From nospam at dfs.com  Fri Dec  2 10:19:45 2022
From: nospam at dfs.com (DFS)
Date: Fri, 2 Dec 2022 10:19:45 -0500
Subject: Python is maybe the most widely used language, but clp gets 0 posts
 some days?
Message-ID: <lIoiL.9591$hPb9.813@fx42.iad>

Usenet is dead.  Long live Usenet.

From arequipeno at gmail.com  Fri Dec  2 15:00:21 2022
From: arequipeno at gmail.com (Ian Pilcher)
Date: Fri, 2 Dec 2022 14:00:21 -0600
Subject: Calling pselect/ppoll/epoll_pwait
Message-ID: <c4b8fdc3-9dd5-7697-ee12-44a9ddce30bc@gmail.com>

Does Python provide any way to call the "p" variants of the I/O
multiplexing functions?

Looking at the documentation of the select[1] and selectors[2] modules,
it appears that they expose only the "non-p" variants.

[1] https://docs.python.org/3/library/select.html
[2] https://docs.python.org/3/library/selectors.html

-- 
========================================================================
Google                                      Where SkyNet meets Idiocracy
========================================================================

From barry at barrys-emacs.org  Fri Dec  2 19:00:34 2022
From: barry at barrys-emacs.org (Barry)
Date: Sat, 3 Dec 2022 00:00:34 +0000
Subject: Calling pselect/ppoll/epoll_pwait
In-Reply-To: <c4b8fdc3-9dd5-7697-ee12-44a9ddce30bc@gmail.com>
References: <c4b8fdc3-9dd5-7697-ee12-44a9ddce30bc@gmail.com>
Message-ID: <427E6CAE-1E77-42BD-924F-F221CBFCB6AC@barrys-emacs.org>



> On 2 Dec 2022, at 20:03, Ian Pilcher <arequipeno at gmail.com> wrote:
> 
> ?Does Python provide any way to call the "p" variants of the I/O
> multiplexing functions?
> 
> Looking at the documentation of the select[1] and selectors[2] modules,
> it appears that they expose only the "non-p" variants.
> 
> [1] https://docs.python.org/3/library/select.html
> [2] https://docs.python.org/3/library/selectors.html

Can you use signalfd and select/poll/epoll?

Barry

> 
> -- 
> ========================================================================
> Google                                      Where SkyNet meets Idiocracy
> ========================================================================
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From gweatherby at uchc.edu  Sat Dec  3 08:12:57 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Sat, 3 Dec 2022 13:12:57 +0000
Subject: Calling pselect/ppoll/epoll_pwait
In-Reply-To: <427E6CAE-1E77-42BD-924F-F221CBFCB6AC@barrys-emacs.org>
References: <c4b8fdc3-9dd5-7697-ee12-44a9ddce30bc@gmail.com>
 <427E6CAE-1E77-42BD-924F-F221CBFCB6AC@barrys-emacs.org>
Message-ID: <SA1PR14MB5855D7381437C77B03B1F42CB9169@SA1PR14MB5855.namprd14.prod.outlook.com>

Signalfd and select could probably be made to work if one codes around the race conditions pselect is provided to avoid. I?m not sure if using the GIL (for CPython) is sufficient or if a dedicated concurrency control (e.g. lock, mutex, semaphore) is necessary.


An alternative is to call the C library function via a wrapper. I had need to use setfsuid on a project a couple of years ago and found this example:

https://gist.github.com/atdt/ebafa299e843a767139b



From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Barry <barry at barrys-emacs.org>
Date: Friday, December 2, 2022 at 7:02 PM
To: Ian Pilcher <arequipeno at gmail.com>
Cc: python-list at python.org <python-list at python.org>
Subject: Re: Calling pselect/ppoll/epoll_pwait
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

> On 2 Dec 2022, at 20:03, Ian Pilcher <arequipeno at gmail.com> wrote:
>
> ?Does Python provide any way to call the "p" variants of the I/O
> multiplexing functions?
>
> Looking at the documentation of the select[1] and selectors[2] modules,
> it appears that they expose only the "non-p" variants.
>
> [1] https://urldefense.com/v3/__https://docs.python.org/3/library/select.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_OD5qBjeA$<https://urldefense.com/v3/__https:/docs.python.org/3/library/select.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_OD5qBjeA$>
> [2] https://urldefense.com/v3/__https://docs.python.org/3/library/selectors.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_MwNjgO8A$<https://urldefense.com/v3/__https:/docs.python.org/3/library/selectors.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_MwNjgO8A$>

Can you use signalfd and select/poll/epoll?

Barry

>
> --
> ========================================================================
> Google                                      Where SkyNet meets Idiocracy
> ========================================================================
> --
> https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$>
>

--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$>

From barry at barrys-emacs.org  Sun Dec  4 04:55:24 2022
From: barry at barrys-emacs.org (Barry)
Date: Sun, 4 Dec 2022 09:55:24 +0000
Subject: Calling pselect/ppoll/epoll_pwait
In-Reply-To: <SA1PR14MB5855D7381437C77B03B1F42CB9169@SA1PR14MB5855.namprd14.prod.outlook.com>
References: <SA1PR14MB5855D7381437C77B03B1F42CB9169@SA1PR14MB5855.namprd14.prod.outlook.com>
Message-ID: <1735D724-0AEF-4FE9-8C92-86FA5041DDDC@barrys-emacs.org>

     On 3 Dec 2022, at 13:13, Weatherby,Gerard <gweatherby at uchc.edu> wrote:

     ?

     Signalfd and select could probably be made to work if one codes around
     the race conditions pselect is provided to avoid. I?m not sure if using
     the GIL (for CPython) is sufficient or if a dedicated concurrency
     control (e.g. lock, mutex, semaphore) is necessary.

     An alternative is to call the C library function via a wrapper. I had
     need to use setfsuid on a project a couple of years ago and found this
     example:

     [1]https://gist.github.com/atdt/ebafa299e843a767139b

     ?

   I read this on SO when researching your question.
   Search for epoll and signal.

   (I would post the link but ipad turns the link into an image?)

   I assume that the lack of pepoll means you can use epoll and

   signalfd without race conditions. The trick seems to be setting

   the signal to ignore.

   Barry

     ?

     From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org>
     on behalf of Barry <barry at barrys-emacs.org>

     Date: Friday, December 2, 2022 at 7:02 PM
     To: Ian Pilcher <arequipeno at gmail.com>
     Cc: python-list at python.org <python-list at python.org>
     Subject: Re: Calling pselect/ppoll/epoll_pwait

     *** Attention: This is an external email. Use caution responding,
     opening attachments or clicking on links. ***

     > On 2 Dec 2022, at 20:03, Ian Pilcher <arequipeno at gmail.com> wrote:
     >
     > ?Does Python provide any way to call the "p" variants of the I/O
     > multiplexing functions?
     >
     > Looking at the documentation of the select[1] and selectors[2]
     modules,
     > it appears that they expose only the "non-p" variants.
     >
     > [1]
     [2]https://urldefense.com/v3/__https://docs.python.org/3/library/select.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_OD5qBjeA$
     > [2]
     [3]https://urldefense.com/v3/__https://docs.python.org/3/library/selectors.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_MwNjgO8A$

     Can you use signalfd and select/poll/epoll?

     Barry

     >
     > --
     >
     ========================================================================
     > Google????????????????????????????????????? Where SkyNet meets
     Idiocracy
     >
     ========================================================================
     > --
     >
     [4]https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$
     >

     --
     [5]https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$

References

   Visible links
   1. https://gist.github.com/atdt/ebafa299e843a767139b
   2. https://urldefense.com/v3/__https:/docs.python.org/3/library/select.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_OD5qBjeA$
   3. https://urldefense.com/v3/__https:/docs.python.org/3/library/selectors.html__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_MwNjgO8A$
   4. https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$
   5. https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hClFFo4XdiwQAhHxDbHA5zFr490Of9uheHSf84V9cREMHyw1kX-baG5HzXWMt-hFLP30q6DpSUb2G_PhasKBfg$

From biglee12672 at gmail.com  Fri Dec  2 17:38:03 2022
From: biglee12672 at gmail.com (biglee12672 at gmail.com)
Date: Fri, 2 Dec 2022 14:38:03 -0800
Subject: unable to resolve readline issues
Message-ID: <002b01d9069e$bd78f2c0$386ad840$@gmail.com>

Dear Sir:

 

For whatever reason I have lost functionality of using Python 3.11.  While
opening Python (standalone or from CMD prompt) as usual this AM the
following message appeared.   Did read that it is not compatible with
Windows but I can't get it to work as I don't know what module will load.

 

Python 3.11.0 (main, Oct 24 2022, 18:26:48) [MSC v.1933 64 bit (AMD64)] on
win32

Type "help", "copyright", "credits" or "license" for more information.

Failed calling sys.__interactivehook__

Traceback (most recent call last):

  File "<frozen site>", line 445, in register_readline

  File
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\re
adline.py", line 34, in <module>

    rl = Readline()

         ^^^^^^^^^^

  File
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\py
readline\rlmain.py", line 422, in __init__

    BaseReadline.__init__(self)

  File
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\py
readline\rlmain.py", line 62, in __init__

    mode.init_editing_mode(None)

  File
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\py
readline\modes\emacs.py", line 633, in init_editing_mode

    self._bind_key('space',       self.self_insert)

  File
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\py
readline\modes\basemode.py", line 162, in _bind_key

    if not callable(func):

           ^^^^^^^^^^^^^^

  File
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\py
readline\py3k_compat.py", line 8, in callable

    return isinstance(x, collections.Callable)rer

                         ^^^^^^^^^^^^^^^^^^^^

AttributeError: module 'collections' has no attribute 'Callable'

 

>From this point on Python became unusable as I uninstalled rebooted then
reinstalled to find I have the same issues as stated.  Finally uninstalled
Python as it doesn't perform as usual especially trying to understand the
use of pyreadline, gnureadline and or just readline.

 

If you can help great. 

 

Regards,

Leon Pearlman

 


From eryksun at gmail.com  Sun Dec  4 15:08:36 2022
From: eryksun at gmail.com (Eryk Sun)
Date: Sun, 4 Dec 2022 14:08:36 -0600
Subject: unable to resolve readline issues
In-Reply-To: <002b01d9069e$bd78f2c0$386ad840$@gmail.com>
References: <002b01d9069e$bd78f2c0$386ad840$@gmail.com>
Message-ID: <CACL+1aurUDeYCc4FBLSy+j9oKrp5KGdFVFUWVPAzwiB0QjnrnA@mail.gmail.com>

On 12/2/22, biglee12672 at gmail.com <biglee12672 at gmail.com> wrote:
>
> From this point on Python became unusable as I uninstalled rebooted then
> reinstalled to find I have the same issues as stated.  Finally uninstalled
> Python as it doesn't perform as usual especially trying to understand the
> use of pyreadline, gnureadline and or just readline.

When Python runs interactively, it implicitly tries to import the
readline module. On POSIX, Python has a builtin readline module that
usually uses the GNU Readline library.

On Windows, Python does not include a readline module. Instead, if
standard I/O is a console, the high-level WinAPI ReadConsoleW()
function is used, which implements its own line editor and
command-line history. It's not as general, flexible, or capable as the
readline interface, so a third-party pyreadline package was
implemented for Windows. However, as far as I know, pyreadline is no
longer actively developed. Thus it has out-of-date code, which may be
broken in newer releases of Python, such as isinstance(x,
collections.Callable).

Your choice is to either patch pyreadline to fix the bug or uninstall it.

From python at mrabarnett.plus.com  Sun Dec  4 15:18:28 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Sun, 4 Dec 2022 20:18:28 +0000
Subject: unable to resolve readline issues
In-Reply-To: <002b01d9069e$bd78f2c0$386ad840$@gmail.com>
References: <002b01d9069e$bd78f2c0$386ad840$@gmail.com>
Message-ID: <7e85d380-6703-47a4-2d9d-be7511eb0f90@mrabarnett.plus.com>

On 2022-12-02 22:38, biglee12672 at gmail.com wrote:
 > Dear Sir:
 >
 > For whatever reason I have lost functionality of using Python 3.11. 
While
 > opening Python (standalone or from CMD prompt) as usual this AM the
 > following message appeared.   Did read that it is not compatible with
 > Windows but I can't get it to work as I don't know what module will load.
 >
 > Python 3.11.0 (main, Oct 24 2022, 18:26:48) [MSC v.1933 64 bit 
(AMD64)] on
 > win32
 > Type "help", "copyright", "credits" or "license" for more information.
 > Failed calling sys.__interactivehook__
 > Traceback (most recent call last):
 >    File "<frozen site>", line 445, in register_readline
 >    File 
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\readline.py", 
line 34, in <module>
 >      rl = Readline()
 >           ^^^^^^^^^^
 >    File 
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\pyreadline\rlmain.py", 
line 422, in __init__
 >      BaseReadline.__init__(self)
 >    File 
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\pyreadline\rlmain.py", 
line 62, in __init__
 >      mode.init_editing_mode(None)
 >    File 
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\pyreadline\modes\emacs.py", 
line 633, in init_editing_mode
 >      self._bind_key('space',       self.self_insert)
 >    File 
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\pyreadline\modes\basemode.py", 
line 162, in _bind_key
 >      if not callable(func):
 >             ^^^^^^^^^^^^^^
 >    File 
"C:\Users\bigle\AppData\Local\Programs\Python\Python311\Lib\site-packages\pyreadline\py3k_compat.py", 
line 8, in callable
 >      return isinstance(x, collections.Callable)rer
 >                           ^^^^^^^^^^^^^^^^^^^^
 > AttributeError: module 'collections' has no attribute 'Callable'
 >
 >   From this point on Python became unusable as I uninstalled rebooted 
then
 > reinstalled to find I have the same issues as stated.  Finally 
uninstalled
 > Python as it doesn't perform as usual especially trying to understand the
 > use of pyreadline, gnureadline and or just readline.
 >
 > If you can help great.
 >
 > Regards,
 > Leon Pearlman
 >
Looking at PyPI, it appears that it was last supported on Python 3.5.

I'd suggest that after uninstalling Python, you delete the Python folder
if it's still there (because of any installed 3rd-party modules) before
re-installing.

From salmodovar at ligumu.com  Sun Dec  4 18:36:19 2022
From: salmodovar at ligumu.com (=?UTF-8?Q?Sabrina_Almod=c3=b3var?=)
Date: Sun, 4 Dec 2022 20:36:19 -0300
Subject: unable to resolve readline issues
References: <002b01d9069e$bd78f2c0$386ad840$@gmail.com>
 <CACL+1aurUDeYCc4FBLSy+j9oKrp5KGdFVFUWVPAzwiB0QjnrnA@mail.gmail.com>
 <mailman.1089.1670184519.20444.python-list@python.org>
Message-ID: <tmjatk$1q8m$1@gioia.aioe.org>

On 04/12/2022 17:08, Eryk Sun wrote:
> On 12/2/22, biglee12672 at gmail.com <biglee12672 at gmail.com> wrote:
>>
>> From this point on Python became unusable as I uninstalled rebooted then
>> reinstalled to find I have the same issues as stated.  Finally uninstalled
>> Python as it doesn't perform as usual especially trying to understand the
>> use of pyreadline, gnureadline and or just readline.
> 
> When Python runs interactively, it implicitly tries to import the
> readline module. On POSIX, Python has a builtin readline module that
> usually uses the GNU Readline library.
> 
> On Windows, Python does not include a readline module. Instead, if
> standard I/O is a console, the high-level WinAPI ReadConsoleW()
> function is used, which implements its own line editor and
> command-line history. It's not as general, flexible, or capable as the
> readline interface, so a third-party pyreadline package was
> implemented for Windows. However, as far as I know, pyreadline is no
> longer actively developed. Thus it has out-of-date code, which may be
> broken in newer releases of Python, such as isinstance(x,
> collections.Callable).
> 
> Your choice is to either patch pyreadline to fix the bug or uninstall it.

(*) How to patch it

Open the file

  Lib/site-packages/pyreadline/py3k_compat.py

and locate the procedure

    def callable(x):
        return isinstance(x, collections.Callable)

Change it to

    def callable(x):
        return isinstance(x, collections.abc.Callable)

You're done.

From mats at wichmann.us  Mon Dec  5 10:25:44 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Mon, 5 Dec 2022 08:25:44 -0700
Subject: unable to resolve readline issues
In-Reply-To: <CACL+1aurUDeYCc4FBLSy+j9oKrp5KGdFVFUWVPAzwiB0QjnrnA@mail.gmail.com>
References: <002b01d9069e$bd78f2c0$386ad840$@gmail.com>
 <CACL+1aurUDeYCc4FBLSy+j9oKrp5KGdFVFUWVPAzwiB0QjnrnA@mail.gmail.com>
Message-ID: <bb192b6c-fceb-5439-c1bf-15a1cd3925d2@wichmann.us>

On 12/4/22 13:08, Eryk Sun wrote:
> On 12/2/22, biglee12672 at gmail.com <biglee12672 at gmail.com> wrote:
>>
>>  From this point on Python became unusable as I uninstalled rebooted then
>> reinstalled to find I have the same issues as stated.  Finally uninstalled
>> Python as it doesn't perform as usual especially trying to understand the
>> use of pyreadline, gnureadline and or just readline.
> 
> When Python runs interactively, it implicitly tries to import the
> readline module. On POSIX, Python has a builtin readline module that
> usually uses the GNU Readline library.
> 
> On Windows, Python does not include a readline module. Instead, if
> standard I/O is a console, the high-level WinAPI ReadConsoleW()
> function is used, which implements its own line editor and
> command-line history. It's not as general, flexible, or capable as the
> readline interface, so a third-party pyreadline package was
> implemented for Windows. However, as far as I know, pyreadline is no
> longer actively developed. Thus it has out-of-date code, which may be
> broken in newer releases of Python, such as isinstance(x,
> collections.Callable).
> 
> Your choice is to either patch pyreadline to fix the bug or uninstall it.

there is a pyreadline3

I tried it for a particular case and didn't have a whole lot of luck 
with it, so YMMV, but somebody has done the porting work to keep it more 
current.




From salmodovar at ligumu.com  Mon Dec  5 20:37:39 2022
From: salmodovar at ligumu.com (=?UTF-8?Q?Sabrina_Almod=c3=b3var?=)
Date: Mon, 5 Dec 2022 22:37:39 -0300
Subject: on the python paradox
Message-ID: <tmm6d3$1fef$1@gioia.aioe.org>

                          The Python Paradox
                             Paul Graham
                             August 2004

In a recent talk [1] I said something that upset a lot of people: that
you could get smarter programmers to work on a Python project than you
could to work on a Java project.

I didn't mean by this that Java programmers are dumb. I meant that
Python programmers are smart. It's a lot of work to learn a new
programming language. And people don't learn Python because it will
get them a job; they learn it because they genuinely like to program
and aren't satisfied with the languages they already know.

Which makes them exactly the kind of programmers companies should want
to hire. Hence what, for lack of a better name, I'll call the Python
paradox: if a company chooses to write its software in a comparatively
esoteric language, they'll be able to hire better programmers, because
they'll attract only those who cared enough to learn it. And for
programmers the paradox is even more pronounced: the language to
learn, if you want to get a good job, is a language that people don't
learn merely to get a job.

Only a few companies have been smart enough to realize this so
far. But there is a kind of selection going on here too: they're
exactly the companies programmers would most like to work for. Google,
for example. When they advertise Java programming jobs, they also want
Python experience.

A friend of mine who knows nearly all the widely used languages uses
Python for most of his projects. He says the main reason is that he
likes the way source code looks. That may seem a frivolous reason to
choose one language over another. But it is not so frivolous as it
sounds: when you program, you spend more time reading code than
writing it. You push blobs of source code around the way a sculptor
does blobs of clay. So a language that makes source code ugly is
maddening to an exacting programmer, as clay full of lumps would be to
a sculptor.

At the mention of ugly source code, people will of course think of
Perl. But the superficial ugliness of Perl is not the sort I
mean. Real ugliness is not harsh-looking syntax, but having to build
programs out of the wrong concepts. Perl may look like a cartoon
character swearing, but there are cases where it surpasses Python
conceptually.

So far, anyway. Both languages are of course moving targets. But they
share, along with Ruby (and Icon, and Joy, and J, and Lisp, and
Smalltalk) the fact that they're created by, and used by, people who
really care about programming. And those tend to be the ones who do it
well.

(*) Footnotes

[1] Audio of the talk, also attached to this post
http://origin.conversationsnetwork.org/Paul%20Graham%20-%20Great%20Hackers.mp3

From gabriele1NOSPAM at hotmail.com  Tue Dec  6 05:07:55 2022
From: gabriele1NOSPAM at hotmail.com (^Bart)
Date: Tue, 6 Dec 2022 11:07:55 +0100
Subject: FTP without username and password
Message-ID: <tmn49r$15jr$1@gioia.aioe.org>

Hi Guys,

usually I use this code on my Debian Bullseye:

# python3 -m pyftpdlib -i 192.168.0.71 -p 21 -d /home/my_user/ftp

It works, it's simply easy and perfect but... a device in my lan needs a 
ftp folder without username and password!

I tried to search on internet how to set the code above to be available 
without username and password but... I didn't understand how to fix it :\

Obviously I could use a workaround like Samba or another machine where I 
have a Vsftp server but... I'd like to fix Python! ;)

Regards.
^Bart

From jon+usenet at unequivocal.eu  Tue Dec  6 10:48:07 2022
From: jon+usenet at unequivocal.eu (Jon Ribbens)
Date: Tue, 6 Dec 2022 15:48:07 -0000 (UTC)
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
Message-ID: <slrntoup1n.6ug.jon+usenet@raven.unequivocal.eu>

On 2022-12-06, ^Bart <gabriele1NOSPAM at hotmail.com> wrote:
> Hi Guys,
>
> usually I use this code on my Debian Bullseye:
>
> # python3 -m pyftpdlib -i 192.168.0.71 -p 21 -d /home/my_user/ftp
>
> It works, it's simply easy and perfect but... a device in my lan needs a 
> ftp folder without username and password!
>
> I tried to search on internet how to set the code above to be available 
> without username and password but... I didn't understand how to fix it :\

The code above already does make the directory available without a
username and password. Do you mean you need the directory to be
*writable* without a username and password? If so try the '-w' option.

From rosuav at gmail.com  Tue Dec  6 10:55:53 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 7 Dec 2022 02:55:53 +1100
Subject: FTP without username and password
In-Reply-To: <tmn49r$15jr$1@gioia.aioe.org>
References: <tmn49r$15jr$1@gioia.aioe.org>
Message-ID: <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>

On Wed, 7 Dec 2022 at 02:51, ^Bart <gabriele1NOSPAM at hotmail.com> wrote:
>
> Hi Guys,
>
> usually I use this code on my Debian Bullseye:
>
> # python3 -m pyftpdlib -i 192.168.0.71 -p 21 -d /home/my_user/ftp
>
> It works, it's simply easy and perfect but... a device in my lan needs a
> ftp folder without username and password!
>
> I tried to search on internet how to set the code above to be available
> without username and password but... I didn't understand how to fix it :\
>
> Obviously I could use a workaround like Samba or another machine where I
> have a Vsftp server but... I'd like to fix Python! ;)
>

I assume it HAS to be FTP, otherwise you'd set up something much more
secure like ssh (or scp or sshfs, which are built on it), done with an
authorized key rather than a password.

In general, "anonymous FTP" is done technically with a username and
password. Can you look at how the device tries to connect, and then
make that username (probably "anonymous") and that password (could be
anything, traditionally was an email address) valid for fetching?

ChrisA

From gabriele1NOSPAM at hotmail.com  Tue Dec  6 14:42:42 2022
From: gabriele1NOSPAM at hotmail.com (^Bart)
Date: Tue, 6 Dec 2022 20:42:42 +0100
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>
 <mailman.1092.1670342166.20444.python-list@python.org>
Message-ID: <tmo5vj$1g9$1@gioia.aioe.org>

> In general, "anonymous FTP" is done technically with a username and
> password. Can you look at how the device tries to connect, and then
> make that username (probably "anonymous") and that password (could be
> anything, traditionally was an email address) valid for fetching?

Thanks for your reply, I needed a TFTP to upload a no brand firmware in 
a Wildix antenna, I solved with a free software of SolarWinds, there's 
something also for Linux!

I tried the written Python code but it needs to insert a username and 
password so it's a different service than TFTP but maybe there's also a 
code to do it in Python! ;)

> ChrisA

Regards.
^Bart

From gabriele1NOSPAM at hotmail.com  Tue Dec  6 14:44:44 2022
From: gabriele1NOSPAM at hotmail.com (^Bart)
Date: Tue, 6 Dec 2022 20:44:44 +0100
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <slrntoup1n.6ug.jon+usenet@raven.unequivocal.eu>
Message-ID: <tmo63c$1g9$2@gioia.aioe.org>

> The code above already does make the directory available without a
> username and password. Do you mean you need the directory to be
> *writable* without a username and password? If so try the '-w' option.

Thanks for your reply, I solved by TFTP SolarWind free tool, like what I 
wrote in another post I needed it to upload a no brand firmware in a 
Wildix antenna.

Regards.
^Bart

From grant.b.edwards at gmail.com  Tue Dec  6 15:11:34 2022
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Tue, 06 Dec 2022 12:11:34 -0800 (PST)
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>
 <mailman.1092.1670342166.20444.python-list@python.org>
 <tmo5vj$1g9$1@gioia.aioe.org>
Message-ID: <638fa1f6.050a0220.9a168.c10c@mx.google.com>

On 2022-12-06, ^Bart <gabriele1NOSPAM at hotmail.com> wrote:
>> In general, "anonymous FTP" is done technically with a username and
>> password. Can you look at how the device tries to connect, and then
>> make that username (probably "anonymous") and that password (could be
>> anything, traditionally was an email address) valid for fetching?
>
> Thanks for your reply, I needed a TFTP to upload a no brand firmware in 
> a Wildix antenna, I solved with a free software of SolarWinds, there's 
> something also for Linux!
>
> I tried the written Python code but it needs to insert a username and 
> password so it's a different service than TFTP but maybe there's also a 
> code to do it in Python! ;)

The Python code you showed was implementing an FTP server. That's a
completely different protocol from TFTP. There are TFTP
implementations for Pythong. This one works well: https://github.com/msoulier/tftpy

--
Grant



From ramvikrams243 at gmail.com  Tue Dec  6 15:24:24 2022
From: ramvikrams243 at gmail.com (ramvikram singh)
Date: Wed, 7 Dec 2022 01:54:24 +0530
Subject: Contributing to cpython
Message-ID: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>

Greetings,
I learnt python this year and visiting the python issue tab for the last
two months, but there is a problem which I am facing I understand the issue
after reading the few times but I can't think about how to modify the code
as per the issue. Could you please help me with this?

From barry at barrys-emacs.org  Tue Dec  6 16:45:08 2022
From: barry at barrys-emacs.org (Barry)
Date: Tue, 6 Dec 2022 21:45:08 +0000
Subject: Contributing to cpython
In-Reply-To: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>
References: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>
Message-ID: <2C2BCA10-D3F2-40A8-984E-0D84BDF6FB0A@barrys-emacs.org>



> On 6 Dec 2022, at 20:55, ramvikram singh <ramvikrams243 at gmail.com> wrote:
> 
> ?Greetings,
> I learnt python this year and visiting the python issue tab for the last
> two months, but there is a problem which I am facing I understand the issue
> after reading the few times but I can't think about how to modify the code
> as per the issue. Could you please help me with this?

no one can help as you have not explained what the issue is.

Barry 

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


From lukasz at langa.pl  Tue Dec  6 18:01:39 2022
From: lukasz at langa.pl (=?utf-8?Q?=C5=81ukasz_Langa?=)
Date: Wed, 7 Dec 2022 00:01:39 +0100
Subject: [RELEASE] Python 3.11.1, 3.10.9, 3.9.16, 3.8.16, 3.7.16, and 3.12.0
 alpha 3 are now available
Message-ID: <820CB8BD-49D6-469B-8DC0-0D7B2B5C984D@langa.pl>

Greetings! We bring you a slew of releases this fine Saint Nicholas / Sinterklaas day. Six simultaneous releases has got to be some record. There?s one more record we broke this time, you?ll see below.

In any case, updating is recommended due to security content:

3.7 - 3.12: gh-98739 <https://github.com/python/cpython/issues/98739>: Updated bundled libexpat to 2.5.0 to fix CVE-2022-43680 <https://nvd.nist.gov/vuln/detail/CVE-2022-43680> (heap use-after-free).
3.7 - 3.12: gh-98433 <https://github.com/python/cpython/issues/98433>: The IDNA codec decoder used on DNS hostnames by socket or asyncio related name resolution functions no longer involves a quadratic algorithm to fix CVE-2022-45061 <https://nvd.nist.gov/vuln/detail/CVE-2022-45061>. This prevents a potential CPU denial of service if an out-of-spec excessive length hostname involving bidirectional characters were decoded. Some protocols such as urllib http 3xx redirects potentially allow for an attacker to supply such a name.
3.7 - 3.12: gh-100001 <https://github.com/python/cpython/issues/100001>: python -m http.server no longer allows terminal control characters sent within a garbage request to be printed to the stderr server log.
3.8 - 3.12: gh-87604 <https://github.com/python/cpython/issues/87604>: Avoid publishing list of active per-interpreter audit hooks via the gc module.
3.9 - 3.10 (already released in 3.11+ before): gh-97514 <https://github.com/python/cpython/issues/97514>: On Linux the multiprocessing module returns to using filesystem backed unix domain sockets for communication with the forkserver process instead of the Linux abstract socket namespace. Only code that chooses to use the ?forkserver? start method is affected. This prevents Linux CVE-2022-42919 <https://nvd.nist.gov/vuln/detail/CVE-2022-42919> (potential privilege escalation) as abstract sockets have no permissions and could allow any user on the system in the same network namespace (often the whole system) to inject code into the multiprocessing forkserver process. This was a potential privilege escalation. Filesystem based socket permissions restrict this to the forkserver process user as was the default in Python 3.8 and earlier.
3.7 - 3.10: gh-98517 <https://github.com/python/cpython/issues/98517>: Port XKCP?s fix for the buffer overflows in SHA-3 to fix CVE-2022-37454 <https://nvd.nist.gov/vuln/detail/CVE-2022-37454>.
3.7 - 3.9 (already released in 3.10+ before): gh-68966 <https://github.com/python/cpython/issues/68966>: The deprecated mailcap module now refuses to inject unsafe text (filenames, MIME types, parameters) into shell commands to address CVE-2015-20107 <https://nvd.nist.gov/vuln/detail/CVE-2015-20107>. Instead of using such text, it will warn and act as if a match was not found (or for test commands, as if the test failed).
 <https://discuss.python.org/t/python-3-11-1-3-10-9-3-9-16-3-8-16-3-7-16-and-3-12-0-alpha-3-are-now-available/21724#python-3120-alpha-3-1>Python 3.12.0 alpha 3

Get it here, read the change log, sing a GPT-3-generated Sinterklaas song:

https://www.python.org/downloads/release/python-3120a3/ <https://www.python.org/downloads/release/python-3120a3/>

216 new commits since 3.12.0 alpha 2 last month.

 <https://discuss.python.org/t/python-3-11-1-3-10-9-3-9-16-3-8-16-3-7-16-and-3-12-0-alpha-3-are-now-available/21724#python-3111-2>Python 3.11.1

Get it here, see the change log, read the recipe for quark soup:

https://www.python.org/downloads/release/python-3111/ <https://www.python.org/downloads/release/python-3111/>

A whopping 495 new commits since 3.11.0. This is a massive increase of changes comparing to 3.10 at the same stage in the release cycle: there were ?only? 339 commits between 3.10.0 and 3.10.1.

 <https://discuss.python.org/t/python-3-11-1-3-10-9-3-9-16-3-8-16-3-7-16-and-3-12-0-alpha-3-are-now-available/21724#python-3109-3>Python 3.10.9

Get it here, read the change log, see circular patterns:

https://www.python.org/downloads/release/python-3109/ <https://www.python.org/downloads/release/python-3109/>

165 new commits.

 <https://discuss.python.org/t/python-3-11-1-3-10-9-3-9-16-3-8-16-3-7-16-and-3-12-0-alpha-3-are-now-available/21724#python-3916-4>Python 3.9.16

Get it here, read the change log, consider upgrading to a newer version:

https://www.python.org/downloads/release/python-3916/ <https://www.python.org/downloads/release/python-3916/>

Security-only release with no binaries. 10 commits.

 <https://discuss.python.org/t/python-3-11-1-3-10-9-3-9-16-3-8-16-3-7-16-and-3-12-0-alpha-3-are-now-available/21724#python-3816-5>Python 3.8.16

Get it here, see the change log, definitely upgrade to a newer version:

https://www.python.org/downloads/release/python-3816/ <https://www.python.org/downloads/release/python-3816/>

Security-only release with no binaries. 9 commits.

 <https://discuss.python.org/t/python-3-11-1-3-10-9-3-9-16-3-8-16-3-7-16-and-3-12-0-alpha-3-are-now-available/21724#python-3716-6>Python 3.7.16

Get it here, read the change log, check PEP 537  <https://peps.python.org/pep-0537/>to confirm EOL is coming to this version in June 2023:

https://www.python.org/downloads/release/python-3716/ <https://www.python.org/downloads/release/python-3716/>

Security-only release with no binaries. 8 commits.

 <https://discuss.python.org/t/python-3-11-1-3-10-9-3-9-16-3-8-16-3-7-16-and-3-12-0-alpha-3-are-now-available/21724#we-hope-you-enjoy-the-new-releases-7>We hope you enjoy the new releases!

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 @nad <https://discuss.python.org/u/nad>
Steve Dower @steve.dower <https://discuss.python.org/u/steve.dower>
Pablo Galindo Salgado @pablogsal <https://discuss.python.org/u/pablogsal>
?ukasz Langa @ambv <https://discuss.python.org/u/ambv>
Thomas Wouters @thomas <https://discuss.python.org/u/thomas>
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From list1 at tompassin.net  Tue Dec  6 17:05:19 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Tue, 6 Dec 2022 17:05:19 -0500
Subject: Contributing to cpython
In-Reply-To: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>
References: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>
Message-ID: <146d844c-f650-8e99-695f-4376fe96cd62@tompassin.net>

On 12/6/2022 3:24 PM, ramvikram singh wrote:
> Greetings,
> I learnt python this year and visiting the python issue tab for the last
> two months, but there is a problem which I am facing I understand the issue
> after reading the few times but I can't think about how to modify the code
> as per the issue. Could you please help me with this?

There is a page about contributing work on code to Python at

https://devguide.python.org

It starts out:

"This guide is a comprehensive resource for contributing to Python ? for 
both new and experienced contributors."

You should study this guide carefully.  If you don't know how to use 
git, clone a repo, work with git branches, what a pull request is, and 
so forth, you need to get some basic familiarity with working with those 
tools and concepts.    You should be able to file new issues on GitHub 
and contribute to their discussion thread.  If you want to actually 
contribute code, you should be able to build Python yourself, as covered 
in the guide.

After that, you should remember that while help is welcome, the Python 
code base has a long history and a change that seems obvious to you may 
not work because of other constraints on that part of the codebase.  I 
once suggested a change in a particular function for finding executable 
files so that it would look in some other locations too. I learnt that 
this function was intended for internal use by distutils, and that it 
needed its quirks to work properly in its intended use.  No one wanted 
to take a chance on changing it.

