some of
>    the operations. I am not aware of Python offering an idiom
>    for this special case.
> 
>    I am always thinking about terminology first. So I'd say:
>    You need to /define/ what "success" and "failure" means in
>    the case of your operation. Then return normally in the case
>    of success and return by exception in the case of failure.


Not arguing - and if I were the logical answer is "not Python", but...

PyTest (runs unit-tests, enables TDD) offers options to stop the 
test-runner at the first error-found or to keep going for up to 
n-errors. We can test for an error condition and if experienced such 
will not 'count' or stop the test-run. It distinguishes between 
hard-errors and warnings, and enables us to choose to 'elevate' one to 
the level of the other, and vice-versa. Its run-report lists which tests 
worked and which didn't (the 'last' or the up-to "n") - a clear advance 
on the OP's experience.


I think someone has already discussed, but if the intent is 
bulk-processing ("batch processing") then I'd expect to find a means of 
'bailing-out' when an error is found, or of back-tracking to locate errors.

Perhaps, like my good-looks, my expectations of a professional standard 
are higher-than-average?
-- 
Regards =dn

From frank at chagford.com  Fri Feb 21 01:59:35 2020
From: frank at chagford.com (Frank Millman)
Date: Fri, 21 Feb 2020 08:59:35 +0200
Subject: Asyncio question
Message-ID: <r2nv4q$2vge$1@ciao.gmane.io>

Hi all

I use asyncio in my project, and it works very well without my having to 
understand what goes on under the hood. It is a multi-user client/server 
system, and I want it to scale to many concurrent users. I have a 
situation where I have to decide between two approaches, and I want to 
choose the least resource-intensive, but I find it hard to reason about 
which, if either, is better.

I use HTTP. On the initial connection from a client, I set up a session 
object, and the session id is passed to the client. All subsequent 
requests from that client include the session id, and the request is 
passed to the session object for handling.

It is possible for a new request to be received from a client before the 
previous one has been completed, and I want each request to be handled 
atomically, so each session maintains its own asyncio.Queue(). The main 
routine gets the session id from the request and 'puts' the request in 
the appropriate queue. The session object 'gets' from the queue and 
handles the request. It works well.

The question is, how to arrange for each session to 'await' its queue. 
My first attempt was to create a background task for each session which 
runs for the life-time of the session, and 'awaits' its queue. It works, 
but I was concerned about having a lot a background tasks active at the 
same time.

Then I came up with what I thought was a better idea. On the initial 
connection, I create the session object, send the response to the 
client, and then 'await' the method that sets up the session's queue. 
This also works, and there is no background task involved. However, I 
then realised that the initial response handler never completes, and 
will 'await' until the session is closed.

Is this better, worse, or does it make no difference? If it makes no 
difference, I will lean towards the first approach, as it is easier to 
reason about what is going on.

Thanks for any advice.

Frank Millman


From rosuav at gmail.com  Fri Feb 21 03:10:07 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 21 Feb 2020 19:10:07 +1100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CA+JhifvAmc66cHGgqF8DOi1yTBGJboveHxoVy7YXUjxjLY70CA@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
 <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
 <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>
 <CAPTjJmpsmvfEx6c0Umkx1cEy0gZWkqarXcyXVOcbN4NHMGE_=w@mail.gmail.com>
 <CA+JhifvAmc66cHGgqF8DOi1yTBGJboveHxoVy7YXUjxjLY70CA@mail.gmail.com>
Message-ID: <CAPTjJmo+Y3_8PeSmdLrngXG5avezEQWhGL8h1eUC_WxT0Ub8mg@mail.gmail.com>

On Fri, Feb 21, 2020 at 6:56 PM Geoff Bache <geoff.bache at gmail.com> wrote:
>
> I'm not sure I understand what you mean by "stick something" there. What did you have in mind? I can't just put anything there or the importing will fail anyhow.
> Also, setting the module back into there afterwards isn't possible unless I've already imported it, and as mentioned I can't do that in practice.
>

The best object to put in there would be something that prints out all
__getattr__ calls. Something like this:

import sys
_this_module = sys.modules[__name__]
print("** Importing %s, module ID is %s **" % (__name__, id(_this_module)))
class Marker:
    def __getattr__(self, attr):
        print("** Sentinel imported, looking for %s.%s **" % (__name__, attr))
sys.modules[__name__] = Marker()

...
# rest of module goes here
...

sys.modules[__name__] = _this_module
del _this_module


Untested, might need some tweaks. The idea is that, if anything
imports the module while it's still running, it should either print
out a second "importing" line with a different ID, or it'll get the
sentinel object, and any use of it will trigger the message.

(Feel free to use the logging module instead of print, same difference.)

ChrisA

From rosuav at gmail.com  Fri Feb 21 06:24:23 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Fri, 21 Feb 2020 22:24:23 +1100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CA+Jhift60N+BZaz+Bahd4-TQwTKAbZ=iO7xvLyVX1zXs=Py+_g@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
 <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
 <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>
 <CAPTjJmpsmvfEx6c0Umkx1cEy0gZWkqarXcyXVOcbN4NHMGE_=w@mail.gmail.com>
 <CA+JhifvAmc66cHGgqF8DOi1yTBGJboveHxoVy7YXUjxjLY70CA@mail.gmail.com>
 <CAPTjJmo+Y3_8PeSmdLrngXG5avezEQWhGL8h1eUC_WxT0Ub8mg@mail.gmail.com>
 <CA+Jhift60N+BZaz+Bahd4-TQwTKAbZ=iO7xvLyVX1zXs=Py+_g@mail.gmail.com>
Message-ID: <CAPTjJmr8GKSapCGOkVZbnEv1NUcWBr4SQG8SoHfLG=PhuEPyrg@mail.gmail.com>

On Fri, Feb 21, 2020 at 8:58 PM Geoff Bache <geoff.bache at gmail.com> wrote:
>
> But, as I say, I don't have the module loaded beforehand, so caching it from sys.modules and restoring it afterwards won't be possible.

Those lines go into the actual file you're importing.

> Basically I'm looking for hints as to information about known problems and whether this kind of thing is likely to work anyway, and also hints for debugging - as in extracting more information about possible causes rather than documenting the symptoms further. I think I already have a fairly good overview of the symptoms.
>

Yeah, changing the actual module that's being messed with might help
with that. I am kinda clutching at straws though.

ChrisA

From geoff.bache at gmail.com  Fri Feb 21 02:55:53 2020
From: geoff.bache at gmail.com (Geoff Bache)
Date: Fri, 21 Feb 2020 08:55:53 +0100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CAPTjJmpsmvfEx6c0Umkx1cEy0gZWkqarXcyXVOcbN4NHMGE_=w@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
 <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
 <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>
 <CAPTjJmpsmvfEx6c0Umkx1cEy0gZWkqarXcyXVOcbN4NHMGE_=w@mail.gmail.com>
Message-ID: <CA+JhifvAmc66cHGgqF8DOi1yTBGJboveHxoVy7YXUjxjLY70CA@mail.gmail.com>

I'm not sure I understand what you mean by "stick something" there. What
did you have in mind? I can't just put anything there or the importing will
fail anyhow.
Also, setting the module back into there afterwards isn't possible unless
I've already imported it, and as mentioned I can't do that in practice.

/Geoff

On Thu, Feb 20, 2020 at 6:59 PM Chris Angelico <rosuav at gmail.com> wrote:

> On Fri, Feb 21, 2020 at 3:06 AM Geoff Bache <geoff.bache at gmail.com> wrote:
> >
> > Hi Chris,
> >
> > Yes, I've tried both of these things already. I can confirm there are
> multiple calls, and that pre-importing the module fixes it. But
> pre-importing it is not a solution in practice.
> >
>
> Cool, good to know.
>
> Crazy idea: What would happen if you stick something temporarily into
> sys.modules["b"], then when you're done importing, set the module back
> into there? Might not help, but would be interesting to try, and might
> show a bit more of what's going on.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From geoff.bache at gmail.com  Fri Feb 21 04:57:51 2020
From: geoff.bache at gmail.com (Geoff Bache)
Date: Fri, 21 Feb 2020 10:57:51 +0100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CAPTjJmo+Y3_8PeSmdLrngXG5avezEQWhGL8h1eUC_WxT0Ub8mg@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
 <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
 <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>
 <CAPTjJmpsmvfEx6c0Umkx1cEy0gZWkqarXcyXVOcbN4NHMGE_=w@mail.gmail.com>
 <CA+JhifvAmc66cHGgqF8DOi1yTBGJboveHxoVy7YXUjxjLY70CA@mail.gmail.com>
 <CAPTjJmo+Y3_8PeSmdLrngXG5avezEQWhGL8h1eUC_WxT0Ub8mg@mail.gmail.com>
Message-ID: <CA+Jhift60N+BZaz+Bahd4-TQwTKAbZ=iO7xvLyVX1zXs=Py+_g@mail.gmail.com>

But, as I say, I don't have the module loaded beforehand, so caching it
from sys.modules and restoring it afterwards won't be possible.
Just investigating which calls are made doesn't seem likely to provide new
information. I already know which call is made, it's the one that produces
the stacktrace...

Basically I'm looking for hints as to information about known problems and
whether this kind of thing is likely to work anyway, and also hints for
debugging - as in extracting more information about possible causes rather
than documenting the symptoms further. I think I already have a fairly good
overview of the symptoms.

/Geoff

On Fri, Feb 21, 2020 at 9:11 AM Chris Angelico <rosuav at gmail.com> wrote:

> On Fri, Feb 21, 2020 at 6:56 PM Geoff Bache <geoff.bache at gmail.com> wrote:
> >
> > I'm not sure I understand what you mean by "stick something" there. What
> did you have in mind? I can't just put anything there or the importing will
> fail anyhow.
> > Also, setting the module back into there afterwards isn't possible
> unless I've already imported it, and as mentioned I can't do that in
> practice.
> >
>
> The best object to put in there would be something that prints out all
> __getattr__ calls. Something like this:
>
> import sys
> _this_module = sys.modules[__name__]
> print("** Importing %s, module ID is %s **" % (__name__, id(_this_module)))
> class Marker:
>     def __getattr__(self, attr):
>         print("** Sentinel imported, looking for %s.%s **" % (__name__,
> attr))
> sys.modules[__name__] = Marker()
>
> ...
> # rest of module goes here
> ...
>
> sys.modules[__name__] = _this_module
> del _this_module
>
>
> Untested, might need some tweaks. The idea is that, if anything
> imports the module while it's still running, it should either print
> out a second "importing" line with a different ID, or it'll get the
> sentinel object, and any use of it will trigger the message.
>
> (Feel free to use the logging module instead of print, same difference.)
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From tdldev at gmail.com  Fri Feb 21 12:32:44 2020
From: tdldev at gmail.com (Jack Dangler)
Date: Fri, 21 Feb 2020 12:32:44 -0500
Subject: pip issue
Message-ID: <2c29d2d0-8efe-e45f-0227-91467ec8dcc4@gmail.com>

Hi, all

Went to setup path and got an error. attempted to update pip and got the 
same error... The error being thrown is -

Traceback (most recent call last):
 ? File "/home/jack/.local/bin/pip", line 11, in <module>
 ??? sys.exit(main())
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_internal/cli/main.py", 
line 73, in main
 ??? command = create_command(cmd_name, isolated=("--isolated" in cmd_args))
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_internal/commands/__init__.py", 
line 96, in create_command
 ??? module = importlib.import_module(module_path)
 ? File "/usr/lib/python2.7/importlib/__init__.py", line 37, in 
import_module
 ??? __import__(name)
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_internal/commands/install.py", 
line 24, in <module>
 ??? from pip._internal.cli.req_command import RequirementCommand
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_internal/cli/req_command.py", 
line 15, in <module>
 ??? from pip._internal.index.package_finder import PackageFinder
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_internal/index/package_finder.py", 
line 21, in <module>
 ??? from pip._internal.index.collector import parse_links
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_internal/index/collector.py", 
line 12, in <module>
 ??? from pip._vendor import html5lib, requests
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_vendor/requests/__init__.py", 
line 97, in <module>
 ??? from pip._vendor.urllib3.contrib import pyopenssl
 ? File 
"/home/jack/.local/lib/python2.7/site-packages/pip/_vendor/urllib3/contrib/pyopenssl.py", 
line 46, in <module>
 ??? import OpenSSL.SSL
 ? File "/usr/lib/python2.7/dist-packages/OpenSSL/__init__.py", line 8, 
in <module>
 ??? from OpenSSL import rand, crypto, SSL
 ? File "/usr/lib/python2.7/dist-packages/OpenSSL/SSL.py", line 118, in 
<module>
 ??? SSL_ST_INIT = _lib.SSL_ST_INIT
AttributeError: 'module' object has no attribute 'SSL_ST_INIT'

Any input, as always, is appreciated.

Regards



From greg.ewing at canterbury.ac.nz  Fri Feb 21 16:13:33 2020
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Sat, 22 Feb 2020 10:13:33 +1300
Subject: Asyncio question
In-Reply-To: <mailman.12.1582268386.9235.python-list@python.org>
References: <r2nv4q$2vge$1@ciao.gmane.io>
 <mailman.12.1582268386.9235.python-list@python.org>
Message-ID: <hbavfvFbia8U1@mid.individual.net>

On 21/02/20 7:59 pm, Frank Millman wrote:
> My first attempt was to create a background task for each session which 
> runs for the life-time of the session, and 'awaits' its queue. It works, 
> but I was concerned about having a lot a background tasks active at the 
> same time.

The whole point of asyncio is to make tasks very lightweight, so you
can use as many of them as is convenient without worries. One task
per client sounds like the right thing to do here.

-- 
Greg

From davidwihl at gmail.com  Fri Feb 21 12:18:10 2020
From: davidwihl at gmail.com (David Wihl)
Date: Fri, 21 Feb 2020 13:18:10 -0400
Subject: Idiom for partial failures
In-Reply-To: <r2mvml$sdr$1@dont-email.me>
References: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
 <mailman.7.1582221685.9235.python-list@python.org>
 <r2mvml$sdr$1@dont-email.me>
Message-ID: <CA+k6q--vn5C6FqRMbEUT+20ZnaHWwu5veJS1BYHxaCNvEtCThw@mail.gmail.com>

Yes, the API has to support partial failures across all six supported
languages. Not all operations need to be atomic and there is considerable
efficiency in having multiple operations sent in a single request. Thanks,
-David

On Thu, Feb 20, 2020 at 6:07 PM Rob Gaddi <rgaddi at highlandtechnology.invalid>
wrote:

> On 2/20/20 9:30 AM, David Wihl wrote:
> > ?
> > (first post)
> >
> > I'm working on the Python client library [0]for the Google Ads API [1].
> In some cases, we can start a request with a partial failure [2] flag =
> True. This means that the request may contain say 1000 operations. If any
> of the operations fail, the request will return with a success status
> without an exception. Then the developer has to iterate through the list of
> operation return statuses to determine which specific ones failed (example
> [3]).
> >
> > I believe that it would be more idiomatic in Python (and other languages
> like Ruby) to throw an exception when one of these partial errors occur.
> That way there would be the same control flow if a major or minor error
> occurred.
> >
> > The team is asking me for other examples or justification of this being
> idiomatic of Python. Can you recommend any examples or related best
> practices?
> >
> > [0] https://github.com/googleads/google-ads-python
> >
> > [1] https://developers.google.com/google-ads/api/docs/start
> >
> > [2]
> https://developers.google.com/google-ads/api/docs/best-practices/partial-failures
> >
> > [3]
> https://github.com/googleads/google-ads-python/blob/master/examples/error_handling/handle_partial_failure.py
> >
> > Thanks!
> > -David
> >
>
> Potentially stupid question, does your library to the API have to support
> partial failures?  Sure Google Ads does, but does it really add value to
> do so?
> And then you've got to decide what to DO with those partially failed
> results.
>
> You could, as a library, just say "No, this library never sets the
> partial_failure field.  We only support atomic transactions that fully
> succeed
> or fully fail and raise an exception."  Makes your life a lot easier; so
> unless
> it makes your customer's lives a lot harder...
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From geoff.bache at gmail.com  Fri Feb 21 11:01:57 2020
From: geoff.bache at gmail.com (Geoff Bache)
Date: Fri, 21 Feb 2020 17:01:57 +0100
Subject: Should PyImport_ImportModule be threadsafe when importing from
 zipfiles?
In-Reply-To: <CAPTjJmr8GKSapCGOkVZbnEv1NUcWBr4SQG8SoHfLG=PhuEPyrg@mail.gmail.com>
References: <CA+JhiftAsDQd_8kgnQD75TG_J=-asZtBG4y2dv+HNZiP4=Pn4g@mail.gmail.com>
 <CAPTjJmroeoDw700QHTTbTFAtRN+gqTmPEggEmfQpAosGWRGPZA@mail.gmail.com>
 <CA+Jhifsn58X4EjG550qHHvGThfW-UL9ixfmkb=UaFQaB9j86iA@mail.gmail.com>
 <CAPTjJmpsmvfEx6c0Umkx1cEy0gZWkqarXcyXVOcbN4NHMGE_=w@mail.gmail.com>
 <CA+JhifvAmc66cHGgqF8DOi1yTBGJboveHxoVy7YXUjxjLY70CA@mail.gmail.com>
 <CAPTjJmo+Y3_8PeSmdLrngXG5avezEQWhGL8h1eUC_WxT0Ub8mg@mail.gmail.com>
 <CA+Jhift60N+BZaz+Bahd4-TQwTKAbZ=iO7xvLyVX1zXs=Py+_g@mail.gmail.com>
 <CAPTjJmr8GKSapCGOkVZbnEv1NUcWBr4SQG8SoHfLG=PhuEPyrg@mail.gmail.com>
Message-ID: <CA+JhifsAbqU=nY+S7_QoijqW7hUUU2vTX772Z1-q9W5QyqTYqw@mail.gmail.com>

OK, I see what you mean with the import backup change now, though it seems
like it changes the semantics of Python's import mechanism a bit...