I'm not saying you cannot or should not try to contribute useful 
changes.  I'm only saying that you need to get prepared - do your 
homework - first, and to not be discouraged if your first efforts are 
not accepted.


From jfong at ms4.hinet.net  Tue Dec  6 21:23:07 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Tue, 6 Dec 2022 18:23:07 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
Message-ID: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>

s0 = r'\x0a'
At this moment it was done by

    def to1byte(matchobj):
    ....return chr(int('0x' + matchobj.group(1), 16))
    s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)

But, is it that difficult on doing this simple thing?

--Jach

From wlfraed at ix.netcom.com  Tue Dec  6 21:32:20 2022
From: wlfraed at ix.netcom.com (Dennis Lee Bieber)
Date: Tue, 06 Dec 2022 21:32:20 -0500
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>
 <mailman.1092.1670342166.20444.python-list@python.org>
 <tmo5vj$1g9$1@gioia.aioe.org>
Message-ID: <okuvoh9h7cp00etk7mjbd15kvodmv5kd2r@4ax.com>

On Tue, 6 Dec 2022 20:42:42 +0100, ^Bart <gabriele1NOSPAM at hotmail.com>
declaimed the following:

>
>I tried the written Python code but it needs to insert a username and 
>password so it's a different service than TFTP but maybe there's also a 
>code to do it in Python! ;)
>

	It's a whole different protocol. TFTP is simplified to the point it
will fit on embedded devices which don't need security (the assumption
being that one has the embedded device physically present, FTP assumes
distributed networks).

https://wiki.python.org/moin/tftp


-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
	wlfraed at ix.netcom.com    http://wlfraed.microdiversity.freeddns.org/

From python at mrabarnett.plus.com  Tue Dec  6 22:01:12 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 7 Dec 2022 03:01:12 +0000
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
Message-ID: <e187df7b-e9dc-4be6-7c3c-94cd5513c008@mrabarnett.plus.com>

On 2022-12-07 02:23, Jach Feng wrote:
> s0 = r'\x0a'
> At this moment it was done by
> 
>      def to1byte(matchobj):
>      ....return chr(int('0x' + matchobj.group(1), 16))
>      s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
> 
> But, is it that difficult on doing this simple thing?
> 
You could try this:

 >>> s0 = r'\x0a'
 >>> ast.literal_eval('"%s"' % s0)
'\n'


From ramvikrams243 at gmail.com  Tue Dec  6 23:18:21 2022
From: ramvikrams243 at gmail.com (ramvikram singh)
Date: Wed, 7 Dec 2022 09:48:21 +0530
Subject: Contributing to cpython
In-Reply-To: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>
References: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>
Message-ID: <CAKhSMdM02t8QuZ9EyFCeys0o+Wy0N82RpfeejMGMUzJxef8=LA@mail.gmail.com>

the issue is that after reading the issue I am not able to think how to
modify the code, this is where I am stuck

On Wed, Dec 7, 2022 at 1:54 AM ramvikram singh <ramvikrams243 at gmail.com>
wrote:

> Greetings,
> I learnt python this year and visiting the python issue tab for the last
> two months, but there is a problem which I am facing I understand the issue
> after reading the few times but I can't think about how to modify the code
> as per the issue. Could you please help me with this?
>

From jfong at ms4.hinet.net  Tue Dec  6 22:37:54 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Tue, 6 Dec 2022 19:37:54 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <mailman.1098.1670382260.20444.python-list@python.org>
References: <e187df7b-e9dc-4be6-7c3c-94cd5513c008@mrabarnett.plus.com>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1098.1670382260.20444.python-list@python.org>
Message-ID: <64271aaf-3896-43b2-8998-30d245fb98fen@googlegroups.com>

MRAB ? 2022?12?7? ?????11:04:43 [UTC+8] ??????
> On 2022-12-07 02:23, Jach Feng wrote: 
> > s0 = r'\x0a' 
> > At this moment it was done by 
> > 
> > def to1byte(matchobj): 
> > ....return chr(int('0x' + matchobj.group(1), 16)) 
> > s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> > 
> > But, is it that difficult on doing this simple thing? 
> >
> You could try this: 
> 
> >>> s0 = r'\x0a' 
> >>> ast.literal_eval('"%s"' % s0) 
> '\n'
Not work in my system:-(

Python 3.8.8 (tags/v3.8.8:024d805, Feb 19 2021, 13:08:11) [MSC v.1928 32 bit (Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> s0 = r'\x0a'
>>> import ast
>>> ast.literal_eval("%s" % s0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "C:\Users\Jach\AppData\Local\Programs\Python\Python38-32\lib\ast.py", line 59, in literal_eval
    node_or_string = parse(node_or_string, mode='eval')
  File "C:\Users\Jach\AppData\Local\Programs\Python\Python38-32\lib\ast.py", line 47, in parse
    return compile(source, filename, mode, flags,
  File "<unknown>", line 1
    \x0a
       ^
SyntaxError: unexpected character after line continuation character

From list1 at tompassin.net  Tue Dec  6 22:55:52 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Tue, 6 Dec 2022 22:55:52 -0500
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
Message-ID: <776e63a0-2bf3-1dd0-87a5-61f587ce0732@tompassin.net>

On 12/6/2022 9:23 PM, Jach Feng wrote:
> s0 = r'\x0a'
> At this moment it was done by
> 
>      def to1byte(matchobj):
>      ....return chr(int('0x' + matchobj.group(1), 16))
>      s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
> 
> But, is it that difficult on doing this simple thing?
> 
> --Jach

I'm not totally clear on what you are trying to do here.  But:

s1 = r'\xdd'  # s1[2:] = 'dd'
n1 = int(s1[2:], 16)  # = 221 decimal or 0xdd in hex
# So
chr(n1) == '?'  # True
# and
'\xdd' == '?' # True

So the conversion you want seems to be chr(int(s1[2:], 16)).

Of course, this will only work if the input string is exactly four 
characters long, and the first two characters are r'\x', and the 
remaining two characters are going to be a hex string representation of 
a number small enough to fit into a byte.

If you know for sure that will be the case, then the conversion above 
seems to be about as simple as it could be.  If those conditions may not 
always be met, then you need to work out exactly what strings you may 
need to convert, and what they should be converted to.



From list1 at tompassin.net  Wed Dec  7 00:12:13 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Wed, 7 Dec 2022 00:12:13 -0500
Subject: Contributing to cpython
In-Reply-To: <CAKhSMdM02t8QuZ9EyFCeys0o+Wy0N82RpfeejMGMUzJxef8=LA@mail.gmail.com>
References: <CAKhSMdMo4-sirtiqBDzwZzMYi1+gBrf+_AMs72T9H9Bp6x8ebA@mail.gmail.com>
 <CAKhSMdM02t8QuZ9EyFCeys0o+Wy0N82RpfeejMGMUzJxef8=LA@mail.gmail.com>
Message-ID: <d24d8b9d-dd8f-1118-afdd-2d8f866d7f17@tompassin.net>

On 12/6/2022 11:18 PM, ramvikram singh wrote:
> the issue is that after reading the issue I am not able to think how to
> modify the code, this is where I am stuck
> 
> On Wed, Dec 7, 2022 at 1:54 AM ramvikram singh <ramvikrams243 at gmail.com>
> wrote:
> 
>> Greetings,
>> I learnt python this year and visiting the python issue tab for the last
>> two months, but there is a problem which I am facing I understand the issue
>> after reading the few times but I can't think about how to modify the code
>> as per the issue. Could you please help me with this?
>>

No one can help you because you have said nothing about the issue.  It 
is as if I were to write "I am having a problem with my car.  Can you 
help me?". And before you can think about modifying the code, you need 
to understand what the issue is, why it is happening, how that could be 
changed, and why that would be a safe kind of change to make. After 
that, you would be prepared to think about details of the code.  And 
that thinking would need to include ways in which you could verify that 
you can make the problem occur and how you can test to make sure that it 
is fixed after changes to the code.


From roel at roelschroeven.net  Wed Dec  7 03:42:18 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Wed, 7 Dec 2022 09:42:18 +0100
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <64271aaf-3896-43b2-8998-30d245fb98fen@googlegroups.com>
References: <e187df7b-e9dc-4be6-7c3c-94cd5513c008@mrabarnett.plus.com>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1098.1670382260.20444.python-list@python.org>
 <64271aaf-3896-43b2-8998-30d245fb98fen@googlegroups.com>
Message-ID: <fd671167-97a0-f9c2-266c-9098b4b6eed4@roelschroeven.net>



Op 7/12/2022 om 4:37 schreef Jach Feng:
> MRAB ? 2022?12?7? ?????11:04:43 [UTC+8] ??????
> > On 2022-12-07 02:23, Jach Feng wrote: 
> > > s0 = r'\x0a' 
> > > At this moment it was done by 
> > > 
> > > def to1byte(matchobj): 
> > > ....return chr(int('0x' + matchobj.group(1), 16)) 
> > > s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> > > 
> > > But, is it that difficult on doing this simple thing? 
> > >
> > You could try this: 
> > 
> > >>> s0 = r'\x0a' 
> > >>> ast.literal_eval('"%s"' % s0) 
> > '\n'
> Not work in my system:-(
>
> Python 3.8.8 (tags/v3.8.8:024d805, Feb 19 2021, 13:08:11) [MSC v.1928 32 bit (Intel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
> >>> s0 = r'\x0a'
> >>> import ast
> >>> ast.literal_eval("%s" % s0)
> Traceback (most recent call last):
>    File "<stdin>", line 1, in <module>
>    File "C:\Users\Jach\AppData\Local\Programs\Python\Python38-32\lib\ast.py", line 59, in literal_eval
>      node_or_string = parse(node_or_string, mode='eval')
>    File "C:\Users\Jach\AppData\Local\Programs\Python\Python38-32\lib\ast.py", line 47, in parse
>      return compile(source, filename, mode, flags,
>    File "<unknown>", line 1
>      \x0a
>         ^
> SyntaxError: unexpected character after line continuation character
You missed a pair of quotes. They are easily overlooked but very 
important. The point is to wrap your string in another pair of quotes so 
it becomes a valid Python string literal in a Python string which can 
then be passed to ast.literal_eval(). Works for me:

In [7]: s0 = r'\x0a'

In [8]: import ast

In [9]: ast.literal_eval('"%s"' % s0)
Out[9]: '\n'

-- 
"Experience is that marvelous thing that enables you to recognize a
mistake when you make it again."
         -- Franklin P. Jones


From david at lowryduda.com  Wed Dec  7 11:05:53 2022
From: david at lowryduda.com (David Lowry-Duda)
Date: Wed, 7 Dec 2022 11:05:53 -0500
Subject: Nonuniform PRNG?
Message-ID: <Y5C54VAA5lCunGOM@icerm-dld>

Inspired by the recent thread about pseudorandom number generators on 
python-ideas (where I also mistakenly first wrote this message), I began 
to wonder: suppose that I had a pseudorandom number generator that 
attempted to generate a nonuniform distribution. Suppose for instance 
that it was to generate a 0 bit 2/3 of the time, and a 1 bit 1/3 of the 
time.

How would one go about testing this PRNG against an idealized (similarly 
biased) PRNG?

- DLD

From david at lowryduda.com  Wed Dec  7 10:58:09 2022
From: david at lowryduda.com (David Lowry-Duda)
Date: Wed, 7 Dec 2022 10:58:09 -0500
Subject: on the python paradox
In-Reply-To: <tmm6d3$1fef$1@gioia.aioe.org>
References: <tmm6d3$1fef$1@gioia.aioe.org>
Message-ID: <Y5C4Ebx0a4VeTgq2@icerm-dld>

On Mon, Dec 05, 2022 at 10:37:39PM -0300, Sabrina Almod?var wrote:
>                          The Python Paradox
>                             Paul Graham
>                             August 2004
>
> [SNIP]
>
> Hence what, for lack of a better name, I'll call the Python paradox: 
> if a company chooses to write its software in a comparatively esoteric 
> language, they'll be able to hire better programmers, because they'll 
> attract only those who cared enough to learn it. And for programmers 
> the paradox is even more pronounced: the language to learn, if you 
> want to get a good job, is a language that people don't learn merely 
> to get a job.
>
> [SNIP]

I wonder what the appropriately esoteric language is today?

We can sort of think of go/rust as esoteric versions of C/C++. But what 
would be the esoteric python?

Perhaps Julia? I don't know of any large software projects happening in 
julia world that aren't essentially scientific computing libraries (but 
this is because *I* work mostly with scientific computing libraries and 
sometimes live under a rock).

- DLD

From jacob.kruger.work at gmail.com  Wed Dec  7 04:16:59 2022
From: jacob.kruger.work at gmail.com (jacob kruger)
Date: Wed, 7 Dec 2022 11:16:59 +0200
Subject: Initial introduction
Message-ID: <71f1c437-2f5c-55be-3d7c-3d706aa724d2@gmail.com>

Hi there


I might shortly be posting about a specific issue with imaplib/poplib, 
but, thought would first introduce myself.


I am 100% blind, but, among other forms of assistive technology 
software, I use windows PC's with the NVDA screenreader, which itself is 
written in python, but, besides that, i generally work with either VS 
code or other programmer-specific text editors when it comes to python 
coding, etc., and, while have been a web application developer for over 
25 years, working with different programming/scripting languages and 
platforms, I am more-or-less a full-time python developer nowadays, and, 
when it comes to web development in this context, I work with either 
flask or django, but anyway.


Regards

-- 

Jacob Kruger
+2782 413 4791
"Resistance is futile...but, acceptance is versatile..."



From jfong at ms4.hinet.net  Wed Dec  7 02:40:12 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Tue, 6 Dec 2022 23:40:12 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <mailman.1100.1670388670.20444.python-list@python.org>
References: <776e63a0-2bf3-1dd0-87a5-61f587ce0732@tompassin.net>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1100.1670388670.20444.python-list@python.org>
Message-ID: <722b829f-977d-4dc7-ab66-693c3593f771n@googlegroups.com>

Thomas Passin ? 2022?12?7? ?????12:51:32 [UTC+8] ??????
> On 12/6/2022 9:23 PM, Jach Feng wrote: 
> > s0 = r'\x0a' 
> > At this moment it was done by 
> > 
> > def to1byte(matchobj): 
> > ....return chr(int('0x' + matchobj.group(1), 16)) 
> > s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> > 
> > But, is it that difficult on doing this simple thing? 
> > 
> > --Jach
> I'm not totally clear on what you are trying to do here. But: 
> 
> s1 = r'\xdd' # s1[2:] = 'dd' 
> n1 = int(s1[2:], 16) # = 221 decimal or 0xdd in hex 
> # So 
> chr(n1) == '?' # True 
> # and 
> '\xdd' == '?' # True 
> 
> So the conversion you want seems to be chr(int(s1[2:], 16)). 
> 
> Of course, this will only work if the input string is exactly four 
> characters long, and the first two characters are r'\x', and the 
> remaining two characters are going to be a hex string representation of 
> a number small enough to fit into a byte. 
> 
> If you know for sure that will be the case, then the conversion above 
> seems to be about as simple as it could be. If those conditions may not 
> always be met, then you need to work out exactly what strings you may 
> need to convert, and what they should be converted to.
Thank you for reminding that the '0x'+ in the to1byte() definition is redundant:-)

Just not sure if there is a better way than using chr(int(...)) to do it. 
Yes, for this specific case, slice is much simpler than re.sub().

From io at io.it  Wed Dec  7 07:28:20 2022
From: io at io.it (^Bart)
Date: Wed, 7 Dec 2022 13:28:20 +0100
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>
 <mailman.1092.1670342166.20444.python-list@python.org>
 <tmo5vj$1g9$1@gioia.aioe.org> <638fa1f6.050a0220.9a168.c10c@mx.google.com>
 <mailman.1093.1670357497.20444.python-list@python.org>
Message-ID: <tmq0t1$1fal$1@gioia.aioe.org>

> The Python code you showed was implementing an FTP server. That's a
> completely different protocol from TFTP. There are TFTP
> implementations for Pythong. This one works well: https://github.com/msoulier/tftpy

I didn't know the difference of FTP and TFTP so... I thought TFTP was 
just a FTP without username and password! LOL! ;)

I'm sorry for my "bad post" and thanks to show me the Python 
implementation! :)

> --
> Grant

Regards.
^Bart


From io at io.it  Wed Dec  7 07:30:14 2022
From: io at io.it (^Bart)
Date: Wed, 7 Dec 2022 13:30:14 +0100
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>
 <mailman.1092.1670342166.20444.python-list@python.org>
 <tmo5vj$1g9$1@gioia.aioe.org> <okuvoh9h7cp00etk7mjbd15kvodmv5kd2r@4ax.com>
Message-ID: <tmq10k$1fal$2@gioia.aioe.org>

> 	It's a whole different protocol. TFTP is simplified to the point it
> will fit on embedded devices which don't need security (the assumption
> being that one has the embedded device physically present, FTP assumes
> distributed networks).
> 
> https://wiki.python.org/moin/tftp

I never used TFTP so, like what I wrote in another post, I thought it 
was just a FTP without username and password...

Thanks to show me the "Python way" to use TFTP! :)

Have a nice day!
^Bart


From salmodovar at ligumu.com  Wed Dec  7 12:34:47 2022
From: salmodovar at ligumu.com (=?UTF-8?Q?Sabrina_Almod=c3=b3var?=)
Date: Wed, 7 Dec 2022 14:34:47 -0300
Subject: Nonuniform PRNG?
References: <Y5C54VAA5lCunGOM@icerm-dld>
 <mailman.1103.1670429159.20444.python-list@python.org>
Message-ID: <tmqirn$8af$1@gioia.aioe.org>

On 07/12/2022 13:05, David Lowry-Duda wrote:
> Inspired by the recent thread about pseudorandom number generators on
> python-ideas (where I also mistakenly first wrote this message), I began
> to wonder: suppose that I had a pseudorandom number generator that
> attempted to generate a nonuniform distribution. Suppose for instance
> that it was to generate a 0 bit 2/3 of the time, and a 1 bit 1/3 of the
> time.
> 
> How would one go about testing this PRNG against an idealized (similarly
> biased) PRNG?

I believe things go like this.  If you have a uniform PRNG, you test it
against the state-of-the-art in statistical tests then build from it
your nonuniform one.  Now you have a nonuniform one that's tested.  But
you want things the other way around.  Having a nonuniform one to start,
you build a uniform one from the nonuniform one and then test it against
the state-of-the-art in statistical tests.

I believe you might be wondering how to build one from the other, but
I'll let you check that.

By the way, there's no such thing as an idealized PRNG.  All PRNG fail
all statistical tests.  The question is when.  A bad PRNG fails quickly
and obviously.  A good one requires large samples or a nontrivial test.

From gweatherby at uchc.edu  Wed Dec  7 12:55:20 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Wed, 7 Dec 2022 17:55:20 +0000
Subject: on the python paradox
In-Reply-To: <Python-20221207174854@ram.dialup.fu-berlin.de>
References: <tmm6d3$1fef$1@gioia.aioe.org>
 <mailman.1104.1670429230.20444.python-list@python.org>
 <Python-20221207174854@ram.dialup.fu-berlin.de>
Message-ID: <SA1PR14MB58559B60537172AC29B5C493B91A9@SA1PR14MB5855.namprd14.prod.outlook.com>

I use asyncio in a couple of places. Haven?t quite grokked it yet, though.

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Stefan Ram <ram at zedat.fu-berlin.de>
Date: Wednesday, December 7, 2022 at 12:28 PM
To: python-list at python.org <python-list at python.org>
Subject: Re: on the python paradox
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

David Lowry-Duda <david at lowryduda.com> writes:
>I wonder what the appropriately esoteric language is today?

  How many Python programmers grog metaclasses or asyncio?
  So, I'd say: The two streams have converged. Python is the
  esoteric mainstream language.


--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!mvBtuPjNnWaXWGLt8aXlimysNpjtW4fP_ls5-vLPv8qWMyafvYcP6sgo0jcV7ngjmV1E3F0zJ5ipXlbjkBF8_l8$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!mvBtuPjNnWaXWGLt8aXlimysNpjtW4fP_ls5-vLPv8qWMyafvYcP6sgo0jcV7ngjmV1E3F0zJ5ipXlbjkBF8_l8$>

From grant.b.edwards at gmail.com  Wed Dec  7 14:10:32 2022
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Wed, 07 Dec 2022 11:10:32 -0800 (PST)
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>
 <mailman.1092.1670342166.20444.python-list@python.org>
 <tmo5vj$1g9$1@gioia.aioe.org> <okuvoh9h7cp00etk7mjbd15kvodmv5kd2r@4ax.com>
Message-ID: <6390e528.020a0220.669f3.f166@mx.google.com>

On 2022-12-07, Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

> It's a whole different protocol. TFTP is simplified to the point it
> will fit on embedded devices which don't need security (the
> assumption being that one has the embedded device physically
> present, FTP assumes distributed networks).

One of the big differences is that FTP uses a pair of TCP connections
(a control connection and a data connection) while TFTP uses UDP.  UDP
is far, far simpler to implement than TCP. Things like bootloaders for
embedded systems often support UDP but don't implement TCP at all.

--
Grant



From salmodovar at ligumu.com  Wed Dec  7 13:28:47 2022
From: salmodovar at ligumu.com (=?UTF-8?Q?Sabrina_Almod=c3=b3var?=)
Date: Wed, 7 Dec 2022 15:28:47 -0300
Subject: Nonuniform PRNG?
References: <mailman.1103.1670429159.20444.python-list@python.org>
 <tests-20221207174425@ram.dialup.fu-berlin.de>
 <tests-20221207180328@ram.dialup.fu-berlin.de>
Message-ID: <tmqm10$1ohb$1@gioia.aioe.org>

On 07/12/2022 14:04, Stefan Ram wrote:
> ram at zedat.fu-berlin.de (Stefan Ram) writes:
>> So, in this case, careful code reviews might be better than
>> tests. For example, assuming, random.intrange( 0, 2 ) works
>> as advertised, we can be pretty sure that 
>> 0 if random.randint( 0, 2 ) else 1
>> fulfills the requirement.
> 
>   In practice, tests should still be done. When such a function 
>   returns the same result a hundred times, it does make sense
>   to become suspicious and investigate it.

Whatever it does a hundred times is not enough.  Code review is
definitely not enough.  The design of PRNGs should be good in theory ---
designed with good mathematical foundations --- and in practice by
passing all tests in the best-designed batteries.  As far as I know, the
state-of-the-art in statistical tests against PRNGs is the TestU01
library, available at

  http://simul.iro.umontreal.ca/testu01/tu01.html


From salmodovar at ligumu.com  Wed Dec  7 13:33:00 2022
From: salmodovar at ligumu.com (=?UTF-8?Q?Sabrina_Almod=c3=b3var?=)
Date: Wed, 7 Dec 2022 15:33:00 -0300
Subject: Nonuniform PRNG?
References: <mailman.1103.1670429159.20444.python-list@python.org>
 <tests-20221207174425@ram.dialup.fu-berlin.de>
Message-ID: <tmqm8t$1s97$1@gioia.aioe.org>

On 07/12/2022 13:45, Stefan Ram wrote:

[...]

> |One of the oldest interpretations is the /limit frequency/
> |interpretation. If the conditioning event /C/ can lead 
> |to either A or "not A", and if in /n/ repetitions of such 
> |a situation the event A occurs /m/ times, then it is asserted
> |that P(A|C) = lim n-->oo (m/n). This provides not only 
> |an interpretation of probability, but also a definition 
> |of probability in terms of a numerical frequency ratio. 
> |Hence the axioms of abstract probability theory can 
> |be derived as theorems of the frequency theory. 
> |
> |In spite of its superficial appeal, the limit frequency
> |interpretation has been widely discarded, primarily because
> |there is no assurance that the above limit really exists for
> |the actual sequences of events to which one wishes to apply
> |probability theory.
> |
> "Quantum Mechanics" (1998) - Leslie E. Ballentine

That's pretty interesting.  Indeed, we really must discard this
frequency interpretation, even though it is what's in my mind when I
think of estimating the probability of a certain event, which I think
would be called the empirical distribution of probability?

From __peter__ at web.de  Wed Dec  7 16:12:27 2022
From: __peter__ at web.de (Peter Otten)
Date: Wed, 7 Dec 2022 22:12:27 +0100
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
Message-ID: <725a6a70-be22-d11a-e0cf-6a29ef2adeeb@web.de>

On 07/12/2022 03:23, Jach Feng wrote:
> s0 = r'\x0a'
> At this moment it was done by
>
>      def to1byte(matchobj):
>      ....return chr(int('0x' + matchobj.group(1), 16))
>      s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>
> But, is it that difficult on doing this simple thing?

 >>> import codecs
 >>> codecs.decode(r"\x68\x65\x6c\x6c\x6f\x0a", "unicode-escape")
'hello\n'


From barry at barrys-emacs.org  Wed Dec  7 16:45:11 2022
From: barry at barrys-emacs.org (Barry)
Date: Wed, 7 Dec 2022 21:45:11 +0000
Subject: FTP without username and password
Message-ID: <C1CC2CFB-DF0B-40D6-93BF-A2353D19538A@barrys-emacs.org>

?

> On 7 Dec 2022, at 16:49, ^Bart <io at io.it> wrote:
> 
> ?
>>   It's a whole different protocol. TFTP is simplified to the point it
>> will fit on embedded devices which don't need security (the assumption
>> being that one has the embedded device physically present, FTP assumes
>> distributed networks).
>> https://wiki.python.org/moin/tftp
> 
> I never used TFTP so, like what I wrote in another post, I thought it was just a FTP without username and password...
> 
> Thanks to show me the "Python way" to use TFTP! :)
> 
> Have a nice day!
> ^Bart

TFTP server and client tools are standard on linux systems.

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


From david at lowryduda.com  Wed Dec  7 17:37:10 2022
From: david at lowryduda.com (David Lowry-Duda)
Date: Wed, 7 Dec 2022 17:37:10 -0500
Subject: Nonuniform PRNG?
In-Reply-To: <tmqm10$1ohb$1@gioia.aioe.org>
References: <mailman.1103.1670429159.20444.python-list@python.org>
 <tests-20221207174425@ram.dialup.fu-berlin.de>
 <tests-20221207180328@ram.dialup.fu-berlin.de>
 <tmqm10$1ohb$1@gioia.aioe.org>
Message-ID: <Y5EVlheJQKPicOxy@icerm-dld>

On Wed, Dec 07, 2022 at 03:28:47PM -0300, Sabrina Almod?var wrote:
>As far as I know, the state-of-the-art in statistical tests against 
>PRNGs is the TestU01 library, available at
>
>  http://simul.iro.umontreal.ca/testu01/tu01.html

I'm familiar with this type of test. But as far as I can tell and have 
seen, these tests only tst against *uniform* PRNGs. I am not aware of 
any written tests against nonuniform PRNGs.

I suspect it would be possible to mirror a lot of the ideas. For 
example, one common PRNG statistical test is to make many of matrices of 
various sizes and to study the ranks of these matrices. Presumably one 
could do a similar statistical analysis against what would be expected 
for any particular probability distribution. Running a candidate PRNG 
through this test will produce some sort of distribution, after all.

But it would be much nicer if work on statistical tests against 
nonuniform PRNGs had already been done somewhere.

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

From caliche-81 at hotmail.com  Wed Dec  7 17:04:56 2022
From: caliche-81 at hotmail.com (=?UTF-8?Q?Carlos_Berm=c3=badez?=)
Date: Wed, 7 Dec 2022 17:04:56 -0500
Subject: FTP without username and password
References: <tmn49r$15jr$1@gioia.aioe.org>
 <CAPTjJmrjzcR5Le=u537PBb6MvCKvppHetNzV0UJQfVxdUv600Q@mail.gmail.com>
 <mailman.1092.1670342166.20444.python-list@python.org>
 <tmo5vj$1g9$1@gioia.aioe.org> <okuvoh9h7cp00etk7mjbd15kvodmv5kd2r@4ax.com>
Message-ID: <e3e3a9e2-39b8-4ef4-8a46-105154c3099c@hotmail.com>

El 6/12/2022 a las 9:32 p.?m., Dennis Lee Bieber escribi?:
> On Tue, 6 Dec 2022 20:42:42 +0100, ^Bart <gabriele1NOSPAM at hotmail.com>
> declaimed the following:
> 
>>
>> I tried the written Python code but it needs to insert a username and
>> password so it's a different service than TFTP but maybe there's also a
>> code to do it in Python! ;)
>>
> 
> 	It's a whole different protocol. TFTP is simplified to the point it
> will fit on embedded devices which don't need security (the assumption
> being that one has the embedded device physically present, FTP assumes
> distributed networks).
> 
> https://wiki.python.org/moin/tftp
> 
> 

TFTP is used usually to manage updates and boot workstations without 
bootable disks using a NIC with a preloaded ROM.

From Richard at Damon-Family.org  Wed Dec  7 20:30:49 2022
From: Richard at Damon-Family.org (Richard Damon)
Date: Wed, 7 Dec 2022 17:30:49 -0800
Subject: Nonuniform PRNG?
In-Reply-To: <Y5EVlheJQKPicOxy@icerm-dld>
References: <mailman.1103.1670429159.20444.python-list@python.org>
 <tests-20221207174425@ram.dialup.fu-berlin.de>
 <tests-20221207180328@ram.dialup.fu-berlin.de> <tmqm10$1ohb$1@gioia.aioe.org>
 <Y5EVlheJQKPicOxy@icerm-dld>
Message-ID: <f52202a0-76ba-a599-d1d4-f8c9107df2bf@Damon-Family.org>

On 12/7/22 2:37 PM, David Lowry-Duda wrote:
> On Wed, Dec 07, 2022 at 03:28:47PM -0300, Sabrina Almod?var wrote:
>> As far as I know, the state-of-the-art in statistical tests against 
>> PRNGs is the TestU01 library, available at
>>
>> ?http://simul.iro.umontreal.ca/testu01/tu01.html
>
> I'm familiar with this type of test. But as far as I can tell and have 
> seen, these tests only tst against *uniform* PRNGs. I am not aware of 
> any written tests against nonuniform PRNGs.
>
> I suspect it would be possible to mirror a lot of the ideas. For 
> example, one common PRNG statistical test is to make many of matrices 
> of various sizes and to study the ranks of these matrices. Presumably 
> one could do a similar statistical analysis against what would be 
> expected for any particular probability distribution. Running a 
> candidate PRNG through this test will produce some sort of 
> distribution, after all.
>
> But it would be much nicer if work on statistical tests against 
> nonuniform PRNGs had already been done somewhere.
>
The big problem is there are MANY variations of nonuniform random 
numbers, and all the variations lead to different statistics to test 
against.

Most of the test can probably apply, but the new test criteria would 
need to be computed based on computing the exected results and expected 
variation in that result, largely based on various cross correlations of 
the numbers.

-- 
Richard Damon


From jfong at ms4.hinet.net  Wed Dec  7 20:16:09 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Wed, 7 Dec 2022 17:16:09 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <mailman.1102.1670402545.20444.python-list@python.org>
References: <e187df7b-e9dc-4be6-7c3c-94cd5513c008@mrabarnett.plus.com>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1098.1670382260.20444.python-list@python.org>
 <fd671167-97a0-f9c2-266c-9098b4b6eed4@roelschroeven.net>
 <64271aaf-3896-43b2-8998-30d245fb98fen@googlegroups.com>
 <mailman.1102.1670402545.20444.python-list@python.org>
Message-ID: <da8083d1-61fb-4b91-8bf1-db5c88aef099n@googlegroups.com>

Roel Schroeven ? 2022?12?7? ?????4:42:48 [UTC+8] ??????
> Op 7/12/2022 om 4:37 schreef Jach Feng:
> > MRAB ? 2022?12?7? ?????11:04:43 [UTC+8] ?????? 
> > > On 2022-12-07 02:23, Jach Feng wrote: 
> > > > s0 = r'\x0a' 
> > > > At this moment it was done by 
> > > > 
> > > > def to1byte(matchobj): 
> > > > ....return chr(int('0x' + matchobj.group(1), 16)) 
> > > > s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> > > > 
> > > > But, is it that difficult on doing this simple thing? 
> > > > 
> > > You could try this: 
> > > 
> > > >>> s0 = r'\x0a' 
> > > >>> ast.literal_eval('"%s"' % s0) 
> > > '\n' 
> > Not work in my system:-( 
> > 
> > Python 3.8.8 (tags/v3.8.8:024d805, Feb 19 2021, 13:08:11) [MSC v.1928 32 bit (Intel)] on win32 
> > Type "help", "copyright", "credits" or "license" for more information. 
> > >>> s0 = r'\x0a' 
> > >>> import ast 
> > >>> ast.literal_eval("%s" % s0) 
> > Traceback (most recent call last): 
> > File "<stdin>", line 1, in <module> 
> > File "C:\Users\Jach\AppData\Local\Programs\Python\Python38-32\lib\ast.py", line 59, in literal_eval 
> > node_or_string = parse(node_or_string, mode='eval') 
> > File "C:\Users\Jach\AppData\Local\Programs\Python\Python38-32\lib\ast.py", line 47, in parse 
> > return compile(source, filename, mode, flags, 
> > File "<unknown>", line 1 
> > \x0a 
> > ^ 
> > SyntaxError: unexpected character after line continuation character
> You missed a pair of quotes. They are easily overlooked but very 
> important. The point is to wrap your string in another pair of quotes so 
> it becomes a valid Python string literal in a Python string which can 
> then be passed to ast.literal_eval(). Works for me: 
> 
> In [7]: s0 = r'\x0a' 
> 
> In [8]: import ast 
> 
> In [9]: ast.literal_eval('"%s"' % s0) 
> Out[9]: '\n' 
> 
> -- 
> "Experience is that marvelous thing that enables you to recognize a 
> mistake when you make it again." 
> -- Franklin P. Jones
Thank you for notifying me. I did notice those  ''' in MRAB's post, but didn't figure out what it is at that time:-(

From jfong at ms4.hinet.net  Wed Dec  7 20:17:22 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Wed, 7 Dec 2022 17:17:22 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <mailman.1108.1670447857.20444.python-list@python.org>
References: <725a6a70-be22-d11a-e0cf-6a29ef2adeeb@web.de>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1108.1670447857.20444.python-list@python.org>
Message-ID: <ac8ef026-05ca-418c-b4c7-01004a941156n@googlegroups.com>

Peter Otten ? 2022?12?8? ?????5:17:59 [UTC+8] ??????
> On 07/12/2022 03:23, Jach Feng wrote: 
> > s0 = r'\x0a' 
> > At this moment it was done by 
> > 
> > def to1byte(matchobj): 
> > ....return chr(int('0x' + matchobj.group(1), 16)) 
> > s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> > 
> > But, is it that difficult on doing this simple thing?
> >>> import codecs 
> >>> codecs.decode(r"\x68\x65\x6c\x6c\x6f\x0a", "unicode-escape") 
> 'hello\n'
Thank you. What I really want to handle is to any r'\xdd'. The r'\x0a' is for example. Sorry, didn't describe it clearly:-)

From rbeaudoin at acm.org  Wed Dec  7 21:50:37 2022
From: rbeaudoin at acm.org (Robert E. Beaudoin)
Date: Wed, 7 Dec 2022 21:50:37 -0500
Subject: Nonuniform PRNG?
References: <Y5C54VAA5lCunGOM@icerm-dld>
 <mailman.1103.1670429159.20444.python-list@python.org>
Message-ID: <20221207215037.4d345dee@euclid>

One thing you could do is to apply von Neumann de-biasing to convert a
string of output bits from your biased PRNG to an unbiased string, and
test the de-biased output.  If such tests pass I don't know that you
can be satisfied thaty your biased PRNG is close to a theorieical
biased random bit stream, but if they fail that should indicate a
problem.