But I still don't really get what information we'd gain from doing this.
What call is being made and is failing is pretty obvious from the
stacktrace.

Thanks for your replies, anyway.

/Geoff

On Fri, Feb 21, 2020 at 12:25 PM Chris Angelico <rosuav at gmail.com> wrote:

> On Fri, Feb 21, 2020 at 8:58 PM Geoff Bache <geoff.bache at gmail.com> wrote:
> >
> > But, as I say, I don't have the module loaded beforehand, so caching it
> from sys.modules and restoring it afterwards won't be possible.
>
> Those lines go into the actual file you're importing.
>
> > Basically I'm looking for hints as to information about known problems
> and whether this kind of thing is likely to work anyway, and also hints for
> debugging - as in extracting more information about possible causes rather
> than documenting the symptoms further. I think I already have a fairly good
> overview of the symptoms.
> >
>
> Yeah, changing the actual module that's being messed with might help
> with that. I am kinda clutching at straws though.
>
> ChrisA
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From rgaddi at highlandtechnology.invalid  Fri Feb 21 17:51:39 2020
From: rgaddi at highlandtechnology.invalid (Rob Gaddi)
Date: Fri, 21 Feb 2020 14:51:39 -0800
Subject: Idiom for partial failures
In-Reply-To: <mailman.18.1582320483.9235.python-list@python.org>
References: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
 <mailman.7.1582221685.9235.python-list@python.org>
 <r2mvml$sdr$1@dont-email.me>
 <CA+k6q--vn5C6FqRMbEUT+20ZnaHWwu5veJS1BYHxaCNvEtCThw@mail.gmail.com>
 <mailman.18.1582320483.9235.python-list@python.org>
Message-ID: <r2pmtt$a7b$1@dont-email.me>

On 2/21/20 9:18 AM, David Wihl wrote:
> Yes, the API has to support partial failures across all six supported
> languages. Not all operations need to be atomic and there is considerable
> efficiency in having multiple operations sent in a single request. Thanks,
> -David
> 
> On Thu, Feb 20, 2020 at 6:07 PM Rob Gaddi <rgaddi at highlandtechnology.invalid>
> wrote:
> 
>> On 2/20/20 9:30 AM, David Wihl wrote:
>>> ?
>>> (first post)
>>>
>>> I'm working on the Python client library [0]for the Google Ads API [1].
>> In some cases, we can start a request with a partial failure [2] flag =
>> True. This means that the request may contain say 1000 operations. If any
>> of the operations fail, the request will return with a success status
>> without an exception. Then the developer has to iterate through the list of
>> operation return statuses to determine which specific ones failed (example
>> [3]).
>>>
>>> I believe that it would be more idiomatic in Python (and other languages
>> like Ruby) to throw an exception when one of these partial errors occur.
>> That way there would be the same control flow if a major or minor error
>> occurred.
>>>
>>> The team is asking me for other examples or justification of this being
>> idiomatic of Python. Can you recommend any examples or related best
>> practices?
>>>
>>> [0] https://github.com/googleads/google-ads-python
>>>
>>> [1] https://developers.google.com/google-ads/api/docs/start
>>>
>>> [2]
>> https://developers.google.com/google-ads/api/docs/best-practices/partial-failures
>>>
>>> [3]
>> https://github.com/googleads/google-ads-python/blob/master/examples/error_handling/handle_partial_failure.py
>>>
>>> Thanks!
>>> -David
>>>
>>
>> Potentially stupid question, does your library to the API have to support
>> partial failures?  Sure Google Ads does, but does it really add value to
>> do so?
>> And then you've got to decide what to DO with those partially failed
>> results.
>>
>> You could, as a library, just say "No, this library never sets the
>> partial_failure field.  We only support atomic transactions that fully
>> succeed
>> or fully fail and raise an exception."  Makes your life a lot easier; so
>> unless
>> it makes your customer's lives a lot harder...
>> --
>> https://mail.python.org/mailman/listinfo/python-list
>>

In that case, I think Richard Damon's answer smells rightest.  A partial failure 
is a partial success and should not trigger a mandatory flow-control change, 
which is what an exception is.

If there is any information in the successes, then I'd expect an operation like 
this to return me a list corresponding 1-to-1 with the list of operations such 
that I could:

results = do_the_thing()
for op, result in zip(operations, results):
    if isinstance(result, GoogleApiError):
       deal_with_error(op, result)

If successes have nothing to add to the party, then I'd expect the operation to 
return a list containing only the errors, and an empty list means no errors.

From frank at chagford.com  Fri Feb 21 23:58:16 2020
From: frank at chagford.com (Frank Millman)
Date: Sat, 22 Feb 2020 06:58:16 +0200
Subject: Asyncio question
In-Reply-To: <hbavfvFbia8U1@mid.individual.net>
References: <r2nv4q$2vge$1@ciao.gmane.io>
 <mailman.12.1582268386.9235.python-list@python.org>
 <hbavfvFbia8U1@mid.individual.net>
Message-ID: <07d16e91-82be-490c-4486-2f8ffd708fb5@chagford.com>

On 2020-02-21 11:13 PM, Greg Ewing wrote:
> On 21/02/20 7:59 pm, Frank Millman wrote:
>> My first attempt was to create a background task for each session 
>> which runs for the life-time of the session, and 'awaits' its queue. 
>> It works, but I was concerned about having a lot a background tasks 
>> active at the same time.
> 
> The whole point of asyncio is to make tasks very lightweight, so you
> can use as many of them as is convenient without worries. One task
> per client sounds like the right thing to do here.
> 

Perfect. Thanks so much.

Frank



From frank at chagford.com  Fri Feb 21 23:58:16 2020
From: frank at chagford.com (Frank Millman)
Date: Sat, 22 Feb 2020 06:58:16 +0200
Subject: Asyncio question
In-Reply-To: <hbavfvFbia8U1@mid.individual.net>
References: <r2nv4q$2vge$1@ciao.gmane.io>
 <mailman.12.1582268386.9235.python-list@python.org>
 <hbavfvFbia8U1@mid.individual.net>
Message-ID: <07d16e91-82be-490c-4486-2f8ffd708fb5@chagford.com>

On 2020-02-21 11:13 PM, Greg Ewing wrote:
> On 21/02/20 7:59 pm, Frank Millman wrote:
>> My first attempt was to create a background task for each session 
>> which runs for the life-time of the session, and 'awaits' its queue. 
>> It works, but I was concerned about having a lot a background tasks 
>> active at the same time.
> 
> The whole point of asyncio is to make tasks very lightweight, so you
> can use as many of them as is convenient without worries. One task
> per client sounds like the right thing to do here.
> 

Perfect. Thanks so much.

Frank


From markos at c2o.pro.br  Sat Feb 22 10:03:58 2020
From: markos at c2o.pro.br (Markos)
Date: Sat, 22 Feb 2020 12:03:58 -0300
Subject: Errors in testing the SciPy installation
Message-ID: <7675e12e-a48f-be56-c536-43fd954c2e2a@c2o.pro.br>

Hi,

Following the guidelines of the book Learning SciPy for Numerical and 
Scientific Computing Second Edition

I did the tests:

 >>> import scipy
 >>> scipy.test()

and got some errors:

Ran 23065 tests in 490.568s

FAILED (KNOWNFAIL=60, SKIP=1795, errors=29)
<nose.result.TextTestResult run=23065 errors=29 failures=0>

What should I do?

Thank you,
Markos


From Saliyusufm at outlook.com  Sat Feb 22 04:45:16 2020
From: Saliyusufm at outlook.com (S Y)
Date: Sat, 22 Feb 2020 09:45:16 +0000
Subject: Help with oop
Message-ID: <BN7PR14MB243539E6D6B96ECD32E09D72CAEE0@BN7PR14MB2435.namprd14.prod.outlook.com>

How can I use remove,add and verify methods in class oop. Which has tuple with allowed values inside class. Like two classes cart and inventory
Get Outlook for iOS<https://aka.ms/o0ukef>

From lberia460 at gmail.com  Sat Feb 22 13:18:09 2020
From: lberia460 at gmail.com (lberia460 at gmail.com)
Date: Sat, 22 Feb 2020 10:18:09 -0800 (PST)
Subject: python
Message-ID: <c3676f40-a37b-4bfd-9932-49355063b319@googlegroups.com>

hi guys can you help me.how to find maximum and minimum in list using while loop python

From python at python.invalid  Sat Feb 22 13:33:38 2020
From: python at python.invalid (Python)
Date: Sat, 22 Feb 2020 19:33:38 +0100
Subject: python
In-Reply-To: <c3676f40-a37b-4bfd-9932-49355063b319@googlegroups.com>
References: <c3676f40-a37b-4bfd-9932-49355063b319@googlegroups.com>
Message-ID: <5e517383$0$20331$426a74cc@news.free.fr>

lberia460 at gmail.com wrote:
> hi guys can you help me.how to find maximum and minimum in list using while loop python

l = [1, 4, 2, -1, 0, 4, 2, 1, 10]
for i in range(100):
     pass
	
maximum = max(l)
minimum = min(l)



From python at mrabarnett.plus.com  Sat Feb 22 15:37:23 2020
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 22 Feb 2020 20:37:23 +0000
Subject: python
In-Reply-To: <c3676f40-a37b-4bfd-9932-49355063b319@googlegroups.com>
References: <c3676f40-a37b-4bfd-9932-49355063b319@googlegroups.com>
Message-ID: <4cd3d10a-9d93-5910-e213-d966d2ca08ac@mrabarnett.plus.com>

On 2020-02-22 18:18, lberia460 at gmail.com wrote:
> hi guys can you help me.how to find maximum and minimum in list using while loop python
> 
You don't need to use a loop. Use the 'max' and 'min' functions.

From countryone77 at gmail.com  Sat Feb 22 15:49:56 2020
From: countryone77 at gmail.com (Bev In TX)
Date: Sat, 22 Feb 2020 14:49:56 -0600
Subject: python
In-Reply-To: <4cd3d10a-9d93-5910-e213-d966d2ca08ac@mrabarnett.plus.com>
References: <4cd3d10a-9d93-5910-e213-d966d2ca08ac@mrabarnett.plus.com>
Message-ID: <21E8B241-370A-4F04-8921-155D4332E2A9@gmail.com>


> On Feb 22, 2020, at 2:42 PM, MRAB <python at mrabarnett.plus.com> wrote:
> 
>> On 2020-02-22 18:18, lberia460 at gmail.com wrote:
>> hi guys can you help me.how to find maximum and minimum in list using while loop python
> You don't need to use a loop. Use the 'max' and 'min' functions.
Unless it was a homework question, in which case a loop might have been required.

From ethan at stoneleaf.us  Sat Feb 22 16:10:05 2020
From: ethan at stoneleaf.us (Ethan Furman)
Date: Sat, 22 Feb 2020 13:10:05 -0800
Subject: Idiom for partial failures
In-Reply-To: <r2pmtt$a7b$1@dont-email.me>
References: <B764B5F0-D32B-4E57-9BFB-9CF4EC51C26E@gmail.com>
 <mailman.7.1582221685.9235.python-list@python.org>
 <r2mvml$sdr$1@dont-email.me>
 <CA+k6q--vn5C6FqRMbEUT+20ZnaHWwu5veJS1BYHxaCNvEtCThw@mail.gmail.com>
 <mailman.18.1582320483.9235.python-list@python.org>
 <r2pmtt$a7b$1@dont-email.me>
Message-ID: <6bb96204-6264-e720-2fc9-da17a7bc55ac@stoneleaf.us>

On 02/21/2020 02:51 PM, Rob Gaddi wrote:
> On 2/21/20 9:18 AM, David Wihl wrote:

>> Yes, the API has to support partial failures across all six supported
>> languages. Not all operations need to be atomic and there is considerable
>> efficiency in having multiple operations sent in a single request. Thanks,
> 
> A partial failure is a partial success and should not trigger a mandatory flow-control change, which is what an exception is.

Whether it should or not is a design question which won't always have the same answer.

> If there is any information in the successes, then I'd expect an operation like this to return me a list corresponding 1-to-1 with the list of operations

Sure, if there is processing still needed for the successes then that is the way I would choose, also.

> If successes have nothing to add to the party, then I'd expect the operation to return a list containing only the errors, and an empty list means no errors.

I would go the exception route here, for two reasons:

- the code that handles failures is very obviously in one place
- the program won't run merrily along if I forget to handle the failure case
   (an exception would draw attention to the problem)

--
~Ethan~

From frank at chagford.com  Sun Feb 23 02:04:00 2020
From: frank at chagford.com (Frank Millman)
Date: Sun, 23 Feb 2020 09:04:00 +0200
Subject: Why is passing loop argument to asyncio.Event deprecated?
Message-ID: <r2t853$ubh$1@ciao.gmane.io>

Hi all

Why is 'explicit passing of a loop argument to asyncio.Event' deprecated 
(see What's new in Python 3.8)?

I use this in my project. I can find a workaround, but it is not elegant.

I can explain my use case if requested, but I was just curious to find 
out the reason.

Thanks

Frank Millman


From lberia460 at gmail.com  Sun Feb 23 02:26:53 2020
From: lberia460 at gmail.com (luka beria)
Date: Sat, 22 Feb 2020 23:26:53 -0800 (PST)
Subject: python
Message-ID: <10593548-6ae6-45f2-96c0-d4f36bf66e63@googlegroups.com>

hi guys i have another question.how to  find the minimum and maximum numbers in this list without using the min () and max () functions use   while loop

From frank at chagford.com  Sun Feb 23 02:44:52 2020
From: frank at chagford.com (Frank Millman)
Date: Sun, 23 Feb 2020 09:44:52 +0200
Subject: python
In-Reply-To: <10593548-6ae6-45f2-96c0-d4f36bf66e63@googlegroups.com>
References: <10593548-6ae6-45f2-96c0-d4f36bf66e63@googlegroups.com>
Message-ID: <444a92af-2898-f810-9869-54b38948fd71@chagford.com>

On 2020-02-23 9:26 AM, luka beria wrote:
> hi guys i have another question.how to  find the minimum and maximum numbers in this list without using the min () and max () functions use   while loop
> 

Hi Luka

Did you read the reply to your previous question from Dennis Lee Bieber?

If not, here it is again -

"""
This smells like a homework assignment. We do NOT provide solutions to
homework. In particular, we will not provide you with an algorithm to 
solve such a simple problem.

We WILL provide help with Python syntax and semantics, but YOU need to
provide a starting point of what you've tried, what the results are, and
what you expected for the results.

Suggestion: pretend you are the computer. Use a piece of paper to track
current MAX and current MIN. You get one item from the list at a time --
how do you determine if it is to become a new MAX, a new MIN, or is ignored
as neither.

Now -- write a program does just that...

"""

Try his suggestion, and come back here if you get stuck.

Frank Millman


From frank at chagford.com  Sun Feb 23 02:44:52 2020
From: frank at chagford.com (Frank Millman)
Date: Sun, 23 Feb 2020 09:44:52 +0200
Subject: python
In-Reply-To: <10593548-6ae6-45f2-96c0-d4f36bf66e63@googlegroups.com>
References: <10593548-6ae6-45f2-96c0-d4f36bf66e63@googlegroups.com>
Message-ID: <444a92af-2898-f810-9869-54b38948fd71@chagford.com>

On 2020-02-23 9:26 AM, luka beria wrote:
> hi guys i have another question.how to  find the minimum and maximum numbers in this list without using the min () and max () functions use   while loop
> 

Hi Luka

Did you read the reply to your previous question from Dennis Lee Bieber?

If not, here it is again -

"""
This smells like a homework assignment. We do NOT provide solutions to
homework. In particular, we will not provide you with an algorithm to 
solve such a simple problem.

We WILL provide help with Python syntax and semantics, but YOU need to
provide a starting point of what you've tried, what the results are, and
what you expected for the results.

Suggestion: pretend you are the computer. Use a piece of paper to track
current MAX and current MIN. You get one item from the list at a time --
how do you determine if it is to become a new MAX, a new MIN, or is ignored
as neither.

Now -- write a program does just that...

"""

Try his suggestion, and come back here if you get stuck.

Frank Millman

From souvik.viksou at gmail.com  Sun Feb 23 03:05:40 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Sun, 23 Feb 2020 13:35:40 +0530
Subject: python
In-Reply-To: <10593548-6ae6-45f2-96c0-d4f36bf66e63@googlegroups.com>
References: <10593548-6ae6-45f2-96c0-d4f36bf66e63@googlegroups.com>
Message-ID: <CADRXHdKmwR=wd8J4a96SunqXX8uiUv3pqa4_e+j32TUn1dTk3A@mail.gmail.com>

Try it yourself first. It is very easy.