Robert E. Beaudoin


On Wed, 7 Dec 2022 11:05:53 -0500
David Lowry-Duda <david at lowryduda.com> wrote:

> Inspired by the recent thread about pseudorandom number generators on 
> python-ideas (where I also mistakenly first wrote this message), I
> began to wonder: suppose that I had a pseudorandom number generator
> that attempted to generate a nonuniform distribution. Suppose for
> instance that it was to generate a 0 bit 2/3 of the time, and a 1 bit
> 1/3 of the time.
> 
> How would one go about testing this PRNG against an idealized
> (similarly biased) PRNG?
> 
> - DLD



From robin at reportlab.com  Thu Dec  8 07:52:25 2022
From: robin at reportlab.com (Robin Becker)
Date: Thu, 8 Dec 2022 12:52:25 +0000
Subject: C extension custom types in abi3 module
Message-ID: <3c066a7e-cbbc-67ea-a880-53fb27d453b4@everest.reportlab.co.uk>

I am trying to split off reportlab C extensions to simplify installations and make use of more advanced packages.

A simple extension is easily converted to being an abi3 module. However, another has a custom type which uses the old 
style mechanisms here

   https://docs.python.org/3.7/extending/newtypes_tutorial.html#the-basics

I made a simple setup based on this abi3 example modified to allow switching between abi3 and normal build

   https://github.com/joerick/python-abi3-package-sample

I made a tiny change to the code example in the newtypes tutorial page the code is here

https://github.com/MrBitBucket/custom-type

In a python 3.7 - 3.12a3 environment I find I can build the wheel OK with

   ABI3_WHEEL=0 pip wheel -w dist .


but I get lots of compile errors if I switch to an abi3 build with

   ABI3_WHEEL=1 pip wheel -w dist .

looking at the errors

>      src/_custom.c:10:1: error: variable ?CustomType? has initializer but incomplete type
>          10 | static PyTypeObject CustomType = {
>             | ^~~~~~
>       In file included from /home/robin/LOCAL/3.7.16/include/python3.7m/Python.h:90,
>                        from src/_custom.c:2:
>       /home/robin/LOCAL/3.7.16/include/python3.7m/object.h:90:5: error: extra brace group at end of initializer
>          90 |     { PyObject_HEAD_INIT(type) size },
>             |     ^
>       src/_custom.c:11:9: note: in expansion of macro ?PyVarObject_HEAD_INIT?
>          11 |         PyVarObject_HEAD_INIT(NULL, 0)

it looks like I have to use a different mechanism to setup custom types in the abi3 world.

I looked in Modules/xxlimited_35.c, but that seems much more complex and provides for a type which supports GC.

Are there any ABI3 examples using the old style strategy?
--
Robin Becker

From gweatherby at uchc.edu  Thu Dec  8 08:23:42 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Thu, 8 Dec 2022 13:23:42 +0000
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <ac8ef026-05ca-418c-b4c7-01004a941156n@googlegroups.com>
References: <725a6a70-be22-d11a-e0cf-6a29ef2adeeb@web.de>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1108.1670447857.20444.python-list@python.org>
 <ac8ef026-05ca-418c-b4c7-01004a941156n@googlegroups.com>
Message-ID: <SA1PR14MB585574C305A6A441801C9F10B91D9@SA1PR14MB5855.namprd14.prod.outlook.com>

I?m not understanding the task. The sample code given is converting the input r?\x0a? to a newline, it appears.


import re


def exam(z):
    print(f"examine {type(z)} {z}")
    for c in z:
        print(f"{ord(c)} {c}")

s0 = r'\x0a'

def to1byte(matchobj):
    return chr(int('0x' + matchobj.group(1), 16))
s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
exam(s0)
exam(s1)

---
examine <class 'str'> \x0a
92 \
120 x
48 0
97 a
examine <class 'str'>

10

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jach Feng <jfong at ms4.hinet.net>
Date: Wednesday, December 7, 2022 at 9:27 PM
To: python-list at python.org <python-list at python.org>
Subject: Re: How to convert a raw string r'xdd' to 'xdd' more gracefully?
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Peter Otten ? 2022?12?8? ?????5:17:59 [UTC+8] ??????
> On 07/12/2022 03:23, Jach Feng wrote:
> > s0 = r'\x0a'
> > At this moment it was done by
> >
> > def to1byte(matchobj):
> > ....return chr(int('0x' + matchobj.group(1), 16))
> > s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
> >
> > But, is it that difficult on doing this simple thing?
> >>> import codecs
> >>> codecs.decode(r"\x68\x65\x6c\x6c\x6f\x0a", "unicode-escape")
> 'hello\n'
Thank you. What I really want to handle is to any r'\xdd'. The r'\x0a' is for example. Sorry, didn't describe it clearly:-)
--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!kUnextA7_cF7EoP_4hGzC5Jq2wRvn8nwLwT8wmeNkgVjK_n6VG19fxb-4SwmDMwepWe8_bGaH9Y2LlkSvFRz$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!kUnextA7_cF7EoP_4hGzC5Jq2wRvn8nwLwT8wmeNkgVjK_n6VG19fxb-4SwmDMwepWe8_bGaH9Y2LlkSvFRz$>

From list1 at tompassin.net  Thu Dec  8 09:12:19 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 8 Dec 2022 09:12:19 -0500
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <SA1PR14MB585574C305A6A441801C9F10B91D9@SA1PR14MB5855.namprd14.prod.outlook.com>
References: <725a6a70-be22-d11a-e0cf-6a29ef2adeeb@web.de>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1108.1670447857.20444.python-list@python.org>
 <ac8ef026-05ca-418c-b4c7-01004a941156n@googlegroups.com>
 <SA1PR14MB585574C305A6A441801C9F10B91D9@SA1PR14MB5855.namprd14.prod.outlook.com>
Message-ID: <f56cf170-8612-246b-dc54-eee529fa94a0@tompassin.net>

The original post started out with r'\x0a' but then talked about '\xdd'. 
  I assumed that there was a pattern here, a raw string containing "\x" 
and two more characters, and made a suggestion for converting any string 
with that pattern.  But the OP was very unclear what the task really 
was, so here we all are, making a variety of guesses.

On 12/8/2022 8:23 AM, Weatherby,Gerard wrote:
> I?m not understanding the task. The sample code given is converting the input r?\x0a? to a newline, it appears.
> 
> 
> import re
> 
> 
> def exam(z):
>      print(f"examine {type(z)} {z}")
>      for c in z:
>          print(f"{ord(c)} {c}")
> 
> s0 = r'\x0a'
> 
> def to1byte(matchobj):
>      return chr(int('0x' + matchobj.group(1), 16))
> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
> exam(s0)
> exam(s1)
> 
> ---
> examine <class 'str'> \x0a
> 92 \
> 120 x
> 48 0
> 97 a
> examine <class 'str'>
> 
> 10
> 
> From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jach Feng <jfong at ms4.hinet.net>
> Date: Wednesday, December 7, 2022 at 9:27 PM
> To: python-list at python.org <python-list at python.org>
> Subject: Re: How to convert a raw string r'xdd' to 'xdd' more gracefully?
> *** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***
> 
> Peter Otten ? 2022?12?8? ?????5:17:59 [UTC+8] ??????
>> On 07/12/2022 03:23, Jach Feng wrote:
>>> s0 = r'\x0a'
>>> At this moment it was done by
>>>
>>> def to1byte(matchobj):
>>> ....return chr(int('0x' + matchobj.group(1), 16))
>>> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>>>
>>> But, is it that difficult on doing this simple thing?
>>>>> import codecs
>>>>> codecs.decode(r"\x68\x65\x6c\x6c\x6f\x0a", "unicode-escape")
>> 'hello\n'
> Thank you. What I really want to handle is to any r'\xdd'. The r'\x0a' is for example. Sorry, didn't describe it clearly:-)
> --
> https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!kUnextA7_cF7EoP_4hGzC5Jq2wRvn8nwLwT8wmeNkgVjK_n6VG19fxb-4SwmDMwepWe8_bGaH9Y2LlkSvFRz$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!kUnextA7_cF7EoP_4hGzC5Jq2wRvn8nwLwT8wmeNkgVjK_n6VG19fxb-4SwmDMwepWe8_bGaH9Y2LlkSvFRz$>


From robin at reportlab.com  Thu Dec  8 10:35:55 2022
From: robin at reportlab.com (Robin Becker)
Date: Thu, 8 Dec 2022 15:35:55 +0000
Subject: C extension custom types in abi3 module
In-Reply-To: <3c066a7e-cbbc-67ea-a880-53fb27d453b4@everest.reportlab.co.uk>
References: <3c066a7e-cbbc-67ea-a880-53fb27d453b4@everest.reportlab.co.uk>
Message-ID: <8c0d3da6-cd0c-aa95-fc4d-c4f10aba9585@everest.reportlab.co.uk>

On 08/12/2022 12:52, Robin Becker wrote:
> I am trying to split off reportlab C extensions to simplify installations and make use of more advanced packages.
> 
> A simple extension is easily converted to being an abi3 module. However, another has a custom type which uses the old 
> style mechanisms here
............
> 
> it looks like I have to use a different mechanism to setup custom types in the abi3 world.
> 
In the docs I see this

"Also, since PyTypeObject is only part of the Limited API as an opaque struct, any extension modules using static types 
must be compiled for a specific Python minor version."

So it seems I must switch to using a heap allocated type or keep compiling in the old way.


> I looked in Modules/xxlimited_35.c, but that seems much more complex and provides for a type which supports GC.
> 
> Are there any ABI3 examples using the old style strategy?
> -- 
> Robin Becker

-- 
Robin Becker


From __peter__ at web.de  Thu Dec  8 11:20:27 2022
From: __peter__ at web.de (Peter Otten)
Date: Thu, 8 Dec 2022 17:20:27 +0100
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <ac8ef026-05ca-418c-b4c7-01004a941156n@googlegroups.com>
References: <725a6a70-be22-d11a-e0cf-6a29ef2adeeb@web.de>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <mailman.1108.1670447857.20444.python-list@python.org>
 <ac8ef026-05ca-418c-b4c7-01004a941156n@googlegroups.com>
Message-ID: <f9355d01-e482-54f9-aa84-11f3c97c3194@web.de>

On 08/12/2022 02:17, Jach Feng wrote:
> Peter Otten ? 2022?12?8? ?????5:17:59 [UTC+8] ??????
>> On 07/12/2022 03:23, Jach Feng wrote:
>>> s0 = r'\x0a'
>>> At this moment it was done by
>>>
>>> def to1byte(matchobj):
>>> ....return chr(int('0x' + matchobj.group(1), 16))
>>> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>>>
>>> But, is it that difficult on doing this simple thing?
>>>>> import codecs
>>>>> codecs.decode(r"\x68\x65\x6c\x6c\x6f\x0a", "unicode-escape")
>> 'hello\n'
> Thank you. What I really want to handle is to any r'\xdd'. The r'\x0a' is for example. Sorry, didn't describe it clearly:-)

Hm, codecs.decode() does work for arbitrary escapes. It will produce the
same result for r"\xdd"-type raw strings where d is in the range 0...F.
It will also convert other escapes like

 >>> codecs.decode(r"\t", "unicode-escape")
'\t'
 >>> codecs.decode(r"\u5728", "unicode-escape")
'?'


From jfong at ms4.hinet.net  Thu Dec  8 03:56:42 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Thu, 8 Dec 2022 00:56:42 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
Message-ID: <a3d9c9b0-aa3a-431a-9275-6f0489f458d6n@googlegroups.com>

Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
> s0 = r'\x0a' 
> At this moment it was done by 
> 
> def to1byte(matchobj): 
> ....return chr(int('0x' + matchobj.group(1), 16)) 
> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> 
> But, is it that difficult on doing this simple thing? 
> 
> --Jach
I find another answer on the web.

>>> s0 = r'\x0a'
>>> s0.encode('Latin-1').decode('unicode-escape')
'\n'

From aarnav.bos at code.berlin  Thu Dec  8 12:52:29 2022
From: aarnav.bos at code.berlin (Aarnav Mahavir Bos)
Date: Thu, 8 Dec 2022 18:52:29 +0100
Subject: Panoptisch - A way to understand your project's dependencies and find
 malicious packages
Message-ID: <CAGKp6MyQYVrxmYr4gNzuSNx53v=XU1uEOaJV65f2qAGN6GgoQw@mail.gmail.com>

Hello all,

I would like to share Panoptisch, a FOSS(Free and Open Source Software)
tool I've been working on.

We all may have encountered the issue of not having a clear dependency tree
or not being sure of the modules our dependencies and sub-dependencies are
using.

Some of us may have also heard of supply chain attacks, where open source
projects are hijacked to distribute malicious code masquerading as the
original package. This can happen deep down in the dependency chain.

Panoptisch was born out of the need to accurately verify the modules used
in my project.
It recursively scans a Python module or file to find modules used and
exports a report in JSON which can be parsed for analysis.

For example, should your yaml parser, or it's sub-dependencies import
socket/os? should your markdown renderer or it's sub-dependencies import
sys/importlib? *Probably not.*

Panoptisch is in early stages, has known limitations and is looking for
help! I would love feedback, contributions, and most important of all,
rigorous testing!

I would also love to help you integrate this tool in your workflow to write
more secure software.

Link: https://github.com/R9295/panoptisch
Short Demo: https://www.youtube.com/watch?v=bDJWl_odXx0

Thanks and Regards,
aarnav

From ilicjelena3105 at gmail.com  Thu Dec  8 15:12:47 2022
From: ilicjelena3105 at gmail.com (=?UTF-8?B?SmVsZW5hIElsacSH?=)
Date: Thu, 8 Dec 2022 12:12:47 -0800 (PST)
Subject: MinecraftEdu
Message-ID: <60a744d6-4994-41c3-a3bc-635cc7d665c3n@googlegroups.com>

Hello,
I'm new to MinecraftEDU programming with Python. I'm wondering if anyone can recommend how to get started with creating lessons and how to get started programming in MinecraftEDU?

From cs at cskk.id.au  Thu Dec  8 16:26:12 2022
From: cs at cskk.id.au (Cameron Simpson)
Date: Fri, 9 Dec 2022 08:26:12 +1100
Subject: MinecraftEdu
In-Reply-To: <60a744d6-4994-41c3-a3bc-635cc7d665c3n@googlegroups.com>
References: <60a744d6-4994-41c3-a3bc-635cc7d665c3n@googlegroups.com>
Message-ID: <Y5JWdImqGO2m5C6q@cskk.homeip.net>

On 08Dec2022 12:12, Jelena Ili? <ilicjelena3105 at gmail.com> wrote:
>I'm new to MinecraftEDU programming with Python. I'm wondering if 
>anyone can recommend how to get started with creating lessons and how 
>to get started programming in MinecraftEDU?

Had you started here?  
https://education.minecraft.net/en-us/resources/computer-science-subject-kit/python-101

That's just from a web search, I've not used it.

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

From jfong at ms4.hinet.net  Thu Dec  8 21:05:02 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Thu, 8 Dec 2022 18:05:02 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
Message-ID: <ce66cc3c-1361-4611-8314-bec0a3ca7abdn@googlegroups.com>

Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
> s0 = r'\x0a' 
> At this moment it was done by 
> 
> def to1byte(matchobj): 
> ....return chr(int('0x' + matchobj.group(1), 16)) 
> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> 
> But, is it that difficult on doing this simple thing? 
> 
> --Jach
The whold story is,

I had a script which accepts an argparse's positional argument. I like this argument may have control character embedded in when required. So I make a post "How to enter escape character in a positional string argument from the command line? on DEC05. But there is no response. I assume that there is no way of doing it and I have to convert it later after I get the whole string from the command line.

I made this convertion using the chr(int(...)) method but not satisfied with. That why this post came out.

At this moment the conversion is done almost the same as Peter's codecs.decode() method but without the need of importing codecs module:-)

def to1byte(matchobj):
....return matchobj.group(0).encode().decode("unicode-escape")

From axy at declassed.art  Thu Dec  8 22:49:58 2022
From: axy at declassed.art (Axy)
Date: Fri, 9 Dec 2022 03:49:58 +0000
Subject: Panoptisch - A way to understand your project's dependencies and
 find malicious packages
In-Reply-To: <CAGKp6MyQYVrxmYr4gNzuSNx53v=XU1uEOaJV65f2qAGN6GgoQw@mail.gmail.com>
References: <CAGKp6MyQYVrxmYr4gNzuSNx53v=XU1uEOaJV65f2qAGN6GgoQw@mail.gmail.com>
Message-ID: <146e747f-bb2b-29e6-b8df-93698495c46a@declassed.art>

On 08/12/2022 17:52, Aarnav Mahavir Bos wrote:
> Hello all,
>
> I would like to share Panoptisch, a FOSS(Free and Open Source Software)
> tool I've been working on.

Hi there,

I added your project to my watch list, keep on your work.

A couple of points:

First, I glanced at the code and in the very first file I opened, 
https://github.com/R9295/panoptisch/blob/master/panoptisch/__init__.py, 
I see main(). I usually place such a code in __main__.py

Second, in addition to AST analysis it would be nice to implement a 
sandbox with import hooks.

Axy.


From gweatherby at uchc.edu  Fri Dec  9 08:29:06 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Fri, 9 Dec 2022 13:29:06 +0000
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <ce66cc3c-1361-4611-8314-bec0a3ca7abdn@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <ce66cc3c-1361-4611-8314-bec0a3ca7abdn@googlegroups.com>
Message-ID: <SA1PR14MB5855E3DF0336F514B506CAF9B91C9@SA1PR14MB5855.namprd14.prod.outlook.com>

That?s actually more of a shell question than a Python question. How you pass certain control characters is going to depend on the shell, operating system, and possibly the keyboard you?re using. (e.g. https://www.alt-codes.net).

Here?s a sample program. The dashes are to help show the boundaries of the string

#!/usr/bin/env python3
import argparse
import logging


parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('data')
args = parser.parse_args()
print(f'Input\n: -{args.data}- length {len(args.data)}')
for c in args.data:
    print(f'{ord(c)} ',end='')
print()


Using bash on Linux:

./cl.py '^M
'
Input
  -
- length 3
13 32 10


From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jach Feng <jfong at ms4.hinet.net>
Date: Thursday, December 8, 2022 at 9:31 PM
To: python-list at python.org <python-list at python.org>
Subject: Re: How to convert a raw string r'xdd' to 'xdd' more gracefully?
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
> s0 = r'\x0a'
> At this moment it was done by
>
> def to1byte(matchobj):
> ....return chr(int('0x' + matchobj.group(1), 16))
> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>
> But, is it that difficult on doing this simple thing?
>
> --Jach
The whold story is,

I had a script which accepts an argparse's positional argument. I like this argument may have control character embedded in when required. So I make a post "How to enter escape character in a positional string argument from the command line? on DEC05. But there is no response. I assume that there is no way of doing it and I have to convert it later after I get the whole string from the command line.

I made this convertion using the chr(int(...)) method but not satisfied with. That why this post came out.

At this moment the conversion is done almost the same as Peter's codecs.decode() method but without the need of importing codecs module:-)

def to1byte(matchobj):
....return matchobj.group(0).encode().decode("unicode-escape")
--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$>

From dankolis at gmail.com  Fri Dec  9 10:38:57 2022
From: dankolis at gmail.com (Dan Kolis)
Date: Fri, 9 Dec 2022 07:38:57 -0800 (PST)
Subject: Panoptisch - A way to understand your project's dependencies and
 find malicious packages
In-Reply-To: <mailman.1119.1670558214.20444.python-list@python.org>
References: <146e747f-bb2b-29e6-b8df-93698495c46a@declassed.art>
 <CAGKp6MyQYVrxmYr4gNzuSNx53v=XU1uEOaJV65f2qAGN6GgoQw@mail.gmail.com>
 <mailman.1119.1670558214.20444.python-list@python.org>
Message-ID: <8903c97c-26a0-486b-a1b8-f4330659f2a3n@googlegroups.com>

I think it needs a built in viewer or at least a human readable output, or nobody will go through the trouble to use it.

Other that that, maybe a pretty good idea, sure


From kermit at polaris.net  Fri Dec  9 12:13:16 2022
From: kermit at polaris.net (kermit at polaris.net)
Date: Fri, 9 Dec 2022 12:13:16 -0500 (EST)
Subject: New computer, new Python
In-Reply-To: <mailman.13.1670605202.8429.python-list@python.org>
References: <mailman.13.1670605202.8429.python-list@python.org>
Message-ID: <1670605996.031430820@webmail.emailsrvr.com>


 
Hello.  I've downloaded the new Python to my new Computer,  and the new Python mystifies me.
 
Instead of an editor, it looks like a Dos executable program.
 
How can I write my own Python Functions and subroutines in the new Python?
 
It is version 3.11 (64 bit).
 
Kermit
 
 
 
 
-----Original Message-----
From: python-list-request at python.org
Sent: Friday, December 9, 2022 12:00pm
To: python-list at python.org
Subject: Python-list Digest, Vol 231, Issue 9



Send Python-list mailing list submissions to
 python-list at python.org

To subscribe or unsubscribe via the World Wide Web, visit
 https://mail.python.org/mailman/listinfo/python-list
or, via email, send a message with subject or body 'help' to
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When replying, please edit your Subject line so it is more specific
than "Re: Contents of Python-list digest..."


Today's Topics:

 1. Re: How to convert a raw string r'\xdd' to '\xdd' more
 gracefully? (Jach Feng)
 2. Re: Nonuniform PRNG? (Stefan Ram)
 3. Panoptisch - A way to understand your project's dependencies
 and find malicious packages (Aarnav Mahavir Bos)
 4. MinecraftEdu (Jelena Ili?)
 5. Re: MinecraftEdu (Cameron Simpson)
 6. Re: How to convert a raw string r'\xdd' to '\xdd' more
 gracefully? (Jach Feng)
 7. Re: Panoptisch - A way to understand your project's
 dependencies and find malicious packages (Axy)
 8. Re: How to convert a raw string r'\xdd' to '\xdd' more
 gracefully? (Weatherby,Gerard)
 9. Re: Panoptisch - A way to understand your project's
 dependencies and find malicious packages (Dan Kolis)


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

Message: 1
Date: Thu, 8 Dec 2022 00:56:42 -0800 (PST)
From: Jach Feng <jfong at ms4.hinet.net>
To: python-list at python.org
Subject: Re: How to convert a raw string r'\xdd' to '\xdd' more
 gracefully?
Message-ID: <a3d9c9b0-aa3a-431a-9275-6f0489f458d6n at googlegroups.com>
Content-Type: text/plain; charset="UTF-8"

Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
> s0 = r'\x0a' 
> At this moment it was done by 
> 
> def to1byte(matchobj): 
> ....return chr(int('0x' + matchobj.group(1), 16)) 
> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> 
> But, is it that difficult on doing this simple thing? 
> 
> --Jach
I find another answer on the web.

>>> s0 = r'\x0a'
>>> s0.encode('Latin-1').decode('unicode-escape')
'\n'


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

Message: 2
Date: 8 Dec 2022 12:17:22 GMT
From: ram at zedat.fu-berlin.de (Stefan Ram)
To: python-list at python.org
Subject: Re: Nonuniform PRNG?
Message-ID: <random-20221208131657 at ram.dialup.fu-berlin.de>
Content-Type: text/plain; charset=UTF-8

"Robert E. Beaudoin" <rbeaudoin at acm.org> writes:
>One thing you could do is to apply von Neumann de-biasing to convert a
>string of output bits from your biased PRNG to an unbiased string, and
>test the de-biased output.

 Some non-uniform generators are based on uniform generators
 whose output then is warped by the application of some function.

 If one has access to the underlying uniform generator used,
 one can test this with the algorithms for uniform generators.




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

Message: 3
Date: Thu, 8 Dec 2022 18:52:29 +0100
From: Aarnav Mahavir Bos <aarnav.bos at code.berlin>
To: python-list at python.org
Subject: Panoptisch - A way to understand your project's dependencies
 and find malicious packages
Message-ID:
 <CAGKp6MyQYVrxmYr4gNzuSNx53v=XU1uEOaJV65f2qAGN6GgoQw at mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"

Hello all,

I would like to share Panoptisch, a FOSS(Free and Open Source Software)
tool I've been working on.

We all may have encountered the issue of not having a clear dependency tree
or not being sure of the modules our dependencies and sub-dependencies are
using.

Some of us may have also heard of supply chain attacks, where open source
projects are hijacked to distribute malicious code masquerading as the
original package. This can happen deep down in the dependency chain.

Panoptisch was born out of the need to accurately verify the modules used
in my project.
It recursively scans a Python module or file to find modules used and
exports a report in JSON which can be parsed for analysis.

For example, should your yaml parser, or it's sub-dependencies import
socket/os? should your markdown renderer or it's sub-dependencies import
sys/importlib? *Probably not.*

Panoptisch is in early stages, has known limitations and is looking for
help! I would love feedback, contributions, and most important of all,
rigorous testing!

I would also love to help you integrate this tool in your workflow to write
more secure software.

Link: https://github.com/R9295/panoptisch
Short Demo: https://www.youtube.com/watch?v=bDJWl_odXx0

Thanks and Regards,
aarnav


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

Message: 4
Date: Thu, 8 Dec 2022 12:12:47 -0800 (PST)
From: Jelena Ili? <ilicjelena3105 at gmail.com>
To: python-list at python.org
Subject: MinecraftEdu
Message-ID: <60a744d6-4994-41c3-a3bc-635cc7d665c3n at googlegroups.com>
Content-Type: text/plain; charset="UTF-8"

Hello,
I'm new to MinecraftEDU programming with Python. I'm wondering if anyone can recommend how to get started with creating lessons and how to get started programming in MinecraftEDU?


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

Message: 5
Date: Fri, 9 Dec 2022 08:26:12 +1100
From: Cameron Simpson <cs at cskk.id.au>
To: Jelena Ili? <ilicjelena3105 at gmail.com>
Cc: python-list at python.org
Subject: Re: MinecraftEdu
Message-ID: <Y5JWdImqGO2m5C6q at cskk.homeip.net>
Content-Type: text/plain; charset=utf-8; format=flowed

On 08Dec2022 12:12, Jelena Ili? <ilicjelena3105 at gmail.com> wrote:
>I'm new to MinecraftEDU programming with Python. I'm wondering if 
>anyone can recommend how to get started with creating lessons and how 
>to get started programming in MinecraftEDU?

Had you started here? 
https://education.minecraft.net/en-us/resources/computer-science-subject-kit/python-101

That's just from a web search, I've not used it.

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


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

Message: 6
Date: Thu, 8 Dec 2022 18:05:02 -0800 (PST)
From: Jach Feng <jfong at ms4.hinet.net>
To: python-list at python.org
Subject: Re: How to convert a raw string r'\xdd' to '\xdd' more
 gracefully?
Message-ID: <ce66cc3c-1361-4611-8314-bec0a3ca7abdn at googlegroups.com>
Content-Type: text/plain; charset="UTF-8"

Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
> s0 = r'\x0a' 
> At this moment it was done by 
> 
> def to1byte(matchobj): 
> ....return chr(int('0x' + matchobj.group(1), 16)) 
> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> 
> But, is it that difficult on doing this simple thing? 
> 
> --Jach
The whold story is,

I had a script which accepts an argparse's positional argument. I like this argument may have control character embedded in when required. So I make a post "How to enter escape character in a positional string argument from the command line? on DEC05. But there is no response. I assume that there is no way of doing it and I have to convert it later after I get the whole string from the command line.

I made this convertion using the chr(int(...)) method but not satisfied with. That why this post came out.

At this moment the conversion is done almost the same as Peter's codecs.decode() method but without the need of importing codecs module:-)

def to1byte(matchobj):
....return matchobj.group(0).encode().decode("unicode-escape")


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

Message: 7
Date: Fri, 9 Dec 2022 03:49:58 +0000
From: Axy <axy at declassed.art>
To: python-list at python.org
Subject: Re: Panoptisch - A way to understand your project's
 dependencies and find malicious packages
Message-ID: <146e747f-bb2b-29e6-b8df-93698495c46a at declassed.art>
Content-Type: text/plain; charset=UTF-8; format=flowed

On 08/12/2022 17:52, Aarnav Mahavir Bos wrote:
> Hello all,
>
> I would like to share Panoptisch, a FOSS(Free and Open Source Software)
> tool I've been working on.

Hi there,

I added your project to my watch list, keep on your work.

A couple of points:

First, I glanced at the code and in the very first file I opened, 
https://github.com/R9295/panoptisch/blob/master/panoptisch/__init__.py, 
I see main(). I usually place such a code in __main__.py

Second, in addition to AST analysis it would be nice to implement a 
sandbox with import hooks.

Axy.



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

Message: 8
Date: Fri, 9 Dec 2022 13:29:06 +0000
From: "Weatherby,Gerard" <gweatherby at uchc.edu>
To: Jach Feng <jfong at ms4.hinet.net>, "python-list at python.org"
 <python-list at python.org>
Subject: Re: How to convert a raw string r'\xdd' to '\xdd' more
 gracefully?
Message-ID:
 <SA1PR14MB5855E3DF0336F514B506CAF9B91C9 at SA1PR14MB5855.namprd14.prod.outlook.com>

Content-Type: text/plain; charset="iso-2022-jp"

That?s actually more of a shell question than a Python question. How you pass certain control characters is going to depend on the shell, operating system, and possibly the keyboard you?re using. (e.g. https://www.alt-codes.net).

Here?s a sample program. The dashes are to help show the boundaries of the string

#!/usr/bin/env python3
import argparse
import logging


parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
parser.add_argument('data')
args = parser.parse_args()
print(f'Input\n: -{args.data}- length {len(args.data)}')
for c in args.data:
 print(f'{ord(c)} ',end='')
print()


Using bash on Linux:

./cl.py '^M
'
Input
 -
- length 3
13 32 10


From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jach Feng <jfong at ms4.hinet.net>
Date: Thursday, December 8, 2022 at 9:31 PM
To: python-list at python.org <python-list at python.org>
Subject: Re: How to convert a raw string r'xdd' to 'xdd' more gracefully?
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
> s0 = r'\x0a'
> At this moment it was done by
>
> def to1byte(matchobj):
> ....return chr(int('0x' + matchobj.group(1), 16))
> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>
> But, is it that difficult on doing this simple thing?
>
> --Jach
The whold story is,

I had a script which accepts an argparse's positional argument. I like this argument may have control character embedded in when required. So I make a post "How to enter escape character in a positional string argument from the command line? on DEC05. But there is no response. I assume that there is no way of doing it and I have to convert it later after I get the whole string from the command line.

I made this convertion using the chr(int(...)) method but not satisfied with. That why this post came out.

At this moment the conversion is done almost the same as Peter's codecs.decode() method but without the need of importing codecs module:-)

def to1byte(matchobj):
....return matchobj.group(0).encode().decode("unicode-escape")
--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$>


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

Message: 9
Date: Fri, 9 Dec 2022 07:38:57 -0800 (PST)
From: Dan Kolis <dankolis at gmail.com>
To: python-list at python.org
Subject: Re: Panoptisch - A way to understand your project's
 dependencies and find malicious packages
Message-ID: <8903c97c-26a0-486b-a1b8-f4330659f2a3n at googlegroups.com>
Content-Type: text/plain; charset="UTF-8"

I think it needs a built in viewer or at least a human readable output, or nobody will go through the trouble to use it.

Other that that, maybe a pretty good idea, sure



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

Subject: Digest Footer

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


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

End of Python-list Digest, Vol 231, Issue 9
*******************************************

From PythonList at DancesWithMice.info  Fri Dec  9 15:30:55 2022
From: PythonList at DancesWithMice.info (dn)
Date: Sat, 10 Dec 2022 09:30:55 +1300
Subject: New computer, new Python
In-Reply-To: <1670605996.031430820@webmail.emailsrvr.com>
References: <mailman.13.1670605202.8429.python-list@python.org>
 <1670605996.031430820@webmail.emailsrvr.com>
Message-ID: <a706b303-dd19-03a8-225d-bd5dc1b25789@DancesWithMice.info>

On 10/12/2022 06.13, kermit at polaris.net wrote:
> 
>   
> Hello.  I've downloaded the new Python to my new Computer,  and the new Python mystifies me.
>   
> Instead of an editor, it looks like a Dos executable program.
>   
> How can I write my own Python Functions and subroutines in the new Python?
>   
> It is version 3.11 (64 bit).


Have you invested time in the documentation? 
https://docs.python.org/3/using/windows.html

-- 
Regards,
=dn

From nospam at dfs.com  Fri Dec  9 15:36:44 2022
From: nospam at dfs.com (DFS)
Date: Fri, 9 Dec 2022 15:36:44 -0500
Subject: New computer, new Python
In-Reply-To: <mailman.1121.1670614920.20444.python-list@python.org>
References: <mailman.13.1670605202.8429.python-list@python.org>
 <1670605996.031430820@webmail.emailsrvr.com>
 <mailman.1121.1670614920.20444.python-list@python.org>
Message-ID: <w%MkL.5246$9sn9.3063@fx17.iad>

On 12/9/2022 12:13 PM, kermit at polaris.net wrote:
> 
>   
> Hello.  I've downloaded the new Python to my new Computer,  and the new Python mystifies me.
>   
> Instead of an editor, it looks like a Dos executable program.

python.exe is a Windows executable.



> How can I write my own Python Functions and subroutines in the new Python?

Open a text editor and write your own functions and subs.  Save the file 
as prog.py.

 From the command line (not from inside the Python shell), type:

$ python prog.py



> It is version 3.11 (64 bit).

The latest and greatest.  Significantly sped up vs 3.10.


From gweatherby at uchc.edu  Fri Dec  9 17:03:19 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Fri, 9 Dec 2022 22:03:19 +0000
Subject: New computer, new Python
In-Reply-To: <w%MkL.5246$9sn9.3063@fx17.iad>
References: <mailman.13.1670605202.8429.python-list@python.org>
 <1670605996.031430820@webmail.emailsrvr.com>
 <mailman.1121.1670614920.20444.python-list@python.org>
 <w%MkL.5246$9sn9.3063@fx17.iad>
Message-ID: <SA1PR14MB5855017BAD3CB64E5128F5F2B91C9@SA1PR14MB5855.namprd14.prod.outlook.com>

Python in an IDE is much easier in the long run. We use PyCharm ? there?s a free version: https://www.jetbrains.com/pycharm/download/#section=windows

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of DFS <nospam at dfs.com>
Date: Friday, December 9, 2022 at 4:36 PM
To: python-list at python.org <python-list at python.org>
Subject: Re: New computer, new Python
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

On 12/9/2022 12:13 PM, kermit at polaris.net wrote:
>
>
> Hello.  I've downloaded the new Python to my new Computer,  and the new Python mystifies me.
>
> Instead of an editor, it looks like a Dos executable program.

python.exe is a Windows executable.



> How can I write my own Python Functions and subroutines in the new Python?

Open a text editor and write your own functions and subs.  Save the file
as prog.py.

 From the command line (not from inside the Python shell), type:

$ python prog.py



> It is version 3.11 (64 bit).

The latest and greatest.  Significantly sped up vs 3.10.

--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!ncQETnsgLM_I29jKwV8WUZPhvn7g3Q5jBnkT_S0CmOf0KCORpl5xSLtMM8ZtE8gMsORNxCKhq01pCww$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!ncQETnsgLM_I29jKwV8WUZPhvn7g3Q5jBnkT_S0CmOf0KCORpl5xSLtMM8ZtE8gMsORNxCKhq01pCww$>

From bowman at montana.com  Fri Dec  9 16:56:34 2022
From: bowman at montana.com (rbowman)
Date: 9 Dec 2022 21:56:34 GMT
Subject: New computer, new Python
References: <mailman.13.1670605202.8429.python-list@python.org>
 <1670605996.031430820@webmail.emailsrvr.com>
 <mailman.1121.1670614920.20444.python-list@python.org>
Message-ID: <jvhp8iF18jcU2@mid.individual.net>

On Fri, 9 Dec 2022 12:13:16 -0500 (EST), kermit at polaris.net wrote:

> How can I write my own Python Functions and subroutines in the new
> Python?

Personally, I would go with VS Code:

https://learn.microsoft.com/en-us/training/modules/python-install-vscode/

It supports virtual environments nicely:

https://code.visualstudio.com/docs/python/environments

From mats at wichmann.us  Fri Dec  9 17:38:59 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Fri, 9 Dec 2022 15:38:59 -0700
Subject: New computer, new Python
In-Reply-To: <jvhp8iF18jcU2@mid.individual.net>
References: <mailman.13.1670605202.8429.python-list@python.org>
 <1670605996.031430820@webmail.emailsrvr.com>
 <mailman.1121.1670614920.20444.python-list@python.org>
 <jvhp8iF18jcU2@mid.individual.net>
Message-ID: <b837b5fe-083c-a83f-ef61-238448edfb84@wichmann.us>

On 12/9/22 14:56, rbowman wrote:
> On Fri, 9 Dec 2022 12:13:16 -0500 (EST), kermit at polaris.net wrote:
> 
>> How can I write my own Python Functions and subroutines in the new
>> Python?
> 
> Personally, I would go with VS Code:
> 
> https://learn.microsoft.com/en-us/training/modules/python-install-vscode/
> 
> It supports virtual environments nicely:
> 
> https://code.visualstudio.com/docs/python/environments

Possibly in some previous setup, IDLE was the thing you opened. IDLE 
*is* an IDE - maybe not the fanciest one available, but it's written in 
Python and comes with the Python distribution.  I don't disagree with 
the two fine editors/IESs suggested previously (I use both of them, in 
slightly different circumstances), but IDLE works well too.

Try telling windows to find and open idle and see if that's more what 
you are expecting?



From list1 at tompassin.net  Fri Dec  9 17:36:10 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Fri, 9 Dec 2022 17:36:10 -0500
Subject: New computer, new Python
In-Reply-To: <1670605996.031430820@webmail.emailsrvr.com>
References: <mailman.13.1670605202.8429.python-list@python.org>
 <1670605996.031430820@webmail.emailsrvr.com>
Message-ID: <dc01032c-4195-cd3f-8b93-e82d48db7a45@tompassin.net>

It sounds like on your old computer, you used some kind of program to 
write python code and perhaps to run it too.  It would help if you could 
say what that program was.  Python itself - the actual program called 
"python.exe" on Windows - runs a Python interpreter inside a Windows 
console window.  That's what you see when you run "python".  You 
probably would like to run the same editor as you used on the old 
computer, but unless you can say what that program was, we can't help 
you.  The best we can do is to suggest various alternative programs and 
editors, as several people have already done.

On 12/9/2022 12:13 PM, kermit at polaris.net wrote:
> 
>   
> Hello.  I've downloaded the new Python to my new Computer,  and the new Python mystifies me.
>   
> Instead of an editor, it looks like a Dos executable program.
>   
> How can I write my own Python Functions and subroutines in the new Python?
>   
> It is version 3.11 (64 bit).
>   
> Kermit
>   
>   
>   
>   
> -----Original Message-----
> From: python-list-request at python.org
> Sent: Friday, December 9, 2022 12:00pm
> To: python-list at python.org
> Subject: Python-list Digest, Vol 231, Issue 9
> 
> 
> 
> Send Python-list mailing list submissions to
>   python-list at python.org
> 
> To subscribe or unsubscribe via the World Wide Web, visit
>   https://mail.python.org/mailman/listinfo/python-list
> or, via email, send a message with subject or body 'help' to
>   python-list-request at python.org
> 
> You can reach the person managing the list at
>   python-list-owner at python.org
> 
> When replying, please edit your Subject line so it is more specific
> than "Re: Contents of Python-list digest..."
> 
> 
> Today's Topics:
> 
>   1. Re: How to convert a raw string r'\xdd' to '\xdd' more
>   gracefully? (Jach Feng)
>   2. Re: Nonuniform PRNG? (Stefan Ram)
>   3. Panoptisch - A way to understand your project's dependencies
>   and find malicious packages (Aarnav Mahavir Bos)
>   4. MinecraftEdu (Jelena Ili?)
>   5. Re: MinecraftEdu (Cameron Simpson)
>   6. Re: How to convert a raw string r'\xdd' to '\xdd' more
>   gracefully? (Jach Feng)
>   7. Re: Panoptisch - A way to understand your project's
>   dependencies and find malicious packages (Axy)
>   8. Re: How to convert a raw string r'\xdd' to '\xdd' more
>   gracefully? (Weatherby,Gerard)
>   9. Re: Panoptisch - A way to understand your project's
>   dependencies and find malicious packages (Dan Kolis)
> 
> 
> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Thu, 8 Dec 2022 00:56:42 -0800 (PST)
> From: Jach Feng <jfong at ms4.hinet.net>
> To: python-list at python.org
> Subject: Re: How to convert a raw string r'\xdd' to '\xdd' more
>   gracefully?
> Message-ID: <a3d9c9b0-aa3a-431a-9275-6f0489f458d6n at googlegroups.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
>> s0 = r'\x0a'
>> At this moment it was done by
>>
>> def to1byte(matchobj):
>> ....return chr(int('0x' + matchobj.group(1), 16))
>> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>>
>> But, is it that difficult on doing this simple thing?
>>
>> --Jach
> I find another answer on the web.
> 
>>>> s0 = r'\x0a'
>>>> s0.encode('Latin-1').decode('unicode-escape')
> '\n'
> 
> 
> ------------------------------
> 
> Message: 2
> Date: 8 Dec 2022 12:17:22 GMT
> From: ram at zedat.fu-berlin.de (Stefan Ram)
> To: python-list at python.org
> Subject: Re: Nonuniform PRNG?
> Message-ID: <random-20221208131657 at ram.dialup.fu-berlin.de>
> Content-Type: text/plain; charset=UTF-8
> 
> "Robert E. Beaudoin" <rbeaudoin at acm.org> writes:
>> One thing you could do is to apply von Neumann de-biasing to convert a
>> string of output bits from your biased PRNG to an unbiased string, and
>> test the de-biased output.
> 
>   Some non-uniform generators are based on uniform generators
>   whose output then is warped by the application of some function.
> 
>   If one has access to the underlying uniform generator used,
>   one can test this with the algorithms for uniform generators.
> 
> 
> 
> 
> ------------------------------
> 
> Message: 3
> Date: Thu, 8 Dec 2022 18:52:29 +0100
> From: Aarnav Mahavir Bos <aarnav.bos at code.berlin>
> To: python-list at python.org
> Subject: Panoptisch - A way to understand your project's dependencies
>   and find malicious packages
> Message-ID:
>   <CAGKp6MyQYVrxmYr4gNzuSNx53v=XU1uEOaJV65f2qAGN6GgoQw at mail.gmail.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> Hello all,
> 
> I would like to share Panoptisch, a FOSS(Free and Open Source Software)
> tool I've been working on.
> 
> We all may have encountered the issue of not having a clear dependency tree
> or not being sure of the modules our dependencies and sub-dependencies are
> using.
> 
> Some of us may have also heard of supply chain attacks, where open source
> projects are hijacked to distribute malicious code masquerading as the
> original package. This can happen deep down in the dependency chain.
> 
> Panoptisch was born out of the need to accurately verify the modules used
> in my project.
> It recursively scans a Python module or file to find modules used and
> exports a report in JSON which can be parsed for analysis.
> 
> For example, should your yaml parser, or it's sub-dependencies import
> socket/os? should your markdown renderer or it's sub-dependencies import
> sys/importlib? *Probably not.*
> 
> Panoptisch is in early stages, has known limitations and is looking for
> help! I would love feedback, contributions, and most important of all,
> rigorous testing!
> 
> I would also love to help you integrate this tool in your workflow to write
> more secure software.
> 
> Link: https://github.com/R9295/panoptisch
> Short Demo: https://www.youtube.com/watch?v=bDJWl_odXx0
> 
> Thanks and Regards,
> aarnav
> 
> 
> ------------------------------
> 
> Message: 4
> Date: Thu, 8 Dec 2022 12:12:47 -0800 (PST)
> From: Jelena Ili? <ilicjelena3105 at gmail.com>
> To: python-list at python.org
> Subject: MinecraftEdu
> Message-ID: <60a744d6-4994-41c3-a3bc-635cc7d665c3n at googlegroups.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> Hello,
> I'm new to MinecraftEDU programming with Python. I'm wondering if anyone can recommend how to get started with creating lessons and how to get started programming in MinecraftEDU?
> 
> 
> ------------------------------
> 
> Message: 5
> Date: Fri, 9 Dec 2022 08:26:12 +1100
> From: Cameron Simpson <cs at cskk.id.au>
> To: Jelena Ili? <ilicjelena3105 at gmail.com>
> Cc: python-list at python.org
> Subject: Re: MinecraftEdu
> Message-ID: <Y5JWdImqGO2m5C6q at cskk.homeip.net>
> Content-Type: text/plain; charset=utf-8; format=flowed
> 
> On 08Dec2022 12:12, Jelena Ili? <ilicjelena3105 at gmail.com> wrote:
>> I'm new to MinecraftEDU programming with Python. I'm wondering if
>> anyone can recommend how to get started with creating lessons and how
>> to get started programming in MinecraftEDU?
> 
> Had you started here?
> https://education.minecraft.net/en-us/resources/computer-science-subject-kit/python-101
> 
> That's just from a web search, I've not used it.
> 
> Cheers,
> Cameron Simpson <cs at cskk.id.au>
> 
> 
> ------------------------------
> 
> Message: 6
> Date: Thu, 8 Dec 2022 18:05:02 -0800 (PST)
> From: Jach Feng <jfong at ms4.hinet.net>
> To: python-list at python.org
> Subject: Re: How to convert a raw string r'\xdd' to '\xdd' more
>   gracefully?
> Message-ID: <ce66cc3c-1361-4611-8314-bec0a3ca7abdn at googlegroups.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
>> s0 = r'\x0a'
>> At this moment it was done by
>>
>> def to1byte(matchobj):
>> ....return chr(int('0x' + matchobj.group(1), 16))
>> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>>
>> But, is it that difficult on doing this simple thing?
>>
>> --Jach
> The whold story is,
> 
> I had a script which accepts an argparse's positional argument. I like this argument may have control character embedded in when required. So I make a post "How to enter escape character in a positional string argument from the command line? on DEC05. But there is no response. I assume that there is no way of doing it and I have to convert it later after I get the whole string from the command line.
> 
> I made this convertion using the chr(int(...)) method but not satisfied with. That why this post came out.
> 
> At this moment the conversion is done almost the same as Peter's codecs.decode() method but without the need of importing codecs module:-)
> 
> def to1byte(matchobj):
> ....return matchobj.group(0).encode().decode("unicode-escape")
> 
> 
> ------------------------------
> 
> Message: 7
> Date: Fri, 9 Dec 2022 03:49:58 +0000
> From: Axy <axy at declassed.art>
> To: python-list at python.org
> Subject: Re: Panoptisch - A way to understand your project's
>   dependencies and find malicious packages
> Message-ID: <146e747f-bb2b-29e6-b8df-93698495c46a at declassed.art>
> Content-Type: text/plain; charset=UTF-8; format=flowed
> 
> On 08/12/2022 17:52, Aarnav Mahavir Bos wrote:
>> Hello all,
>>
>> I would like to share Panoptisch, a FOSS(Free and Open Source Software)
>> tool I've been working on.
> 
> Hi there,
> 
> I added your project to my watch list, keep on your work.
> 
> A couple of points:
> 
> First, I glanced at the code and in the very first file I opened,
> https://github.com/R9295/panoptisch/blob/master/panoptisch/__init__.py,
> I see main(). I usually place such a code in __main__.py
> 
> Second, in addition to AST analysis it would be nice to implement a
> sandbox with import hooks.
> 
> Axy.
> 
> 
> 
> ------------------------------
> 
> Message: 8
> Date: Fri, 9 Dec 2022 13:29:06 +0000
> From: "Weatherby,Gerard" <gweatherby at uchc.edu>
> To: Jach Feng <jfong at ms4.hinet.net>, "python-list at python.org"
>   <python-list at python.org>
> Subject: Re: How to convert a raw string r'\xdd' to '\xdd' more
>   gracefully?
> Message-ID:
>   <SA1PR14MB5855E3DF0336F514B506CAF9B91C9 at SA1PR14MB5855.namprd14.prod.outlook.com>
> 
> Content-Type: text/plain; charset="iso-2022-jp"
> 
> That?s actually more of a shell question than a Python question. How you pass certain control characters is going to depend on the shell, operating system, and possibly the keyboard you?re using. (e.g. https://www.alt-codes.net).
> 
> Here?s a sample program. The dashes are to help show the boundaries of the string
> 
> #!/usr/bin/env python3
> import argparse
> import logging
> 
> 
> parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
> parser.add_argument('data')
> args = parser.parse_args()
> print(f'Input\n: -{args.data}- length {len(args.data)}')
> for c in args.data:
>   print(f'{ord(c)} ',end='')
> print()
> 
> 
> Using bash on Linux:
> 
> ./cl.py '^M
> '
> Input
>   -
> - length 3
> 13 32 10
> 
> 
> From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jach Feng <jfong at ms4.hinet.net>
> Date: Thursday, December 8, 2022 at 9:31 PM
> To: python-list at python.org <python-list at python.org>
> Subject: Re: How to convert a raw string r'xdd' to 'xdd' more gracefully?
> *** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***
> 
> Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ??????
>> s0 = r'\x0a'
>> At this moment it was done by
>>
>> def to1byte(matchobj):
>> ....return chr(int('0x' + matchobj.group(1), 16))
>> s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0)
>>
>> But, is it that difficult on doing this simple thing?
>>
>> --Jach
> The whold story is,
> 
> I had a script which accepts an argparse's positional argument. I like this argument may have control character embedded in when required. So I make a post "How to enter escape character in a positional string argument from the command line? on DEC05. But there is no response. I assume that there is no way of doing it and I have to convert it later after I get the whole string from the command line.
> 
> I made this convertion using the chr(int(...)) method but not satisfied with. That why this post came out.
> 
> At this moment the conversion is done almost the same as Peter's codecs.decode() method but without the need of importing codecs module:-)
> 
> def to1byte(matchobj):
> ....return matchobj.group(0).encode().decode("unicode-escape")
> --
> https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$>
> 
> 
> ------------------------------
> 
> Message: 9
> Date: Fri, 9 Dec 2022 07:38:57 -0800 (PST)
> From: Dan Kolis <dankolis at gmail.com>
> To: python-list at python.org
> Subject: Re: Panoptisch - A way to understand your project's
>   dependencies and find malicious packages
> Message-ID: <8903c97c-26a0-486b-a1b8-f4330659f2a3n at googlegroups.com>
> Content-Type: text/plain; charset="UTF-8"
> 
> I think it needs a built in viewer or at least a human readable output, or nobody will go through the trouble to use it.
> 
> Other that that, maybe a pretty good idea, sure
> 
> 
> 
> ------------------------------
> 
> Subject: Digest Footer
> 


From jfong at ms4.hinet.net  Fri Dec  9 21:06:54 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Fri, 9 Dec 2022 18:06:54 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <mailman.1120.1670592955.20444.python-list@python.org>
References: <AQHZCeOrKILFBfR0UkOGPPbbPTW9zq5k0YQAgAC9zXM=>
 <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <SA1PR14MB5855E3DF0336F514B506CAF9B91C9@SA1PR14MB5855.namprd14.prod.outlook.com>
 <ce66cc3c-1361-4611-8314-bec0a3ca7abdn@googlegroups.com>
 <mailman.1120.1670592955.20444.python-list@python.org>
Message-ID: <1b7bc8dd-06cd-4f2a-897f-76fd6f0f7ec9n@googlegroups.com>

Weatherby,Gerard ? 2022?12?9? ?????9:36:18 [UTC+8] ??????
> That?s actually more of a shell question than a Python question. How you pass certain control characters is going to depend on the shell, operating system, and possibly the keyboard you?re using. (e.g. https://www.alt-codes.net). 
> 
> Here?s a sample program. The dashes are to help show the boundaries of the string 
> 
> #!/usr/bin/env python3 
> import argparse 
> import logging 
> 
> 
> parser = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter) 
> parser.add_argument('data') 
> args = parser.parse_args() 
> print(f'Input\n: -{args.data}- length {len(args.data)}') 
> for c in args.data: 
> print(f'{ord(c)} ',end='') 
> print() 
> 
> 
> Using bash on Linux: 
> 
> ./cl.py '^M 
> ' 
> Input 
> - 
> - length 3 
> 13 32 10
> From: Python-list <python-list-bounces+gweatherby=uchc... at python.org> on behalf of Jach Feng <jf... at ms4.hinet.net> 
> Date: Thursday, December 8, 2022 at 9:31 PM 
> To: pytho... at python.org <pytho... at python.org> 
> Subject: Re: How to convert a raw string r'xdd' to 'xdd' more gracefully? 
> *** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***
> Jach Feng ? 2022?12?7? ?????10:23:20 [UTC+8] ?????? 
> > s0 = r'\x0a' 
> > At this moment it was done by 
> > 
> > def to1byte(matchobj): 
> > ....return chr(int('0x' + matchobj.group(1), 16)) 
> > s1 = re.sub(r'\\x([0-9a-fA-F]{2})', to1byte, s0) 
> > 
> > But, is it that difficult on doing this simple thing? 
> > 
> > --Jach 
> The whold story is, 
> 
> I had a script which accepts an argparse's positional argument. I like this argument may have control character embedded in when required. So I make a post "How to enter escape character in a positional string argument from the command line? on DEC05. But there is no response. I assume that there is no way of doing it and I have to convert it later after I get the whole string from the command line. 
> 
> I made this convertion using the chr(int(...)) method but not satisfied with. That why this post came out. 
> 
> At this moment the conversion is done almost the same as Peter's codecs.decode() method but without the need of importing codecs module:-) 
> 
> def to1byte(matchobj): 
> ....return matchobj.group(0).encode().decode("unicode-escape")
> -- 
> https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hcg9ULzmtVUzMJ87Emlfsf6PGAfC-MEzUs3QQNVzWwK4aWDEtePG34hRX0ZFVvWcqZXRcM67JkkIg-l-K9vB$>

> That?s actually more of a shell question than a Python question. How you pass certain control characters is going to depend on the shell, operating system, and possibly the keyboard you?re using. (e.g. https://www.alt-codes.net).

You are right, that's why I found later that it's easier to enter it using a preferred pattern. But there is a case, as moi mentioned in his previous post, will cause failure when a Windows path in the form of \xdd just happen in the string:-(

From jfong at ms4.hinet.net  Fri Dec  9 21:12:41 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Fri, 9 Dec 2022 18:12:41 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <fae37303-791b-407c-925f-95b8d8a6112fn@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <fae37303-791b-407c-925f-95b8d8a6112fn@googlegroups.com>
Message-ID: <6d435f5a-f8ab-4f65-acdb-7996eff9fc25n@googlegroups.com>

moi ? 2022?12?9? ?????11:41:20 [UTC+8] ??????
> PS C:\humour> py38 sysargwithliteral.py a\x0ab\x09c\x0a\x80uro\x0ax\x08z cp1252 
> a 
> b c 
> ?uro 
> z 
> 
> PS C:\humour> $a = py38 sysargwithliteral.py a\x0ab\x09c\x0a\x80uro\x0ax\x08z cp1252 
> 
> PS C:\humour> licp($a) 
> a U+0061 
> b U+0062 
> U+0009 
> c U+0063 
> ? U+20AC 
> u U+0075 
> r U+0072 
> o U+006F 
> x U+0078 
> U+0008 
> z U+007A 
> 
> PS C:\humour> 
> 
> PS C:\humour> py38 sysargwithliteral.py a\u000ab\u0009c\u000a\u20acuro\u000ax\u0008z\u000aend\U0001f60a unicode 
> a 
> b c 
> ?uro 
> z 
> end? 
> 
> PS C:\humour> 
> 
> PS C:\humour> py38 sysargwithliteral.py a\x0ab\x09c\x0a\x80uro\x0ax\x08z cp1252 | py38 -c "import sys; s = sys.stdin.read(); print(s.rstrip())" 
> a 
> b c 
> ?uro 
> z 
> 
> PS C:\humour> 
> Note: In a terminal "\t" is correct.
Where is the sysargwithliteral.py?

From axy at declassed.art  Sat Dec 10 01:36:01 2022
From: axy at declassed.art (Axy)
Date: Sat, 10 Dec 2022 06:36:01 +0000
Subject: Announcing Clabate 0.5.0: minimalistic class-based templates for
 Python
Message-ID: <c28ac4e2-2a29-a9b1-7d82-8b82c1149394@declassed.art>

Hi there,

although it's quite old my side project, it has reached the point where 
I don't want to add anything more.

It's a simple template system based on standard string formatting. You 
declare your template strings as class attributes and they are formatted 
in the right order. For dynamic content you can use class properties, 
and inline invocations, such as 'hello, {my_db:get_name({person_id!r})}'

https://github.com/declassed-art/clabate

Axy

From h.goebel at crazy-compilers.com  Sat Dec 10 12:17:13 2022
From: h.goebel at crazy-compilers.com (Hartmut Goebel)
Date: Sat, 10 Dec 2022 18:17:13 +0100
Subject: ANN: pdfdecrypt 1.0
Message-ID: <00201355-03de-1f6d-95a6-93f65ad94fdd@crazy-compilers.com>

I'm pleased to announce pdfdecrypt 1.0, a command line tool to
remove passwords from PDF documents.? It will read the encrypted
document, ask for the password and write the decrypted document
without touching any internal structure.


:Licence:??? GNU Affero General Public License v3 or later (AGPLv3+)
:Homepage:?? https://pdfdecrypt.readthedocs.io/
:Repository: https://gitlab.com/pdftools/pdfdecrypt/


Download
---------------

:Quick Installation:
 ??? pip install -U pdfdecrypt



Relevant Changes since last release
---------------------------------------

* Initial release

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel at crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |


From martinp.dipaola at gmail.com  Sun Dec 11 08:57:36 2022
From: martinp.dipaola at gmail.com (Martin Di Paola)
Date: Sun, 11 Dec 2022 10:57:36 -0300
Subject: on the python paradox
In-Reply-To: <Y5C4Ebx0a4VeTgq2@icerm-dld>
References: <tmm6d3$1fef$1@gioia.aioe.org>
 <Y5C4Ebx0a4VeTgq2@icerm-dld>
Message-ID: <20221211135736.i2s2j3wndzxlrxxf@gmail.com>

>On Mon, Dec 05, 2022 at 10:37:39PM -0300, Sabrina Almod?var wrote:
>>                         The Python Paradox
>>                            Paul Graham
>>                            August 2004
>>
>>[SNIP]
>>
>>Hence what, for lack of a better name, I'll call the Python paradox: 
>>if a company chooses to write its software in a comparatively 
>>esoteric language, they'll be able to hire better programmers, 
>>because they'll attract only those who cared enough to learn it. And 
>>for programmers the paradox is even more pronounced: the language to 
>>learn, if you want to get a good job, is a language that people 
>>don't learn merely to get a job.
>>
>>[SNIP]

I don't think that an esoteric language leads to better programmers.

I know really good people that work mostly in assembly which by today
standard would be considered "esoteric".

They are really good at their field but they write shitty code in higher
languages as python.

That same goes for the other direction: I saw Ruby programmers writing C
code and trust me, it didn't result in good quality code.

I would be more inclined to think that a good programmer is not the one
that knows an esoteric language but the one that can jump from one
programming paradigm to another.

And when I say "jump" I mean that he/she can understand the problem to
solve, find the best tech stack to solve it and do it in an efficient
manner using that tech stack correctly.

It is in the "using that tech stack correctly" where some programmers
that "think" they know languages A, B and C get it wrong.

Just writing code that "compiles" and "it does not immediately crash" is
not enough to say that "you are using the tech stack correctly".


On Wed, Dec 07, 2022 at 10:58:09AM -0500, David Lowry-Duda wrote:
>On Mon, Dec 05, 2022 at 10:37:39PM -0300, Sabrina Almod?var wrote:
>>                         The Python Paradox
>>                            Paul Graham
>>                            August 2004
>>
>>[SNIP]
>>
>>Hence what, for lack of a better name, I'll call the Python paradox: 
>>if a company chooses to write its software in a comparatively 
>>esoteric language, they'll be able to hire better programmers, 
>>because they'll attract only those who cared enough to learn it. And 
>>for programmers the paradox is even more pronounced: the language to 
>>learn, if you want to get a good job, is a language that people 
>>don't learn merely to get a job.
>>
>>[SNIP]
>
>I wonder what the appropriately esoteric language is today?
>
>We can sort of think of go/rust as esoteric versions of C/C++. But 
>what would be the esoteric python?
>
>Perhaps Julia? I don't know of any large software projects happening 
>in julia world that aren't essentially scientific computing libraries 
>(but this is because *I* work mostly with scientific computing 
>libraries and sometimes live under a rock).
>
>- DLD
>-- 
>https://mail.python.org/mailman/listinfo/python-list

From cl at isbd.net  Sun Dec 11 05:09:59 2022
From: cl at isbd.net (Chris Green)
Date: Sun, 11 Dec 2022 10:09:59 +0000
Subject: Does one have to use curses to read single characters from keyboard?
Message-ID: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>

Is the only way to read single characters from the keyboard to use
curses.cbreak() or curses.raw()?  If so how do I then read characters,
it's not at all obvious from the curses documentation as that seems to
think I'm using a GUI in some shape or form.

All I actually want to do is get 'Y' or 'N' answers to questions on
the command line.

Searching for ways to do this produces what seem to me rather clumsy
ways of doing it.

-- 
Chris Green
?

From nospam at dfs.com  Sun Dec 11 07:37:56 2022
From: nospam at dfs.com (DFS)
Date: Sun, 11 Dec 2022 07:37:56 -0500
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
Message-ID: <EaklL.20493$iU59.10222@fx14.iad>

On 12/11/2022 5:09 AM, Chris Green wrote:
> Is the only way to read single characters from the keyboard to use
> curses.cbreak() or curses.raw()?  If so how do I then read characters,
> it's not at all obvious from the curses documentation as that seems to
> think I'm using a GUI in some shape or form.
> 
> All I actually want to do is get 'Y' or 'N' answers to questions on
> the command line.
> 
> Searching for ways to do this produces what seem to me rather clumsy
> ways of doing it.


resp = 'x'
while resp.lower() not in 'yn':
     resp = input("Did you say Y or did you say N?: ")





From cl at isbd.net  Sun Dec 11 08:59:27 2022
From: cl at isbd.net (Chris Green)
Date: Sun, 11 Dec 2022 13:59:27 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
Message-ID: <va4h6j-33jl.ln1@esprimo.zbmc.eu>

Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> Chris Green <cl at isbd.net> writes:
> >Is the only way to read single characters from the keyboard to use
> >curses.cbreak() or curses.raw()?  If so how do I then read characters,
> 
>   It seems that you want to detect keypresses and not read
>   characters from a line-buffered console with editing
>   features.
> 
>   Curses is not portable IIRC. A more portable means would 
>   be to use tkinter with the "bind" function to bind keys.
> 
> >All I actually want to do is get 'Y' or 'N' answers to questions on
> >the command line.
> 
>   answer = input( 'Format drive C: (Y/N)?' )
> 
... and therein lies the fundamental problem, you have to type Y or N
followed by Return.  See my own follow-up though.

-- 
Chris Green
?

From oscar.j.benjamin at gmail.com  Sun Dec 11 12:19:53 2022
From: oscar.j.benjamin at gmail.com (Oscar Benjamin)
Date: Sun, 11 Dec 2022 17:19:53 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
Message-ID: <CAHVvXxQ0e3Yr3UShS8Sw37G27=fBtpzpKGMkUzj0mWAJGZWpZg@mail.gmail.com>

On Sun, 11 Dec 2022 at 15:55, Chris Green <cl at isbd.net> wrote:
>
> Is the only way to read single characters from the keyboard to use
> curses.cbreak() or curses.raw()?  If so how do I then read characters,
> it's not at all obvious from the curses documentation as that seems to
> think I'm using a GUI in some shape or form.
>
> All I actually want to do is get 'Y' or 'N' answers to questions on
> the command line.
>
> Searching for ways to do this produces what seem to me rather clumsy
> ways of doing it.

What you are asking for is known as getch. On Windows Python's msvcrt
module provides precisely this function. There are ways to do it on
non-Windows platforms but nothing as simple as the getch function is
in the stdlib. Some modules and recipes are available which I guess it
what you've already seen:

https://pypi.org/project/getch/
https://github.com/joeyespo/py-getch
https://stackoverflow.com/questions/510357/how-to-read-a-single-character-from-the-user

This seems to be the most well maintained option:
https://pypi.org/project/readchar/

I've often thought that getch was a good candidate for the stdlib.
There are plenty of recipes around but it would ideally just be
available as a cross platform function. Using curses would have been
overkill in any of my use cases where I really just wanted getch to
make a more efficient interface for a terminal program having some
limited interactivity. Actually slightly more than getch is readchar's
readkey which also works for pressing non-character keys. There were
times in the past where I might have used that if I'd known about it.

--
Oscar

From menyland at gmail.com  Sun Dec 11 12:34:25 2022
From: menyland at gmail.com (Chris Nyland)
Date: Sun, 11 Dec 2022 12:34:25 -0500
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <two-liner-20221211160939@ram.dialup.fu-berlin.de>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
 <key-20221211123114@ram.dialup.fu-berlin.de>
 <two-liner-20221211160939@ram.dialup.fu-berlin.de>
Message-ID: <CALGOvYZ_rMiMuFoab-L1r3mf0_x30+GT-u1R6J2VMO4cP97EgA@mail.gmail.com>

You should try the input function. I use it all the time. It does require
the user to hit enter but that is pretty typical of that kind of interface.
So I would write a loop like

while True:
   answer = input("Please answer the question (y/n):")
  if answer == 'y':
    break

Chris

On Sun, Dec 11, 2022 at 11:03 AM Stefan Ram <ram at zedat.fu-berlin.de> wrote:

> ram at zedat.fu-berlin.de (Stefan Ram) writes:
> >import tkinter
>
>   This two-liner allows to answer with just one keypress ([Y]/[N]) here.
>
> import tkinter.messagebox
> tkinter.messagebox.askyesno( "Question", "Format harddisk?" )
>
>
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From antoon.pardon at vub.be  Sun Dec 11 13:00:36 2022
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Sun, 11 Dec 2022 19:00:36 +0100
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <key-20221211123114@ram.dialup.fu-berlin.de>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
 <key-20221211123114@ram.dialup.fu-berlin.de>
Message-ID: <2103ade1-0f0d-9036-f625-011f25516c72@vub.be>



Op 11/12/2022 om 12:32 schreef Stefan Ram:
> ram at zedat.fu-berlin.de (Stefan Ram) writes:
>> Curses is not portable IIRC. A more portable means would
>> be to use tkinter with the "bind" function to bind keys.
> import tkinter
>
> text = tkinter.Text()
> text.pack()
> text.bind\
> ( "<y>",
>    lambda event:
>    text.insert
>    ( tkinter.END, "Y\nFormatting drive C:\n...\n" )or "break" )
> text.insert( tkinter.END, "Format drive C:?\n" )
> text.focus()
>
> tkinter.mainloop()
>
>    Not allowing users to edit their keypresses before confirming
>    them with [Return]. What could possibly go wrong?

Nothing that can't go wrong otherwise. It is my experience that
when a [Return] is needed, people just type in a two key combination.
They don't type one key, then check, then type [Return].

So in practice the same things go wrong, either way.

-- 
Antoon Pardon.

From salmodovar at ligumu.com  Sun Dec 11 13:22:11 2022
From: salmodovar at ligumu.com (=?UTF-8?Q?Sabrina_Almod=c3=b3var?=)
Date: Sun, 11 Dec 2022 15:22:11 -0300
Subject: on the python paradox
References: <tmm6d3$1fef$1@gioia.aioe.org> <Y5C4Ebx0a4VeTgq2@icerm-dld>
 <20221211135736.i2s2j3wndzxlrxxf@gmail.com>
 <mailman.1128.1670767109.20444.python-list@python.org>
Message-ID: <tn574k$ant$1@gioia.aioe.org>

On 11/12/2022 10:57, Martin Di Paola wrote:
>> On Mon, Dec 05, 2022 at 10:37:39PM -0300, Sabrina Almod?var wrote:
>>> ??????????????????????? The Python Paradox
>>> ?????????????????????????? Paul Graham
>>> ?????????????????????????? August 2004
>>>
>>> [SNIP]
>>>
>>> Hence what, for lack of a better name, I'll call the Python paradox:
>>> if a company chooses to write its software in a comparatively
>>> esoteric language, they'll be able to hire better programmers,
>>> because they'll attract only those who cared enough to learn it. And
>>> for programmers the paradox is even more pronounced: the language to
>>> learn, if you want to get a good job, is a language that people don't
>>> learn merely to get a job.
>>>
>>> [SNIP]
> 
> I don't think that an esoteric language leads to better programmers.

When you say this, I interpret it as a theorem, A implies B, but surely
nobody would be so foolish to claim such thing, so perhaps you can
review your reading or writing.

> I know really good people that work mostly in assembly which by today
> standard would be considered "esoteric".

So, I wouldn't consider assembly esoteric, but I certainly would not try
to define esoteric.

> They are really good at their field but they write shitty code in higher
> languages as python.

I bet.  If all they know is assembly, then they master very few
linguistic abstractions.

> That same goes for the other direction: I saw Ruby programmers writing C
> code and trust me, it didn't result in good quality code.

A Ruby person who doesn't know C must also know very little about
machines and operating systems, so that is bound to failure in C.

> I would be more inclined to think that a good programmer is not the one
> that knows an esoteric language but the one that can jump from one
> programming paradigm to another.

That makes a lot of sense.  Such person knows so many ways of
expression, which most likely implies mastery of linguistic abstractions
and expression.

> And when I say "jump" I mean that he/she can understand the problem to
> solve, find the best tech stack to solve it and do it in an efficient
> manner using that tech stack correctly.

Got ya.

> It is in the "using that tech stack correctly" where some programmers
> that "think" they know languages A, B and C get it wrong.

I agree with that too.

> Just writing code that "compiles" and "it does not immediately crash" is
> not enough to say that "you are using the tech stack correctly".