On Sun, Feb 23, 2020, 1:00 PM luka beria <lberia460 at gmail.com> wrote:

> hi guys i have another question.how to  find the minimum and maximum
> numbers in this list without using the min () and max () functions use
>  while loop
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From grant.b.edwards at gmail.com  Sun Feb 23 10:52:25 2020
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sun, 23 Feb 2020 15:52:25 -0000 (UTC)
Subject: python
References: <c3676f40-a37b-4bfd-9932-49355063b319@googlegroups.com>
 <5e517383$0$20331$426a74cc@news.free.fr>
Message-ID: <r2u73o$14el$1@ciao.gmane.io>

On 2020-02-22, Python <python at python.invalid> wrote:
> lberia460 at gmail.com wrote:
>> hi guys can you help me.how to find maximum and minimum in list using while loop python
>
> l = [1, 4, 2, -1, 0, 4, 2, 1, 10]
> for i in range(100):
>      pass
> 	
> maximum = max(l)
> minimum = min(l)

The requirement is to use a _while_ loop:

    l = [1, 4, 2, -1, 0, 4, 2, 1, 10]
    while True:
        maximum = max(l)
        minimum = min(l)
        break



From PythonList at DancesWithMice.info  Sun Feb 23 16:41:54 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 24 Feb 2020 10:41:54 +1300
Subject: Help with oop
In-Reply-To: <BN7PR14MB243539E6D6B96ECD32E09D72CAEE0@BN7PR14MB2435.namprd14.prod.outlook.com>
References: <BN7PR14MB243539E6D6B96ECD32E09D72CAEE0@BN7PR14MB2435.namprd14.prod.outlook.com>
Message-ID: <81c4eae3-326c-ced7-7582-b0385603b26e@DancesWithMice.info>

On 22/02/20 10:45 PM, S Y wrote:
> How can I use remove,add and verify methods in class oop. Which has tuple with allowed values inside class. Like two classes cart and inventory

Please show the code you have so-far.
What are you removing, adding, and verifying?
Are you aware of the Python-Tutor Discussion List?

-- 
Regards =dn

From PythonList at DancesWithMice.info  Sun Feb 23 17:22:27 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 24 Feb 2020 11:22:27 +1300
Subject: Help with oop
In-Reply-To: <BN7PR14MB2435960045223D884594F844CAEF0@BN7PR14MB2435.namprd14.prod.outlook.com>
References: <BN7PR14MB243539E6D6B96ECD32E09D72CAEE0@BN7PR14MB2435.namprd14.prod.outlook.com>
 <81c4eae3-326c-ced7-7582-b0385603b26e@DancesWithMice.info>
 <BN7PR14MB2435960045223D884594F844CAEF0@BN7PR14MB2435.namprd14.prod.outlook.com>
Message-ID: <dfc05dc7-4627-76e5-12b4-876b52284257@DancesWithMice.info>

On 24/02/20 10:45 AM, S Y wrote:
> """ The class Baggage will track inventory items added to or removed 
> from it. Inventory items will be represented by
> inventory item objects created using the ?InventoryItem? class. When an 
> attempt is made to add an inventory
> item to a Baggage object, the number of items in the Baggage object is 
> compared with maximum capacity and
> allowable items. If space is left and the item is allowed, the item is 
> added, otherwise, the class returns a response indicating failure with a 
> short reason why"""
> class Baggage:
>  ?#Constructor - sets initial values for all object attributes.
>  ?def __init__(self,capacity, inventory= [],allow_items=()):
>  ?self.inventory = []
>  ?self.capacity = 5
>  ?self.allow_items = (
...

>  ?#Adds an item object to the Baggage object after checking that the mx 
> capacity has not been reached (i.e. 5 items)
>  ?def add_item(self, item_object):
>  ?if len(self.inventory) <= self.capacity:
>  ?self.inventory.append(item_object)
>  ?return True
>  ?else:
>  ?print("Reached max capacity")
>  ?return False

> <python-list-bounces+saliyusufm=outlook.com at python.org> on behalf of DL 
> Neil via Python-list <python-list at python.org>
> *Sent:* Sunday, February 23, 2020 4:41:54 PM
> *To:* python-list at python.org <python-list at python.org>
> *Subject:* Re: Help with oop
> On 22/02/20 10:45 PM, S Y wrote:
>> How can I use remove,add and verify methods in class oop. Which has tuple with allowed values inside class. Like two classes cart and inventory
> 
> Please show the code you have so-far.
> What are you removing, adding, and verifying?
> Are you aware of the Python-Tutor Discussion List?

Given that the data-structure is a list, perhaps list.remove()?
What is the relevance of Baggage.allow_items()?

Sorry to be nagging you but perhaps take a look at how Discussion Lists 
work:
- top/bottom posting, ie not answer then question,
- replying to list (not individual) so that others may also benefit,
- formatting and readability (cf 'Microsoft makes it look nice because 
they know better than you')

WebRef:
5. Data Structures?
https://docs.python.org/3/tutorial/datastructures.html
-- 
Regards =dn

From PythonList at DancesWithMice.info  Sun Feb 23 17:45:52 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Mon, 24 Feb 2020 11:45:52 +1300
Subject: Managing plug-ins
Message-ID: <5f6a0ccf-7210-d0ec-463a-644232201c8b@etelligence.info>

Please recommend a library which will manage plug-ins.


(Regret that searching PyPi or using a web SE results in an overwhelming 
number of 'false positives')

Not wanting to 'reinvent the wheel, have been looking for an 'approved' 
way to manage a set of previously-prepared routines plus user-added 
functionality:
- user selects particular type of analysis (cmdLN)
- take that string and convert to a function/method
- 'plug-in' code could be located within application
- 'plug-in' could be 'included' from user
- interface standardisation/checking not part of question
- Python3

Application is statistical analysis. Users want to control aspects such 
as data selection/inclusion policies, other data 
pre-processing/massaging, distribution curve to be applied, and similar.
NB not looking for stats-code, but to easily manage a range of plug-ins 
from which users may select to suit their particular research objective.
-- 
Regards,
=dn

From souvik.viksou at gmail.com  Mon Feb 24 11:02:36 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Mon, 24 Feb 2020 21:32:36 +0530
Subject: How to get a place's longitude and latitude?
Message-ID: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>

Hi guys I want to make a program that kinda sends an sos message with the
measures of longitude and latitude (which is super inconvenient) to
someone. How can I do that I mean how can I get the longitude and latitude?
Any help would be appreciated.

From arj.python at gmail.com  Mon Feb 24 11:06:41 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Mon, 24 Feb 2020 20:06:41 +0400
Subject: How to get a place's longitude and latitude?
In-Reply-To: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
References: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
Message-ID: <CADrxXXnZynSaViVpow_J4OiO4u2YaB3q6f2_d8pW34=s7dYmBw@mail.gmail.com>

On phone?

On Mon, 24 Feb 2020, 20:02 Souvik Dutta, <souvik.viksou at gmail.com> wrote:

> Hi guys I want to make a program that kinda sends an sos message with the
> measures of longitude and latitude (which is super inconvenient) to
> someone. How can I do that I mean how can I get the longitude and latitude?
> Any help would be appreciated.
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From rosuav at gmail.com  Mon Feb 24 11:07:35 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 25 Feb 2020 03:07:35 +1100
Subject: How to get a place's longitude and latitude?
In-Reply-To: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
References: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
Message-ID: <CAPTjJmpdsU76jSsJG6K+o=Am7eD1sHZPXO=7KgEm3h9M8ouAEg@mail.gmail.com>

On Tue, Feb 25, 2020 at 3:04 AM Souvik Dutta <souvik.viksou at gmail.com> wrote:
>
> Hi guys I want to make a program that kinda sends an sos message with the
> measures of longitude and latitude (which is super inconvenient) to
> someone. How can I do that I mean how can I get the longitude and latitude?
> Any help would be appreciated.

This is a difficult thing to do in general, so you're going to have to
get specific. Are you building a desktop app? A phone app? Is it
something that runs via a web browser? What sort of platform are you
using, and are you okay with requiring the user to do some
configuration beforehand in order to have an easy one-click "send help
now"?

ChrisA

From aakashjana2002 at gmail.com  Mon Feb 24 11:08:29 2020
From: aakashjana2002 at gmail.com (Aakash Jana)
Date: Mon, 24 Feb 2020 21:38:29 +0530
Subject: How to get a place's longitude and latitude?
In-Reply-To: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
References: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
Message-ID: <CA+gHiQ6fypcYOCSxe-g4bRU3S-ZA8hPBaZK2x1tEPjgrRxC+-w@mail.gmail.com>

You might use webscraping with requests and beautiful soup to scrape up
some website for that gives such utility


On Mon, 24 Feb 2020, 9:36 pm Souvik Dutta <souvik.viksou at gmail.com wrote:

> Hi guys I want to make a program that kinda sends an sos message with the
> measures of longitude and latitude (which is super inconvenient) to
> someone. How can I do that I mean how can I get the longitude and latitude?
> Any help would be appreciated.
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From arj.python at gmail.com  Mon Feb 24 11:11:19 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Mon, 24 Feb 2020 20:11:19 +0400
Subject: How to get a place's longitude and latitude?
In-Reply-To: <CADRXHdKAWbrjE=b20sFb=zzxg+0Jo9P-LkeyrTq2FRmstVSf2g@mail.gmail.com>
References: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
 <CADrxXXnZynSaViVpow_J4OiO4u2YaB3q6f2_d8pW34=s7dYmBw@mail.gmail.com>
 <CADRXHdKAWbrjE=b20sFb=zzxg+0Jo9P-LkeyrTq2FRmstVSf2g@mail.gmail.com>
Message-ID: <CADrxXXnokmt=aAOz7jEAcT295Dk3ry2z5BGO4ntHuRtzbjywpA@mail.gmail.com>

Ever heard of QPython? It has a sl4a  Api

http://edu.qpython.org/qsl4a-develop/index.html?form=web

You can pull in GPS coordinates!

On Mon, 24 Feb 2020, 20:07 Souvik Dutta, <souvik.viksou at gmail.com> wrote:

> Yes.
>
> On Mon, 24 Feb, 2020, 9:36 pm Abdur-Rahmaan Janhangeer, <
> arj.python at gmail.com> wrote:
>
>> On phone?
>>
>> On Mon, 24 Feb 2020, 20:02 Souvik Dutta, <souvik.viksou at gmail.com> wrote:
>>
>>> Hi guys I want to make a program that kinda sends an sos message with the
>>> measures of longitude and latitude (which is super inconvenient) to
>>> someone. How can I do that I mean how can I get the longitude and
>>> latitude?
>>> Any help would be appreciated.
>>> --
>>> https://mail.python.org/mailman/listinfo/python-list
>>>
>>

From joel.goldstick at gmail.com  Mon Feb 24 11:12:51 2020
From: joel.goldstick at gmail.com (Joel Goldstick)
Date: Mon, 24 Feb 2020 11:12:51 -0500
Subject: How to get a place's longitude and latitude?
In-Reply-To: <CA+gHiQ6fypcYOCSxe-g4bRU3S-ZA8hPBaZK2x1tEPjgrRxC+-w@mail.gmail.com>
References: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
 <CA+gHiQ6fypcYOCSxe-g4bRU3S-ZA8hPBaZK2x1tEPjgrRxC+-w@mail.gmail.com>
Message-ID: <CAPM-O+zDyFf=fLMfkDg6OjZtPVm24SNsRBzWnV8BsXDiYqL-tw@mail.gmail.com>

On Mon, Feb 24, 2020 at 11:10 AM Aakash Jana <aakashjana2002 at gmail.com> wrote:
>
> You might use webscraping with requests and beautiful soup to scrape up
> some website for that gives such utility
>
>
> On Mon, 24 Feb 2020, 9:36 pm Souvik Dutta <souvik.viksou at gmail.com wrote:
>
> > Hi guys I want to make a program that kinda sends an sos message with the
> > measures of longitude and latitude (which is super inconvenient) to
> > someone. How can I do that I mean how can I get the longitude and latitude?
> > Any help would be appreciated.
> > --
> > https://mail.python.org/mailman/listinfo/python-list
> >
> --
> https://mail.python.org/mailman/listinfo/python-list

I found this article for using a raspberry pi and a gps card.  It
might give you some ideas:

https://tutorials-raspberrypi.com/build-raspberry-pi-gps-location-navigation-device/

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

From walkerqt at gmail.com  Mon Feb 24 08:18:17 2020
From: walkerqt at gmail.com (qbit)
Date: Mon, 24 Feb 2020 05:18:17 -0800 (PST)
Subject: time.localtime add a parameter for timezone
Message-ID: <d9ee3c41-517c-4260-9cf8-7b49678f3030@googlegroups.com>

How about adding a time zone parameter to time.localtime?

A  offset just like the form: ? hh[:mm[:ss]].

From legaulph at gmail.com  Mon Feb 24 12:16:49 2020
From: legaulph at gmail.com (legaulph at gmail.com)
Date: Mon, 24 Feb 2020 12:16:49 -0500
Subject: How to get a place's longitude and latitude?
In-Reply-To: <CA+gHiQ6fypcYOCSxe-g4bRU3S-ZA8hPBaZK2x1tEPjgrRxC+-w@mail.gmail.com>
References: <CADRXHdJYGcdjNrXoaqymKgdg=F6QA8oHtgw5GPxi-61k4Gw8Jg@mail.gmail.com>
 <CA+gHiQ6fypcYOCSxe-g4bRU3S-ZA8hPBaZK2x1tEPjgrRxC+-w@mail.gmail.com>
Message-ID: <03f901d5eb36$338170a0$9a8451e0$@gmail.com>

Try something like

import requests
import json

url =
"https://nominatim.openstreetmap.org/search.php?q=city+country&format=json&l
imit=1"
result = requests.get(url)
dataobj = result.json()
x = dataobj[0]['lat'] + "," + dataobj[0]['lon']
print(x)



-----Original Message-----
From: Python-list <python-list-bounces+legaulph=gmail.com at python.org> On
Behalf Of Aakash Jana
Sent: Monday, February 24, 2020 11:08 AM
To: Souvik Dutta <souvik.viksou at gmail.com>
Cc: python-list at python.org
Subject: Re: How to get a place's longitude and latitude?

You might use webscraping with requests and beautiful soup to scrape up some
website for that gives such utility


On Mon, 24 Feb 2020, 9:36 pm Souvik Dutta <souvik.viksou at gmail.com wrote:

> Hi guys I want to make a program that kinda sends an sos message with 
> the measures of longitude and latitude (which is super inconvenient) 
> to someone. How can I do that I mean how can I get the longitude and
latitude?
> Any help would be appreciated.
> --
> https://mail.python.org/mailman/listinfo/python-list
>
--
https://mail.python.org/mailman/listinfo/python-list


From dieter at handshake.de  Mon Feb 24 12:21:29 2020
From: dieter at handshake.de (Dieter Maurer)
Date: Mon, 24 Feb 2020 18:21:29 +0100
Subject: time.localtime add a parameter for timezone
In-Reply-To: <d9ee3c41-517c-4260-9cf8-7b49678f3030@googlegroups.com>
References: <d9ee3c41-517c-4260-9cf8-7b49678f3030@googlegroups.com>
Message-ID: <24148.1561.992531.425307@ixdm.fritz.box>

qbit wrote at 2020-2-24 05:18 -0800:
>How about adding a time zone parameter to time.localtime?
>
>A  offset just like the form: ? hh[:mm[:ss]].

Why should this be necessary? `localtime` returns the time
in the "local timezone" -- and the "local timezone" usually
does not change between different calls to `localtime`.
Thus, it is best not to pass the timezone to each call to `localtime`
but use environment information.

If your "local timezone" does change frequently, you have (at least)
the following options:

 * use `time.tzset` to reset the internal variables used by
   `localtime` from the envvar `TZ` (which your have appropriately
   set earlier)

 * use `time.time` (instead of `time.localtime`) and add the offset
   yourself. `time.time` returns the UTC time.


--
Dieter

From rhodri at kynesim.co.uk  Mon Feb 24 12:43:58 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Mon, 24 Feb 2020 17:43:58 +0000
Subject: time.localtime add a parameter for timezone
In-Reply-To: <24148.1561.992531.425307@ixdm.fritz.box>
References: <d9ee3c41-517c-4260-9cf8-7b49678f3030@googlegroups.com>
 <24148.1561.992531.425307@ixdm.fritz.box>
Message-ID: <9b0d96eb-9fd9-a31d-e4b3-4d21245aa708@kynesim.co.uk>

On 24/02/2020 17:21, Dieter Maurer wrote:
> qbit wrote at 2020-2-24 05:18 -0800:
>> How about adding a time zone parameter to time.localtime?
>>
>> A  offset just like the form: ? hh[:mm[:ss]].
> 
> Why should this be necessary? `localtime` returns the time
> in the "local timezone" -- and the "local timezone" usually
> does not change between different calls to `localtime`.

It can if your calls to localtime() happen either side of a daylight 
saving time switch.

That said, I agree that the timezone doesn't really belong in the output 
of localtime().  There are a very few occasions when you want it, but 
more often you should be working in UTC not local time.


-- 
Rhodri James *-* Kynesim Ltd

From none at invalid.com  Mon Feb 24 16:29:17 2020
From: none at invalid.com (mm0fmf)
Date: Mon, 24 Feb 2020 21:29:17 +0000
Subject: Tkinter layout designer
Message-ID: <r31f7f$q0k$1@dont-email.me>

Can anyone recommend a graphic layout designer for Tkinter programs. I 
have a number of older C# Windows Forms apps that need porting so they 
can run on Linux and Windows and this is the chance to re-write them in 
Python. However, after using the forms designer in Visual Studio, 
manually coding up the widget positions etc. is a real pain in the 
backside.

So please, recommendations for a designer that is usable and functional 
please to save me working through everything a Google search throws up.

Thanks,
Andy



From auriocus at gmx.de  Tue Feb 25 01:32:47 2020
From: auriocus at gmx.de (Christian Gollwitzer)
Date: Tue, 25 Feb 2020 07:32:47 +0100
Subject: Tkinter layout designer
In-Reply-To: <r31f7f$q0k$1@dont-email.me>
References: <r31f7f$q0k$1@dont-email.me>
Message-ID: <r32f2g$ctv$1@dont-email.me>

Am 24.02.20 um 22:29 schrieb mm0fmf:
> Can anyone recommend a graphic layout designer for Tkinter programs.

There is no such thing for Tkinter. There is an outdated designer for Tk 
called Visual Tcl, but it can generate only Tcl code, not TkInter, and 
uses only old-style widgets.

> I 
> have a number of older C# Windows Forms apps that need porting so they 
> can run on Linux and Windows and this is the chance to re-write them in 
> Python. However, after using the forms designer in Visual Studio, 
> manually coding up the widget positions etc. is a real pain in the 
> backside

> So please, recommendations for a designer that is usable and functional 
> please to save me working through everything a Google search throws up.


If you want a designer, use QT, which brings the Qt Designer. Be careful 
though - if you misuse them, you can end up with inflexible GUIs, where 
changes in the font or display resolution can mess up your interface. 
Always test that your windows act sensibly upon resizing.

	Christian

From souvik.viksou at gmail.com  Tue Feb 25 02:06:35 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Tue, 25 Feb 2020 12:36:35 +0530
Subject: Tkinter layout designer
In-Reply-To: <r32f2g$ctv$1@dont-email.me>
References: <r31f7f$q0k$1@dont-email.me> <r32f2g$ctv$1@dont-email.me>
Message-ID: <CADRXHd+v0uYU0tVe4_a7=VJHRhr6AE49AOKvkP1_eV4Qgh8BmQ@mail.gmail.com>

There is one called PAGES

On Tue, Feb 25, 2020, 12:05 PM Christian Gollwitzer <auriocus at gmx.de> wrote:

> Am 24.02.20 um 22:29 schrieb mm0fmf:
> > Can anyone recommend a graphic layout designer for Tkinter programs.
>
> There is no such thing for Tkinter. There is an outdated designer for Tk
> called Visual Tcl, but it can generate only Tcl code, not TkInter, and
> uses only old-style widgets.
>
> > I
> > have a number of older C# Windows Forms apps that need porting so they
> > can run on Linux and Windows and this is the chance to re-write them in
> > Python. However, after using the forms designer in Visual Studio,
> > manually coding up the widget positions etc. is a real pain in the
> > backside
>
> > So please, recommendations for a designer that is usable and functional
> > please to save me working through everything a Google search throws up.
>
>
> If you want a designer, use QT, which brings the Qt Designer. Be careful
> though - if you misuse them, you can end up with inflexible GUIs, where
> changes in the font or display resolution can mess up your interface.
> Always test that your windows act sensibly upon resizing.
>
>         Christian
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From nulla.epistola at web.de  Tue Feb 25 03:26:29 2020
From: nulla.epistola at web.de (Sibylle Koczian)
Date: Tue, 25 Feb 2020 09:26:29 +0100
Subject: Tkinter layout designer
In-Reply-To: <r32f2g$ctv$1@dont-email.me>
References: <r31f7f$q0k$1@dont-email.me> <r32f2g$ctv$1@dont-email.me>
Message-ID: <93108354-0420-2c16-c0fd-d2cce7f1498b@web.de>

Am 25.02.2020 um 07:32 schrieb Christian Gollwitzer:
> Am 24.02.20 um 22:29 schrieb mm0fmf:
>> Can anyone recommend a graphic layout designer for Tkinter programs.
> 
>> I have a number of older C# Windows Forms apps that need porting so 
>> they can run on Linux and Windows and this is the chance to re-write 
>> them in Python. However, after using the forms designer in Visual 
>> Studio, manually coding up the widget positions etc. is a real pain in 
>> the backside
> 
> If you want a designer, use QT, which brings the Qt Designer. Be careful 
> though - if you misuse them, you can end up with inflexible GUIs, where 
> changes in the font or display resolution can mess up your interface. 
> Always test that your windows act sensibly upon resizing.
> 
Coming from Windows Forms this is especially important. Windows Forms 
doesn't have a sensible geometry manager. Tkinter and PyQt / PySide both 
have them, and it's quite a change at first. But in the long run it's 
much more comfortable to put your controls into layouts (or pack / grid 
them - tkinter) instead of placing each and every thing yourself.

Greetings
Sibylle



From nulla.epistola at web.de  Tue Feb 25 03:26:29 2020
From: nulla.epistola at web.de (Sibylle Koczian)
Date: Tue, 25 Feb 2020 09:26:29 +0100
Subject: Tkinter layout designer
In-Reply-To: <r32f2g$ctv$1@dont-email.me>
References: <r31f7f$q0k$1@dont-email.me> <r32f2g$ctv$1@dont-email.me>
Message-ID: <93108354-0420-2c16-c0fd-d2cce7f1498b@web.de>

Am 25.02.2020 um 07:32 schrieb Christian Gollwitzer:
> Am 24.02.20 um 22:29 schrieb mm0fmf:
>> Can anyone recommend a graphic layout designer for Tkinter programs.
> 
>> I have a number of older C# Windows Forms apps that need porting so 
>> they can run on Linux and Windows and this is the chance to re-write 
>> them in Python. However, after using the forms designer in Visual 
>> Studio, manually coding up the widget positions etc. is a real pain in 
>> the backside
> 
> If you want a designer, use QT, which brings the Qt Designer. Be careful 
> though - if you misuse them, you can end up with inflexible GUIs, where 
> changes in the font or display resolution can mess up your interface. 
> Always test that your windows act sensibly upon resizing.
> 
Coming from Windows Forms this is especially important. Windows Forms 
doesn't have a sensible geometry manager. Tkinter and PyQt / PySide both 
have them, and it's quite a change at first. But in the long run it's 
much more comfortable to put your controls into layouts (or pack / grid 
them - tkinter) instead of placing each and every thing yourself.

Greetings
Sibylle


From blindanagram at nowhere.com  Tue Feb 25 07:38:36 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 12:38:36 +0000
Subject: encapsulating a global variable
Message-ID: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>

I would appreciate advice on whether it is possible to avoid the use of
a global variable used in a function by encapsulating it in a class
without maaking any changes to the call interface (which I cannot change).

I have:

----------------
seen = dict()

def get_it(piece):
   ...
   return seen[piece]
----------------

and I am wondering if it is possible to use a class something like

----------------
class get_it(object):

  seen = dict()

  def __call__(piece):
    return seen[piece]
----------------

to avoid the global variable.

  Brian Gladman

From rosuav at gmail.com  Tue Feb 25 07:56:27 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 25 Feb 2020 23:56:27 +1100
Subject: encapsulating a global variable
In-Reply-To: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
Message-ID: <CAPTjJmohADje-zFmrTPDyCpvecqUWfTVC0YcAM4DNPx+O9Hs0g@mail.gmail.com>

On Tue, Feb 25, 2020 at 11:41 PM BlindAnagram <blindanagram at nowhere.com> wrote:
>
> I would appreciate advice on whether it is possible to avoid the use of
> a global variable used in a function by encapsulating it in a class
> without maaking any changes to the call interface (which I cannot change).

Why bother? If you aren't changing where the function's called, then
its state is effectively global anyway, so what's the point of the
class?

ChrisA

From musbur at posteo.org  Tue Feb 25 07:50:43 2020
From: musbur at posteo.org (Musbur)
Date: Tue, 25 Feb 2020 13:50:43 +0100
Subject: encapsulating a global variable
Message-ID: <0156cd74837f4a9a8afba3f0e086d8f5@posteo.de>


Am 25.02.2020 13:38 schrieb BlindAnagram:
> and I am wondering if it is possible to use a class something like
> 
> class get_it(object):
> 
>   seen = dict()
> 
>   def __call__(piece):
>     return seen[piece]

What happened when you tried it?


From blindanagram at nowhere.com  Tue Feb 25 08:09:27 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 13:09:27 +0000
Subject: encapsulating a global variable
In-Reply-To: <mailman.49.1582635400.9235.python-list@python.org>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <CAPTjJmohADje-zFmrTPDyCpvecqUWfTVC0YcAM4DNPx+O9Hs0g@mail.gmail.com>
 <mailman.49.1582635400.9235.python-list@python.org>
Message-ID: <Zpqdnbe64u4VgcjDnZ2dnUU78cPNnZ2d@brightview.co.uk>

On 25/02/2020 12:56, Chris Angelico wrote:
> On Tue, Feb 25, 2020 at 11:41 PM BlindAnagram <blindanagram at nowhere.com> wrote:
>>
>> I would appreciate advice on whether it is possible to avoid the use of
>> a global variable used in a function by encapsulating it in a class
>> without maaking any changes to the call interface (which I cannot change).
> 
> Why bother? If you aren't changing where the function's called, then
> its state is effectively global anyway, so what's the point of the
> class?

It's a good question!

The main reason is that I would like to know if it is possible as I then
have a choice.  The choice might not be there.

  Brian

From blindanagram at nowhere.com  Tue Feb 25 09:06:58 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 14:06:58 +0000
Subject: encapsulating a global variable
In-Reply-To: <mailman.50.1582635647.9235.python-list@python.org>
References: <0156cd74837f4a9a8afba3f0e086d8f5@posteo.de>
 <mailman.50.1582635647.9235.python-list@python.org>
Message-ID: <U6adnUY6HbGet8jDnZ2dnUU78XXNnZ2d@brightview.co.uk>

On 25/02/2020 12:50, Musbur wrote:
> 
> Am 25.02.2020 13:38 schrieb BlindAnagram:
>> and I am wondering if it is possible to use a class something like
>>
>> class get_it(object):
>>
>> ? seen = dict()
>>
>> ? def __call__(piece):
>> ??? return seen[piece]
> 
> What happened when you tried it?

The nearest I got was:

-------------------------
class orientate(object):

  seen = defaultdict()
  @classmethod
  def do(self, piece, two_sided=False):
------------------------

which works but requires a change to the function call interface from
orientate(piece) to  orientate.do(piece).

I was hoping that repalcing the above with:

-------------------------
class orientate(object):

  seen = defaultdict()
  @classmethod
  def __call__(self, piece, two_sided=False):
------------------------

would eliminate the need for the 'do' but this gives the error:

builtins.TypeError: orientate() takes no arguments

  Brian

From rosuav at gmail.com  Tue Feb 25 09:13:57 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 26 Feb 2020 01:13:57 +1100
Subject: encapsulating a global variable
In-Reply-To: <Zpqdnbe64u4VgcjDnZ2dnUU78cPNnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <CAPTjJmohADje-zFmrTPDyCpvecqUWfTVC0YcAM4DNPx+O9Hs0g@mail.gmail.com>
 <mailman.49.1582635400.9235.python-list@python.org>
 <Zpqdnbe64u4VgcjDnZ2dnUU78cPNnZ2d@brightview.co.uk>
Message-ID: <CAPTjJmrvJbW+vyhj4YTyCqWYJSTNbMx5kc8Cf70HGjp=RoOA4A@mail.gmail.com>

On Wed, Feb 26, 2020 at 12:11 AM BlindAnagram <blindanagram at nowhere.com> wrote:
>
> On 25/02/2020 12:56, Chris Angelico wrote:
> > On Tue, Feb 25, 2020 at 11:41 PM BlindAnagram <blindanagram at nowhere.com> wrote:
> >>
> >> I would appreciate advice on whether it is possible to avoid the use of
> >> a global variable used in a function by encapsulating it in a class
> >> without maaking any changes to the call interface (which I cannot change).
> >
> > Why bother? If you aren't changing where the function's called, then
> > its state is effectively global anyway, so what's the point of the
> > class?
>
> It's a good question!
>
> The main reason is that I would like to know if it is possible as I then
> have a choice.  The choice might not be there.
>

Well, yes, you can, but you would need a global instance of that class
(or use the global class object itself). So you'd still have a global.

But if this is a transitional thing, then the answer is a resounding
YES. You can start by packaging up all your state with a class, and
have a single global instance of that class; but then you can rework
your function to take an optional parameter which is a non-global
instance of the class. Then all your state is kept in there, and you
actually truly *do* avoid global state. As a good example of how this
works, check out Python's random module - you can call
random.randrange() to get a random number in a particular range, or
you can instantiate your own random.Random() object and call its
randrange() method. The first form uses global state; the second form
doesn't.

ChrisA

From rhodri at kynesim.co.uk  Tue Feb 25 09:14:54 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 25 Feb 2020 14:14:54 +0000
Subject: encapsulating a global variable
In-Reply-To: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
Message-ID: <5f52945b-c0f9-bbfa-2afb-9be5364941eb@kynesim.co.uk>

On 25/02/2020 12:38, BlindAnagram wrote:
> I would appreciate advice on whether it is possible to avoid the use of
> a global variable used in a function by encapsulating it in a class
> without maaking any changes to the call interface (which I cannot change).
> 
> I have:
> 
> ----------------
> seen = dict()
> 
> def get_it(piece):
>     ...
>     return seen[piece]
> ----------------
> 
> and I am wondering if it is possible to use a class something like
> 
> ----------------
> class get_it(object):
> 
>    seen = dict()
> 
>    def __call__(piece):
>      return seen[piece]
> ----------------
> 
> to avoid the global variable.

I wouldn't.  Calling the class name creates an instance of the class, so 
won't actually do what you want.  You could rewrite the class and create 
an instance to call instead:

class GetIt:
   seen = dict()

   def __call__(self, piece):
     return GetIt.seen[piece]

get_it = GetIt()

but then you have a global class instance hanging around, which is not 
actually any better than a global dictionary.


-- 
Rhodri James *-* Kynesim Ltd

From hjp-python at hjp.at  Tue Feb 25 09:26:42 2020
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Tue, 25 Feb 2020 15:26:42 +0100
Subject: time.localtime add a parameter for timezone
In-Reply-To: <9b0d96eb-9fd9-a31d-e4b3-4d21245aa708@kynesim.co.uk>
References: <d9ee3c41-517c-4260-9cf8-7b49678f3030@googlegroups.com>
 <24148.1561.992531.425307@ixdm.fritz.box>
 <9b0d96eb-9fd9-a31d-e4b3-4d21245aa708@kynesim.co.uk>
Message-ID: <20200225142642.GA640@hjp.at>

On 2020-02-24 17:43:58 +0000, Rhodri James wrote:
> On 24/02/2020 17:21, Dieter Maurer wrote:
> > qbit wrote at 2020-2-24 05:18 -0800:
> > > How about adding a time zone parameter to time.localtime?
> > > 
> > > A  offset just like the form: ? hh[:mm[:ss]].
> > 
> > Why should this be necessary? `localtime` returns the time
> > in the "local timezone" -- and the "local timezone" usually
> > does not change between different calls to `localtime`.
> 
> It can if your calls to localtime() happen either side of a daylight saving
> time switch.
> 
> That said, I agree that the timezone doesn't really belong in the output of
> localtime().

I think it does (that POSIX omits it (and only includes the rather
useless tm_isdst) is a historical oversight which was unfortunately
never corrected).

However, it doesn't have to be added, since it is already there:

https://docs.python.org/3/library/time.html#time.struct_time

1084% python3
Python 3.6.9 (default, Nov  7 2019, 10:44:02)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import time
>>> t = time.localtime()
>>> t.tm_gmtoff
3600
>>> t.tm_zone
'CET'

However, this not a parameter but a field of the return value.

I'm not sure what a parameter would do: Return the broken-down time for
the specified timezone? If so, an offset is not sufficient: It needs to
be a timezone name (something like "Europe/Vienna").

Proper general handling of timezones should probably be in datetime.

> There are a very few occasions when you want it, but more often you
> should be working in UTC not local time.

If you are working in UTC, you don't need localtime().