So true.

Good thoughts.

From cl at isbd.net  Sun Dec 11 13:50:51 2022
From: cl at isbd.net (Chris Green)
Date: Sun, 11 Dec 2022 18:50:51 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
 <key-20221211123114@ram.dialup.fu-berlin.de>
 <2103ade1-0f0d-9036-f625-011f25516c72@vub.be>
 <mailman.1131.1670781641.20444.python-list@python.org>
Message-ID: <bdlh6j-onkm.ln1@esprimo.zbmc.eu>

My solution in the end was copied from one I found that was much
simpler and straightforward than most.  I meant to post this earlier
but it got lost somewhere:-

    import sys, termios, tty
    #
    #
    # Read a single character from teminal, specifically for 'Y/N' 
    #
    fdInput = sys.stdin.fileno()
    termAttr = termios.tcgetattr(0)
    #
    #
    # Get a single character, setcbreak rather than setraw meands CTRL/C
    etc. still work
    #
    def getch():
        sys.stdout.flush()
        tty.setcbreak(fdInput)
        ch = sys.stdin.buffer.raw.read(1).decode(sys.stdin.encoding)
        termios.tcsetattr(fdInput, termios.TCSAFLUSH, termAttr)
        sys.stdout.write(ch)
        return ch
    #
    #
    # Get a y or n answer, ignore other characters
    #
    def getyn():
        ch = 'x'
        while ch != 'y' and ch != 'n':
            ch = getch().lower()
        return ch

So getyn() reads a y or an n, ignores anything else and doesn't wait
for a return key.  Keyboard input operation is restored to normal
after doing this. Using tty.setcbreak() rather than tty.setraw() means
that CTRL/C etc. still work if things go really wrong.


-- 
Chris Green
?

From arj.python at gmail.com  Sun Dec 11 15:43:05 2022
From: arj.python at gmail.com (Abdur-Rahmaan Janhangeer)
Date: Mon, 12 Dec 2022 00:43:05 +0400
Subject: on the python paradox
In-Reply-To: <tmm6d3$1fef$1@gioia.aioe.org>
References: <tmm6d3$1fef$1@gioia.aioe.org>
Message-ID: <CADrxXX=+wZZq36Sj+FZVfKEPPzZfq=6ON0dQRdqLTcqwLse+Pw@mail.gmail.com>

I choose Python and still stick with it as default as I choose
Python because of its design beauty. Typing does not mean
mandatory braces. There can be an indentation-based language
that is strongly typed.

Python is beautiful in itself. Beautiful to look at. Source code should
be easy for the average human to relate to and connect with easily.
Being more alien-ware-like does not magically increase performance.
Our taste and quality bar should be high after so much time has passed.

I don't see a language as beautiful as it is front-end wise.

"And people don't learn Python because it will
get them a job; they learn it because they genuinely like to program
and aren't satisfied with the languages they already know."

Kind Regards,

Abdur-Rahmaan Janhangeer
about <https://compileralchemy.github.io/> | blog
<https://www.pythonkitchen.com>
github <https://github.com/Abdur-RahmaanJ>
Mauritius

From PythonList at DancesWithMice.info  Sun Dec 11 16:07:37 2022
From: PythonList at DancesWithMice.info (dn)
Date: Mon, 12 Dec 2022 10:07:37 +1300
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
Message-ID: <d67ecf78-bbf0-4d60-b846-a5f1d08cc173@DancesWithMice.info>

On 11/12/2022 23.09, Chris Green wrote:
> Is the only way to read single characters from the keyboard to use
> curses.cbreak() or curses.raw()?  If so how do I then read characters,
> it's not at all obvious from the curses documentation as that seems to
> think I'm using a GUI in some shape or form.
> 
> All I actually want to do is get 'Y' or 'N' answers to questions on
> the command line.
> 
> Searching for ways to do this produces what seem to me rather clumsy
> ways of doing it.

You may like to re-ask this question over on the Python-Tutor list. The 
ListAdmin over there (literally) wrote the book on Python+curses...


Did such research include the keyboard module?
https://pypi.org/project/keyboard/

This project includes an (Enter-free) "hot-key" feature which firstly 
detects the specific key or key-combination, and then calls an action 
if/when True.
(amongst other functionality)

Quick read tutorial: 
https://www.thepythoncode.com/article/control-keyboard-python

Disclaimer: have had it on my 'radar', but never actually employed.
(if you have considered, will be interested to hear conclusions...)
-- 
Regards,
=dn

From barry at barrys-emacs.org  Sun Dec 11 17:22:45 2022
From: barry at barrys-emacs.org (Barry Scott)
Date: Sun, 11 Dec 2022 22:22:45 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <bdlh6j-onkm.ln1@esprimo.zbmc.eu>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
 <key-20221211123114@ram.dialup.fu-berlin.de>
 <2103ade1-0f0d-9036-f625-011f25516c72@vub.be>
 <mailman.1131.1670781641.20444.python-list@python.org>
 <bdlh6j-onkm.ln1@esprimo.zbmc.eu>
Message-ID: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>



> On 11 Dec 2022, at 18:50, Chris Green <cl at isbd.net> wrote:
> 
> My solution in the end was copied from one I found that was much
> simpler and straightforward than most.  I meant to post this earlier
> but it got lost somewhere:-
> 
>    import sys, termios, tty
>    #
>    #
>    # Read a single character from teminal, specifically for 'Y/N' 
>    #
>    fdInput = sys.stdin.fileno()
>    termAttr = termios.tcgetattr(0)
>    #
>    #
>    # Get a single character, setcbreak rather than setraw meands CTRL/C
>    etc. still work
>    #
>    def getch():
>        sys.stdout.flush()
>        tty.setcbreak(fdInput)
>        ch = sys.stdin.buffer.raw.read(1).decode(sys.stdin.encoding)

Will not work for uncode code points above 255.

This is what happened when I typed ? key:

:>>> a.getch()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/private/var/folders/ll/08dwwqkx6v9bcd15sh06x14w0000gn/T/a.py", line 15, in getch
    ch = sys.stdin.buffer.raw.read(1).decode(sys.stdin.encoding)
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe2 in position 0: unexpected end of data

You would need to have a loop that collected all the utf-8 bytes of a single code point.
You can to look at the first byte of know if the utf-8 is 1, 2, 3 or 4 bytes for a code point.

Barry

>        termios.tcsetattr(fdInput, termios.TCSAFLUSH, termAttr)
>        sys.stdout.write(ch)
>        return ch
>    #
>    #
>    # Get a y or n answer, ignore other characters
>    #
>    def getyn():
>        ch = 'x'
>        while ch != 'y' and ch != 'n':
>            ch = getch().lower()
>        return ch
> 
> So getyn() reads a y or an n, ignores anything else and doesn't wait
> for a return key.  Keyboard input operation is restored to normal
> after doing this. Using tty.setcbreak() rather than tty.setraw() means
> that CTRL/C etc. still work if things go really wrong.

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


From rosuav at gmail.com  Sun Dec 11 17:32:49 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 12 Dec 2022 09:32:49 +1100
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
 <key-20221211123114@ram.dialup.fu-berlin.de>
 <2103ade1-0f0d-9036-f625-011f25516c72@vub.be>
 <mailman.1131.1670781641.20444.python-list@python.org>
 <bdlh6j-onkm.ln1@esprimo.zbmc.eu>
 <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
Message-ID: <CAPTjJmom9p=tzkthCU0jX6dy8BUcqAtJr9_6zkNKpxor5vzY8g@mail.gmail.com>

On Mon, 12 Dec 2022 at 09:24, Barry Scott <barry at barrys-emacs.org> wrote:
> You would need to have a loop that collected all the utf-8 bytes of a single code point.
> You can to look at the first byte of know if the utf-8 is 1, 2, 3 or 4 bytes for a code point.

And cope with escape sequences too - if you press an arrow key, for
instance, you'll get a multi-character string to signal that.

This is why it's probably easier to let someone else do the work.

ChrisA

From cs at cskk.id.au  Sun Dec 11 17:54:11 2022
From: cs at cskk.id.au (Cameron Simpson)
Date: Mon, 12 Dec 2022 09:54:11 +1100
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
Message-ID: <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>

On 11Dec2022 22:22, Barry Scott <barry at barrys-emacs.org> wrote:
>>    # Get a single character, setcbreak rather than setraw meands 
>>    CTRL/C
>>    etc. still work
>>    #
>>    def getch():
>>        sys.stdout.flush()
>>        tty.setcbreak(fdInput)
>>        ch = sys.stdin.buffer.raw.read(1).decode(sys.stdin.encoding)
>
>Will not work for uncode code points above 255.

Aye. But one could write a little loop to collect bytes until a complete 
character was received. A little experiment:

     >>> try: bytes((0xf0,)).decode('utf8')
     ... except UnicodeDecodeError as e:
     ...   e2=e
     ...
     >>> e2
     UnicodeDecodeError('utf-8', b'\xf0', 0, 1, 'unexpected end of data')
     >>> e2.reason
     'unexpected end of data'

Keep collecting while you get `UnicodeDecodeError`s with a `.reason` of 
'unexpected end of data'. Can be encoding agnostic (obviously you need 
to _choose_ an encoding, it is needn't be utf-8).

(For the OP: `UnicodeDecodeError` doesn't necessarily mean you're 
decoding Unicode data, you're decoding _into_ a Python string which is a 
Unicode string.)

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

From Gronicus at SGA.Ninja  Mon Dec 12 01:01:43 2022
From: Gronicus at SGA.Ninja (Steve GS)
Date: Mon, 12 Dec 2022 01:01:43 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
Message-ID: <003901d90def$36620a80$a3261f80$@SGA.Ninja>

How do I subtract two time/dates and calculate the hours and minutes
between?
Steve


From miked at dewhirst.com.au  Mon Dec 12 03:13:02 2022
From: miked at dewhirst.com.au (Mike Dewhirst)
Date: Mon, 12 Dec 2022 19:13:02 +1100
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <003901d90def$36620a80$a3261f80$@SGA.Ninja>
Message-ID: <4NVvlL0707znVFL@mail.python.org>

I have seen vast conversations on this topic but if everything is in the same time-zone and daylight saving switchovers are not involved it is relatively straightforward.Check the timedelta docs. Or convert datetimes to ordinals and subtract then convert the result to whatever units please you.M--(Unsigned mail from my phone)
-------- Original message --------From: Steve GS <Gronicus at SGA.Ninja> Date: 12/12/22  17:34  (GMT+10:00) To: python-list at python.org Subject: Subtracting dates to get hours and minutes How do I subtract two time/dates and calculate the hours and minutesbetween?Steve-- https://mail.python.org/mailman/listinfo/python-list

From cl at isbd.net  Sun Dec 11 16:13:19 2022
From: cl at isbd.net (Chris Green)
Date: Sun, 11 Dec 2022 21:13:19 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
 <key-20221211123114@ram.dialup.fu-berlin.de>
 <2103ade1-0f0d-9036-f625-011f25516c72@vub.be>
 <mailman.1131.1670781641.20444.python-list@python.org>
 <bdlh6j-onkm.ln1@esprimo.zbmc.eu>
 <termios-20221211200937@ram.dialup.fu-berlin.de>
Message-ID: <foth6j-6c5n.ln1@esprimo.zbmc.eu>

Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> Chris Green <cl at isbd.net> writes:
> >import sys, termios, tty
> 
>   There might be some versions of Python and the Microsoft?
>   Windows operating system where "termios" is not available.
> 

Ah, I did originally say that this was a Unix/Linux only solution but
that was in my first response that got lost somewhere.

-- 
Chris Green
?

From marc at marcsnet.com  Mon Dec 12 01:40:21 2022
From: marc at marcsnet.com (Marc Lucke)
Date: Mon, 12 Dec 2022 17:40:21 +1100
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <003901d90def$36620a80$a3261f80$@SGA.Ninja>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
Message-ID: <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>

my approach would be to convert your two date/times to seconds from 
epoch - e.g. 
https://www.geeksforgeeks.org/convert-python-datetime-to-epoch/ - then 
subtract the number, divide the resultant by 3600 (hours) & get the 
modulus for minutes.? There's probably a standard function - it should 
be /very/ easy to do.

- Marc

On 12/12/2022 5:01 pm, Steve GS wrote:
> How do I subtract two time/dates and calculate the hours and minutes
> between?
> Steve
>

From jfong at ms4.hinet.net  Mon Dec 12 06:03:48 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Mon, 12 Dec 2022 03:03:48 -0800 (PST)
Subject: How to convert a raw string r'\xdd' to '\xdd' more gracefully?
In-Reply-To: <2e9969b0-7a81-46bc-995c-23c033eb6683n@googlegroups.com>
References: <fd6a97f0-9e29-4631-832f-c2a642e804e7n@googlegroups.com>
 <fae37303-791b-407c-925f-95b8d8a6112fn@googlegroups.com>
 <6d435f5a-f8ab-4f65-acdb-7996eff9fc25n@googlegroups.com>
 <8cf595cb-3e5b-4de2-9d3a-79ac44065cebn@googlegroups.com>
 <2e9969b0-7a81-46bc-995c-23c033eb6683n@googlegroups.com>
Message-ID: <d3ed9a27-f637-4a51-840e-bfb5c560ff0dn@googlegroups.com>

moi ? 2022?12?12? ?????5:38:50 [UTC+8] ??????
> >>> ast.literal_eval("r'\x7a'") == ast.literal_eval("r'z'") 
> True 
> >>> ast.literal_eval("r'\xe0'") == ast.literal_eval("r'?'") 
> True 
> >>> ast.literal_eval("r'\x9c'") == ast.literal_eval("r'?'") 
> False 
> 
> --------- 
> 
> 
> >>> print(codecs.decode(r'z', 'unicode-escape')) 
> z 
> >>> print(codecs.decode(r'g\hz', 'unicode-escape')) 
> g\hz 
> >>> print(codecs.decode(r'g\az', 'unicode-escape')) 
> g\u0007z 
> >>> print(codecs.decode(r'g\nz', 'unicode-escape')) 
> g 
> z 
> >>> 
> print(codecs.decode(r'abc?', 'unicode-escape')) 
> abc?? 
> >>>
I have a different result:-)

>>> print(codecs.decode(r'g\hz', 'unicode-escape'))
<stdin>:1: DeprecationWarning: invalid escape sequence '\h'
g\hz
>>> print(codecs.decode(r'g\az', 'unicode-escape'))
gz  # with a companioning bell

From cl at isbd.net  Mon Dec 12 06:12:12 2022
From: cl at isbd.net (Chris Green)
Date: Mon, 12 Dec 2022 11:12:12 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <keypresses-20221211120940@ram.dialup.fu-berlin.de>
 <key-20221211123114@ram.dialup.fu-berlin.de>
 <2103ade1-0f0d-9036-f625-011f25516c72@vub.be>
 <mailman.1131.1670781641.20444.python-list@python.org>
 <bdlh6j-onkm.ln1@esprimo.zbmc.eu>
 <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <mailman.1134.1670797378.20444.python-list@python.org>
Message-ID: <ctej6j-gp7q.ln1@esprimo.zbmc.eu>

Barry Scott <barry at barrys-emacs.org> wrote:
> 
> 
> > On 11 Dec 2022, at 18:50, Chris Green <cl at isbd.net> wrote:
> > 
> > My solution in the end was copied from one I found that was much
> > simpler and straightforward than most.  I meant to post this earlier
> > but it got lost somewhere:-
> > 
> >    import sys, termios, tty
> >    #
> >    #
> >    # Read a single character from teminal, specifically for 'Y/N' 
> >    #
> >    fdInput = sys.stdin.fileno()
> >    termAttr = termios.tcgetattr(0)
> >    #
> >    #
> >    # Get a single character, setcbreak rather than setraw meands CTRL/C
> >    etc. still work
> >    #
> >    def getch():
> >        sys.stdout.flush()
> >        tty.setcbreak(fdInput)
> >        ch = sys.stdin.buffer.raw.read(1).decode(sys.stdin.encoding)
> 
> Will not work for uncode code points above 255.
> 
> This is what happened when I typed ? key:
> 
> :>>> a.getch()
> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>
>   File "/private/var/folders/ll/08dwwqkx6v9bcd15sh06x14w0000gn/T/a.py", line 15, in getch
>     ch = sys.stdin.buffer.raw.read(1).decode(sys.stdin.encoding)
> UnicodeDecodeError: 'utf-8' codec can't decode byte 0xe2 in position 0: unexpected end of data
> 
Since it's just for me to use the above doesn't worry me! :-)  I'd
have to try quite hard to enter a multi-byte character from my
keyboard so it's very unlikely to happen by mistake.

-- 
Chris Green
?

From learn2program at gmail.com  Mon Dec 12 12:45:21 2022
From: learn2program at gmail.com (Alan Gauld)
Date: Mon, 12 Dec 2022 17:45:21 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <d67ecf78-bbf0-4d60-b846-a5f1d08cc173@DancesWithMice.info>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <d67ecf78-bbf0-4d60-b846-a5f1d08cc173@DancesWithMice.info>
Message-ID: <aaf44b6e-d179-5cdc-fe59-e547e0ee3af4@yahoo.co.uk>

On 11/12/2022 21:07, dn wrote:
> On 11/12/2022 23.09, Chris Green wrote:
>> Is the only way to read single characters from the keyboard to use
>> curses.cbreak() or curses.raw()?  If so how do I then read characters,
>> it's not at all obvious from the curses documentation as that seems to
>> think I'm using a GUI in some shape or form.
>>
>> All I actually want to do is get 'Y' or 'N' answers to questions on
>> the command line.
>>
>> Searching for ways to do this produces what seem to me rather clumsy
>> ways of doing it.
> 
> You may like to re-ask this question over on the Python-Tutor list. The 
> ListAdmin over there (literally) wrote the book on Python+curses...
> 
> 
> Did such research include the keyboard module?
> https://pypi.org/project/keyboard/
> 
> This project includes an (Enter-free) "hot-key" feature which firstly 
> detects the specific key or key-combination, and then calls an action 
> if/when True.
> (amongst other functionality)
> 
> Quick read tutorial: 
> https://www.thepythoncode.com/article/control-keyboard-python
> 
> Disclaimer: have had it on my 'radar', but never actually employed.
> (if you have considered, will be interested to hear conclusions...)

-- 
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 gweatherby at uchc.edu  Mon Dec 12 12:49:32 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Mon, 12 Dec 2022 17:49:32 +0000
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
Message-ID: <SA1PR14MB58558E649689893F9D1F2585B9E29@SA1PR14MB5855.namprd14.prod.outlook.com>

The difference between two datetime objects is a timedelta object. https://docs.python.org/3/library/datetime.html#timedelta-objects . It has a total_seconds() method.

This is a simple task, unless one of the datetimes has a time zone specified and the other doesn?t.

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Marc Lucke <marc at marcsnet.com>
Date: Monday, December 12, 2022 at 11:37 AM
To: python-list at python.org <python-list at python.org>
Subject: Re: Subtracting dates to get hours and minutes
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

my approach would be to convert your two date/times to seconds from
epoch - e.g.
https://urldefense.com/v3/__https://www.geeksforgeeks.org/convert-python-datetime-to-epoch/__;!!Cn_UX_p3!hBXQeMkZ3QYS6BI0yTHsADseWTXcDXOhKFkg35NnRMicvYQvwLo9c_ihSaTrG60LywsKQm6UNd7mAAYr$<https://urldefense.com/v3/__https:/www.geeksforgeeks.org/convert-python-datetime-to-epoch/__;!!Cn_UX_p3!hBXQeMkZ3QYS6BI0yTHsADseWTXcDXOhKFkg35NnRMicvYQvwLo9c_ihSaTrG60LywsKQm6UNd7mAAYr$>  - then
subtract the number, divide the resultant by 3600 (hours) & get the
modulus for minutes.  There's probably a standard function - it should
be /very/ easy to do.

- Marc

On 12/12/2022 5:01 pm, Steve GS wrote:
> How do I subtract two time/dates and calculate the hours and minutes
> between?
> Steve
>
--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hBXQeMkZ3QYS6BI0yTHsADseWTXcDXOhKFkg35NnRMicvYQvwLo9c_ihSaTrG60LywsKQm6UNSbh5q0S$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!hBXQeMkZ3QYS6BI0yTHsADseWTXcDXOhKFkg35NnRMicvYQvwLo9c_ihSaTrG60LywsKQm6UNSbh5q0S$>

From grant.b.edwards at gmail.com  Mon Dec 12 13:47:13 2022
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Mon, 12 Dec 2022 10:47:13 -0800 (PST)
Subject: Does one have to use curses to read single characters from
 keyboard?
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
Message-ID: <63977731.920a0220.558eb.4863@mx.google.com>

On 2022-12-11, Chris Green <cl at isbd.net> wrote:

> Is the only way to read single characters from the keyboard to use
> curses.cbreak() or curses.raw()?

No.

> If so how do I then read characters,

Use a termios.tcsetattr() to put fd 0 into raw mode and then use
os.read().

Recent versions of Python include a "tty" module that has conveniece
functions to handle that:

--
Grant






From parejkoj at gmail.com  Mon Dec 12 19:41:53 2022
From: parejkoj at gmail.com (John K. Parejko)
Date: Mon, 12 Dec 2022 16:41:53 -0800
Subject: sqlite3 double quote behavior
Message-ID: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>

Asking here before I file an improvement request issue on the python GitHub:

sqlite has a known misfeature with double-quoted strings, whereby they will be interpreted as string literals if they don?t match a valid identifier [1]. The note in the sqlite docs describe a way to disable this misfeature at compile time or by calling an `sqlite3_db_config` C-function, but I don?t see any way to do that in the python sqlite library [2].

Am I missing a way to manage this setting, or is it not available within python? This would be very useful to enable, so that python?s sqlite library will treat queries more like standard sql, instead of this particular version of MySQL. I was just burned by this, where some tests I?d written against an sqlite database did not fail in the way that they ?should? have, because of this double-quoted string issue.

It doesn?t look like `sqlite3_db_config` is used within the python sqlite3 codebase at all, so this might not be a trivial change? I only see two references to it in the cpython github.

Thank you in advance for any suggestions,
John

1: https://www.sqlite.org/quirks.html#double_quoted_string_literals_are_accepted
2: https://docs.python.org/3/library/sqlite3.html

From lal at solute.de  Tue Dec 13 03:02:49 2022
From: lal at solute.de (Lars Liedtke)
Date: Tue, 13 Dec 2022 09:02:49 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
References: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
Message-ID: <2da757b3-52b9-65b1-bc2d-73c55d3f5787@solute.de>

Hey,

this might be not the answer you are searching for at all, and it is only a mitigation. But as far as I know, sqlalchemy (and other ORMs) do that for you. I am mention sqlalchemy, because it has got a query builder as well. So you don't have to change your DB-Layer to full ORM, but you could let it build the queries for you.

Of course, I know that this would mean a dependency and additional complexity. I just could not leave it unmentioned ;-)

Cheers

Lars


Lars Liedtke
Software Entwickler

[Tel.]  +49 721 98993-
[Fax]   +49 721 98993-
[E-Mail]        lal at solute.de<mailto:lal at solute.de>


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Am 13.12.22 um 01:41 schrieb John K. Parejko:

Asking here before I file an improvement request issue on the python GitHub:

sqlite has a known misfeature with double-quoted strings, whereby they will be interpreted as string literals if they don?t match a valid identifier [1]. The note in the sqlite docs describe a way to disable this misfeature at compile time or by calling an `sqlite3_db_config` C-function, but I don?t see any way to do that in the python sqlite library [2].

Am I missing a way to manage this setting, or is it not available within python? This would be very useful to enable, so that python?s sqlite library will treat queries more like standard sql, instead of this particular version of MySQL. I was just burned by this, where some tests I?d written against an sqlite database did not fail in the way that they ?should? have, because of this double-quoted string issue.

It doesn?t look like `sqlite3_db_config` is used within the python sqlite3 codebase at all, so this might not be a trivial change? I only see two references to it in the cpython github.

Thank you in advance for any suggestions,
John

1: https://www.sqlite.org/quirks.html#double_quoted_string_literals_are_accepted
2: https://docs.python.org/3/library/sqlite3.html


From learn2program at gmail.com  Tue Dec 13 03:46:48 2022
From: learn2program at gmail.com (Alan Gauld)
Date: Tue, 13 Dec 2022 08:46:48 +0000
Subject: Does one have to use curses to read single characters from
 keyboard?
In-Reply-To: <aaf44b6e-d179-5cdc-fe59-e547e0ee3af4@yahoo.co.uk>
References: <nsmg6j-asnk.ln1@esprimo.zbmc.eu>
 <d67ecf78-bbf0-4d60-b846-a5f1d08cc173@DancesWithMice.info>
 <aaf44b6e-d179-5cdc-fe59-e547e0ee3af4@yahoo.co.uk>
Message-ID: <fcf8e083-4a47-0f3e-d82f-dec583fcb90f@gmail.com>

On 12/12/2022 17:45, Alan Gauld wrote:

Absolutely nothing apparently!

But in practce I did pen some esponses to Davids post. However
this list seems to strip out what I've written, its happened
a few times now. Not every time but enough that I rarely post
here.

But I'll try once more...

> On 11/12/2022 21:07, dn wrote:
>> On 11/12/2022 23.09, Chris Green wrote:
>>> Is the only way to read single characters from the keyboard to use
>>> curses.cbreak() or curses.raw()?

>> You may like to re-ask this question over on the Python-Tutor list. The 
>> ListAdmin over there (literally) wrote the book on Python+curses...

Thanks for the plug David, but...

While my book is, I think, the only one specifically for curses with
Python, it's hardly a definitive tome on the subject, rather a
beginner's tutorial. An expanded HowTo if you like..

>> Did such research include the keyboard module?
>> https://pypi.org/project/keyboard/

There are several such modules, including a good one by Fred Lundh.
They are cross platform and probably the best solution for the
OP if he doesn't mind using a third party module. I think Fred's
was called terminal? But its been a while I normally just use curses
for anything terminal related.

-- 
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 roel at roelschroeven.net  Tue Dec 13 03:51:07 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 13 Dec 2022 09:51:07 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
References: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
Message-ID: <adf80dc8-0166-5a90-caf9-dc67a246e390@roelschroeven.net>

Op 13/12/2022 om 1:41 schreef John K. Parejko:
> Asking here before I file an improvement request issue on the python GitHub:
>
> sqlite has a known misfeature with double-quoted strings, whereby they will be interpreted as string literals if they don?t match a valid identifier [1]. The note in the sqlite docs describe a way to disable this misfeature at compile time or by calling an `sqlite3_db_config` C-function, but I don?t see any way to do that in the python sqlite library [2].
>
> Am I missing a way to manage this setting, or is it not available within python? This would be very useful to enable, so that python?s sqlite library will treat queries more like standard sql, instead of this particular version of MySQL. I was just burned by this, where some tests I?d written against an sqlite database did not fail in the way that they ?should? have, because of this double-quoted string issue.
>
> It doesn?t look like `sqlite3_db_config` is used within the python sqlite3 codebase at all, so this might not be a trivial change? I only see two references to it in the cpython github.
>
Like Lars Liedtke this is not an exact answer to your question, but you 
can side-step the issue by using parametrized queries, i.e. instead of

 ??? cur.execute('SELECT name, location FROM persons WHERE name = "John 
Doe"')

do

 ??? cur.execute('SELECT name, location FROM persons WHERE name = ?', 
('John Doe',))


-- 
"Life ain't no fairy tale
Just give me another ale
And I'll drink to Rock 'n Roll"
         -- Barkeep (The Scabs)


From rosuav at gmail.com  Tue Dec 13 04:09:58 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 13 Dec 2022 20:09:58 +1100
Subject: sqlite3 double quote behavior
In-Reply-To: <adf80dc8-0166-5a90-caf9-dc67a246e390@roelschroeven.net>
References: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
 <adf80dc8-0166-5a90-caf9-dc67a246e390@roelschroeven.net>
Message-ID: <CAPTjJmo7fDX-s9ut4X1H9bGeQpFMV2jXZqgVMFJDSsMQ3yOaOw@mail.gmail.com>

On Tue, 13 Dec 2022 at 19:52, Roel Schroeven <roel at roelschroeven.net> wrote:
> Like Lars Liedtke this is not an exact answer to your question, but you
> can side-step the issue by using parametrized queries, i.e. instead of
>
>      cur.execute('SELECT name, location FROM persons WHERE name = "John
> Doe"')
>
> do
>
>      cur.execute('SELECT name, location FROM persons WHERE name = ?',
> ('John Doe',))
>

That's the wrong behaviour though. According to the SQL standard, the
second query should be equivalent to this:

cur.execute("SELECT name, location FROM persons WHERE name = 'John Doe'")

What the OP wanted was like your first query, and proper DBMSes like
PostgreSQL will handle it accordingly. The question is how to get
SQLite3 to also do so.

I don't use SQLite3 much so I'm not really one to judge, but maybe it
would be worth exposing the sqlite3_db_config() function to Python?
Yes, it would be more than a trivial change, but it should be
reasonably straight-forward. In order to be useful, it would probably
also need an associated IntEnum for all those lovely opaque numbers
that define the verbs.

ChrisA

From list1 at tompassin.net  Tue Dec 13 08:23:13 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Tue, 13 Dec 2022 08:23:13 -0500
Subject: sqlite3 double quote behavior
In-Reply-To: <CAPTjJmo7fDX-s9ut4X1H9bGeQpFMV2jXZqgVMFJDSsMQ3yOaOw@mail.gmail.com>
References: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
 <adf80dc8-0166-5a90-caf9-dc67a246e390@roelschroeven.net>
 <CAPTjJmo7fDX-s9ut4X1H9bGeQpFMV2jXZqgVMFJDSsMQ3yOaOw@mail.gmail.com>
Message-ID: <52fe72f2-f3b5-e962-9609-89eadf7f389b@tompassin.net>

On 12/13/2022 4:09 AM, Chris Angelico wrote:
> On Tue, 13 Dec 2022 at 19:52, Roel Schroeven <roel at roelschroeven.net> wrote:
>> Like Lars Liedtke this is not an exact answer to your question, but you
>> can side-step the issue by using parametrized queries, i.e. instead of
>>
>>       cur.execute('SELECT name, location FROM persons WHERE name = "John
>> Doe"')
>>
>> do
>>
>>       cur.execute('SELECT name, location FROM persons WHERE name = ?',
>> ('John Doe',))
>>
> 
> That's the wrong behaviour though. According to the SQL standard, the
> second query should be equivalent to this:
> 
> cur.execute("SELECT name, location FROM persons WHERE name = 'John Doe'")
> 
> What the OP wanted was like your first query, and proper DBMSes like
> PostgreSQL will handle it accordingly. The question is how to get
> SQLite3 to also do so.

 From reading the SQLite3 documentation on this issue (not from personal 
experience), in fact the second form is actually what one wants, even if 
SQLite3 will usually handle the first form correctly.  The rule is "Use 
single quotes for string values and double quotes for database names 
such as schema, table and column names; for backwards compatibility 
SQLite will accept double quotes for string values, but you may get a 
surprise if the string value looks like a database name."

> I don't use SQLite3 much so I'm not really one to judge, but maybe it
> would be worth exposing the sqlite3_db_config() function to Python?
> Yes, it would be more than a trivial change, but it should be
> reasonably straight-forward. In order to be useful, it would probably
> also need an associated IntEnum for all those lovely opaque numbers
> that define the verbs.
> 
> ChrisA


From rosuav at gmail.com  Tue Dec 13 09:00:21 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 14 Dec 2022 01:00:21 +1100
Subject: sqlite3 double quote behavior
In-Reply-To: <52fe72f2-f3b5-e962-9609-89eadf7f389b@tompassin.net>
References: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
 <adf80dc8-0166-5a90-caf9-dc67a246e390@roelschroeven.net>
 <CAPTjJmo7fDX-s9ut4X1H9bGeQpFMV2jXZqgVMFJDSsMQ3yOaOw@mail.gmail.com>
 <52fe72f2-f3b5-e962-9609-89eadf7f389b@tompassin.net>
Message-ID: <CAPTjJmrZMY56=a=6qLAudgD3pue3n04CEn-=AQj0RtKzTSVzYw@mail.gmail.com>

On Wed, 14 Dec 2022 at 00:30, Thomas Passin <list1 at tompassin.net> wrote:
>
> On 12/13/2022 4:09 AM, Chris Angelico wrote:
> > On Tue, 13 Dec 2022 at 19:52, Roel Schroeven <roel at roelschroeven.net> wrote:
> >> Like Lars Liedtke this is not an exact answer to your question, but you
> >> can side-step the issue by using parametrized queries, i.e. instead of
> >>
> >>       cur.execute('SELECT name, location FROM persons WHERE name = "John
> >> Doe"')
> >>
> >> do
> >>
> >>       cur.execute('SELECT name, location FROM persons WHERE name = ?',
> >> ('John Doe',))
> >>
> >
> > That's the wrong behaviour though. According to the SQL standard, the
> > second query should be equivalent to this:
> >
> > cur.execute("SELECT name, location FROM persons WHERE name = 'John Doe'")
> >
> > What the OP wanted was like your first query, and proper DBMSes like
> > PostgreSQL will handle it accordingly. The question is how to get
> > SQLite3 to also do so.
>
>  From reading the SQLite3 documentation on this issue (not from personal
> experience), in fact the second form is actually what one wants, even if
> SQLite3 will usually handle the first form correctly.

No, the two have distinct semantics. BOTH are valid, they just mean
different things.

ChrisA

From roel at roelschroeven.net  Tue Dec 13 09:15:36 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 13 Dec 2022 15:15:36 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <52fe72f2-f3b5-e962-9609-89eadf7f389b@tompassin.net>
References: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
 <adf80dc8-0166-5a90-caf9-dc67a246e390@roelschroeven.net>
 <CAPTjJmo7fDX-s9ut4X1H9bGeQpFMV2jXZqgVMFJDSsMQ3yOaOw@mail.gmail.com>
 <52fe72f2-f3b5-e962-9609-89eadf7f389b@tompassin.net>
Message-ID: <86352d40-99ee-9deb-d3c8-557dfd9ccac1@roelschroeven.net>



Op 13/12/2022 om 14:23 schreef Thomas Passin:
> On 12/13/2022 4:09 AM, Chris Angelico wrote:
>> On Tue, 13 Dec 2022 at 19:52, Roel Schroeven <roel at roelschroeven.net> 
>> wrote:
>>> Like Lars Liedtke this is not an exact answer to your question, but you
>>> can side-step the issue by using parametrized queries, i.e. instead of
>>>
>>> ????? cur.execute('SELECT name, location FROM persons WHERE name = 
>>> "John
>>> Doe"')
>>>
>>> do
>>>
>>> ????? cur.execute('SELECT name, location FROM persons WHERE name = ?',
>>> ('John Doe',))
>>>
>>
>> That's the wrong behaviour though. According to the SQL standard, the
>> second query should be equivalent to this:
>>
>> cur.execute("SELECT name, location FROM persons WHERE name = 'John 
>> Doe'")
>>
>> What the OP wanted was like your first query, and proper DBMSes like
>> PostgreSQL will handle it accordingly. The question is how to get
>> SQLite3 to also do so.
>
> From reading the SQLite3 documentation on this issue (not from 
> personal experience), in fact the second form is actually what one 
> wants, even if SQLite3 will usually handle the first form correctly.? 
> The rule is "Use single quotes for string values and double quotes for 
> database names such as schema, table and column names; for backwards 
> compatibility SQLite will accept double quotes for string values, but 
> you may get a surprise if the string value looks like a database name."
What I missed at first is the case where you really want to use an 
identifier, not a string. Then you use double quotes, and would like to 
get an error ("unknown identifier" or something like that) in case of a 
typo, instead of the database engine silently presuming your 
wrongly-spelled identifier is a string. That case can't be solved with 
parametrized queries, and does really require the ability to enable more 
strict behavior.