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
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From blindanagram at nowhere.com  Tue Feb 25 09:56:52 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 14:56:52 +0000
Subject: encapsulating a global variable
In-Reply-To: <mailman.52.1582640097.9235.python-list@python.org>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <5f52945b-c0f9-bbfa-2afb-9be5364941eb@kynesim.co.uk>
 <mailman.52.1582640097.9235.python-list@python.org>
Message-ID: <qNydneM_ju8oqMjDnZ2dnUU78e_NnZ2d@brightview.co.uk>

On 25/02/2020 14:14, Rhodri James wrote:
> On 25/02/2020 12:38, BlindAnagram wrote:
>> I would appreciate advice on whether it is possible to avoid the use of
>> a global variable used in a function by encapsulating it in a class
>> without maaking any changes to the call interface (which I cannot
>> change).
>>
>> I have:
>>
>> ----------------
>> seen = dict()
>>
>> def get_it(piece):
>> ??? ...
>> ??? return seen[piece]
>> ----------------
>>
>> and I am wondering if it is possible to use a class something like
>>
>> ----------------
>> class get_it(object):
>>
>> ?? seen = dict()
>>
>> ?? def __call__(piece):
>> ???? return seen[piece]
>> ----------------
>>
>> to avoid the global variable.
> 
> I wouldn't.? Calling the class name creates an instance of the class, so
> won't actually do what you want.? You could rewrite the class and create
> an instance to call instead:
> 
> class GetIt:
> ? seen = dict()
> 
> ? def __call__(self, piece):
> ??? return GetIt.seen[piece]
> 
> get_it = GetIt()
> 
> but then you have a global class instance hanging around, which is not
> actually any better than a global dictionary.

Thanks. Does that not have the advantage of preventing the global
directory being directly fiddled with elsewhere?  Which is one of my
reasons for thinking about this.

   Brian

From blindanagram at nowhere.com  Tue Feb 25 10:06:30 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 15:06:30 +0000
Subject: encapsulating a global variable
In-Reply-To: <mailman.51.1582640052.9235.python-list@python.org>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <CAPTjJmohADje-zFmrTPDyCpvecqUWfTVC0YcAM4DNPx+O9Hs0g@mail.gmail.com>
 <mailman.49.1582635400.9235.python-list@python.org>
 <Zpqdnbe64u4VgcjDnZ2dnUU78cPNnZ2d@brightview.co.uk>
 <CAPTjJmrvJbW+vyhj4YTyCqWYJSTNbMx5kc8Cf70HGjp=RoOA4A@mail.gmail.com>
 <mailman.51.1582640052.9235.python-list@python.org>
Message-ID: <l9ydnV1ZCepqqsjDnZ2dnUU78WHNnZ2d@brightview.co.uk>

On 25/02/2020 14:13, Chris Angelico wrote:
> On Wed, Feb 26, 2020 at 12:11 AM BlindAnagram <blindanagram at nowhere.com> wrote:
>>
>> On 25/02/2020 12:56, Chris Angelico wrote:
>>> On Tue, Feb 25, 2020 at 11:41 PM BlindAnagram <blindanagram at nowhere.com> wrote:
>>>>
>>>> I would appreciate advice on whether it is possible to avoid the use of
>>>> a global variable used in a function by encapsulating it in a class
>>>> without maaking any changes to the call interface (which I cannot change).
>>>
>>> Why bother? If you aren't changing where the function's called, then
>>> its state is effectively global anyway, so what's the point of the
>>> class?
>>
>> It's a good question!
>>
>> The main reason is that I would like to know if it is possible as I then
>> have a choice.  The choice might not be there.
>>
> 
> Well, yes, you can, but you would need a global instance of that class
> (or use the global class object itself). So you'd still have a global.
> 
> But if this is a transitional thing, then the answer is a resounding
> YES. You can start by packaging up all your state with a class, and
> have a single global instance of that class; but then you can rework
> your function to take an optional parameter which is a non-global
> instance of the class. Then all your state is kept in there, and you
> actually truly *do* avoid global state. As a good example of how this
> works, check out Python's random module - you can call
> random.randrange() to get a random number in a particular range, or
> you can instantiate your own random.Random() object and call its
> randrange() method. The first form uses global state; the second form
> doesn't.

Thanks, I think I understand most of this but the eample will help a lot.

My interest in this stems from wanting to keep the dictionary only
available to the function that uses it and also a worry about being
called from threaded code.

   Brian

From blindanagram at nowhere.com  Tue Feb 25 10:20:39 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 15:20:39 +0000
Subject: encapsulating a global variable
In-Reply-To: <mailman.52.1582640097.9235.python-list@python.org>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <5f52945b-c0f9-bbfa-2afb-9be5364941eb@kynesim.co.uk>
 <mailman.52.1582640097.9235.python-list@python.org>
Message-ID: <86SdnQTPl7vapsjDnZ2dnUU78W-dnZ2d@brightview.co.uk>

On 25/02/2020 14:14, Rhodri James wrote:
> On 25/02/2020 12:38, BlindAnagram wrote:
>> I would appreciate advice on whether it is possible to avoid the use of
>> a global variable used in a function by encapsulating it in a class
>> without maaking any changes to the call interface (which I cannot
>> change).
>>
>> I have:
>>
>> ----------------
>> seen = dict()
>>
>> def get_it(piece):
>> ??? ...
>> ??? return seen[piece]
>> ----------------
>>
>> and I am wondering if it is possible to use a class something like
>>
>> ----------------
>> class get_it(object):
>>
>> ?? seen = dict()
>>
>> ?? def __call__(piece):
>> ???? return seen[piece]
>> ----------------
>>
>> to avoid the global variable.
> 
> I wouldn't.? Calling the class name creates an instance of the class, so
> won't actually do what you want.? You could rewrite the class and create
> an instance to call instead:
> 
> class GetIt:
> ? seen = dict()
> 
> ? def __call__(self, piece):
> ??? return GetIt.seen[piece]
> 
> get_it = GetIt()
> 
> but then you have a global class instance hanging around, which is not
> actually any better than a global dictionary.

This doesn't work for me since get_it(piece) returns the error:

builtins.TypeError: get_it() takes no arguments

   Brian

From rhodri at kynesim.co.uk  Tue Feb 25 11:36:18 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Tue, 25 Feb 2020 16:36:18 +0000
Subject: encapsulating a global variable
In-Reply-To: <86SdnQTPl7vapsjDnZ2dnUU78W-dnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <5f52945b-c0f9-bbfa-2afb-9be5364941eb@kynesim.co.uk>
 <mailman.52.1582640097.9235.python-list@python.org>
 <86SdnQTPl7vapsjDnZ2dnUU78W-dnZ2d@brightview.co.uk>
Message-ID: <12624652-efaf-0ed4-5279-f89bfb0b192d@kynesim.co.uk>

On 25/02/2020 15:20, BlindAnagram wrote:
>> class GetIt:
>>  ? seen = dict()
>>
>>  ? def __call__(self, piece):
>>  ??? return GetIt.seen[piece]
>>
>> get_it = GetIt()
>>
>> but then you have a global class instance hanging around, which is not
>> actually any better than a global dictionary.
> This doesn't work for me since get_it(piece) returns the error:
> 
> builtins.TypeError: get_it() takes no arguments

It works for me (pace sticking something in GetIt.seen to avoid getting 
a KeyError).  You aren't muddling up the class name and instance name 
are you?

-- 
Rhodri James *-* Kynesim Ltd

From blindanagram at nowhere.com  Tue Feb 25 12:05:57 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 17:05:57 +0000
Subject: encapsulating a global variable
In-Reply-To: <mailman.54.1582648582.9235.python-list@python.org>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <5f52945b-c0f9-bbfa-2afb-9be5364941eb@kynesim.co.uk>
 <mailman.52.1582640097.9235.python-list@python.org>
 <86SdnQTPl7vapsjDnZ2dnUU78W-dnZ2d@brightview.co.uk>
 <12624652-efaf-0ed4-5279-f89bfb0b192d@kynesim.co.uk>
 <mailman.54.1582648582.9235.python-list@python.org>
Message-ID: <aYOdncrSTehrzsjDnZ2dnUU78LnNnZ2d@brightview.co.uk>

On 25/02/2020 16:36, Rhodri James wrote:
> On 25/02/2020 15:20, BlindAnagram wrote:
>>> class GetIt:
>>> ?? seen = dict()
>>>
>>> ?? def __call__(self, piece):
>>> ???? return GetIt.seen[piece]
>>>
>>> get_it = GetIt()
>>>
>>> but then you have a global class instance hanging around, which is not
>>> actually any better than a global dictionary.
>> This doesn't work for me since get_it(piece) returns the error:
>>
>> builtins.TypeError: get_it() takes no arguments
> 
> It works for me (pace sticking something in GetIt.seen to avoid getting
> a KeyError).? You aren't muddling up the class name and instance name
> are you?

Apologies, I misunderstoof your proposal - it woks fine now I have
understood it

  Brian

From dvl at psu.edu  Tue Feb 25 12:16:18 2020
From: dvl at psu.edu (Christman, Roger Graydon)
Date: Tue, 25 Feb 2020 17:16:18 +0000
Subject: encapsulating a global variable (BlindAnagram)
Message-ID: <DM6PR02MB550024D0D5544DDBA23636B4A8ED0@DM6PR02MB5500.namprd02.prod.outlook.com>

> On Tue, 25 Feb 2020 3:06 PM BlindAnagram <blindanagram at nowhere.com> wrote:

> My interest in this stems from wanting to keep the dictionary only
> available to the function that uses it and also a worry about being
> called from threaded code.

It seems like the simplest solution for this is to make
a completely new file (module) containing nothing but
the dictionary and this one function that uses it.
Then you can import the function from the module
wherever it is called without importing the dictionary.

The thing I find curious is that apparently no other
function is allowed to create or populate the dictionary
in the first place.   Is it practical to have the entire
dictionary statically defined?

Roger Christman
Pennsylvania State University

From dieter at handshake.de  Tue Feb 25 12:17:00 2020
From: dieter at handshake.de (Dieter Maurer)
Date: Tue, 25 Feb 2020 18:17:00 +0100
Subject: encapsulating a global variable
In-Reply-To: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
Message-ID: <24149.22156.38724.693449@ixdm.fritz.box>

BlindAnagram wrote at 2020-2-25 12:38 +0000:
>I would appreciate advice on whether it is possible to avoid the use of
>a global variable used in a function by encapsulating it in a class
>without maaking any changes to the call interface (which I cannot change).
>
>I have:
>
>----------------
>seen = dict()
>
>def get_it(piece):
>   ...
>   return seen[piece]
>----------------
>
>and I am wondering if it is possible to use a class something like
>
>----------------
>class get_it(object):
>
>  seen = dict()
>
>  def __call__(piece):
>    return seen[piece]
>----------------
>
>to avoid the global variable.

Apparently, you are ready to change the function.
In this case, you might be interested in `rebindFunction` from
the package `dm.reuse`.
Its primary purpose is to reuse a foreign function in one's own
code with minor modifications. One of the supported minor
modifications is to change globals seen by the function.

From jfong at ms4.hinet.net  Tue Feb 25 05:59:16 2020
From: jfong at ms4.hinet.net (jfong at ms4.hinet.net)
Date: Tue, 25 Feb 2020 02:59:16 -0800 (PST)
Subject: Tkinter layout designer
In-Reply-To: <r31f7f$q0k$1@dont-email.me>
References: <r31f7f$q0k$1@dont-email.me>
Message-ID: <7d5a689b-6087-4908-8435-a8a71426c035@googlegroups.com>

mm0fmf? 2020?2?25???? UTC+8??5?29?33????
> Can anyone recommend a graphic layout designer for Tkinter programs. I 
> have a number of older C# Windows Forms apps that need porting so they 
> can run on Linux and Windows and this is the chance to re-write them in 
> Python. However, after using the forms designer in Visual Studio, 
> manually coding up the widget positions etc. is a real pain in the 
> backside.
> 
> So please, recommendations for a designer that is usable and functional 
> please to save me working through everything a Google search throws up.
> 
> Thanks,
> Andy

Download PAGE here:
https://sourceforge.net/projects/page/

--Jach

From blindanagram at nowhere.com  Tue Feb 25 13:10:37 2020
From: blindanagram at nowhere.com (BlindAnagram)
Date: Tue, 25 Feb 2020 18:10:37 +0000
Subject: encapsulating a global variable (BlindAnagram)
In-Reply-To: <mailman.55.1582650982.9235.python-list@python.org>
References: <DM6PR02MB550024D0D5544DDBA23636B4A8ED0@DM6PR02MB5500.namprd02.prod.outlook.com>
 <mailman.55.1582650982.9235.python-list@python.org>
Message-ID: <ZsSdndMSF7eD_sjDnZ2dnUU78Y3NnZ2d@brightview.co.uk>

On 25/02/2020 17:16, Christman, Roger Graydon wrote:
>> On Tue, 25 Feb 2020 3:06 PM BlindAnagram <blindanagram at nowhere.com> wrote:
> 
>> My interest in this stems from wanting to keep the dictionary only
>> available to the function that uses it and also a worry about being
>> called from threaded code.
> 
> It seems like the simplest solution for this is to make
> a completely new file (module) containing nothing but
> the dictionary and this one function that uses it.
> Then you can import the function from the module
> wherever it is called without importing the dictionary.
> 
> The thing I find curious is that apparently no other
> function is allowed to create or populate the dictionary
> in the first place.   Is it practical to have the entire
> dictionary statically defined?

The dictionary is a static variable of the function. It is updated by
the function and must maintain values across function calls.

Reading some more, it seems that I can create static function variables
using attributes.

  Brian

From none at invalid.com  Tue Feb 25 13:23:41 2020
From: none at invalid.com (mm0fmf)
Date: Tue, 25 Feb 2020 18:23:41 +0000
Subject: Tkinter layout designer
In-Reply-To: <r31f7f$q0k$1@dont-email.me>
References: <r31f7f$q0k$1@dont-email.me>
Message-ID: <r33one$hna$1@dont-email.me>

I don't claim to be an expert on Windows Forms, I inherited the support 
role and have added the odd widget over the years. The apps work but 
scream that their UI has been incrementally arrived at by someone who 
was just tinkering. :-)

Thanks for the suggestions, I'll give Page a try.


From aakashjana2002 at gmail.com  Tue Feb 25 15:45:39 2020
From: aakashjana2002 at gmail.com (Aakash Jana)
Date: Wed, 26 Feb 2020 02:15:39 +0530
Subject: Difficulty in generating .exe from .py file
Message-ID: <CA+gHiQ4ucTy6ZwSPTZzj9Q4ah=W6cMq5U51e5apEwrPr-AXrgA@mail.gmail.com>

I have made a simple web scraper that scrapes Wikipedia and prints some
info on to the command line using requests and BeautifulSoup. Whenever I
execute pyinstaller it gives an error "expected integer got type bytes"
although the code runs perfectly. I am using python 3.8

From greg.ewing at canterbury.ac.nz  Tue Feb 25 17:41:26 2020
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Wed, 26 Feb 2020 11:41:26 +1300
Subject: encapsulating a global variable
In-Reply-To: <l9ydnV1ZCepqqsjDnZ2dnUU78WHNnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <CAPTjJmohADje-zFmrTPDyCpvecqUWfTVC0YcAM4DNPx+O9Hs0g@mail.gmail.com>
 <mailman.49.1582635400.9235.python-list@python.org>
 <Zpqdnbe64u4VgcjDnZ2dnUU78cPNnZ2d@brightview.co.uk>
 <CAPTjJmrvJbW+vyhj4YTyCqWYJSTNbMx5kc8Cf70HGjp=RoOA4A@mail.gmail.com>
 <mailman.51.1582640052.9235.python-list@python.org>
 <l9ydnV1ZCepqqsjDnZ2dnUU78WHNnZ2d@brightview.co.uk>
Message-ID: <hblm4qFj91dU1@mid.individual.net>

On 26/02/20 4:06 am, BlindAnagram wrote:
> My interest in this stems from wanting to keep the dictionary only
> available to the function that uses it and also a worry about being
> called from threaded code.

Doing this won't make any difference to the way threaded code behaves.
Threading problems need to be addressed by appropriate use of locks,
etc.

-- 
Greg

From greg.ewing at canterbury.ac.nz  Tue Feb 25 17:49:16 2020
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Wed, 26 Feb 2020 11:49:16 +1300
Subject: encapsulating a global variable
In-Reply-To: <qNydneM_ju8oqMjDnZ2dnUU78e_NnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <5f52945b-c0f9-bbfa-2afb-9be5364941eb@kynesim.co.uk>
 <mailman.52.1582640097.9235.python-list@python.org>
 <qNydneM_ju8oqMjDnZ2dnUU78e_NnZ2d@brightview.co.uk>
Message-ID: <hblmjgFjbp6U1@mid.individual.net>

On 26/02/20 3:56 am, BlindAnagram wrote:
> Does that not have the advantage of preventing the global
> directory being directly fiddled with elsewhere?

That depends on what you mean by "prevent". There is nothing
to stop any code from directly accessing the .seen attribute
of the class.

It might make it less likely that someone will inadvertently
write code that does this.

If there will only ever be one instance of the dict, another
approach would be to put it into a dedicated module together
with the functions that access it. That will give you the
same amount of protection, while ensuring that there really
is only one instance, and making this fact clear to anyone
reading the code.

-- 
Greg

From lukasz at langa.pl  Tue Feb 25 19:56:59 2020
From: lukasz at langa.pl (=?utf-8?Q?=C5=81ukasz_Langa?=)
Date: Wed, 26 Feb 2020 01:56:59 +0100
Subject: Python 3.8.2 and 3.9.0a4 are now available
Message-ID: <E1415B6D-2922-4852-91C9-2D5B778989D1@langa.pl>

On behalf of the entire Python development community, and the currently serving Python release team in particular, I?m pleased to announce the release of two of the latest Python editions.

Python 3.8.2

Python 3.8.2 is the second maintenance release of Python 3.8 and contains two months worth of bug fixes. Detailed information about all changes made in 3.8.2 can be found in its change log <https://docs.python.org/release/3.8.2/whatsnew/changelog.html#python-3-8-2-final>. Note that compared to 3.8.1, version 3.8.2 also contains the changes introduced in 3.8.2rc1 and 3.8.2rc2.

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 3.8.2 here:
https://www.python.org/downloads/release/python-382/ <https://www.python.org/downloads/release/python-382/>
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.

Maintenance releases for the 3.8 series will continue at regular bi-monthly intervals, with 3.8.3 planned for April 2020 (at the PyCon US sprints <https://us.pycon.org/2020/events/sprints/>).

Python 3.9.0a4

An early developer preview of Python 3.9 is also ready:
https://www.python.org/downloads/release/python-390a4/ <https://www.python.org/downloads/release/python-390a4/>
Python 3.9 is still in development. This releasee, 3.9.0a4 is the fourth 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.

We hope you enjoy both!

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

From arj.python at gmail.com  Wed Feb 26 02:08:16 2020
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Wed, 26 Feb 2020 11:08:16 +0400
Subject: Difficulty in generating .exe from .py file
In-Reply-To: <CA+gHiQ4ucTy6ZwSPTZzj9Q4ah=W6cMq5U51e5apEwrPr-AXrgA@mail.gmail.com>
References: <CA+gHiQ4ucTy6ZwSPTZzj9Q4ah=W6cMq5U51e5apEwrPr-AXrgA@mail.gmail.com>
Message-ID: <CADrxXXm7Pd77dEFUt9=kQof4k4GdJt5_qGzFrSa_xtra0uU+zA@mail.gmail.com>

Can you share your codes? Thank you!

On Wed, 26 Feb 2020, 00:45 Aakash Jana, <aakashjana2002 at gmail.com> wrote:

> I have made a simple web scraper that scrapes Wikipedia and prints some
> info on to the command line using requests and BeautifulSoup. Whenever I
> execute pyinstaller it gives an error "expected integer got type bytes"
> although the code runs perfectly. I am using python 3.8
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From rhodri at kynesim.co.uk  Wed Feb 26 08:59:30 2020
From: rhodri at kynesim.co.uk (Rhodri James)
Date: Wed, 26 Feb 2020 13:59:30 +0000
Subject: encapsulating a global variable
In-Reply-To: <l9ydnV1ZCepqqsjDnZ2dnUU78WHNnZ2d@brightview.co.uk>
References: <S5qdneRN77TRiMjDnZ2dnUU78bnNnZ2d@brightview.co.uk>
 <CAPTjJmohADje-zFmrTPDyCpvecqUWfTVC0YcAM4DNPx+O9Hs0g@mail.gmail.com>
 <mailman.49.1582635400.9235.python-list@python.org>
 <Zpqdnbe64u4VgcjDnZ2dnUU78cPNnZ2d@brightview.co.uk>
 <CAPTjJmrvJbW+vyhj4YTyCqWYJSTNbMx5kc8Cf70HGjp=RoOA4A@mail.gmail.com>
 <mailman.51.1582640052.9235.python-list@python.org>
 <l9ydnV1ZCepqqsjDnZ2dnUU78WHNnZ2d@brightview.co.uk>
Message-ID: <0964100a-63ca-71bf-da2c-d29d688f71b8@kynesim.co.uk>

On 25/02/2020 15:06, BlindAnagram wrote:
> My interest in this stems from wanting to keep the dictionary only
> available to the function that uses it and also a worry about being
> called from threaded code.

Hiding your dictionary away inside a class or instance isn't going to 
protect it from threading disasters by itself, though it will make it 
easier to protect it as you need.

-- 
Rhodri James *-* Kynesim Ltd

From prakashsamal0105 at gmail.com  Wed Feb 26 00:32:58 2020
From: prakashsamal0105 at gmail.com (Prakash Samal)
Date: Tue, 25 Feb 2020 21:32:58 -0800 (PST)
Subject: Need Help Urgently
Message-ID: <b78e3534-a985-4829-9320-1a0bff051686@googlegroups.com>

[ABCD client error]: Connection to broker at ?126.0.0.1:0000 lost!
"timestamp":"Wed Feb 19 11:48:41

[XYZ]: Connection to broker at ?126.0.0.1:0000 lost!
"timestamp":"Wed Feb 19 11:48:40

Note: I want to read the error code i.e ABCD Client error from the line and also wrt timestamp value.
Let me know how to do?


From mal at europython.eu  Wed Feb 26 11:50:03 2020
From: mal at europython.eu (M.-A. Lemburg)
Date: Wed, 26 Feb 2020 17:50:03 +0100
Subject: EuroPython 2020: Call for Proposals opens on March 9th
Message-ID: <b4a8fc35-b1ea-79f1-6815-67f84e11d3d0@europython.eu>

We are happy to announce that the Call for Proposals will open on
March 9. It will be left open for three weeks and then close on:

    Sunday, March 29 23:59:59 CEST

While you wait for submissions to open, please check out the Call for
Proposals details on our pre-launch website:

    https://ep2020.europython.eu/call-for-proposals/

We?re looking for proposals on every aspect of Python: all levels of
programming from novice to advanced, applications, frameworks, data
science, Python projects, internals or topics which you?re excited
about, your experiences with Python and its ecosystem, creative or
artistic things you?ve done with Python, to name a few.

EuroPython is a community conference and we are eager to hear about
your use of Python.

Since feedback shows that our audience is very interested in advanced
topics, we?d appreciate more entries in this category for EuroPython
2020.

Please help spread word about Call for Proposals to anyone who might
be interested. Thanks.


Some additional updates:
------------------------

- We?re working on launching the website, CfP and ticket sales in
  March.

- We are also preparing the sponsorship packages and should have them
  ready early in March as well. Early bird sponsors will again receive
  a 10% discount on the package price. If you?re interested in
  becoming a launch sponsor, please contact our sponsor team at
  sponsoring at europython.eu.


Help spread the word
--------------------

Please help us spread this message by sharing it on your social
networks as widely as possible. Thank you !

Link to the blog post:

https://blog.europython.eu/post/611042486524280832/europython-2020-call-for-proposals-opens-on-march

Tweet:

https://twitter.com/europython/status/1232708258525302784


Enjoy,
--
EuroPython 2020 Team
https://ep2020.europython.eu/
https://www.europython-society.org/


From bgailer at gmail.com  Wed Feb 26 12:21:29 2020
From: bgailer at gmail.com (Bob Gailer)
Date: Wed, 26 Feb 2020 12:21:29 -0500
Subject: Need Help Urgently
In-Reply-To: <b78e3534-a985-4829-9320-1a0bff051686@googlegroups.com>
References: <b78e3534-a985-4829-9320-1a0bff051686@googlegroups.com>
Message-ID: <CAP1rxO6z_BHyzDnAwFBXRBLHzQqwDYczFyLCx2jH+apmAMB0Aw@mail.gmail.com>

On Feb 26, 2020 10:56 AM, "Prakash Samal" <prakashsamal0105 at gmail.com>
wrote:
>
> [ABCD client error]: Connection to broker at  126.0.0.1:0000 lost!
> "timestamp":"Wed Feb 19 11:48:41
>
> [XYZ]: Connection to broker at  126.0.0.1:0000 lost!
> "timestamp":"Wed Feb 19 11:48:40
>
> Note: I want to read the error code i.e ABCD Client error from the line
and also wrt timestamp value.

First a couple of pointers to help you get the results you want in future
communications.

Use a meaningful subject rather than help. Why? Because we keep track of a
communication thread by the subject. It also helps us decide whether or not
we can even tackle that particular problem.

Send such requests to tutor at python.org.

Understand that urgency on your part does not translate to urgency on our
part. We are volunteers who donate some of our time to giving help.

You can accomplish your objective by using various string processing
functions or by using regular expressions. I will assume that you want to
extract everything between square brackets as the error and everything
following the 2nd quote as the timestamp. Let's use the string find method.
With that you can get the index of a particular character and use string
slicing with those indexes to get the actual strings. If you have a basic
understanding of python that should be enough to get you started. Otherwise
I suggest you start with a tutorial that will get you those basics.

if you just want someone to write the program for you then one of us will
be glad to act as a paid consultant and do that for you.

Bob Gailer

From grant.b.edwards at gmail.com  Wed Feb 26 17:34:59 2020
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 26 Feb 2020 22:34:59 -0000 (UTC)
Subject: encapsulating a global variable (BlindAnagram)
References: <DM6PR02MB550024D0D5544DDBA23636B4A8ED0@DM6PR02MB5500.namprd02.prod.outlook.com>
 <mailman.55.1582650982.9235.python-list@python.org>
 <ZsSdndMSF7eD_sjDnZ2dnUU78Y3NnZ2d@brightview.co.uk>
 <ehcb5fljh9lpjh9fritc8rh4g88rf0tlcp@4ax.com>
Message-ID: <r36rqj$3eip$1@ciao.gmane.io>

On 2020-02-25, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

> We seem to have some confusion with the use of the word "static"...

No doubt carrying on the tradition from C, where the 'static' keyword
is used to mean two completely different, orthogonal things.

-- 
Grant Edwards               grant.b.edwards        Yow! My face is new, my
                                  at               license is expired, and I'm
                              gmail.com            under a doctor's care!!!!


From rosuav at gmail.com  Wed Feb 26 17:58:17 2020
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 27 Feb 2020 09:58:17 +1100
Subject: encapsulating a global variable (BlindAnagram)
In-Reply-To: <r36rqj$3eip$1@ciao.gmane.io>
References: <DM6PR02MB550024D0D5544DDBA23636B4A8ED0@DM6PR02MB5500.namprd02.prod.outlook.com>
 <mailman.55.1582650982.9235.python-list@python.org>
 <ZsSdndMSF7eD_sjDnZ2dnUU78Y3NnZ2d@brightview.co.uk>
 <ehcb5fljh9lpjh9fritc8rh4g88rf0tlcp@4ax.com> <r36rqj$3eip$1@ciao.gmane.io>
Message-ID: <CAPTjJmo2RVd=kbCL7-XJCKFs_e3sBWrX-fcDvYsf7rKwC5qhaA@mail.gmail.com>

On Thu, Feb 27, 2020 at 9:45 AM Grant Edwards <grant.b.edwards at gmail.com> wrote:
>
> On 2020-02-25, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>
> > We seem to have some confusion with the use of the word "static"...
>
> No doubt carrying on the tradition from C, where the 'static' keyword
> is used to mean two completely different, orthogonal things.
>

... neither of which has anything to do with what a physicist would
define "static" as.

ChrisA

From grant.b.edwards at gmail.com  Wed Feb 26 18:36:36 2020
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 26 Feb 2020 23:36:36 -0000 (UTC)
Subject: encapsulating a global variable (BlindAnagram)
References: <DM6PR02MB550024D0D5544DDBA23636B4A8ED0@DM6PR02MB5500.namprd02.prod.outlook.com>
 <mailman.55.1582650982.9235.python-list@python.org>
 <ZsSdndMSF7eD_sjDnZ2dnUU78Y3NnZ2d@brightview.co.uk>
 <ehcb5fljh9lpjh9fritc8rh4g88rf0tlcp@4ax.com> <r36rqj$3eip$1@ciao.gmane.io>
 <CAPTjJmo2RVd=kbCL7-XJCKFs_e3sBWrX-fcDvYsf7rKwC5qhaA@mail.gmail.com>
Message-ID: <r36ve3$2am2$1@ciao.gmane.io>

On 2020-02-26, Chris Angelico <rosuav at gmail.com> wrote:
> On Thu, Feb 27, 2020 at 9:45 AM Grant Edwards <grant.b.edwards at gmail.com> wrote:
>>
>> On 2020-02-25, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:
>>
>> > We seem to have some confusion with the use of the word "static"...
>>
>> No doubt carrying on the tradition from C, where the 'static' keyword
>> is used to mean two completely different, orthogonal things.
>>
>
> ... neither of which has anything to do with what a physicist would
> define "static" as.

I'm not sure what the physics usage of 'static' is, but when used for
local variables in C, it sort of makes sense: it means that the
location of the variable within the address space won't ever change
during the program's lifetime.  However, that's only half of what it
does in that context: it also means that the location won't be reused
for other things, and the location's contents will not change unless
it is "intentionally" written to by the program.

OTOH, the C usage of 'static' for file-scope variables is completely
off the wall.  I suspect somebody just put all of the existing
keywords that weren't yet valid in that context into a hat...

-- 
Grant Edwards               grant.b.edwards        Yow! Remember, in 2039,
                                  at               MOUSSE & PASTA will
                              gmail.com            be available ONLY by
                                                   prescription!!


From mocramis at gmail.com  Thu Feb 27 05:48:05 2020
From: mocramis at gmail.com (Remy NOEL)
Date: Thu, 27 Feb 2020 11:48:05 +0100
Subject: Managing concurrent.futures exit-handlers
Message-ID: <CAPcjNjkJXLuH9OgAqA-+hmDnpR8Gh5GSoBSDaMqvkmviD7Ojcg@mail.gmail.com>

Hello !

I am currently using concurrent.futures ThreadPoolExecutor, but i am
annoyed by its exit_handler preventing program exit if any of the jobs it
is running is blocked.

Currently i can workaround it by either unregister the exit handler
concurrent.futures.thread._python_exit or by subclassing the
threadpoolExecutor and overriding the _adjust_thread_count method with one
that does not register its threads queues.

Both seems kinda ugly though.

I was wondering if there was a better way.
Also, would adding an option to executors so that their worker threads is
not be globally joined  was conceivable.

Thanks !

Remy Noel

From valon.januzaj98 at gmail.com  Thu Feb 27 15:29:04 2020
From: valon.januzaj98 at gmail.com (valon.januzaj98 at gmail.com)
Date: Thu, 27 Feb 2020 12:29:04 -0800 (PST)
Subject: Logging all the requests into a specific file
Message-ID: <ef84d428-8c92-47aa-8d67-811106b03c27@googlegroups.com>

Hello guys,

I am new to python and all of this, I am  using this FastAPI, to build API, 
I want when users hit any endpoint for ex /products, that to be written into a file , how do I do it?

From PythonList at DancesWithMice.info  Thu Feb 27 16:24:16 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Fri, 28 Feb 2020 10:24:16 +1300
Subject: Logging all the requests into a specific file
In-Reply-To: <ef84d428-8c92-47aa-8d67-811106b03c27@googlegroups.com>
References: <ef84d428-8c92-47aa-8d67-811106b03c27@googlegroups.com>
Message-ID: <f087b3eb-ca6b-c6e8-892d-fff87aad9ae6@DancesWithMice.info>

On 28/02/20 9:29 AM, valon.januzaj98 at gmail.com wrote:
> I am new to python and all of this, I am  using this FastAPI, to build API,
> I want when users hit any endpoint for ex /products, that to be written into a file , how do I do it?

The Python Standard Library offers a Logging library.
It has "handlers" to decide where each message to go, "filters" to 
determine 'levels' of messages, and "formatters" to organise the output.

-- 
Regards =dn

From rmlibre at riseup.net  Thu Feb 27 18:37:31 2020
From: rmlibre at riseup.net (rmlibre at riseup.net)
Date: Thu, 27 Feb 2020 15:37:31 -0800
Subject: Asyncio question (rmlibre)
In-Reply-To: <mailman.29.1582304403.27734.python-list@python.org>
References: <mailman.29.1582304403.27734.python-list@python.org>
Message-ID: <ad3ef727964ac634fd3db0954433356a@riseup.net>

What resources are you trying to conserve? 


If you want to try conserving time, you shouldn't have to worry about
starting too many background tasks. That's because asyncio code was
designed to be extremely time efficient at handling large numbers of
concurrent async tasks. 

For your application, it seems starting background tasks that
appropriately await execution based on their designated queue is a good
idea. This is more time efficient since it takes full advantage of async
concurrency, while also allowing you to control the order of execution.

Although, there may be other efficiency boosts to be had, for instance,
if all but the precise changes that need to be atomic are run
concurrently. 


However, if you want to conserve cpu cycles per unit time, then
staggering the processing of requests sequentially is the best option,
although, there's little need for async code if this is the case. 


Or, if you'd like to conserve memory, making the code more
generator-based is a good option. Lazy computation is quite efficient on
memory and time. Although, rewriting your codebase to run on generators
can be a lot of work, and their efficiency won't really be felt unless
your code is handling "big data" or very large requests.


In any case, you'd probably want to run some benchmark and profiling
tools against a mock-up runtime of your code and optimize/experiment
only after you've noticed there's an efficiency problem and have deduced
its causes. Barring that, it's just guess-work & may just be a waste of
time.