+1 to expose the sqlite3_db_config() function, or maybe just a special 
case for this specific option.

-- 

"Honest criticism is hard to take, particularly from a relative, a friend,
an acquaintance, or a stranger."
         -- Franklin P. Jones


From roel at roelschroeven.net  Tue Dec 13 09:19:16 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 13 Dec 2022 15:19:16 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <86352d40-99ee-9deb-d3c8-557dfd9ccac1@roelschroeven.net>
References: <8156D69B-3E35-4A75-98B5-9C3DD36AF78E@gmail.com>
 <adf80dc8-0166-5a90-caf9-dc67a246e390@roelschroeven.net>
 <CAPTjJmo7fDX-s9ut4X1H9bGeQpFMV2jXZqgVMFJDSsMQ3yOaOw@mail.gmail.com>
 <52fe72f2-f3b5-e962-9609-89eadf7f389b@tompassin.net>
 <86352d40-99ee-9deb-d3c8-557dfd9ccac1@roelschroeven.net>
Message-ID: <c8849d74-711e-5907-6ead-ebad729302c0@roelschroeven.net>

Op 13/12/2022 om 15:15 schreef Roel Schroeven:
>
> +1 to expose the sqlite3_db_config() function, or maybe just a special 
> case for this specific option.
>
Actually I'm surprised SQLite doesn't have a PRAGMA command to customize 
this behavior. That would make it possible to customize from any client.

-- 
"Honest criticism is hard to take, particularly from a relative, a friend,
an acquaintance, or a stranger."
         -- Franklin P. Jones


From michael.stemper at gmail.com  Tue Dec 13 09:46:29 2022
From: michael.stemper at gmail.com (Michael F. Stemper)
Date: Tue, 13 Dec 2022 08:46:29 -0600
Subject: Top level of a recursive function
Message-ID: <tna385$2hmog$1@dont-email.me>

It's easy enough -- in fact necessary -- to handle the bottom
level of a function differently than the levels above it. What
about the case where you want to handle something differently
in the top level than in lower levels? Is there any way to tell
from within a function that it wasn't invoked by itself?

I've come up with a hack to support different processing, by
use of an extra argument, as shown in this simplified example:

def fred(cf,toplevel=True):
   x = cf[0]
   if len(cf)>1:
     if toplevel:
       return x + fred(cf[1:],False)
     else:
       return "(" + x + fred(cf[1:],False) + ")"
   else:
     if toplevel:
       return x
     else:
       return "(" + x + ")"

Aside from being ugly, this lets the caller diddle with "toplevel",
which shouldn't really be externally modifiable.

Are there better ways to do this?
-- 
Michael F. Stemper
I refuse to believe that a corporation is a person until Texas executes one.

From Joseph.Schachner at Teledyne.com  Tue Dec 13 12:19:07 2022
From: Joseph.Schachner at Teledyne.com (Schachner, Joseph (US))
Date: Tue, 13 Dec 2022 17:19:07 +0000
Subject: Top level of a recursive function
In-Reply-To: <reduce-20221213162138@ram.dialup.fu-berlin.de>
References: <tna385$2hmog$1@dont-email.me>
 <rest-20221213160153@ram.dialup.fu-berlin.de>
 <reduce-20221213162138@ram.dialup.fu-berlin.de>
Message-ID: <BN8PR14MB28519EB777170BBA98755198F5E39@BN8PR14MB2851.namprd14.prod.outlook.com>

Reducing repetitiveness has made this code harder to read. I had to think about what it is doing.  It might be slightly faster, but in my opinion it is not worth it.  

--- Joseph S.


Teledyne Confidential; Commercially Sensitive Business Data

-----Original Message-----
From: Stefan Ram <ram at zedat.fu-berlin.de> 
Sent: Tuesday, December 13, 2022 10:25 AM
To: python-list at python.org
Subject: Re: Top level of a recursive function

Supersedes: <reduce-20221213161758 at ram.dialup.fu-berlin.de>

ram at zedat.fu-berlin.de (Stefan Ram) writes:
>def rest( s ):
>    return "(" + s[ 0 ] +( rest( s[1:] ) if len( s )> 1 else '' )+ ')'
>def nest( s ):
>    return( s[ 0 ] if s else '' )+( rest( s[1:] )if len( s )> 1 else '' )

  Below, I have tried to reduce repetitiveness a bit.

  (PS: Now, one "if" remains; less ifs are not possible
  in the case of controlled recursion.)

def rest( s ):
    return '(' + nest( s )+ ')'

def nest( s ):
    return s[ :1 ]+( rest( s[ 1: ])if s[ 1: ]else '' )

fred = nest



From rosuav at gmail.com  Tue Dec 13 12:36:46 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 14 Dec 2022 04:36:46 +1100
Subject: Top level of a recursive function
In-Reply-To: <tna385$2hmog$1@dont-email.me>
References: <tna385$2hmog$1@dont-email.me>
Message-ID: <CAPTjJmqz55ZLm6pzffYrnS74erBJ6a2020MY_q9P3ECo-xYJPQ@mail.gmail.com>

On Wed, 14 Dec 2022 at 03:35, Michael F. Stemper
<michael.stemper at gmail.com> wrote:
>
> It's easy enough -- in fact necessary -- to handle the bottom
> level of a function differently than the levels above it. What
> about the case where you want to handle something differently
> in the top level than in lower levels? Is there any way to tell
> from within a function that it wasn't invoked by itself?
>

Why does it have to be the same function?

def _sort_recursive(stuff, keys, start, end):
    """imagine a nice implementation of some sorting algorithm here"""

def sort(stuff, key=None):
    if key:
        keys = [key(x) for x in stuff]
    else:
        keys = stuff
    return _sort_recursive(stuff, 0, len(stuff))

With purely recursive functions (where every call to the function
truly could have been a top-level call - a lot of mathematical
functions work out this way), it makes sense to call the
externally-callable function recursively; but for anything more messy,
it's usually easiest to make the recursive part internal, and then
have a top-level function that calls into the recursive one.

ChrisA

From mats at wichmann.us  Tue Dec 13 12:57:59 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Tue, 13 Dec 2022 10:57:59 -0700
Subject: Top level of a recursive function
In-Reply-To: <CAPTjJmqz55ZLm6pzffYrnS74erBJ6a2020MY_q9P3ECo-xYJPQ@mail.gmail.com>
References: <tna385$2hmog$1@dont-email.me>
 <CAPTjJmqz55ZLm6pzffYrnS74erBJ6a2020MY_q9P3ECo-xYJPQ@mail.gmail.com>
Message-ID: <56717951-1d27-1ea7-75aa-e607e90476ce@wichmann.us>

On 12/13/22 10:36, Chris Angelico wrote:
> On Wed, 14 Dec 2022 at 03:35, Michael F. Stemper
> <michael.stemper at gmail.com> wrote:
>>
>> It's easy enough -- in fact necessary -- to handle the bottom
>> level of a function differently than the levels above it. What
>> about the case where you want to handle something differently
>> in the top level than in lower levels? Is there any way to tell
>> from within a function that it wasn't invoked by itself?
>>
> 
> Why does it have to be the same function?
> 
> def _sort_recursive(stuff, keys, start, end):
>      """imagine a nice implementation of some sorting algorithm here"""
> 
> def sort(stuff, key=None):
>      if key:
>          keys = [key(x) for x in stuff]
>      else:
>          keys = stuff
>      return _sort_recursive(stuff, 0, len(stuff))

if some support for this position is needed, this is roughly how the 
stdlib glob() function is implemented.


From rosuav at gmail.com  Tue Dec 13 13:06:04 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 14 Dec 2022 05:06:04 +1100
Subject: Top level of a recursive function
In-Reply-To: <56717951-1d27-1ea7-75aa-e607e90476ce@wichmann.us>
References: <tna385$2hmog$1@dont-email.me>
 <CAPTjJmqz55ZLm6pzffYrnS74erBJ6a2020MY_q9P3ECo-xYJPQ@mail.gmail.com>
 <56717951-1d27-1ea7-75aa-e607e90476ce@wichmann.us>
Message-ID: <CAPTjJmorJxKp17Ep3mjDkE7vNiKOxkkzs8xkHePc_UB5WKbwbw@mail.gmail.com>

On Wed, 14 Dec 2022 at 05:01, Mats Wichmann <mats at wichmann.us> wrote:
>
> On 12/13/22 10:36, Chris Angelico wrote:
> > On Wed, 14 Dec 2022 at 03:35, Michael F. Stemper
> > <michael.stemper at gmail.com> wrote:
> >>
> >> It's easy enough -- in fact necessary -- to handle the bottom
> >> level of a function differently than the levels above it. What
> >> about the case where you want to handle something differently
> >> in the top level than in lower levels? Is there any way to tell
> >> from within a function that it wasn't invoked by itself?
> >>
> >
> > Why does it have to be the same function?
> >
> > def _sort_recursive(stuff, keys, start, end):
> >      """imagine a nice implementation of some sorting algorithm here"""
> >
> > def sort(stuff, key=None):
> >      if key:
> >          keys = [key(x) for x in stuff]
> >      else:
> >          keys = stuff
> >      return _sort_recursive(stuff, 0, len(stuff))
>
> if some support for this position is needed, this is roughly how the
> stdlib glob() function is implemented.
>

Yeah, lots of things are done that way. You'll find a variety of
naming conventions around different languages and libraries, including
"_low_FUNCTIONNAME" or "_internal_FUNCTIONNAME" etc. It's definitely
easier than trying to mess with tracking toplevel status.

ChrisA

From arequipeno at gmail.com  Tue Dec 13 13:50:34 2022
From: arequipeno at gmail.com (Ian Pilcher)
Date: Tue, 13 Dec 2022 12:50:34 -0600
Subject: Calling pselect/ppoll/epoll_pwait
In-Reply-To: <c4b8fdc3-9dd5-7697-ee12-44a9ddce30bc@gmail.com>
References: <c4b8fdc3-9dd5-7697-ee12-44a9ddce30bc@gmail.com>
Message-ID: <6e304a4e-39fe-1b68-478f-495c46ba0338@gmail.com>

On 12/2/22 14:00, Ian Pilcher wrote:
> Does Python provide any way to call the "p" variants of the I/O
> multiplexing functions?

Just to close this out ...

As others suggested, there's no easy way to call the "p" variants of the
I/O multiplexing functions, but this can be worked around by "mapping"
signals to file descriptors.

There are a few ways to accomplish this.

1. Use a Linux signalfd.  There's at least one library out there that
    provides signalfd support to Python.

2. Use signal.set_wakeup_fd()[1].  I didn't really explore this, as it
    appears that there isn't any way to filter the signals that will be
    reported.

3. Roll your own.  This turned out to be really simple for my use case,
    which is simply to set an exit flag and wake my program up if it
    receives SIGINT or SIGTERM.

    _sel = selectors.DefaultSelector()
    _exit_flag = False
    _sig_pipe_r, _sig_pipe_w = os.pipe2(os.O_NONBLOCK | os.O_CLOEXEC)

    def _sig_handler(signum, frame):
        global _exit_flag
        _exit_flag = True
        os.write(_sig_pipe_w, b'\x00')

    _sel.register(_sig_pipe_r, selectors.EVENT_READ)
    # register other file descriptors of interest
    signal.signal(signal.SIGINT, _sig_handler)
    signal.signal(signal.SIGTERM, _sig_handler)
    while not _exit_flag:
        ready = _sel.select()
        # handle other file descriptors

[1] https://docs.python.org/3/library/signal.html#signal.set_wakeup_fd

-- 
========================================================================
Google                                      Where SkyNet meets Idiocracy
========================================================================


From roel at roelschroeven.net  Tue Dec 13 13:58:35 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 13 Dec 2022 19:58:35 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <quotes-20221213084150@ram.dialup.fu-berlin.de>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
Message-ID: <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>

Stefan Ram schreef op 13/12/2022 om 8:42:
> "John K. Parejko" <parejkoj at gmail.com> writes:
> >I was just burned by this, where some tests I?d written
> >against an sqlite database did not fail in the way that they
> >?should? have, because of this double-quoted string issue.
>
>    In standard SQL, double quotes denote identifiers that are
>    allowed to contain special characters.
Or that are equal SQL keywords, which can be a reason to double-quote 
them. SQL engines sometimes add new keywords; explicitly marking string 
literals as string literals prevents future conflicts and confusion.

Perhaps it's a better idea to use [identifier] or `identifier` instead 
though (I just learned about those on 
https://sqlite.org/lang_keywords.html). Both are not standard SQL ([] is 
used in MS Access and SQL Server, `` is used in MySQL) but both work in 
SQLite. That should prevent any ambiguity and confusion, if it doesn't 
bother you too much that it's not standard SQL.

-- 
"I love science, and it pains me to think that to so many are terrified
of the subject or feel that choosing science means you cannot also
choose compassion, or the arts, or be awed by nature. Science is not
meant to cure us of mystery, but to reinvent and reinvigorate it."
         -- Robert Sapolsky


From rosuav at gmail.com  Tue Dec 13 14:01:43 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 14 Dec 2022 06:01:43 +1100
Subject: sqlite3 double quote behavior
In-Reply-To: <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
Message-ID: <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>

On Wed, 14 Dec 2022 at 06:00, Roel Schroeven <roel at roelschroeven.net> wrote:
>
> Stefan Ram schreef op 13/12/2022 om 8:42:
> > "John K. Parejko" <parejkoj at gmail.com> writes:
> > >I was just burned by this, where some tests I?d written
> > >against an sqlite database did not fail in the way that they
> > >?should? have, because of this double-quoted string issue.
> >
> >    In standard SQL, double quotes denote identifiers that are
> >    allowed to contain special characters.
> Or that are equal SQL keywords, which can be a reason to double-quote
> them. SQL engines sometimes add new keywords; explicitly marking string
> literals as string literals prevents future conflicts and confusion.
>
> Perhaps it's a better idea to use [identifier] or `identifier` instead
> though (I just learned about those on
> https://sqlite.org/lang_keywords.html). Both are not standard SQL ([] is
> used in MS Access and SQL Server, `` is used in MySQL) but both work in
> SQLite. That should prevent any ambiguity and confusion, if it doesn't
> bother you too much that it's not standard SQL.
>

Why not just use "identifier" which is standard SQL?

ChrisA

From michael.stemper at gmail.com  Tue Dec 13 15:28:26 2022
From: michael.stemper at gmail.com (Michael F. Stemper)
Date: Tue, 13 Dec 2022 14:28:26 -0600
Subject: Top level of a recursive function
In-Reply-To: <rest-20221213160153@ram.dialup.fu-berlin.de>
References: <tna385$2hmog$1@dont-email.me>
 <rest-20221213160153@ram.dialup.fu-berlin.de>
Message-ID: <tnan9a$2ja6s$1@dont-email.me>

On 13/12/2022 09.03, Stefan Ram wrote:
> "Michael F. Stemper" <michael.stemper at gmail.com> writes:
>> def fred(cf,toplevel=True):
>>    x = cf[0]
>>    if len(cf)>1:
>>      if toplevel:
>>        return x + fred(cf[1:],False)
>>      else:
>>        return "(" + x + fred(cf[1:],False) + ")"
>>    else:
>>      if toplevel:
>>        return x
>>      else:
>>        return "(" + x + ")"
> 
> def rest( s ):
>      return "(" + s[ 0 ] +( rest( s[1:] ) if len( s )> 1 else '' )+ ')'
> 
> def nest( s ):
>      return( s[ 0 ] if s else '' )+( rest( s[1:] )if len( s )> 1 else '' )

Hey, that's slick! And if I define rest within nest, it's not going
to be externally accessible.

Thanks

-- 
Michael F. Stemper
No animals were harmed in the composition of this message.

From roel at roelschroeven.net  Tue Dec 13 16:18:16 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 13 Dec 2022 22:18:16 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
 <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
Message-ID: <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>

Chris Angelico schreef op 13/12/2022 om 20:01:
> On Wed, 14 Dec 2022 at 06:00, Roel Schroeven <roel at roelschroeven.net> wrote:
> >
> > Stefan Ram schreef op 13/12/2022 om 8:42:
> > > "John K. Parejko" <parejkoj at gmail.com> writes:
> > > >I was just burned by this, where some tests I?d written
> > > >against an sqlite database did not fail in the way that they
> > > >?should? have, because of this double-quoted string issue.
> > >
> > >    In standard SQL, double quotes denote identifiers that are
> > >    allowed to contain special characters.
> > Or that are equal SQL keywords, which can be a reason to double-quote
> > them. SQL engines sometimes add new keywords; explicitly marking string
> > literals as string literals prevents future conflicts and confusion.
> >
> > Perhaps it's a better idea to use [identifier] or `identifier` instead
> > though (I just learned about those on
> > https://sqlite.org/lang_keywords.html). Both are not standard SQL ([] is
> > used in MS Access and SQL Server, `` is used in MySQL) but both work in
> > SQLite. That should prevent any ambiguity and confusion, if it doesn't
> > bother you too much that it's not standard SQL.
> >
>
> Why not just use "identifier" which is standard SQL?

If you accidentally type [identifire] or `identifire`, SQLite will 
produce an unknown identifier error, alerting you immediately to your typo.
If you accidentally type "identifire", SQLite will silently treat it as 
a string literal instead of an identifier, causing more difficult to 
diagnose problems.

-- 
"In the old days, writers used to sit in front of a typewriter and stare out of
the window. Nowadays, because of the marvels of convergent technology, the thing
you type on and the window you stare out of are now the same thing.?
         -- Douglas Adams


From roel at roelschroeven.net  Tue Dec 13 16:36:24 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 13 Dec 2022 22:36:24 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
 <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
 <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
Message-ID: <407f0447-edf1-46e5-6c52-b8634876c684@roelschroeven.net>

Roel Schroeven schreef op 13/12/2022 om 22:18:
> Chris Angelico schreef op 13/12/2022 om 20:01:
> > > Perhaps it's a better idea to use [identifier] or `identifier` instead
> > > though (I just learned about those on
> > > https://sqlite.org/lang_keywords.html). Both are not standard SQL ([] is
> > > used in MS Access and SQL Server, `` is used in MySQL) but both work in
> > > SQLite. That should prevent any ambiguity and confusion, if it doesn't
> > > bother you too much that it's not standard SQL.
> > >
> >
> > Why not just use "identifier" which is standard SQL?
>
> If you accidentally type [identifire] or `identifire`, SQLite will
> produce an unknown identifier error, alerting you immediately to your typo.
> If you accidentally type "identifire", SQLite will silently treat it as
> a string literal instead of an identifier, causing more difficult to
> diagnose problems.
Example:

-- Preparation:
sqlite> create table foo ("columna" text, "columnb" text);
sqlite> insert into foo values ("xyzzy", "xyzzy");

-- Variant with "":
sqlite> select count(*) from foo where "columna" = "colummb";
0

Not at all at first sight clear why there seem to be no matching rows, 
if you even notice straightaway that the result is not correct.

-- Variant with []:
sqlite> select count(*) from foo where [columna] = [colummb];
Error: no such column: colummb

Immediately clear that there is a problem, and what the problem is.


-- 
"In the old days, writers used to sit in front of a typewriter and stare out of
the window. Nowadays, because of the marvels of convergent technology, the thing
you type on and the window you stare out of are now the same thing.?
         -- Douglas Adams


From roel at roelschroeven.net  Tue Dec 13 16:44:37 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Tue, 13 Dec 2022 22:44:37 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <407f0447-edf1-46e5-6c52-b8634876c684@roelschroeven.net>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
 <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
 <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
 <407f0447-edf1-46e5-6c52-b8634876c684@roelschroeven.net>
Message-ID: <9ff67425-065b-5c19-43fe-f3690fff446a@roelschroeven.net>

Roel Schroeven schreef op 13/12/2022 om 22:36:
> sqlite> insert into foo values ("xyzzy", "xyzzy");
SQLite accepts it like that, but I really should have used single quotes 
there instead of double quotes. It's a bad habit from using MySQL for 
too long I guess.

-- 
"In the old days, writers used to sit in front of a typewriter and stare out of
the window. Nowadays, because of the marvels of convergent technology, the thing
you type on and the window you stare out of are now the same thing.?
         -- Douglas Adams


From rosuav at gmail.com  Tue Dec 13 16:58:12 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 14 Dec 2022 08:58:12 +1100
Subject: sqlite3 double quote behavior
In-Reply-To: <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
 <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
 <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
Message-ID: <CAPTjJmo=DG88FR9UJFUcBkm8aDJFT5etDRQjH75XFk9unDB04g@mail.gmail.com>

On Wed, 14 Dec 2022 at 08:19, Roel Schroeven <roel at roelschroeven.net> wrote:
>
> Chris Angelico schreef op 13/12/2022 om 20:01:
> > On Wed, 14 Dec 2022 at 06:00, Roel Schroeven <roel at roelschroeven.net> wrote:
> > >
> > > Stefan Ram schreef op 13/12/2022 om 8:42:
> > > > "John K. Parejko" <parejkoj at gmail.com> writes:
> > > > >I was just burned by this, where some tests I?d written
> > > > >against an sqlite database did not fail in the way that they
> > > > >?should? have, because of this double-quoted string issue.
> > > >
> > > >    In standard SQL, double quotes denote identifiers that are
> > > >    allowed to contain special characters.
> > > Or that are equal SQL keywords, which can be a reason to double-quote
> > > them. SQL engines sometimes add new keywords; explicitly marking string
> > > literals as string literals prevents future conflicts and confusion.
> > >
> > > Perhaps it's a better idea to use [identifier] or `identifier` instead
> > > though (I just learned about those on
> > > https://sqlite.org/lang_keywords.html). Both are not standard SQL ([] is
> > > used in MS Access and SQL Server, `` is used in MySQL) but both work in
> > > SQLite. That should prevent any ambiguity and confusion, if it doesn't
> > > bother you too much that it's not standard SQL.
> > >
> >
> > Why not just use "identifier" which is standard SQL?
>
> If you accidentally type [identifire] or `identifire`, SQLite will
> produce an unknown identifier error, alerting you immediately to your typo.
> If you accidentally type "identifire", SQLite will silently treat it as
> a string literal instead of an identifier, causing more difficult to
> diagnose problems.
>

Okay, so..... exactly the same as if you use standard double quotes,
but change the configuration option. So the options are: make
everything worse for everyone by exacerbating the problem of
non-standard identifier quoting, or get this API so SQLite can be
configured, like the OP actually asked for.

Yeah. Let's not do the wrong thing.

ChrisA

From roel at roelschroeven.net  Tue Dec 13 18:34:18 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Wed, 14 Dec 2022 00:34:18 +0100
Subject: sqlite3 double quote behavior
In-Reply-To: <CAPTjJmo=DG88FR9UJFUcBkm8aDJFT5etDRQjH75XFk9unDB04g@mail.gmail.com>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
 <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
 <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
 <CAPTjJmo=DG88FR9UJFUcBkm8aDJFT5etDRQjH75XFk9unDB04g@mail.gmail.com>
Message-ID: <291f4801-055a-3f11-e6f0-5881f28ceb15@roelschroeven.net>

Chris Angelico schreef op 13/12/2022 om 22:58:
> Okay, so..... exactly the same as if you use standard double quotes,
> but change the configuration option. So the options are: make
> everything worse for everyone by exacerbating the problem of
> non-standard identifier quoting, or get this API so SQLite can be
> configured, like the OP actually asked for.
>
I'm not advocating for one above the other, I think they complement each 
other. Having the option to change SQLite's behavior is clearly the 
better solution if/when that happens (and is released and available in 
our development environments), but that doesn't mean there's no value in 
having a workaround here and now.

-- 
"Most quotes are misattributed"
         -- Einstein


From Gronicus at SGA.Ninja  Tue Dec 13 22:43:35 2022
From: Gronicus at SGA.Ninja (Gronicus at SGA.Ninja)
Date: Tue, 13 Dec 2022 22:43:35 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
Message-ID: <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>

 As is, Test A works.
 Comment out Test A and uncomment Test B it fails.
 In Test B, I move the data into a variable resulting with the report:
            "TypeError: an integer is required (got type tuple)

How do I fix this?

#-----------------------------------------------------------------------------
import datetime
#=================================================
#         Test A   Hard coded Date/Time
Startt = datetime.datetime(2022, 12, 13,  5,  3, 30) 
Stopp =  datetime.datetime(2022, 12, 12, 21, 15, 30) 

# =================================================
#         Test B   Date/Time data as a variable
#Startt = (2022, 12, 13,  5,  3, 30)
#Stopp =  (2022, 12, 12, 21, 15, 30)

#Startt = datetime.datetime(Startt)
#Stopp =  datetime.datetime(Stopp)

# =================================================
c = Startt - Stopp 
minutes = c.total_seconds() / 60
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
        minutes = minutes - 60
        hours += 1
minutes = round(minutes)
print()
print ("       Hours =  <" + str(hours) + ">")
print ("     Minutes =  <" + str(minutes) + ">")

# -----------------------------------------------------------------------------


From list1 at tompassin.net  Tue Dec 13 23:19:58 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Tue, 13 Dec 2022 23:19:58 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
Message-ID: <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>

Your problem is that datetime.datetime does not accept a tuple as an 
argument.  It expects an integer value for the first argument, but you 
supplied a tuple.  In Python, you can use a sequence (e.g., tuple or 
list) the way you want by prefixing it with an asterisk.  This causes 
the sequence of items to be treated as individual arguments. So:

Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
st1 = (2022, 12, 13,  5,  3, 30)
dts1 = datetime.datetime(*st1)  # NOT datetime.datetime(st1)
dts1 == Startt  # True

On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>   As is, Test A works.
>   Comment out Test A and uncomment Test B it fails.
>   In Test B, I move the data into a variable resulting with the report:
>              "TypeError: an integer is required (got type tuple)
> 
> How do I fix this?
> 
> #-----------------------------------------------------------------------------
> import datetime
> #=================================================
> #         Test A   Hard coded Date/Time
> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
> Stopp =  datetime.datetime(2022, 12, 12, 21, 15, 30)
> 
> # =================================================
> #         Test B   Date/Time data as a variable
> #Startt = (2022, 12, 13,  5,  3, 30)
> #Stopp =  (2022, 12, 12, 21, 15, 30)
> 
> #Startt = datetime.datetime(Startt)
> #Stopp =  datetime.datetime(Stopp)
> 
> # =================================================
> c = Startt - Stopp
> minutes = c.total_seconds() / 60
> minutes = c.seconds / 60
> hours = 0
> 
> while (minutes > 59):
>          minutes = minutes - 60
>          hours += 1
> minutes = round(minutes)
> print()
> print ("       Hours =  <" + str(hours) + ">")
> print ("     Minutes =  <" + str(minutes) + ">")
> 
> # -----------------------------------------------------------------------------
> 


From Gronicus at SGA.Ninja  Wed Dec 14 00:55:49 2022
From: Gronicus at SGA.Ninja (Gronicus at SGA.Ninja)
Date: Wed, 14 Dec 2022 00:55:49 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
Message-ID: <016d01d90f80$b7e1a830$27a4f890$@SGA.Ninja>

I realized it had something to do with tupilation
The simple fix is to add the * into the original code.
Startt = datetime.datetime(*Startt)

I am not sure what "dts1 == Startt  # True" does....

Thank you.....


-----Original Message-----
From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org> On
Behalf Of Thomas Passin
Sent: Tuesday, December 13, 2022 11:20 PM
To: python-list at python.org
Subject: Re: Subtracting dates to get hours and minutes

Your problem is that datetime.datetime does not accept a tuple as an
argument.  It expects an integer value for the first argument, but you
supplied a tuple.  In Python, you can use a sequence (e.g., tuple or
list) the way you want by prefixing it with an asterisk.  This causes the
sequence of items to be treated as individual arguments. So:

Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
st1 = (2022, 12, 13,  5,  3, 30)
dts1 = datetime.datetime(*st1)  # NOT datetime.datetime(st1)
dts1 == Startt  # True

On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>   As is, Test A works.
>   Comment out Test A and uncomment Test B it fails.
>   In Test B, I move the data into a variable resulting with the report:
>              "TypeError: an integer is required (got type tuple)
> 
> How do I fix this?
> 
> #---------------------------------------------------------------------
> --------
> import datetime
> #=================================================
> #         Test A   Hard coded Date/Time
> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30) Stopp =  
> datetime.datetime(2022, 12, 12, 21, 15, 30)
> 
> # =================================================
> #         Test B   Date/Time data as a variable
> #Startt = (2022, 12, 13,  5,  3, 30)
> #Stopp =  (2022, 12, 12, 21, 15, 30)
> 
> #Startt = datetime.datetime(Startt)
> #Stopp =  datetime.datetime(Stopp)
> 
> # =================================================
> c = Startt - Stopp
> minutes = c.total_seconds() / 60
> minutes = c.seconds / 60
> hours = 0
> 
> while (minutes > 59):
>          minutes = minutes - 60
>          hours += 1
> minutes = round(minutes)
> print()
> print ("       Hours =  <" + str(hours) + ">")
> print ("     Minutes =  <" + str(minutes) + ">")
> 
> # 
> ----------------------------------------------------------------------
> -------
> 

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


From Cecil at decebal.nl  Wed Dec 14 03:55:34 2022
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Wed, 14 Dec 2022 09:55:34 +0100
Subject: How to get the needed version of a dependency
Message-ID: <875yee1i0p.fsf@munus.decebal.nl>

If I want to know the dependencies for requests I use:
    pip show requests

And one of the lines I get is:
    Requires: certifi, charset-normalizer, idna, urllib3

But I want (in this case) to know with version of charset-normalizer
requests needs.
How do I get that?

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof

From nospam at dfs.com  Wed Dec 14 08:38:54 2022
From: nospam at dfs.com (DFS)
Date: Wed, 14 Dec 2022 08:38:54 -0500
Subject: How to get the needed version of a dependency
In-Reply-To: <875yee1i0p.fsf@munus.decebal.nl>
References: <875yee1i0p.fsf@munus.decebal.nl>
Message-ID: <NlkmL.39210$iU59.15110@fx14.iad>

On 12/14/2022 3:55 AM, Cecil Westerhof wrote:
> If I want to know the dependencies for requests I use:
>      pip show requests
> 
> And one of the lines I get is:
>      Requires: certifi, charset-normalizer, idna, urllib3
> 
> But I want (in this case) to know with version of charset-normalizer
> requests needs.
> How do I get that?

Check the METADATA file in the *dist-info package files usually found in 
Lib\site-packages.

ie  \Python\3.11.0\Lib\site-packages\pandas-1.5.2.dist-info

Look for config lines beginning with 'Requires':

Requires-Python: >=3.8
Requires-Dist: python-dateutil (>=2.8.1)

$ pip list will show you which version of the package you have 
installed, so you can search for the matching .dist-info file

From list1 at tompassin.net  Wed Dec 14 09:30:54 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Wed, 14 Dec 2022 09:30:54 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <016d01d90f80$b7e1a830$27a4f890$@SGA.Ninja>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <016d01d90f80$b7e1a830$27a4f890$@SGA.Ninja>
Message-ID: <81edaf57-f286-d8c3-9035-c5144dc570e6@tompassin.net>

On 12/14/2022 12:55 AM, Gronicus at SGA.Ninja wrote:
> I realized it had something to do with tupilation
> The simple fix is to add the * into the original code.
> Startt = datetime.datetime(*Startt)
> 
> I am not sure what "dts1 == Startt  # True" does....

It demonstrates that the version with the "*" gives the same result as 
the first expression.  That line is not needed by any code, it's just 
there to show you that the proposed expression gives the desired result.

> Thank you.....
> 
> 
> -----Original Message-----
> From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org> On
> Behalf Of Thomas Passin
> Sent: Tuesday, December 13, 2022 11:20 PM
> To: python-list at python.org
> Subject: Re: Subtracting dates to get hours and minutes
> 
> Your problem is that datetime.datetime does not accept a tuple as an
> argument.  It expects an integer value for the first argument, but you
> supplied a tuple.  In Python, you can use a sequence (e.g., tuple or
> list) the way you want by prefixing it with an asterisk.  This causes the
> sequence of items to be treated as individual arguments. So:
> 
> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
> st1 = (2022, 12, 13,  5,  3, 30)
> dts1 = datetime.datetime(*st1)  # NOT datetime.datetime(st1)
> dts1 == Startt  # True
> 
> On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>>    As is, Test A works.
>>    Comment out Test A and uncomment Test B it fails.
>>    In Test B, I move the data into a variable resulting with the report:
>>               "TypeError: an integer is required (got type tuple)
>>
>> How do I fix this?
>>
>> #---------------------------------------------------------------------
>> --------
>> import datetime
>> #=================================================
>> #         Test A   Hard coded Date/Time
>> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30) Stopp =
>> datetime.datetime(2022, 12, 12, 21, 15, 30)
>>
>> # =================================================
>> #         Test B   Date/Time data as a variable
>> #Startt = (2022, 12, 13,  5,  3, 30)
>> #Stopp =  (2022, 12, 12, 21, 15, 30)
>>
>> #Startt = datetime.datetime(Startt)
>> #Stopp =  datetime.datetime(Stopp)
>>
>> # =================================================
>> c = Startt - Stopp
>> minutes = c.total_seconds() / 60
>> minutes = c.seconds / 60
>> hours = 0
>>
>> while (minutes > 59):
>>           minutes = minutes - 60
>>           hours += 1
>> minutes = round(minutes)
>> print()
>> print ("       Hours =  <" + str(hours) + ">")
>> print ("     Minutes =  <" + str(minutes) + ">")
>>
>> #
>> ----------------------------------------------------------------------
>> -------
>>
> 
> --
> https://mail.python.org/mailman/listinfo/python-list
> 


From songbird at anthive.com  Wed Dec 14 13:50:14 2022
From: songbird at anthive.com (songbird)
Date: Wed, 14 Dec 2022 13:50:14 -0500
Subject: Keeping a list of records with named fields that can be updated
Message-ID: <6gip6j-698.ln1@anthive.com>


  I'm relatively new to python but not new to programming in general.

  The program domain is accounting and keeping track of stock trades and other related information (dates, cash accounts, interest, dividends, transfers of funds, etc.)

  Assume that all data is CSV format.  There are multiple files.

  Assume there is a coherent starting point and that all data is in order.

  Assume each line contains a description.  The description determines what the line is.  The number of fields in the line does not change within the data file but it may happen that later lines in other files may be different other than the fact that they all must contain a description.

  All descriptions are deterministic (none are recursive or referencing things from the future).  All things referenced in the description which do not already exist are added to a list (or perhaps more than one in a few cases) and may contain some basic information (the date, how many and for how much, or a total amount or a fee or ...)  If the field of the line isn't a number it is either a symbol or a description.

  A default action is simply to keep most parts of the line and to adjust any totals of a previously seen description that matches by whatever amounts are on the line.  The key is the description.

  I've already written one program based upon the files I already have which works but what happens is that new descriptions are added (new accounts, new stocks, etc.) and I don't want to have to write new code manually every time a description changes.