On 2020-02-21 17:00, python-list-request at python.org wrote:
> Hi all

> I use asyncio in my project, and it works very well without my having to understand what goes on under the hood. It is a multi-user client/server system, and I want it to scale to many concurrent users. I have a situation where I have to decide between two approaches, and I want to choose the least resource-intensive, but I find it hard to reason about which, if either, is better.
>
> I use HTTP. On the initial connection from a client, I set up a session object, and the session id is passed to the client. All subsequent requests from that client include the session id, and the request is passed to the session object for handling.
>
> It is possible for a new request to be received from a client before the previous one has been completed, and I want each request to be handled atomically, so each session maintains its own asyncio.Queue(). The main routine gets the session id from the request and 'puts' the request in the appropriate queue. The session object 'gets' from the queue and handles the request. It works well.
>
> The question is, how to arrange for each session to 'await' its queue. My first attempt was to create a background task for each session which runs for the life-time of the session, and 'awaits' its queue. It works, but I was concerned about having a lot a background tasks active at the same time.
>
> Then I came up with what I thought was a better idea. On the initial connection, I create the session object, send the response to the client, and then 'await' the method that sets up the session's queue. This also works, and there is no background task involved. However, I then realised that the initial response handler never completes, and will 'await' until the session is closed.
>
> Is this better, worse, or does it make no difference? If it makes no difference, I will lean towards the first approach, as it is easier to reason about what is going on.
>
> Thanks for any advice.
>
> Frank Millman

From python at python.invalid  Thu Feb 27 17:39:11 2020
From: python at python.invalid (Python)
Date: Thu, 27 Feb 2020 23:39:11 +0100
Subject: Mental model of lookahead assertions
In-Reply-To: <lookahead-20200227224717@ram.dialup.fu-berlin.de>
References: <lookahead-20200227224717@ram.dialup.fu-berlin.de>
Message-ID: <5e584471$0$4044$426a74cc@news.free.fr>

Stefan Ram wrote:
>    One can count overlapping occurences as follows.
> 
> |>>> print(len(findall('(?=aa)','caaaab')))
> |3
> 
>    Every web page says that lookahead assertions do
>    not consume nor move the "current position".
> 
>    But what mental model can I make of the regex
>    engine that explains why it is not caught in an
>    endless loop matching "aa" at the same position
>    again and again and never advancing to the other
>    occurences?
> 
>    (Something with nondeterminism?)

Old but EXCELLENT insight into how regular expressions works:

https://perl.plover.com/yak/regex/

(pdf and html slides)

From adam.preble at gmail.com  Fri Feb 28 02:21:12 2020
From: adam.preble at gmail.com (Adam Preble)
Date: Thu, 27 Feb 2020 23:21:12 -0800 (PST)
Subject: Data model and attribute resolution in subclasses
Message-ID: <584c712a-2476-44a6-b3e0-9b58c5695eea@googlegroups.com>

I have been making some progress on my custom interpreter project but I found I have totally blown implementing proper subclassing in the data model. What I have right now is PyClass defining what a PyObject is. When I make a PyObject from a PyClass, the PyObject sets up a __dict__ that is used for attribute lookup. When I realized I needed to worry about looking up parent namespace stuff, this fell apart because my PyClass had no real notion of a namespace.

I'm looking at the Python data model for inspiration. While I don't have to implement the full specifications, it helps me where I don't have an alternative. However, the data model is definitely a programmer document; it's one of those things where the prose is being very precise in what it's saying and that can foil a casual reading.

Here's what I think is supposed to exist:
1. PyObject is the base.
2. It has an "internal dictionary." This isn't exposed as __dict__
3. PyClass subclasses PyObject.
4. PyClass has a __dict__

Is there a term for PyObject's internal dictionary. It wasn't called __dict__ and I think that's for good reasons. I guess the idea is a PyObject doesn't have a namespace, but a PyClass does (?).

Now to look something up. I assume that __getattribute__ is supposed to do something like:
1. The PyClass __dict__ for the given PyObject is consulted.
2. The implementation for __getattribute__ for the PyObject will default to looking into the "internal dictionary."
3. Assuming the attribute is not found, the subclasses are then consulted using the subclass' __getattribute__ calls. We might recurse on this. There's probably some trivia here regarding multiple inheritance; I'm not entirely concerned (yet).
4. Assuming it's never found, then the user sees an AttributeError

Would each of these failed lookups result in an AttributeError? I don't know how much it matters to me right now that I implement exactly to that, but I was curious if that's really how that goes under the hood.

From jon+usenet at unequivocal.eu  Fri Feb 28 06:02:32 2020
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Fri, 28 Feb 2020 11:02:32 -0000 (UTC)
Subject: Mental model of lookahead assertions
References: <lookahead-20200227224717@ram.dialup.fu-berlin.de>
Message-ID: <slrnr5hsq8.43a.jon+usenet@sable.unequivocal.eu>

On 2020-02-27, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>   One can count overlapping occurences as follows.
>
>|>>> print(len(findall('(?=aa)','caaaab')))
>|3
>
>   Every web page says that lookahead assertions do
>   not consume nor move the "current position".
>
>   But what mental model can I make of the regex
>   engine that explains why it is not caught in an
>   endless loop matching "aa" at the same position
>   again and again and never advancing to the other
>   occurences?

Simply that when it's returning multiple matches it knows once it's
found a match at position <x> to start looking for the next potential
match at position <x + 1> ?

From quintin9g at gmail.com  Fri Feb 28 07:13:48 2020
From: quintin9g at gmail.com (Edward Montague)
Date: Sat, 29 Feb 2020 01:13:48 +1300
Subject: wxFormBuilder
Message-ID: <CAG0UXCkmbzgEUdykasJsk8gO8rbfvLD39Z=+BqOWzt_PYG_H6A@mail.gmail.com>

 The videos on YouTube by fandangleproductions, have been
of some use.

 However as I also use the Geany editor, I find that I need to
append this extra code to the Python script generated from
wxFormBuilder.

 # --------------------- extra code -------------------

class MyApp(wx.App):
    def OnInit(self):
        self.frame = frameMain(None)
        self.SetTopWindow(self.frame)
        self.frame.Show()
        return True

# end of class MyApp

if __name__ == "__main__":
    app = MyApp(0)
    app.MainLoop()


 Where frameMain is the name of this particular frame.

 This may help you with your Python coding.

From PythonList at DancesWithMice.info  Fri Feb 28 19:34:25 2020
From: PythonList at DancesWithMice.info (DL Neil)
Date: Sat, 29 Feb 2020 13:34:25 +1300
Subject: Friday Finking: Poly more thick
Message-ID: <39e3ffcb-628a-1761-67d7-2b020b80ca60@etelligence.info>

How does one code a function/method signature so that it will accept 
either a set of key-value pairs, or the same data enclosed as a dict, as 
part of a general-case and polymorphic solution?

Wikipedia: polymorphism is the provision of a single interface to 
entities of different types.
( https://en.wikipedia.org/wiki/Polymorphism_(computer_science) )


<tldr;>
At the end of a code-sprint, one of 'my' teams was presenting. 
Everything went well. Fatefully, the client-manager then remembered that 
the latest work would extend a previous sprint's work. Despite it not 
being a deliverable (?), he asked to be shown the two working together. 
The team, flushed with pride at their 'success' (foolishly) agreed, and 
the attempt immediately crashed. (as such live-demos are wont to do!) 
Wisely, a 'coffee/tea break' was suggested, to give the team time to 
'fix' things.

Hence a panic-call to me, working from home. It turned-out that a 
new-ish and less-experienced coder had been given this job, and she had 
been shown the interface as key-value pairs (her interpretation) - and 
even on the white-board there were no braces to show it as a dict! 
Whereas the more experienced programmer who originally assembled the 
class/signature/interface, had used a dict. Unhappiness was evident, 
argument threatened...

I quickly mocked-up the situation. (code below). The fastest solution, 
which didn't require altering any calling-code, seemed to be to change 
the class's signature to use *args and **kwargs, which thereafter 
required only a single 'normalisation' step to turn any/the kwargs into 
a dict - which in-turn enabled the existing code, unchanged.

Quick and dirty to be sure! However, it allowed the demo to go ahead and 
recovered everyone's feelings of satisfaction/success!

Aside from 'repairing' team spirit, (as regular readers will recognise) 
I wasn't going to let this pass without some thought and discussion (and 
perhaps I might learn something about Python interfacing)!
</tldr;>


Python's powerful polymorphic capabilities [insert expression of thanks 
here!] allow us to substitute collections - with care. So, a simple 
function, such as:)

def f( colln ):
	for element in colln:
		print( element )

will work quite happily when (separately) fed either a tuple or a list.

It will also work with a string (a collection of characters) - as long 
as we are happy with single characters being output.

What about dicts as collections? It will work with dicts, as long as we 
consider the dict's keys to be 'the dict' (cf its collection of values).

Well that's very flexible!

However, whilst a set of key-value arguments 'quack' somewhat like a 
dict, or even a tuple (of k-v pairs), they will not be accepted as 
parameters. Crash!

Yes it can be solved, with a 'normalisation' function, as described 
above, perhaps as a working-theory:

def f( *colln_as_tuple, **key_value_pairs_as_dict ):
	my_dict = key_value_pairs_as_dict if key_value_pairs_as_dict \
						else colln_as_tuple[ 0 ]
	# no change to existing code using my_dict
	...


However, this seems like a situation that "quacks like a duck", yet the 
built-in polymorphism doesn't auto-magically extend to cover it.

So:
- is that the way 'polymorphism' really works/should work?
- is expecting the dict to work as a "collection", already 'taking 
things too far'?
- is expecting the key-values to work, really 'taking things too far'?

Remember that I am not an OOP-native! The discussion around-the-office 
diverged into two topics: (1) theoretical: the limits and capability of 
polymorphism, and (2) practical: the understanding and limits of a 
Python "collection".


How do you see it? How would you solve the Python coding problem - 
without re-writing both sprints-worth of code? Did we leave polymorphism 
'behind' and expect Python to perform magic?


### investigative and prototyping code ###

def print_dict( dictionary ):
     # helper function only
     for key, value in dictionary.items():
            print( "\t", key, value )


def f( **kwargs ):
     print( kwargs, type( kwargs ) )
     print_dict( kwargs )


f( a=1, b=2 )				# arguments as key-value pairs
### {'a': 1, 'b': 2} <class 'dict'>
### 	 a 1
### 	 b 2

d={ 'a':1, 'b':2 }			# arguments as a dictionary
try:
	f( d )
except TypeError:
	print( "N/A" )
### N/A

### Traceback (most recent call last):
###   File "<stdin>", line 1, in <module>
### TypeError: f() takes 0 positional arguments but 1 was given


f( **d )			# yes, easy to edit arguments, but...
### {'a': 1, 'b': 2} <class 'dict'>
### 	 a 1
### 	 b 2

try:
	f( { 'a':1, 'b':2 } )	# or modify API to accept single dict
except TypeError:
	print( "N/A" )
### N/A


print( "\nwith g()\n" )
### with g()

def g( *args, **kwargs ):
     print( args, type( args ), kwargs, type( kwargs ) )
     for arg in args:			# handle single-objects, eg dict
     	print( arg, type( arg ) )
     	print_dict( arg )
     for k, v in kwargs.items():		# handle key-value pairs
         print( "\t\t", k, v )


g( a=1, b=2 )				# arguments as key-value pairs
### () <class 'tuple'> {'a': 1, 'b': 2} <class 'dict'>
### 		 a 1
### 		 b 2

g( d )					# argument as a dictionary
### {'a': 1, 'b': 2},) <class 'tuple'> {} <class 'dict'>
### {'a': 1, 'b': 2} <class 'dict'>
### 	 a 1
### 	 b 2


-- 
Regards,
=dn

From kenzi.sml at gmail.com  Fri Feb 28 19:24:18 2020
From: kenzi.sml at gmail.com (Kenzi)
Date: Fri, 28 Feb 2020 19:24:18 -0500
Subject: =?UTF-8?B?44CQUmVnYXJkaW5nIFBlcmZvcm1hbmNlIG9mIGEgUHl0aG9uIFNjcmlwdC4uLi7jgJE=?=
Message-ID: <CAKN2n45ArcvDowa8g069=cV5hfL8Dm+Q+Ovf6-M8wbbyhFWTaw@mail.gmail.com>

Hello there,

 I have a question regarding a simple code snippet in Python:

from subprocess import check_output
for i in range(1024):
    check_output(['/bin/bash', '-c', 'echo 42'], close_fds=True)

*I wonder why running it in Python 3.7 is much faster than Python 2.7? *
(Python 3.7 is still faster, after I used *xrange * in Python 2.7)

Thanks all!

From tjreedy at udel.edu  Fri Feb 28 13:04:23 2020
From: tjreedy at udel.edu (Terry Reedy)
Date: Fri, 28 Feb 2020 13:04:23 -0500
Subject: Data model and attribute resolution in subclasses
In-Reply-To: <584c712a-2476-44a6-b3e0-9b58c5695eea@googlegroups.com>
References: <584c712a-2476-44a6-b3e0-9b58c5695eea@googlegroups.com>
Message-ID: <r3bkn7$3n64$1@ciao.gmane.io>

On 2/28/2020 2:21 AM, Adam Preble wrote:
> I have been making some progress on my custom interpreter project but I found I have totally blown implementing proper subclassing in the data model. What I have right now is PyClass defining what a PyObject is. When I make a PyObject from a PyClass, the PyObject sets up a __dict__ that is used for attribute lookup. When I realized I needed to worry about looking up parent namespace stuff, this fell apart because my PyClass had no real notion of a namespace.
> 
> I'm looking at the Python data model for inspiration. While I don't have to implement the full specifications, it helps me where I don't have an alternative. However, the data model is definitely a programmer document; it's one of those things where the prose is being very precise in what it's saying and that can foil a casual reading.
> 
> Here's what I think is supposed to exist:
> 1. PyObject is the base.
> 2. It has an "internal dictionary." This isn't exposed as __dict__

The internal mapping *is* visible.

 >>> object.__dict__
mappingproxy({'__repr__': <slot wrapper '__repr__' of 'object' objects>, 
'__hash__': <slot wrapper '__hash__' of 'object' objects>, '__str__': 
<slot wrapper '__str__' of 'object' objects>, '__getattribute__': <slot 
wrapper '__getattribute__' of 'object' objects>, '__setattr__': <slot 
wrapper '__setattr__' of 'object' objects>, '__delattr__': <slot wrapper 
'__delattr__' of 'object' objects>, '__lt__': <slot wrapper '__lt__' of 
'object' objects>, '__le__': <slot wrapper '__le__' of 'object' 
objects>, '__eq__': <slot wrapper '__eq__' of 'object' objects>, 
'__ne__': <slot wrapper '__ne__' of 'object' objects>, '__gt__': <slot 
wrapper '__gt__' of 'object' objects>, '__ge__': <slot wrapper '__ge__' 
of 'object' objects>, '__init__': <slot wrapper '__init__' of 'object' 
objects>, '__new__': <built-in method __new__ of type object at 
0x00007FFBEFE989A0>, '__reduce_ex__': <method '__reduce_ex__' of 
'object' objects>, '__reduce__': <method '__reduce__' of 'object' 
objects>, '__subclasshook__': <method '__subclasshook__' of 'object' 
objects>, '__init_subclass__': <method '__init_subclass__' of 'object' 
objects>, '__format__': <method '__format__' of 'object' objects>, 
'__sizeof__': <method '__sizeof__' of 'object' objects>, '__dir__': 
<method '__dir__' of 'object' objects>, '__class__': <attribute 
'__class__' of 'object' objects>, '__doc__': 'The base class of the 
class hierarchy.\n\nWhen called, it accepts no arguments and returns a 
new featureless\ninstance that has no instance attributes and cannot be 
given any.\n'})

The internal mapping is not an instance of dict, and need/should not be 
as it is frozen.

 >>> o = object()
 >>> o.a = 3
Traceback (most recent call last):
   File "<pyshell#2>", line 1, in <module>
     o.a = 3
AttributeError: 'object' object has no attribute 'a'

When classes and objects do have a dict __dict__, __dict__ is not in 
__dict__, to avoid recursion.  gettattribute or __getattribute__ must 
special case '__dict__'.  I am guessing this as what must be from the 
evidence, without seeing the actual code.

> 3. PyClass subclasses PyObject.
> 4. PyClass has a __dict__
> 
> Is there a term for PyObject's internal dictionary. It wasn't called __dict__ and I think that's for good reasons. I guess the idea is a PyObject doesn't have a namespace, but a PyClass does (?).
> 
> Now to look something up. I assume that __getattribute__ is supposed to do something like:
> 1. The PyClass __dict__ for the given PyObject is consulted.
> 2. The implementation for __getattribute__ for the PyObject will default to looking into the "internal dictionary."
> 3. Assuming the attribute is not found, the subclasses are then consulted using the subclass' __getattribute__ calls. We might recurse on this. There's probably some trivia here regarding multiple inheritance; I'm not entirely concerned (yet).

For non-reserved names Attribute lookup starts with the object dict, 
then object class, then superclasses.  Dunder names usually start with 
the object class.

> 4. Assuming it's never found, then the user sees an AttributeError
> 
> Would each of these failed lookups result in an AttributeError?

I presume so.  They are caught and only re-raised only if there is no 
where else to look.