  I started using named tuples (it works for reading in the files and accessing the fields) but I cannot update those so I need to use something else to give me the list of unique descriptions and fields that I need to update.  I've not gotten beyond that yet as I'm still learning.

  Suggestions?

  Thanks!  :)


  songbird

From transreductionist at gmail.com  Wed Dec 14 13:53:10 2022
From: transreductionist at gmail.com (Aaron P)
Date: Wed, 14 Dec 2022 10:53:10 -0800 (PST)
Subject: Single line if statement with a continue
Message-ID: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>

I occasionally run across something like:

for idx, thing in enumerate(things):
    if idx == 103: 
        continue
    do_something_with(thing)

It seems more succinct and cleaner to use:

if idx == 103: continue.

Of course this would be considered an anti-pattern, and Flake8 will complain.

Any opinions, or feedback on the matter.

From Cecil at decebal.nl  Wed Dec 14 16:05:26 2022
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Wed, 14 Dec 2022 22:05:26 +0100
Subject: How to get the needed version of a dependency
References: <875yee1i0p.fsf@munus.decebal.nl> <NlkmL.39210$iU59.15110@fx14.iad>
Message-ID: <87tu1xzofd.fsf@munus.decebal.nl>

DFS <nospam at dfs.com> writes:

> On 12/14/2022 3:55 AM, Cecil Westerhof wrote:
>> If I want to know the dependencies for requests I use:
>>      pip show requests
>> And one of the lines I get is:
>>      Requires: certifi, charset-normalizer, idna, urllib3
>> But I want (in this case) to know with version of charset-normalizer
>> requests needs.
>> How do I get that?
>
> Check the METADATA file in the *dist-info package files usually found in
> Lib\site-packages.
>
> ie  \Python\3.11.0\Lib\site-packages\pandas-1.5.2.dist-info
>
> Look for config lines beginning with 'Requires':
>
> Requires-Python: >=3.8
> Requires-Dist: python-dateutil (>=2.8.1)
>
> $ pip list will show you which version of the package you have
> installed, so you can search for the matching .dist-info file

Works. In
/usr/local/lib/python3.9/dist-packages/requests-2.28.1.dist-info/METADATA
I see:
    Requires-Dist: charset-normalizer (<3,>=2)

That already keeps charset-normalizer two months from being updated.
Maybe I should contact Kenneth Reitz.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof

From list1 at tompassin.net  Wed Dec 14 22:54:04 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Wed, 14 Dec 2022 22:54:04 -0500
Subject: Keeping a list of records with named fields that can be updated
In-Reply-To: <6gip6j-698.ln1@anthive.com>
References: <6gip6j-698.ln1@anthive.com>
Message-ID: <49bbb11a-a33d-b883-b3e4-7418840dbb99@tompassin.net>

Dictionaries and sets are your friends here.

On 12/14/2022 1:50 PM, songbird wrote:
> 
>    I'm relatively new to python but not new to programming in general.
> 
>    The program domain is accounting and keeping track of stock trades and other related information (dates, cash accounts, interest, dividends, transfers of funds, etc.)
> 
>    Assume that all data is CSV format.  There are multiple files.
> 
>    Assume there is a coherent starting point and that all data is in order.
> 
>    Assume each line contains a description.  The description determines what the line is.  The number of fields in the line does not change within the data file but it may happen that later lines in other files may be different other than the fact that they all must contain a description.
> 
>    All descriptions are deterministic (none are recursive or referencing things from the future).  All things referenced in the description which do not already exist are added to a list (or perhaps more than one in a few cases) and may contain some basic information (the date, how many and for how much, or a total amount or a fee or ...)  If the field of the line isn't a number it is either a symbol or a description.
> 
>    A default action is simply to keep most parts of the line and to adjust any totals of a previously seen description that matches by whatever amounts are on the line.  The key is the description.
> 
>    I've already written one program based upon the files I already have which works but what happens is that new descriptions are added (new accounts, new stocks, etc.) and I don't want to have to write new code manually every time a description changes.
> 
>    I started using named tuples (it works for reading in the files and accessing the fields) but I cannot update those so I need to use something else to give me the list of unique descriptions and fields that I need to update.  I've not gotten beyond that yet as I'm still learning.
> 
>    Suggestions?
> 
>    Thanks!  :)
> 
> 
>    songbird


From rosuav at gmail.com  Wed Dec 14 23:35:28 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 15 Dec 2022 15:35:28 +1100
Subject: Single line if statement with a continue
In-Reply-To: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
Message-ID: <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>

On Thu, 15 Dec 2022 at 14:41, Aaron P <transreductionist at gmail.com> wrote:
>
> I occasionally run across something like:
>
> for idx, thing in enumerate(things):
>     if idx == 103:
>         continue
>     do_something_with(thing)
>
> It seems more succinct and cleaner to use:
>
> if idx == 103: continue.
>
> Of course this would be considered an anti-pattern, and Flake8 will complain.
>
> Any opinions, or feedback on the matter.

Nothing at all wrong with writing that on a single line. If you have
issues with Flake8 not accepting your choices, reconfigure Flake8 :)

ChrisA

From PythonList at DancesWithMice.info  Thu Dec 15 00:24:15 2022
From: PythonList at DancesWithMice.info (dn)
Date: Thu, 15 Dec 2022 18:24:15 +1300
Subject: Single line if statement with a continue
In-Reply-To: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
Message-ID: <bdc418ed-b1cc-7e57-b23d-8765e7a8398e@DancesWithMice.info>

On 15/12/2022 07.53, Aaron P wrote:
> I occasionally run across something like:
> 
> for idx, thing in enumerate(things):
>      if idx == 103:
>          continue
>      do_something_with(thing)
> 
> It seems more succinct and cleaner to use:
> 
> if idx == 103: continue.
> 
> Of course this would be considered an anti-pattern, and Flake8 will complain.
> 
> Any opinions, or feedback on the matter.


These aged-eyes prefer the second line and indentation.


However, another alternative (given simplicity of example):

for ...
     if idx != 103:
         do_something ...


Which could, in-turn, be boiled-down to a 'one-liner'.

-- 
Regards,
=dn

From list1 at tompassin.net  Thu Dec 15 00:06:43 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 15 Dec 2022 00:06:43 -0500
Subject: Single line if statement with a continue
In-Reply-To: <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
Message-ID: <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>

PEP-8, which is Guido's style guide and generally good to follow, does 
not completely discourage single-line usage like the example.  It's not 
clear to me how Chris's example fits into the guidelines.

PEP-8:
"While sometimes it?s okay to put an if/for/while with a small body on 
the same line, never do this for multi-clause statements.
...
# Wrong:
if foo == 'blah': do_blah_thing()
for x in lst: total += x
while t < 10: t = delay()
"

If the one-liner were not in a multi-statement block, it would be all 
right with PEP-8.  OTOH, there is nothing that says one has to fully 
comply with PEP-8. I personally tend to use

if test: return

even inside larger blocks.  If one is working with other someone else's 
project and there is a style guide, it's important to follow that guide 
because the other people involved will find it easier to read and 
understand your code.

If you are working on your own project, PEP-8 is always a good starting 
point, and flake8 and pylint will be happier.  That's worth something.

On 12/14/2022 11:35 PM, Chris Angelico wrote:
> On Thu, 15 Dec 2022 at 14:41, Aaron P <transreductionist at gmail.com> wrote:
>>
>> I occasionally run across something like:
>>
>> for idx, thing in enumerate(things):
>>      if idx == 103:
>>          continue
>>      do_something_with(thing)
>>
>> It seems more succinct and cleaner to use:
>>
>> if idx == 103: continue.
>>
>> Of course this would be considered an anti-pattern, and Flake8 will complain.
>>
>> Any opinions, or feedback on the matter.
> 
> Nothing at all wrong with writing that on a single line. If you have
> issues with Flake8 not accepting your choices, reconfigure Flake8 :)
> 
> ChrisA


From rosuav at gmail.com  Thu Dec 15 01:56:08 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 15 Dec 2022 17:56:08 +1100
Subject: Single line if statement with a continue
In-Reply-To: <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
Message-ID: <CAPTjJmqSHxHtH7rOyCeU28C4sT=hnz5xf9VZAqqiD=wuXiVRcQ@mail.gmail.com>

On Thu, 15 Dec 2022 at 16:29, Thomas Passin <list1 at tompassin.net> wrote:
>
> PEP-8, which is Guido's style guide and generally good to follow, does
> not completely discourage single-line usage like the example.  It's not
> clear to me how Chris's example fits into the guidelines.
>
> PEP-8:
> "While sometimes it?s okay to put an if/for/while with a small body on
> the same line, never do this for multi-clause statements.
> ...
> # Wrong:
> if foo == 'blah': do_blah_thing()
> for x in lst: total += x
> while t < 10: t = delay()
> "
>
> If the one-liner were not in a multi-statement block, it would be all
> right with PEP-8.

Not sure what your point is about it being "in" a multi-statement
block - PEP 8 has nothing to say about that. What it's saying is that
you shouldn't do this:

if foo == 'blah': one(); two(); three()

And I agree; if you're putting more than one statement after your
'if', it's generally clearest to have it on multiple lines. But a
simple "continue" or "break" statement works just fine on the same
line as the if.

ChrisA

From avi.e.gross at gmail.com  Thu Dec 15 01:58:11 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Thu, 15 Dec 2022 01:58:11 -0500
Subject: Single line if statement with a continue
In-Reply-To: <bdc418ed-b1cc-7e57-b23d-8765e7a8398e@DancesWithMice.info>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <bdc418ed-b1cc-7e57-b23d-8765e7a8398e@DancesWithMice.info>
Message-ID: <005401d91052$98eb2410$cac16c30$@gmail.com>

Unless someone is counting lines of code for some purpose, like number of
error found per thousand lines of code, many short one-liners strike me as
more readable and especially if followed by a blank line so it is a bit
obvious.

Consider a similar issue in many languages that use curly braces and where
they can be skipped in a one liner like "if (condition) statement" rather
than the style some use on multiple lines like:

If (condition) {
  Statement
}

Or even:

If (condition)
  {
  Statement
  }


Of course, once you have additional parts following like an "else" that
contains multiple statements, it seems more symmetric to do both parts the
same style.

And in commented code, a one-liner may get long and harder to read as in 

If (condition) statement # long comment

Note the above are not python and the absence of a colon is intentional. No
one language is being discussed and some have their own vagaries and
variants such as not knowing if your code is done if you change lines in
ambiguous situations.  And note some languages support methods like the ?:
operator or the inline if/else python allows as in this:

min = 5
low = 12
x = low if low >= 12 else min
x
12
low = 3
x = low if low >= 12 else min
result
12

Clearly that is a one-liner that almost has to be a one liner as there is no
obvious easy way to wrap it into multiple lines.

I mean the following works, albeit darned if I know if any of it should be
indented or who wants to read it this way:

x = low \
    if \
      low >= 12 \
    else \
      min
    
x
5

As many have discussed, it is a matter of taste and people should be
flexible enough to program in whatever style others want to see when that
applies such as working in a group project or fixing someone else's code.


-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
Behalf Of dn
Sent: Thursday, December 15, 2022 12:24 AM
To: python-list at python.org
Subject: Re: Single line if statement with a continue

On 15/12/2022 07.53, Aaron P wrote:
> I occasionally run across something like:
> 
> for idx, thing in enumerate(things):
>      if idx == 103:
>          continue
>      do_something_with(thing)
> 
> It seems more succinct and cleaner to use:
> 
> if idx == 103: continue.
> 
> Of course this would be considered an anti-pattern, and Flake8 will
complain.
> 
> Any opinions, or feedback on the matter.


These aged-eyes prefer the second line and indentation.


However, another alternative (given simplicity of example):

for ...
     if idx != 103:
         do_something ...


Which could, in-turn, be boiled-down to a 'one-liner'.

-- 
Regards,
=dn
-- 
https://mail.python.org/mailman/listinfo/python-list


From __peter__ at web.de  Thu Dec 15 03:39:54 2022
From: __peter__ at web.de (Peter Otten)
Date: Thu, 15 Dec 2022 09:39:54 +0100
Subject: Top level of a recursive function
In-Reply-To: <tna385$2hmog$1@dont-email.me>
References: <tna385$2hmog$1@dont-email.me>
Message-ID: <1d28e5ea-4877-adc0-f945-c6c79a532cc1@web.de>

On 13/12/2022 15:46, Michael F. Stemper wrote:
> It's easy enough -- in fact necessary -- to handle the bottom
> level of a function differently than the levels above it. What
> about the case where you want to handle something differently
> in the top level than in lower levels? Is there any way to tell
> from within a function that it wasn't invoked by itself?
>
> I've come up with a hack to support different processing, by
> use of an extra argument, as shown in this simplified example:
>
> def fred(cf,toplevel=True):
>  ? x = cf[0]
>  ? if len(cf)>1:
>  ??? if toplevel:
>  ????? return x + fred(cf[1:],False)
>  ??? else:
>  ????? return "(" + x + fred(cf[1:],False) + ")"
>  ? else:
>  ??? if toplevel:
>  ????? return x
>  ??? else:
>  ????? return "(" + x + ")"
>
> Aside from being ugly, this lets the caller diddle with "toplevel",
> which shouldn't really be externally modifiable.
>
> Are there better ways to do this?

For adepts of functional programming the above is a "fold right"
operation, first hit for "foldr in python":

https://burgaud.com/foldl-foldr-python

With that

 >>> from functools import reduce
 >>> def foldr(func, items):
	return reduce(lambda x, y: func(y, x), items[::-1])

your problem reduces ;) to

 >>> foldr("{0}({1})".format, [1,2,3,4])
'1(2(3(4)))'


From __peter__ at web.de  Thu Dec 15 04:21:14 2022
From: __peter__ at web.de (Peter Otten)
Date: Thu, 15 Dec 2022 10:21:14 +0100
Subject: Keeping a list of records with named fields that can be updated
In-Reply-To: <6gip6j-698.ln1@anthive.com>
References: <6gip6j-698.ln1@anthive.com>
Message-ID: <9158537c-f561-e666-f60c-34d50f61d7b7@web.de>

On 14/12/2022 19:50, songbird wrote:
>
>    I'm relatively new to python but not new to programming in general.
>
>    The program domain is accounting and keeping track of stock trades and other related information (dates, cash accounts, interest, dividends, transfers of funds, etc.)
>
>    Assume that all data is CSV format.  There are multiple files.
>
>    Assume there is a coherent starting point and that all data is in order.
>
>    Assume each line contains a description.  The description determines what the line is.  The number of fields in the line does not change within the data file but it may happen that later lines in other files may be different other than the fact that they all must contain a description.
>
>    All descriptions are deterministic (none are recursive or referencing things from the future).  All things referenced in the description which do not already exist are added to a list (or perhaps more than one in a few cases) and may contain some basic information (the date, how many and for how much, or a total amount or a fee or ...)  If the field of the line isn't a number it is either a symbol or a description.
>
>    A default action is simply to keep most parts of the line and to adjust any totals of a previously seen description that matches by whatever amounts are on the line.  The key is the description.
>
>    I've already written one program based upon the files I already have which works but what happens is that new descriptions are added (new accounts, new stocks, etc.) and I don't want to have to write new code manually every time a description changes.
>
>    I started using named tuples (it works for reading in the files and accessing the fields) but I cannot update those so I need to use something else to give me the list of unique descriptions and fields that I need to update.  I've not gotten beyond that yet as I'm still learning.
>
>    Suggestions?
>
>    Thanks!  :)

While I think what you need is a database instead of the collection of
csv files the way to alter namedtuples is to create  a new one:

 >>> from collections import namedtuple
 >>> Row = namedtuple("Row", "foo bar baz")
 >>> row = Row(1, 2, 3)
 >>> row._replace(bar=42)
Row(foo=1, bar=42, baz=3)

An alternative would be dataclasses where basic usage is just as easy:

 >>> from dataclasses import make_dataclass
 >>> Row = make_dataclass("Row", "foo bar baz".split())
 >>> row = Row(1, 2, 3)
 >>> row
Row(foo=1, bar=2, baz=3)
 >>> row.bar = 42
 >>> row
Row(foo=1, bar=42, baz=3)



From gweatherby at uchc.edu  Thu Dec 15 08:00:15 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Thu, 15 Dec 2022 13:00:15 +0000
Subject: Keeping a list of records with named fields that can be updated
In-Reply-To: <6gip6j-698.ln1@anthive.com>
References: <6gip6j-698.ln1@anthive.com>
Message-ID: <SA1PR14MB5855FCF33DDDBA034167958CB9E19@SA1PR14MB5855.namprd14.prod.outlook.com>

I have a lot of NamedTuples in my codebase, and I now add new ones never. They were a good option prior to Python 3.7 but dataclasses are much easier to work with and are almost a drop-in substitute.

A combination of a default dictionary and a dataclass might meet your needs:



import collections
from dataclasses import dataclass


@dataclass
class AccountingEntry:
    description: str
    # other fields


ledger = collections.defaultdict(list)

for ae in get_accounting_entries():
    ledger[ae.description] = ae



From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of songbird <songbird at anthive.com>
Date: Wednesday, December 14, 2022 at 10:38 PM
To: python-list at python.org <python-list at python.org>
Subject: Keeping a list of records with named fields that can be updated
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

  I'm relatively new to python but not new to programming in general.

  The program domain is accounting and keeping track of stock trades and other related information (dates, cash accounts, interest, dividends, transfers of funds, etc.)

  Assume that all data is CSV format.  There are multiple files.

  Assume there is a coherent starting point and that all data is in order.

  Assume each line contains a description.  The description determines what the line is.  The number of fields in the line does not change within the data file but it may happen that later lines in other files may be different other than the fact that they all must contain a description.

  All descriptions are deterministic (none are recursive or referencing things from the future).  All things referenced in the description which do not already exist are added to a list (or perhaps more than one in a few cases) and may contain some basic information (the date, how many and for how much, or a total amount or a fee or ...)  If the field of the line isn't a number it is either a symbol or a description.

  A default action is simply to keep most parts of the line and to adjust any totals of a previously seen description that matches by whatever amounts are on the line.  The key is the description.

  I've already written one program based upon the files I already have which works but what happens is that new descriptions are added (new accounts, new stocks, etc.) and I don't want to have to write new code manually every time a description changes.

  I started using named tuples (it works for reading in the files and accessing the fields) but I cannot update those so I need to use something else to give me the list of unique descriptions and fields that I need to update.  I've not gotten beyond that yet as I'm still learning.

  Suggestions?

  Thanks!  :)


  songbird
--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!ndkoYjlClLoELvhzTpXFZEtJ70fXjdFllo-ce0fJ4f0AdRLQXvryO11ZSJ16tf-Ke-pko3kmBxW1cesvrQAQUQ$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!ndkoYjlClLoELvhzTpXFZEtJ70fXjdFllo-ce0fJ4f0AdRLQXvryO11ZSJ16tf-Ke-pko3kmBxW1cesvrQAQUQ$>

From Gronicus at SGA.Ninja  Thu Dec 15 13:14:43 2022
From: Gronicus at SGA.Ninja (Gronicus at SGA.Ninja)
Date: Thu, 15 Dec 2022 13:14:43 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
Message-ID: <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>

So far so good , I can now use a variable in datetime.datetime but it only
works if I hard-code the time/date information. Now I want to have the code
read from a file but I get: TypeError: function takes at most 9 arguments
(26 given)

I figure that the structure in the file is incorrect. What should it be? The
entry in the file is (2022, 12, 13,  5,  3, 30) but when my program tries to
use it I get the error.

The program is a bit more sophisticated now but here is the update with a
sample of the SPECIFICATIONS.txt file:
=====================================================================

# This program compares two Timedate values, subtracts the two and
# converts the difference to seconds and hours.
#

#  %A Monday    #  %a Mon           #  %B January   #  %b Jan
#  %d 05 day    #  %m month as 01   #  %Y 2020      #  %y 20
#  %H 24        #  %I 12            #  %M 30 min    #  %S Seconds

import time
import datetime
from time import gmtime, strftime ##define strftime as time/date right now
# ======================================================

def GetSpecByItem(GetThisOne):  #get line by item in column 4 - 7
    ItemValue = "--"
    
    with open("SPECIFICATIONS.txt" , 'r') as infile:
     for lineEQN in infile: # loop to find each line in the file for that
dose
        if ((lineEQN[4:7]== GetThisOne)):
           ItemValue = lineEQN[30:60].strip()   # Just the Data
    return(ItemValue)

"""
SPECIFICATIONS.txt

IYf HRB Humalog R Date           (2018, 12, 4, 10,  7, 00)           ##
IYf HRG Humulin R Date           (2022, 12, 13,  5,  3, 30)          ##
"""
# ====================== Main() ======================================
print()
Startt = "404"
Stopp  = "404"

Answer = "Y"
Answer = input("Run test A? (" + Answer + ")" )

if Answer == "Y" or Answer == "y" or Answer == "":
   print()
   print("     Running Test A:")
#           Year  Mth Day Hour Min Sec
   Startt  =   2018, 12, 4, 10,  7, 00  
   Stopp   =   2022, 12, 12, 1, 15, 30
   NowTime =   2022, 12, 14, 21, 15, 30
else:
   print("     Running Test B:")
   Startt = GetSpecByItem("HRG")
   Stopp =  GetSpecByItem("HRB")
   NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")
   
print()
print("55    NowTime = " + str(NowTime))
print("56     Startt = " + str(Startt))
print("57      Stopp = " + str(Stopp))
print()

NowTime =  datetime.datetime(*NowTime)
Startt =   datetime.datetime(*Startt)
Stopp =    datetime.datetime(*Stopp)

#Start == Startt  # True" 
#print("Startt test = " + Start)
# =================================================
print()
c = NowTime - Stopp 
minutes = c.total_seconds() / 60 
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
        minutes = minutes - 60
        hours += 1
minutes = round(minutes)
print ("77 Hours =     <" + str(hours) + ">")
print ("78 Minutes =   <" + str(minutes) + ">")
if hours > 7:
    print(" Time to inject Humulin R u500.")

pause = input("Pause")    
# ======================================================


-----Original Message-----
From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org> On
Behalf Of Thomas Passin
Sent: Tuesday, December 13, 2022 11:20 PM
To: python-list at python.org
Subject: Re: Subtracting dates to get hours and minutes

Your problem is that datetime.datetime does not accept a tuple as an
argument.  It expects an integer value for the first argument, but you
supplied a tuple.  In Python, you can use a sequence (e.g., tuple or
list) the way you want by prefixing it with an asterisk.  This causes the
sequence of items to be treated as individual arguments. So:

Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
st1 = (2022, 12, 13,  5,  3, 30)
dts1 = datetime.datetime(*st1)  # NOT datetime.datetime(st1)
dts1 == Startt  # True

On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>   As is, Test A works.
>   Comment out Test A and uncomment Test B it fails.
>   In Test B, I move the data into a variable resulting with the report:
>              "TypeError: an integer is required (got type tuple)
> 
> How do I fix this?
> 
> #---------------------------------------------------------------------
> --------
> import datetime
> #=================================================
> #         Test A   Hard coded Date/Time
> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30) Stopp =  
> datetime.datetime(2022, 12, 12, 21, 15, 30)
> 
> # =================================================
> #         Test B   Date/Time data as a variable
> #Startt = (2022, 12, 13,  5,  3, 30)
> #Stopp =  (2022, 12, 12, 21, 15, 30)
> 
> #Startt = datetime.datetime(Startt)
> #Stopp =  datetime.datetime(Stopp)
> 
> # =================================================
> c = Startt - Stopp
> minutes = c.total_seconds() / 60
> minutes = c.seconds / 60
> hours = 0
> 
> while (minutes > 59):
>          minutes = minutes - 60
>          hours += 1
> minutes = round(minutes)
> print()
> print ("       Hours =  <" + str(hours) + ">")
> print ("     Minutes =  <" + str(minutes) + ">")
> 
> # 
> ----------------------------------------------------------------------
> -------
> 

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


From cl at isbd.net  Thu Dec 15 03:58:26 2022
From: cl at isbd.net (Chris Green)
Date: Thu, 15 Dec 2022 08:58:26 +0000
Subject: Single line if statement with a continue
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
 <mailman.1171.1671081943.20444.python-list@python.org>
Message-ID: <i64r6j-b7c91.ln1@esprimo.zbmc.eu>

Thomas Passin <list1 at tompassin.net> wrote:
>                    I personally tend to use
> 
> if test: return
> 
> even inside larger blocks.

I always try to avoid multiple returns from functions/methods, as soon
as things get complex it's all to easy to miss clean-up etc.

"No multiple returns" is often found in programming guidelines.

-- 
Chris Green
?

From Cecil at decebal.nl  Thu Dec 15 08:09:54 2022
From: Cecil at decebal.nl (Cecil Westerhof)
Date: Thu, 15 Dec 2022 14:09:54 +0100
Subject: Single line if statement with a continue
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
 <mailman.1171.1671081943.20444.python-list@python.org>
 <i64r6j-b7c91.ln1@esprimo.zbmc.eu>
 <return-20221215133614@ram.dialup.fu-berlin.de>
Message-ID: <87edt0zucd.fsf@munus.decebal.nl>

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

>>"No multiple returns" is often found in programming guidelines.
>
>   I religiously followed that when I did more C programming
>   than today. Then, I read an article about how the result
>   pattern makes functions measurably slower. (It should not
>   with an optimizing compiler, but it did due to those
>   measurements. Can't find that article now, though.)

That makes me think about the quote from Edsger W. Dijkstra about the
go to statement:
    Please do not fall into the trap of believing that I am terribly
    dogmatic about the go to statement. I have the uncomfortable
    feeling that others are making a religion out of it, as if the
    conceptual problems of programming could be solved by a simple
    trick, by a simple form of coding discipline! 

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof

From songbird at anthive.com  Thu Dec 15 08:41:57 2022
From: songbird at anthive.com (songbird)
Date: Thu, 15 Dec 2022 08:41:57 -0500
Subject: Keeping a list of records with named fields that can be updated
References: <6gip6j-698.ln1@anthive.com>
 <9158537c-f561-e666-f60c-34d50f61d7b7@web.de>
 <mailman.1175.1671096336.20444.python-list@python.org>
Message-ID: <5qkr6j-dk2.ln1@anthive.com>

Peter Otten wrote:
>
> While I think what you need is a database instead of the collection of
> csv files the way to alter namedtuples is to create  a new one:

  the files are coming from the web site that stores the
accounts.  i already have manually created files from many
years ago with some of the same information but to go back
and reformat all of those would be a lot of work.  it is
much easier to just take the files as supplied and process
them if i can do that instead.

  i do know database stuff well enough but this is fairly
simple math and i'd like to avoid creating yet another
copy in yet another format to have to deal with.


> >>> from collections import namedtuple
> >>> Row = namedtuple("Row", "foo bar baz")
> >>> row = Row(1, 2, 3)
> >>> row._replace(bar=42)
> Row(foo=1, bar=42, baz=3)
>
> An alternative would be dataclasses where basic usage is just as easy:
>
> >>> from dataclasses import make_dataclass
> >>> Row = make_dataclass("Row", "foo bar baz".split())
> >>> row = Row(1, 2, 3)
> >>> row
> Row(foo=1, bar=2, baz=3)
> >>> row.bar = 42
> >>> row
> Row(foo=1, bar=42, baz=3)

  thanks, i'll give these a try.  :)


  songbird

From avi.e.gross at gmail.com  Thu Dec 15 14:05:32 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Thu, 15 Dec 2022 14:05:32 -0500
Subject: Single line if statement with a continue
In-Reply-To: <return-20221215133614@ram.dialup.fu-berlin.de>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
 <mailman.1171.1671081943.20444.python-list@python.org>
 <i64r6j-b7c91.ln1@esprimo.zbmc.eu>
 <return-20221215133614@ram.dialup.fu-berlin.de>
Message-ID: <055e01d910b8$349de450$9dd9acf0$@gmail.com>

Multiple returns is not always a problem as it depends on the nature of a
task whether it has complex enough cases. 

I have seen code that instead sets Boolean variables when it is ready to
return and everything else keeps checking the variables to skip further
processing so the program then slides down to a single return statement. If
done properly, it boils down to the same result if VERY carefully done but
with lots of sometimes complex IF statements that may be not be updated well
if the logic changes a bit.

In such cases, I vastly prefer clean and unambiguous returns  from the
function right at the point where the decision is made, UNLESS the exit is
not always clean as there may be cleanup or finalization of some kind
required that is best done at a single point.

If efficiency is an issue, then clearly a rapid exit may beat one where
processing continues for a while and also often beats a method that involves
creating and calling multiple smaller functions with lots of overhead.

Having said all that, of course, if you can find a fairly simple algorithm
that only returns from one place, use it instead of a convoluted one. The
issue is not necessarily that multiple return points are bad, but that they
are often a symptom of sloppy planning. But for some problems, they fit well
and simplify things.

-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
Behalf Of Stefan Ram
Sent: Thursday, December 15, 2022 7:42 AM
To: python-list at python.org
Subject: Re: Single line if statement with a continue

Chris Green <cl at isbd.net> writes:
>I always try to avoid multiple returns from functions/methods, as soon 
>as things get complex it's all to easy to miss clean-up etc.

  This "complexity" could also mean that the function has
  become too large. In such a case, one could say that the
  /size/ of the function is the actual cause of problems
  and not multiple returns.

|Fools ignore complexity. Pragmatists suffer it. Some can avoid it. 
|Geniuses remove it.
Alan Perlis (1922/1990)

  Within a small function, multiple returns are rarely
  a problem.

  When a function is large, one can apply well-known
  refactors. For an example, look at the code in the
  first post of the thread

Python script not letting go of files
Date: Tue, 29 Nov 2022 12:52:15 +0000

  and then at my reply of

29 Nov 2022 14:44:39 GMT.

>"No multiple returns" is often found in programming guidelines.

  I religiously followed that when I did more C programming
  than today. Then, I read an article about how the result
  pattern makes functions measurably slower. (It should not
  with an optimizing compiler, but it did due to those
  measurements. Can't find that article now, though.)

  "Result pattern" I call writing,

if a:
    result = 123
else:
    result = 456
return result

  , instead of,

if a:
    return 123
else
    return 456 

  .


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


From parejkoj at gmail.com  Thu Dec 15 14:18:55 2022
From: parejkoj at gmail.com (John K. Parejko)
Date: Thu, 15 Dec 2022 11:18:55 -0800
Subject: sqlite3 double quote behavior
In-Reply-To: <CAPTjJmo=DG88FR9UJFUcBkm8aDJFT5etDRQjH75XFk9unDB04g@mail.gmail.com>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
 <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
 <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
 <CAPTjJmo=DG88FR9UJFUcBkm8aDJFT5etDRQjH75XFk9unDB04g@mail.gmail.com>
Message-ID: <9ED49723-3E93-41F5-8CDA-4CA322F6B105@gmail.com>

Thanks for the discussion. I?m aware that SQLite has several different options for identifier quoting, but they?re not cross-compatible with other SQL, whereas double quotes are (modulo this strange SQLite behavior).

Is anyone here familiar with the python sqlite3 implementation? I wonder how hard it would be to raise up the `sqlite3_db_config` generically, or have a specific function to set just the DQS_DDL and DQS_DML settings? It looks like everything interesting is in `Modules/_sqlite/module.c`, but I?m not familiar with the cpython internals.

John

> On 13Dec 2022, at 13:58, Chris Angelico <rosuav at gmail.com> wrote:
> 
> On Wed, 14 Dec 2022 at 08:19, Roel Schroeven <roel at roelschroeven.net> wrote:
>> 
>> Chris Angelico schreef op 13/12/2022 om 20:01:
>>> On Wed, 14 Dec 2022 at 06:00, Roel Schroeven <roel at roelschroeven.net> wrote:
>>>> 
>>>> Stefan Ram schreef op 13/12/2022 om 8:42:
>>>>> "John K. Parejko" <parejkoj at gmail.com> writes:
>>>>>> I was just burned by this, where some tests I?d written
>>>>>> against an sqlite database did not fail in the way that they
>>>>>> ?should? have, because of this double-quoted string issue.
>>>>> 
>>>>>   In standard SQL, double quotes denote identifiers that are
>>>>>   allowed to contain special characters.
>>>> Or that are equal SQL keywords, which can be a reason to double-quote
>>>> them. SQL engines sometimes add new keywords; explicitly marking string
>>>> literals as string literals prevents future conflicts and confusion.
>>>> 
>>>> Perhaps it's a better idea to use [identifier] or `identifier` instead
>>>> though (I just learned about those on
>>>> https://sqlite.org/lang_keywords.html). Both are not standard SQL ([] is
>>>> used in MS Access and SQL Server, `` is used in MySQL) but both work in
>>>> SQLite. That should prevent any ambiguity and confusion, if it doesn't
>>>> bother you too much that it's not standard SQL.
>>>> 
>>> 
>>> Why not just use "identifier" which is standard SQL?
>> 
>> If you accidentally type [identifire] or `identifire`, SQLite will
>> produce an unknown identifier error, alerting you immediately to your typo.
>> If you accidentally type "identifire", SQLite will silently treat it as
>> a string literal instead of an identifier, causing more difficult to
>> diagnose problems.
>> 
> 
> Okay, so..... exactly the same as if you use standard double quotes,
> but change the configuration option. So the options are: make
> everything worse for everyone by exacerbating the problem of
> non-standard identifier quoting, or get this API so SQLite can be
> configured, like the OP actually asked for.
> 
> Yeah. Let's not do the wrong thing.
> 
> ChrisA
> -- 
> https://mail.python.org/mailman/listinfo/python-list


From gweatherby at uchc.edu  Thu Dec 15 14:22:59 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Thu, 15 Dec 2022 19:22:59 +0000
Subject: Single line if statement with a continue
In-Reply-To: <055e01d910b8$349de450$9dd9acf0$@gmail.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
 <mailman.1171.1671081943.20444.python-list@python.org>
 <i64r6j-b7c91.ln1@esprimo.zbmc.eu>
 <return-20221215133614@ram.dialup.fu-berlin.de>
 <055e01d910b8$349de450$9dd9acf0$@gmail.com>
Message-ID: <SA1PR14MB585541E08D29723575C798FDB9E19@SA1PR14MB5855.namprd14.prod.outlook.com>

I once saw a C function full of GOTOs which jumped to the return state at the bottom of the functions because the programmer had learned that ?multiple returns are a bad idea.?

I totally agree multiple returns causing confusion is a symptom of poor design, not a cause.

Required cleanup is easily handled by the try / finally construct.

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of avi.e.gross at gmail.com <avi.e.gross at gmail.com>
Date: Thursday, December 15, 2022 at 2:07 PM
To: python-list at python.org <python-list at python.org>
Subject: RE: Single line if statement with a continue
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Multiple returns is not always a problem as it depends on the nature of a
task whether it has complex enough cases.

I have seen code that instead sets Boolean variables when it is ready to
return and everything else keeps checking the variables to skip further
processing so the program then slides down to a single return statement. If
done properly, it boils down to the same result if VERY carefully done but
with lots of sometimes complex IF statements that may be not be updated well
if the logic changes a bit.

In such cases, I vastly prefer clean and unambiguous returns  from the
function right at the point where the decision is made, UNLESS the exit is
not always clean as there may be cleanup or finalization of some kind
required that is best done at a single point.