-- 
Terry Jan Reedy


From lee.chiffre at secmail.pro  Fri Feb 28 21:49:58 2020
From: lee.chiffre at secmail.pro (Mr. Lee Chiffre)
Date: Fri, 28 Feb 2020 18:49:58 -0800
Subject: Help building python application from source
Message-ID: <f8d3fbb356aee40b97b2003f0377c8ff.squirrel@giyzk7o6dcunb2ry.onion>

sorry re posting because I forgot subject line in last email.





I am a python noob. This is why I ask the python masters. There is a
python software I want to install on the server it is called Electrumx.
https://github.com/kyuupichan/electrumx is the link. I am having troubles
with installing this.
The short version is I am wanting to build this python application and
needed dependencies from source code all from a local directory without
relying on the python pip package servers. I only run software I can
compile from source code because this is the only way to trust open source
software. I also want to archive the software I use and be able to install
it on systems in a grid down situation without relying on other servers
such as python package servers.

 Here is a snippet from
https://github.com/lee-chiffre/Announcements/blob/master/02.26.2020 that
describes what I am trying to do

>
1. I need a way I can download the source of ElectrumX and the dependency
tree.
2. In a way that also verifies the integrity of those downloads. I dont
think many of these
python packages are even signed.
3. Then to be able to build ElectrumX and the needed dependencies from
source on a computer
that does not have connection to internet. Node2.0 does not connect to
internet except for
the Tor process. Torsocks is not an option here.
I will be running ElectrumX and the python dependencies in a venv virtual
environment.
If I cannot build ElectrumX and the dependencies for it from source in a
way that also verifies
the integrity of the downloads then for security reasons I will not run
it. If someone has a
solution to this I will then run ElectrumX, and give you credit for the help.
If you need me to pay bounty for this please reach out to me to negotiate
on a price.
<


Python might be easy to code but simplicity of coding comes at the cost of
complexity of the software. With C++ I usually only have only a few
dependencies. With python it seems like it is almost 20 dependencies. With
Electrumx I counted at least 15 dependencies in the dependency tree. Is it
possible to download then build this from source with all needed
dependencies?



-- 
lee.chiffre at secmail.pro
PGP 97F0C3AE985A191DA0556BCAA82529E2025BDE35



From frank at chagford.com  Sat Feb 29 01:36:10 2020
From: frank at chagford.com (Frank Millman)
Date: Sat, 29 Feb 2020 08:36:10 +0200
Subject: Asyncio question (rmlibre)
In-Reply-To: <ad3ef727964ac634fd3db0954433356a@riseup.net>
References: <mailman.29.1582304403.27734.python-list@python.org>
 <ad3ef727964ac634fd3db0954433356a@riseup.net>
Message-ID: <8d29039f-9f02-ce6c-083f-91842e858cee@chagford.com>


On 2020-02-28 1:37 AM, rmlibre at riseup.net wrote:
 > What resources are you trying to conserve?
 >
 > If you want to try conserving time, you shouldn't have to worry about
 > starting too many background tasks. That's because asyncio code was
 > designed to be extremely time efficient at handling large numbers of
 > concurrent async tasks.
 >

Thanks for the reply.

That is exactly what I want, and in an earlier response Greg echoes what 
what you say here - background tasks are lightweight and are ideal for 
my situation.

Frank


From frank at chagford.com  Sat Feb 29 01:36:10 2020
From: frank at chagford.com (Frank Millman)
Date: Sat, 29 Feb 2020 08:36:10 +0200
Subject: Asyncio question (rmlibre)
In-Reply-To: <ad3ef727964ac634fd3db0954433356a@riseup.net>
References: <mailman.29.1582304403.27734.python-list@python.org>
 <ad3ef727964ac634fd3db0954433356a@riseup.net>
Message-ID: <8d29039f-9f02-ce6c-083f-91842e858cee@chagford.com>


On 2020-02-28 1:37 AM, rmlibre at riseup.net wrote:
 > What resources are you trying to conserve?
 >
 > If you want to try conserving time, you shouldn't have to worry about
 > starting too many background tasks. That's because asyncio code was
 > designed to be extremely time efficient at handling large numbers of
 > concurrent async tasks.
 >

Thanks for the reply.

That is exactly what I want, and in an earlier response Greg echoes what 
what you say here - background tasks are lightweight and are ideal for 
my situation.

Frank

From frank.rentmeister at gmail.com  Sat Feb 29 05:27:50 2020
From: frank.rentmeister at gmail.com (Frank Rentmeister)
Date: Sat, 29 Feb 2020 02:27:50 -0800 (PST)
Subject: Groovy to Python Converter ?
Message-ID: <519395d5-75a8-4ce5-9a09-2df138e1c928@googlegroups.com>

In my new project, I am supposed to bring the current test cases, all written in Groovy, to a Python base. We are talking about several thousand test cases that have accumulated over the last years.

Since the test cases are also to be extended towards API gateway testing, and since we work with Python requests here, we want and need to convert everything.

But here is the question, which I could not answer even after an intensive search:

Is there a converter that can convert Groovy based test cases to Python?

An example of how the tests are structured. They are pure web tests that ask for links and other questions with just one click.

Actually, it's absolutely simple, but not suitable for us for broad-based tests, even in the direction of expansion.

From hjp-python at hjp.at  Sat Feb 29 09:23:55 2020
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 29 Feb 2020 15:23:55 +0100
Subject: =?utf-8?Q?=E3=80=90Regarding_Performan?=
 =?utf-8?B?Y2Ugb2YgYSBQeXRob24gU2NyaXB0Li4uLuOAkQ==?=
In-Reply-To: <CAKN2n45ArcvDowa8g069=cV5hfL8Dm+Q+Ovf6-M8wbbyhFWTaw@mail.gmail.com>
References: <CAKN2n45ArcvDowa8g069=cV5hfL8Dm+Q+Ovf6-M8wbbyhFWTaw@mail.gmail.com>
Message-ID: <20200229142355.GA28707@hjp.at>

On 2020-02-28 19:24:18 -0500, Kenzi wrote:
>  I have a question regarding a simple code snippet in Python:
> 
> from subprocess import check_output
> for i in range(1024):
>     check_output(['/bin/bash', '-c', 'echo 42'], close_fds=True)
> 
> *I wonder why running it in Python 3.7 is much faster than Python 2.7? *
> (Python 3.7 is still faster, after I used *xrange * in Python 2.7)

I think almost all of the time is spent in the child processes, so it
doesn't matter whether you use range or xrange.

On my laptop, the program takes about 2.1 seconds with python 2.7 and
1.6 seconds with python 3.6. So the difference is 0.5 seconds overall or
about 500 ?s per execution.

strace shows that python 2.7 explicitely closes all unneeded file
descriptors below 1024 (even though most of them aren't actually open)
in the child before execing bash, python 3 doesn't do that.

I can see no other obvious difference. 

So that's ~ 1020 extra system calls. If this is indeed the only
difference, that's about 500 ns per system call. That sounds plausible.

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
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From souvik.viksou at gmail.com  Sat Feb 29 11:23:16 2020
From: souvik.viksou at gmail.com (Souvik Dutta)
Date: Sat, 29 Feb 2020 21:53:16 +0530
Subject: What is the meaning of Building Wheel for <package name>?
Message-ID: <CADRXHdKgART0vqXgpjvNyyC8UBXHY6JHuWWWTGhuZmBwXB1Gcg@mail.gmail.com>

What is the meaning of the subject I mean what does python internally do
when it says this?

From pkpearson at nowhere.invalid  Sat Feb 29 13:54:22 2020
From: pkpearson at nowhere.invalid (Peter Pearson)
Date: 29 Feb 2020 18:54:22 GMT
Subject: Help building python application from source
References: <f8d3fbb356aee40b97b2003f0377c8ff.squirrel@giyzk7o6dcunb2ry.onion>
 <mailman.74.1582947680.9235.python-list@python.org>
Message-ID: <hbvqauFnpl8U1@mid.individual.net>

On Fri, 28 Feb 2020 18:49:58 -0800, Mr. Lee Chiffre wrote:
[snip]
> I am a python noob. This is why I ask the python masters. There is a
> python software I want to install on the server it is called Electrumx.
> https://github.com/kyuupichan/electrumx is the link. I am having troubles
> with installing this.
> The short version is I am wanting to build this python application and
> needed dependencies from source code all from a local directory without
> relying on the python pip package servers. I only run software I can
> compile from source code because this is the only way to trust open source
> software. I also want to archive the software I use and be able to install
> it on systems in a grid down situation without relying on other servers
> such as python package servers.

(To make OP's requirements plainly visible, note that this appears to
be a cryptocurrency application.)

I'd suggest that building everything from source code might not be a
realistic solution to your security concerns.  I don't know what your
threat model is, but if it's something like, "Hackers and gangsters
who scatter password-harvesting trojans across the globe and then shlurp
up what they can," you might find that you get better security by
generating your keys on a computer that never communicates with the
outside world.  

Your concerns are (1) that the random numbers from which your keys have
been corrupted to make them predictable, or (2) that malicious software
will send your keys to the bad guys.  Isolating the key-generation
machine takes care of #2.  If you have Python code for generating keys,
something as simple as XORing a fixed value of your choice with its
random numbers will take care of #1.  I admit that using an isolated
machine introduces a lot of inconveniences, but I bet it compares
favorably with building everything from source.

-- 
To email me, substitute nowhere->runbox, invalid->com.

From lee.chiffre at secmail.pro  Sat Feb 29 18:01:13 2020
From: lee.chiffre at secmail.pro (Mr. Lee Chiffre)
Date: Sat, 29 Feb 2020 15:01:13 -0800
Subject: Help building python application from source
In-Reply-To: <hbvqauFnpl8U1@mid.individual.net>
References: <f8d3fbb356aee40b97b2003f0377c8ff.squirrel@giyzk7o6dcunb2ry.onion>
 <mailman.74.1582947680.9235.python-list@python.org>
 <hbvqauFnpl8U1@mid.individual.net>
Message-ID: <fc2eed017c58722b3db0d431587a39bc.squirrel@giyzk7o6dcunb2ry.onion>

Thanks for the comments.

> (To make OP's requirements plainly visible, note that this appears to
> be a cryptocurrency application.)

Correct. It is a software that does not store private keys but acts as a
server to serve lightweight wallets that would connect to it remotely.


Electrumx does not store or generate private keys but my concern is
running binary blobs that someone else created. The advantages of open
source software only apply if you can confirm it was created from the
source code. This is why I compile everything I can or use binaries based
on reproducible build process. I am also wanting to run electrumx in a
virtual environment under a dedicated user account on the linux box with
lowest privileges. And the reason I want to be able to build from a local
directory so that I can be self sufficient and be able to archive the
software source code and all needed dependencies to spin up other servers
or replace the server in a post disaster situation where internet or
python pip package servers might be down. My bitcoin server also has very
strict firewall rules that would inhibit the ability to connect to python
servers. This is why I want to download the all the source code on my
laptop then transfer to the server. But there are SO MANY dependencies.
Electrumx has a few dependencies then each of those dependencies have more
dependencies and on and on. I guess it might be possible to do what I want
by manually downloading the source code of the close to 20 dependencies,
manually verify the git tags and signatures. Then "python setup.py
install" each one individually in the right order. This might work? I
didn't know if there was an easier way. I did find out I could "pip
download -r requirements.txt" but this downloads binaries specific for
x86. My cpu architecture is aarch64.

Is there a way to pip download -r requirements.txt source only or specify
aarch64?

Thank you


-- 
lee.chiffre at secmail.pro
PGP 97F0C3AE985A191DA0556BCAA82529E2025BDE35


From dvl at psu.edu  Sat Feb 29 21:08:20 2020
From: dvl at psu.edu (Christman, Roger Graydon)
Date: Sun, 1 Mar 2020 02:08:20 +0000
Subject: Friday Finking: Poly more thick
Message-ID: <DM6PR02MB5500B4A374EC6259635A1884A8E60@DM6PR02MB5500.namprd02.prod.outlook.com>

DL Neil asked:

> How does one code a function/method signature so that
> it will accept either a set of key-value pairs,
> or the same data enclosed as a dict, as part of
> a general-case and polymorphic solution?


Will this do for you?

def any_as_dict(*args, **kwargs):
if len(args) == 0:
my_dict = kwargs
elif type(args[0]) == type(dict()):
my_dict = args[0]
else:
my_dict = dict(args)
print(type(my_dict),my_dict)


>>> any_as_dict(a=1,b=2)
<class 'dict'> {'a': 1, 'b': 2}
>>> any_as_dict({'a':1, 'b':2})
<class 'dict'> {'a': 1, 'b': 2}
>>> any_as_dict([('a',1), ('b',2)])
<class 'dict'> {('a', 1): ('b', 2)}
>>> any_as_dict({('a',1), ('b',2)})
<class 'dict'> {('b', 2): ('a', 1)}

This seems to address your apparent definition of
"key-value pairs" in the form of a=1, b=2
and my interpretation as key-value tuples,
either in a list, or set, or presumably any
iterable collection, in addition to taking an
actual dictionary.

Roger Christman
Pennsylvania State University

From dvl at psu.edu  Sat Feb 29 21:17:57 2020
From: dvl at psu.edu (Christman, Roger Graydon)
Date: Sun, 1 Mar 2020 02:17:57 +0000
Subject: Friday Finking: Poly more thick
Message-ID: <DM6PR02MB5500E5FB454E08B2D71C3126A8E60@DM6PR02MB5500.namprd02.prod.outlook.com>

Emending my own note from moments ago:

 def any_as_dict(*args, **kwargs):
if len(args) == 0:
my_dict = kwargs
elif type(args[0]) == type(dict()):
my_dict = args[0]
else:
my_dict = dict(args[0])
print(type(my_dict),my_dict)


>>> any_as_dict(a=1,b=2)
<class 'dict'> {'a': 1, 'b': 2}
>>> any_as_dict({'a':1, 'b':2})
<class 'dict'> {'a': 1, 'b': 2}
>>> any_as_dict([('a',1), ('b',2)])
<class 'dict'> {'a': 1, 'b': 2}
>>> any_as_dict({('a',1), ('b',2)})
<class 'dict'> {'b': 2, 'a': 1}

From python at mrabarnett.plus.com  Sat Feb 29 21:33:26 2020
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 1 Mar 2020 02:33:26 +0000
Subject: Friday Finking: Poly more thick
In-Reply-To: <DM6PR02MB5500B4A374EC6259635A1884A8E60@DM6PR02MB5500.namprd02.prod.outlook.com>
References: <DM6PR02MB5500B4A374EC6259635A1884A8E60@DM6PR02MB5500.namprd02.prod.outlook.com>
Message-ID: <a3827b66-d83e-40c8-9d0b-75f8ba6e1ee7@mrabarnett.plus.com>

On 2020-03-01 02:08, Christman, Roger Graydon wrote:
> DL Neil asked:
> 
>> How does one code a function/method signature so that
>> it will accept either a set of key-value pairs,
>> or the same data enclosed as a dict, as part of
>> a general-case and polymorphic solution?
> 
> 
> Will this do for you?
> 
> def any_as_dict(*args, **kwargs):
> if len(args) == 0:
> my_dict = kwargs
> elif type(args[0]) == type(dict()):
> my_dict = args[0]
> else:
> my_dict = dict(args)
> print(type(my_dict),my_dict)
> 
> 
>>>> any_as_dict(a=1,b=2)
> <class 'dict'> {'a': 1, 'b': 2}
>>>> any_as_dict({'a':1, 'b':2})
> <class 'dict'> {'a': 1, 'b': 2}
>>>> any_as_dict([('a',1), ('b',2)])
> <class 'dict'> {('a', 1): ('b', 2)}
>>>> any_as_dict({('a',1), ('b',2)})
> <class 'dict'> {('b', 2): ('a', 1)}
> 
> This seems to address your apparent definition of
> "key-value pairs" in the form of a=1, b=2
> and my interpretation as key-value tuples,
> either in a list, or set, or presumably any
> iterable collection, in addition to taking an
> actual dictionary.
> 
That function can be simplified:

def any_as_dict(*args, **kwargs):
     return dict(args[0]) if args else kwargs

>>> any_as_dict(a=1,b=2)
{'a': 1, 'b': 2}
>>> any_as_dict({'a':1, 'b':2})
{'a': 1, 'b': 2}
>>> any_as_dict([('a',1), ('b',2)])
{'a': 1, 'b': 2}
>>> any_as_dict({('a',1), ('b',2)})
{'b': 2, 'a': 1}

From tjreedy at udel.edu  Sat Feb 29 14:20:27 2020
From: tjreedy at udel.edu (Terry Reedy)
Date: Sat, 29 Feb 2020 14:20:27 -0500
Subject: What is the meaning of Building Wheel for <package name>?
In-Reply-To: <CADRXHdKgART0vqXgpjvNyyC8UBXHY6JHuWWWTGhuZmBwXB1Gcg@mail.gmail.com>
References: <CADRXHdKgART0vqXgpjvNyyC8UBXHY6JHuWWWTGhuZmBwXB1Gcg@mail.gmail.com>
Message-ID: <r3edhr$2bai$1@ciao.gmane.io>

On 2/29/2020 11:23 AM, Souvik Dutta wrote:
> What is the meaning of the subject I mean what does python internally do
> when it says this?

Python does not normally 'build wheels'.  So you must be running some 
particular program.  Check the docs for that program.


-- 
Terry Jan Reedy