If efficiency is an issue, then clearly a rapid exit may beat one where
processing continues for a while and also often beats a method that involves
creating and calling multiple smaller functions with lots of overhead.

Having said all that, of course, if you can find a fairly simple algorithm
that only returns from one place, use it instead of a convoluted one. The
issue is not necessarily that multiple return points are bad, but that they
are often a symptom of sloppy planning. But for some problems, they fit well
and simplify things.

-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
Behalf Of Stefan Ram
Sent: Thursday, December 15, 2022 7:42 AM
To: python-list at python.org
Subject: Re: Single line if statement with a continue

Chris Green <cl at isbd.net> writes:
>I always try to avoid multiple returns from functions/methods, as soon
>as things get complex it's all to easy to miss clean-up etc.

  This "complexity" could also mean that the function has
  become too large. In such a case, one could say that the
  /size/ of the function is the actual cause of problems
  and not multiple returns.

|Fools ignore complexity. Pragmatists suffer it. Some can avoid it.
|Geniuses remove it.
Alan Perlis (1922/1990)

  Within a small function, multiple returns are rarely
  a problem.

  When a function is large, one can apply well-known
  refactors. For an example, look at the code in the
  first post of the thread

Python script not letting go of files
Date: Tue, 29 Nov 2022 12:52:15 +0000

  and then at my reply of

29 Nov 2022 14:44:39 GMT.

>"No multiple returns" is often found in programming guidelines.

  I religiously followed that when I did more C programming
  than today. Then, I read an article about how the result
  pattern makes functions measurably slower. (It should not
  with an optimizing compiler, but it did due to those
  measurements. Can't find that article now, though.)

  "Result pattern" I call writing,

if a:
    result = 123
else:
    result = 456
return result

  , instead of,

if a:
    return 123
else
    return 456

  .


--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!lVeLOl91qPUjowC1ch_u353upn8X-V4rsReaNberWpIXBlBP6CYcDgr_aaMb0ZHoYX4YWO8id1biCn6sW7V6vJM$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!lVeLOl91qPUjowC1ch_u353upn8X-V4rsReaNberWpIXBlBP6CYcDgr_aaMb0ZHoYX4YWO8id1biCn6sW7V6vJM$>

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From python at mrabarnett.plus.com  Thu Dec 15 14:27:46 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 15 Dec 2022 19:27:46 +0000
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
Message-ID: <f62c0213-efe6-3268-feb9-d238d934974c@mrabarnett.plus.com>

On 2022-12-15 18:14, Gronicus at SGA.Ninja wrote:
> So far so good , I can now use a variable in datetime.datetime but it only
> works if I hard-code the time/date information. Now I want to have the code
> read from a file but I get: TypeError: function takes at most 9 arguments
> (26 given)
> 
> I figure that the structure in the file is incorrect. What should it be? The
> entry in the file is (2022, 12, 13,  5,  3, 30) but when my program tries to
> use it I get the error.
> 
> The program is a bit more sophisticated now but here is the update with a
> sample of the SPECIFICATIONS.txt file:
> =====================================================================
> 
> # This program compares two Timedate values, subtracts the two and
> # converts the difference to seconds and hours.
> #
> 
> #  %A Monday    #  %a Mon           #  %B January   #  %b Jan
> #  %d 05 day    #  %m month as 01   #  %Y 2020      #  %y 20
> #  %H 24        #  %I 12            #  %M 30 min    #  %S Seconds
> 
> import time
> import datetime
> from time import gmtime, strftime ##define strftime as time/date right now
> # ======================================================
> 
> def GetSpecByItem(GetThisOne):  #get line by item in column 4 - 7
>      ItemValue = "--"
>      
>      with open("SPECIFICATIONS.txt" , 'r') as infile:
>       for lineEQN in infile: # loop to find each line in the file for that
> dose
>          if ((lineEQN[4:7]== GetThisOne)):

You don't need the parentheses, and certainly 2 pairs of them!

>             ItemValue = lineEQN[30:60].strip()   # Just the Data
>      return(ItemValue)

You're returning a _string_.

I suggest using 'literal_eval' from the 'ast' module to convert the 
string safely into a tuple.

However, if the 'for' loop fails to match a line, the function will 
return "--", which won't be of any use later on unless you check for it 
specifically and, say, report an error to the user.

> 
> """
> SPECIFICATIONS.txt
> 
> IYf HRB Humalog R Date           (2018, 12, 4, 10,  7, 00)           ##
> IYf HRG Humulin R Date           (2022, 12, 13,  5,  3, 30)          ##
> """
> # ====================== Main() ======================================
> print()
> Startt = "404"
> Stopp  = "404"
> 
> Answer = "Y"
> Answer = input("Run test A? (" + Answer + ")" )
> 
> if Answer == "Y" or Answer == "y" or Answer == "":
>     print()
>     print("     Running Test A:")
> #           Year  Mth Day Hour Min Sec
>     Startt  =   2018, 12, 4, 10,  7, 00
>     Stopp   =   2022, 12, 12, 1, 15, 30
>     NowTime =   2022, 12, 14, 21, 15, 30

'Startt' and 'Stopp' here are tuples.

> else:
>     print("     Running Test B:")
>     Startt = GetSpecByItem("HRG")
>     Stopp =  GetSpecByItem("HRB")

'Startt' and 'Stopp' here are _strings_.

>     NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")
>     
> print()
> print("55    NowTime = " + str(NowTime))
> print("56     Startt = " + str(Startt))
> print("57      Stopp = " + str(Stopp))
> print()
> 
> NowTime =  datetime.datetime(*NowTime)
> Startt =   datetime.datetime(*Startt)
> Stopp =    datetime.datetime(*Stopp)
> 
These will work if 'Startt' and 'Stopp' are tuples, but not if they're 
strings. In the latter case, you're effectively passing multiple 
single-characters strings into 'datetime'.

> #Start == Startt  # True"
> #print("Startt test = " + Start)
> # =================================================
> print()
> c = NowTime - Stopp
> minutes = c.total_seconds() / 60
> minutes = c.seconds / 60
> hours = 0
> 
> while (minutes > 59):
>          minutes = minutes - 60
>          hours += 1
> minutes = round(minutes)
> print ("77 Hours =     <" + str(hours) + ">")
> print ("78 Minutes =   <" + str(minutes) + ">")
> if hours > 7:
>      print(" Time to inject Humulin R u500.")
> 
> pause = input("Pause")
> # ======================================================
> 
> -----Original Message-----
> From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org> On
> Behalf Of Thomas Passin
> Sent: Tuesday, December 13, 2022 11:20 PM
> To: python-list at python.org
> Subject: Re: Subtracting dates to get hours and minutes
> 
> Your problem is that datetime.datetime does not accept a tuple as an
> argument.  It expects an integer value for the first argument, but you
> supplied a tuple.  In Python, you can use a sequence (e.g., tuple or
> list) the way you want by prefixing it with an asterisk.  This causes the
> sequence of items to be treated as individual arguments. So:
> 
> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
> st1 = (2022, 12, 13,  5,  3, 30)
> dts1 = datetime.datetime(*st1)  # NOT datetime.datetime(st1)
> dts1 == Startt  # True
> 
> On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>>   As is, Test A works.
>>   Comment out Test A and uncomment Test B it fails.
>>   In Test B, I move the data into a variable resulting with the report:
>>              "TypeError: an integer is required (got type tuple)
>> 
>> How do I fix this?
>> 
>> #---------------------------------------------------------------------
>> --------
>> import datetime
>> #=================================================
>> #         Test A   Hard coded Date/Time
>> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30) Stopp =  
>> datetime.datetime(2022, 12, 12, 21, 15, 30)
>> 
>> # =================================================
>> #         Test B   Date/Time data as a variable
>> #Startt = (2022, 12, 13,  5,  3, 30)
>> #Stopp =  (2022, 12, 12, 21, 15, 30)
>> 
>> #Startt = datetime.datetime(Startt)
>> #Stopp =  datetime.datetime(Stopp)
>> 
>> # =================================================
>> c = Startt - Stopp
>> minutes = c.total_seconds() / 60
>> minutes = c.seconds / 60
>> hours = 0
>> 
>> while (minutes > 59):
>>          minutes = minutes - 60
>>          hours += 1
>> minutes = round(minutes)
>> print()
>> print ("       Hours =  <" + str(hours) + ">")
>> print ("     Minutes =  <" + str(minutes) + ">")
>> 
>> # 
>> ----------------------------------------------------------------------
>> -------
>> 
> 
> --
> https://mail.python.org/mailman/listinfo/python-list
> 


From python at mrabarnett.plus.com  Thu Dec 15 14:34:28 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Thu, 15 Dec 2022 19:34:28 +0000
Subject: Single line if statement with a continue
In-Reply-To: <055e01d910b8$349de450$9dd9acf0$@gmail.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
 <mailman.1171.1671081943.20444.python-list@python.org>
 <i64r6j-b7c91.ln1@esprimo.zbmc.eu>
 <return-20221215133614@ram.dialup.fu-berlin.de>
 <055e01d910b8$349de450$9dd9acf0$@gmail.com>
Message-ID: <f14535db-bf39-0569-ec59-34677ba4d7f8@mrabarnett.plus.com>

On 2022-12-15 19:05, avi.e.gross at gmail.com wrote:
> Multiple returns is not always a problem as it depends on the nature of a
> task whether it has complex enough cases.
> 
> I have seen code that instead sets Boolean variables when it is ready to
> return and everything else keeps checking the variables to skip further
> processing so the program then slides down to a single return statement. If
> done properly, it boils down to the same result if VERY carefully done but
> with lots of sometimes complex IF statements that may be not be updated well
> if the logic changes a bit.
> 
> In such cases, I vastly prefer clean and unambiguous returns  from the
> function right at the point where the decision is made, UNLESS the exit is
> not always clean as there may be cleanup or finalization of some kind
> required that is best done at a single point.
> 
A problem with having a single return is that it can lead to excessive 
indentation:

     if test_1:
         ...

         if test_2:
             ...

             if test_3:
                 ...

     return

With multiple returns, however:

     if not test_1:
         return

     ...

     if not test_2:
         return

     ...

     if not test_3:
         return

     ...

     return

> If efficiency is an issue, then clearly a rapid exit may beat one where
> processing continues for a while and also often beats a method that involves
> creating and calling multiple smaller functions with lots of overhead.
> 
> Having said all that, of course, if you can find a fairly simple algorithm
> that only returns from one place, use it instead of a convoluted one. The
> issue is not necessarily that multiple return points are bad, but that they
> are often a symptom of sloppy planning. But for some problems, they fit well
> and simplify things.
> 
> -----Original Message-----
> From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
> Behalf Of Stefan Ram
> Sent: Thursday, December 15, 2022 7:42 AM
> To: python-list at python.org
> Subject: Re: Single line if statement with a continue
> 
> Chris Green <cl at isbd.net> writes:
>>I always try to avoid multiple returns from functions/methods, as soon 
>>as things get complex it's all to easy to miss clean-up etc.
> 
>    This "complexity" could also mean that the function has
>    become too large. In such a case, one could say that the
>    /size/ of the function is the actual cause of problems
>    and not multiple returns.
> 
> |Fools ignore complexity. Pragmatists suffer it. Some can avoid it.
> |Geniuses remove it.
> Alan Perlis (1922/1990)
> 
>    Within a small function, multiple returns are rarely
>    a problem.
> 
>    When a function is large, one can apply well-known
>    refactors. For an example, look at the code in the
>    first post of the thread
> 
> Python script not letting go of files
> Date: Tue, 29 Nov 2022 12:52:15 +0000
> 
>    and then at my reply of
> 
> 29 Nov 2022 14:44:39 GMT.
> 
>>"No multiple returns" is often found in programming guidelines.
> 
>    I religiously followed that when I did more C programming
>    than today. Then, I read an article about how the result
>    pattern makes functions measurably slower. (It should not
>    with an optimizing compiler, but it did due to those
>    measurements. Can't find that article now, though.)
> 
>    "Result pattern" I call writing,
> 
> if a:
>      result = 123
> else:
>      result = 456
> return result
> 
>    , instead of,
> 
> if a:
>      return 123
> else
>      return 456
> 
>    .
> 
> 
> --
> https://mail.python.org/mailman/listinfo/python-list
> 


From list1 at tompassin.net  Thu Dec 15 13:56:05 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 15 Dec 2022 13:56:05 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
Message-ID: <c8d190d9-f60c-1569-b438-4ae70a29f8e9@tompassin.net>

It's hard to be sure from what you have offered, but I suspect that you 
are taking the string "(2022, 12, 13,  5,  3, 30)" from the file and 
using it as is.  When you feed that in as a starred argument, the string 
gets treated as a sequence where each item is a character in the string. 
  Your example contains 26 characters, which matches the error message, 
so that's probably what is going on.

You need to convert the string into the correct integers, because is the 
datetime function expects to get integers, not strings.  It isn't going 
to work with a string that looks like a tuple when it is printed.

Here is one way you could do this.  From the input file, extract the 
string. Call it dstr.  Then you have to get rid of the parentheses and 
separate out each item so you can convert it into an integer.  So:

items = dstr[1:-2].split(',')  # This creates a list of strings.
# print(items) --> ['2022', ' 12', ' 13', '  5', '  3', ' 3']

# Create a tuple of integers from the string items
seq = (int(n) for n in items)
# or make it a list instead: seq = [int(n) for n in items]

# And here is the datetime object you wanted
d1 = datetime.datetime(*seq)


On 12/15/2022 1:14 PM, Gronicus at SGA.Ninja wrote:
> So far so good , I can now use a variable in datetime.datetime but it only
> works if I hard-code the time/date information. Now I want to have the code
> read from a file but I get: TypeError: function takes at most 9 arguments
> (26 given)
> 
> I figure that the structure in the file is incorrect. What should it be? The
> entry in the file is (2022, 12, 13,  5,  3, 30) but when my program tries to
> use it I get the error.
> 
> The program is a bit more sophisticated now but here is the update with a
> sample of the SPECIFICATIONS.txt file:
> =====================================================================
> 
> # This program compares two Timedate values, subtracts the two and
> # converts the difference to seconds and hours.
> #
> 
> #  %A Monday    #  %a Mon           #  %B January   #  %b Jan
> #  %d 05 day    #  %m month as 01   #  %Y 2020      #  %y 20
> #  %H 24        #  %I 12            #  %M 30 min    #  %S Seconds
> 
> import time
> import datetime
> from time import gmtime, strftime ##define strftime as time/date right now
> # ======================================================
> 
> def GetSpecByItem(GetThisOne):  #get line by item in column 4 - 7
>      ItemValue = "--"
>      
>      with open("SPECIFICATIONS.txt" , 'r') as infile:
>       for lineEQN in infile: # loop to find each line in the file for that
> dose
>          if ((lineEQN[4:7]== GetThisOne)):
>             ItemValue = lineEQN[30:60].strip()   # Just the Data
>      return(ItemValue)
> 
> """
> SPECIFICATIONS.txt
> 
> IYf HRB Humalog R Date           (2018, 12, 4, 10,  7, 00)           ##
> IYf HRG Humulin R Date           (2022, 12, 13,  5,  3, 30)          ##
> """
> # ====================== Main() ======================================
> print()
> Startt = "404"
> Stopp  = "404"
> 
> Answer = "Y"
> Answer = input("Run test A? (" + Answer + ")" )
> 
> if Answer == "Y" or Answer == "y" or Answer == "":
>     print()
>     print("     Running Test A:")
> #           Year  Mth Day Hour Min Sec
>     Startt  =   2018, 12, 4, 10,  7, 00
>     Stopp   =   2022, 12, 12, 1, 15, 30
>     NowTime =   2022, 12, 14, 21, 15, 30
> else:
>     print("     Running Test B:")
>     Startt = GetSpecByItem("HRG")
>     Stopp =  GetSpecByItem("HRB")
>     NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")
>     
> print()
> print("55    NowTime = " + str(NowTime))
> print("56     Startt = " + str(Startt))
> print("57      Stopp = " + str(Stopp))
> print()
> 
> NowTime =  datetime.datetime(*NowTime)
> Startt =   datetime.datetime(*Startt)
> Stopp =    datetime.datetime(*Stopp)
> 
> #Start == Startt  # True"
> #print("Startt test = " + Start)
> # =================================================
> print()
> c = NowTime - Stopp
> minutes = c.total_seconds() / 60
> minutes = c.seconds / 60
> hours = 0
> 
> while (minutes > 59):
>          minutes = minutes - 60
>          hours += 1
> minutes = round(minutes)
> print ("77 Hours =     <" + str(hours) + ">")
> print ("78 Minutes =   <" + str(minutes) + ">")
> if hours > 7:
>      print(" Time to inject Humulin R u500.")
> 
> pause = input("Pause")
> # ======================================================
> 
> 
> -----Original Message-----
> From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org> On
> Behalf Of Thomas Passin
> Sent: Tuesday, December 13, 2022 11:20 PM
> To: python-list at python.org
> Subject: Re: Subtracting dates to get hours and minutes
> 
> Your problem is that datetime.datetime does not accept a tuple as an
> argument.  It expects an integer value for the first argument, but you
> supplied a tuple.  In Python, you can use a sequence (e.g., tuple or
> list) the way you want by prefixing it with an asterisk.  This causes the
> sequence of items to be treated as individual arguments. So:
> 
> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30)
> st1 = (2022, 12, 13,  5,  3, 30)
> dts1 = datetime.datetime(*st1)  # NOT datetime.datetime(st1)
> dts1 == Startt  # True
> 
> On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>>    As is, Test A works.
>>    Comment out Test A and uncomment Test B it fails.
>>    In Test B, I move the data into a variable resulting with the report:
>>               "TypeError: an integer is required (got type tuple)
>>
>> How do I fix this?
>>
>> #---------------------------------------------------------------------
>> --------
>> import datetime
>> #=================================================
>> #         Test A   Hard coded Date/Time
>> Startt = datetime.datetime(2022, 12, 13,  5,  3, 30) Stopp =
>> datetime.datetime(2022, 12, 12, 21, 15, 30)
>>
>> # =================================================
>> #         Test B   Date/Time data as a variable
>> #Startt = (2022, 12, 13,  5,  3, 30)
>> #Stopp =  (2022, 12, 12, 21, 15, 30)
>>
>> #Startt = datetime.datetime(Startt)
>> #Stopp =  datetime.datetime(Stopp)
>>
>> # =================================================
>> c = Startt - Stopp
>> minutes = c.total_seconds() / 60
>> minutes = c.seconds / 60
>> hours = 0
>>
>> while (minutes > 59):
>>           minutes = minutes - 60
>>           hours += 1
>> minutes = round(minutes)
>> print()
>> print ("       Hours =  <" + str(hours) + ">")
>> print ("     Minutes =  <" + str(minutes) + ">")
>>
>> #
>> ----------------------------------------------------------------------
>> -------
>>
> 
> --
> https://mail.python.org/mailman/listinfo/python-list
> 


From list1 at tompassin.net  Thu Dec 15 15:13:52 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 15 Dec 2022 15:13:52 -0500
Subject: sqlite3 double quote behavior
In-Reply-To: <9ED49723-3E93-41F5-8CDA-4CA322F6B105@gmail.com>
References: <mailman.1143.1670892417.20444.python-list@python.org>
 <quotes-20221213084150@ram.dialup.fu-berlin.de>
 <49fa4d80-7a40-5425-be63-07c08cab2b58@roelschroeven.net>
 <CAPTjJmo6FXLZeMUE-TarD9pyY7-exn+zb+dWJcbVkNbWm7POHg@mail.gmail.com>
 <0c4ce444-4235-2091-67f9-6dc92d5fac73@roelschroeven.net>
 <CAPTjJmo=DG88FR9UJFUcBkm8aDJFT5etDRQjH75XFk9unDB04g@mail.gmail.com>
 <9ED49723-3E93-41F5-8CDA-4CA322F6B105@gmail.com>
Message-ID: <3253d206-34b5-554c-661c-af2ee2c2e8e0@tompassin.net>

There is a Python adapter for SQLITE called "APSW".  It has a config() 
function.  I looked in the codebase and it defines the two configuration 
constants needed to turn off the double quote behavior (see 
https://sqlite.org/quirks.html).  These constants are 
SQLITE_DBCONFIG_DQS_DDL and SQLITE_DBCONFIG_DQS_DML.

This makes me think that the double-quote behavior can be turned off by 
Python code, though I haven't tried it.

 From the APSW docs (see 
https://rogerbinns.github.io/apsw/tips.html#about-python-apsw-and-sqlite-versions):

"APSW wraps the SQLite C API. That means when SQLite adds new constant 
or API, then so does APSW. You can think of APSW as the Python 
expression of SQLite?s C API. You can lookup SQLite APIs to find which 
APSW functions and attributes call them."

On 12/15/2022 2:18 PM, John K. Parejko wrote:
> Thanks for the discussion. I?m aware that SQLite has several different options for identifier quoting, but they?re not cross-compatible with other SQL, whereas double quotes are (modulo this strange SQLite behavior).
> 
> Is anyone here familiar with the python sqlite3 implementation? I wonder how hard it would be to raise up the `sqlite3_db_config` generically, or have a specific function to set just the DQS_DDL and DQS_DML settings? It looks like everything interesting is in `Modules/_sqlite/module.c`, but I?m not familiar with the cpython internals.
> 
> John
> 
>> On 13Dec 2022, at 13:58, Chris Angelico <rosuav at gmail.com> wrote:
>>
>> On Wed, 14 Dec 2022 at 08:19, Roel Schroeven <roel at roelschroeven.net> wrote:
>>>
>>> Chris Angelico schreef op 13/12/2022 om 20:01:
>>>> On Wed, 14 Dec 2022 at 06:00, Roel Schroeven <roel at roelschroeven.net> wrote:
>>>>>
>>>>> Stefan Ram schreef op 13/12/2022 om 8:42:
>>>>>> "John K. Parejko" <parejkoj at gmail.com> writes:
>>>>>>> I was just burned by this, where some tests I?d written
>>>>>>> against an sqlite database did not fail in the way that they
>>>>>>> ?should? have, because of this double-quoted string issue.
>>>>>>
>>>>>>    In standard SQL, double quotes denote identifiers that are
>>>>>>    allowed to contain special characters.
>>>>> Or that are equal SQL keywords, which can be a reason to double-quote
>>>>> them. SQL engines sometimes add new keywords; explicitly marking string
>>>>> literals as string literals prevents future conflicts and confusion.
>>>>>
>>>>> Perhaps it's a better idea to use [identifier] or `identifier` instead
>>>>> though (I just learned about those on
>>>>> https://sqlite.org/lang_keywords.html). Both are not standard SQL ([] is
>>>>> used in MS Access and SQL Server, `` is used in MySQL) but both work in
>>>>> SQLite. That should prevent any ambiguity and confusion, if it doesn't
>>>>> bother you too much that it's not standard SQL.
>>>>>
>>>>
>>>> Why not just use "identifier" which is standard SQL?
>>>
>>> If you accidentally type [identifire] or `identifire`, SQLite will
>>> produce an unknown identifier error, alerting you immediately to your typo.
>>> If you accidentally type "identifire", SQLite will silently treat it as
>>> a string literal instead of an identifier, causing more difficult to
>>> diagnose problems.
>>>
>>
>> Okay, so..... exactly the same as if you use standard double quotes,
>> but change the configuration option. So the options are: make
>> everything worse for everyone by exacerbating the problem of
>> non-standard identifier quoting, or get this API so SQLite can be
>> configured, like the OP actually asked for.
>>
>> Yeah. Let's not do the wrong thing.
>>
>> ChrisA
>> -- 
>> https://mail.python.org/mailman/listinfo/python-list
> 


From list1 at tompassin.net  Thu Dec 15 14:56:03 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 15 Dec 2022 14:56:03 -0500
Subject: Single line if statement with a continue
In-Reply-To: <i64r6j-b7c91.ln1@esprimo.zbmc.eu>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
 <mailman.1171.1671081943.20444.python-list@python.org>
 <i64r6j-b7c91.ln1@esprimo.zbmc.eu>
Message-ID: <a497c7ce-32fe-4c3e-21c7-8eb429b6e71e@tompassin.net>

On 12/15/2022 3:58 AM, Chris Green wrote:
> Thomas Passin <list1 at tompassin.net> wrote:
>>                     I personally tend to use
>>
>> if test: return
>>
>> even inside larger blocks.
> 
> I always try to avoid multiple returns from functions/methods, as soon
> as things get complex it's all to easy to miss clean-up etc.
> 
> "No multiple returns" is often found in programming guidelines.

Yes, or alternatively, "If any branch uses a return, they all should."



From grant.b.edwards at gmail.com  Thu Dec 15 16:34:54 2022
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Thu, 15 Dec 2022 13:34:54 -0800 (PST)
Subject: Single line if statement with a continue
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <1ad0365c-486c-1305-4e65-6b1bcf035b0a@tompassin.net>
 <mailman.1171.1671081943.20444.python-list@python.org>
 <i64r6j-b7c91.ln1@esprimo.zbmc.eu>
 <return-20221215133614@ram.dialup.fu-berlin.de>
 <055e01d910b8$349de450$9dd9acf0$@gmail.com>
 <f14535db-bf39-0569-ec59-34677ba4d7f8@mrabarnett.plus.com>
Message-ID: <639b92fe.050a0220.26f48.0575@mx.google.com>

On 2022-12-15, MRAB <python at mrabarnett.plus.com> wrote:

> A problem with having a single return is that it can lead to excessive 
> indentation:
>
>      if test_1:
>          ...
>
>          if test_2:
>              ...
>
>              if test_3:
>                  ...
>
>      return

I sometimes have to work on code like that with bocks nested 8-10
levels deep spread out over hundreds of lines. The first thing I do is
convert it to something like the code below. Check for error
conditions up front and exit accordingly.

When working in C, a "goto error" or "goto done" instead of "return"
can provide a "single return" if that's deemed important.

>
> With multiple returns, however:
>
>      if not test_1:
>          return
>
>      ...
>
>      if not test_2:
>          return
>
>      ...
>
>      if not test_3:
>          return
>
>      ...
>
>      return


From Gronicus at SGA.Ninja  Thu Dec 15 17:00:11 2022
From: Gronicus at SGA.Ninja (Gronicus at SGA.Ninja)
Date: Thu, 15 Dec 2022 17:00:11 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <252f3f64.8d86.185171c7cb3.Webtop.120@btinternet.com>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
 <252f3f64.8d86.185171c7cb3.Webtop.120@btinternet.com>
Message-ID: <00e201d910d0$9b083a70$d118af50$@SGA.Ninja>

Yes, it works like a charm. On the tupility of it all.
Special thanks for the explanation too?..

 

Now that the code no longer produces the errors, I see that the year and month not included in the calculation? How do I fix this?

 

From: anthony.flury <anthony.flury at btinternet.com> 
Sent: Thursday, December 15, 2022 1:47 PM
To: Gronicus at SGA.Ninja
Subject: RE: Subtracting dates to get hours and minutes

 

What is likely happening is that when you read the data from the file you are not reading a tuple, you are reading a 26 charcter string.

You have to convert that string into a tuple - the easiest way will be somthing like this : 

 

timet = tuple(int(x.strip()) for x in timestring[1:-1].split(','))

 

where timestring is the data you get from the file

The [1:-1] removes the () from the data

The .split(",") method creates a temporary list from the remaining string breaking the string where there are commas

The x.strip() removes spaces from each item in the temporary list.

 

Note that the * unpack operator doesn't just unpack tuples, it works on an iterable, so when you read the data from the file currently, and then use * on it, it will pass 26 separate characters to the function.

 



------ Original Message ------
From: Gronicus at SGA.Ninja <mailto:Gronicus at SGA.Ninja> 
To: "'Thomas Passin'" <list1 at tompassin.net <mailto:list1 at tompassin.net> >; python-list at python.org <mailto:python-list at python.org> 
Sent: Thursday, 15 Dec, 22 At 18:14
Subject: RE: Subtracting dates to get hours and minutes

So far so good , I can now use a variable in datetime.datetime but it only
works if I hard-code the time/date information. Now I want to have the code
read from a file but I get: TypeError: function takes at most 9 arguments
(26 given)

I figure that the structure in the file is incorrect. What should it be? The
entry in the file is (2022, 12, 13, 5, 3, 30) but when my program tries to
use it I get the error.

The program is a bit more sophisticated now but here is the update with a
sample of the SPECIFICATIONS.txt file:
=====================================================================

# This program compares two Timedate values, subtracts the two and
# converts the difference to seconds and hours.
#

# %A Monday # %a Mon # %B January # %b Jan
# %d 05 day # %m month as 01 # %Y 2020 # %y 20
# %H 24 # %I 12 # %M 30 min # %S Seconds

import time
import datetime
from time import gmtime, strftime ##define strftime as time/date right now
# ======================================================

def GetSpecByItem(GetThisOne): #get line by item in column 4 - 7
ItemValue = "--"

with open("SPECIFICATIONS.txt" , 'r') as infile:
for lineEQN in infile: # loop to find each line in the file for that
dose
if ((lineEQN[4:7]== GetThisOne)):
ItemValue = lineEQN[30:60].strip() # Just the Data
return(ItemValue)

"""
SPECIFICATIONS.txt

IYf HRB Humalog R Date (2018, 12, 4, 10, 7, 00) ##
IYf HRG Humulin R Date (2022, 12, 13, 5, 3, 30) ##
"""
# ====================== Main() ======================================
print()
Startt = "404"
Stopp = "404"

Answer = "Y"
Answer = input("Run test A? (" + Answer + ")" )

if Answer == "Y" or Answer == "y" or Answer == "":
print()
print(" Running Test A:")
# Year Mth Day Hour Min Sec
Startt = 2018, 12, 4, 10, 7, 00 
Stopp = 2022, 12, 12, 1, 15, 30
NowTime = 2022, 12, 14, 21, 15, 30
else:
print(" Running Test B:")
Startt = GetSpecByItem("HRG")
Stopp = GetSpecByItem("HRB")
NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")

print()
print("55 NowTime = " + str(NowTime))
print("56 Startt = " + str(Startt))
print("57 Stopp = " + str(Stopp))
print()

NowTime = datetime.datetime(*NowTime)
Startt = datetime.datetime(*Startt)
Stopp = datetime.datetime(*Stopp)

#Start == Startt # True" 
#print("Startt test = " + Start)
# =================================================
print()
c = NowTime - Stopp 
minutes = c.total_seconds() / 60 
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
minutes = minutes - 60
hours += 1
minutes = round(minutes)
print ("77 Hours = <" + str(hours) + ">")
print ("78 Minutes = <" + str(minutes) + ">")
if hours > 7:
print(" Time to inject Humulin R u500.")

pause = input("Pause") 
# ======================================================


-----Original Message-----
From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org <mailto:python-list-bounces+gronicus=sga.ninja at python.org> > On
Behalf Of Thomas Passin
Sent: Tuesday, December 13, 2022 11:20 PM
To: python-list at python.org <mailto:python-list at python.org> 
Subject: Re: Subtracting dates to get hours and minutes

Your problem is that datetime.datetime does not accept a tuple as an
argument. It expects an integer value for the first argument, but you
supplied a tuple. In Python, you can use a sequence (e.g., tuple or
list) the way you want by prefixing it with an asterisk. This causes the
sequence of items to be treated as individual arguments. So:

Startt = datetime.datetime(2022, 12, 13, 5, 3, 30)
st1 = (2022, 12, 13, 5, 3, 30)
dts1 = datetime.datetime(*st1) # NOT datetime.datetime(st1)
dts1 == Startt # True

On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja <mailto:Gronicus at SGA.Ninja>  wrote:

			
As is, Test A works.
Comment out Test A and uncomment Test B it fails.
In Test B, I move the data into a variable resulting with the report:
"TypeError: an integer is required (got type tuple)

How do I fix this?

#---------------------------------------------------------------------
--------
import datetime
#=================================================
# Test A Hard coded Date/Time
Startt = datetime.datetime(2022, 12, 13, 5, 3, 30) Stopp = 
datetime.datetime(2022, 12, 12, 21, 15, 30)

# =================================================
# Test B Date/Time data as a variable
#Startt = (2022, 12, 13, 5, 3, 30)
#Stopp = (2022, 12, 12, 21, 15, 30)

#Startt = datetime.datetime(Startt)
#Stopp = datetime.datetime(Stopp)

# =================================================
c = Startt - Stopp
minutes = c.total_seconds() / 60
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
minutes = minutes - 60
hours += 1
minutes = round(minutes)
print()
print (" Hours = <" + str(hours) + ">")
print (" Minutes = <" + str(minutes) + ">")

# 
----------------------------------------------------------------------
-------


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

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


From gweatherby at uchc.edu  Thu Dec 15 17:22:44 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Thu, 15 Dec 2022 22:22:44 +0000
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <00e201d910d0$9b083a70$d118af50$@SGA.Ninja>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
 <252f3f64.8d86.185171c7cb3.Webtop.120@btinternet.com>
 <00e201d910d0$9b083a70$d118af50$@SGA.Ninja>
Message-ID: <SA1PR14MB5855DF9D51191DCD36F23309B9E19@SA1PR14MB5855.namprd14.prod.outlook.com>



Not sure what you mean:

x = datetime.datetime(year=2018,month=12,day=4,hour=10)
y = datetime.datetime(year=2022,month=12,day=13,hour=5)
print(x -y)


-1470 days, 5:00:00

If you want to display years, (x-y).days /365

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Gronicus at SGA.Ninja <Gronicus at SGA.Ninja>
Date: Thursday, December 15, 2022 at 5:02 PM
To: 'anthony.flury' <anthony.flury at btinternet.com>, python-list at python.org <python-list at python.org>
Subject: RE: Subtracting dates to get hours and minutes
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Yes, it works like a charm. On the tupility of it all.
Special thanks for the explanation too?..



Now that the code no longer produces the errors, I see that the year and month not included in the calculation? How do I fix this?



From: anthony.flury <anthony.flury at btinternet.com>
Sent: Thursday, December 15, 2022 1:47 PM
To: Gronicus at SGA.Ninja
Subject: RE: Subtracting dates to get hours and minutes



What is likely happening is that when you read the data from the file you are not reading a tuple, you are reading a 26 charcter string.

You have to convert that string into a tuple - the easiest way will be somthing like this :



timet = tuple(int(x.strip()) for x in timestring[1:-1].split(','))



where timestring is the data you get from the file

The [1:-1] removes the () from the data

The .split(",") method creates a temporary list from the remaining string breaking the string where there are commas

The x.strip() removes spaces from each item in the temporary list.



Note that the * unpack operator doesn't just unpack tuples, it works on an iterable, so when you read the data from the file currently, and then use * on it, it will pass 26 separate characters to the function.





------ Original Message ------
From: Gronicus at SGA.Ninja <mailto:Gronicus at SGA.Ninja>
To: "'Thomas Passin'" <list1 at tompassin.net <mailto:list1 at tompassin.net> >; python-list at python.org <mailto:python-list at python.org>
Sent: Thursday, 15 Dec, 22 At 18:14
Subject: RE: Subtracting dates to get hours and minutes

So far so good , I can now use a variable in datetime.datetime but it only
works if I hard-code the time/date information. Now I want to have the code
read from a file but I get: TypeError: function takes at most 9 arguments
(26 given)

I figure that the structure in the file is incorrect. What should it be? The
entry in the file is (2022, 12, 13, 5, 3, 30) but when my program tries to
use it I get the error.

The program is a bit more sophisticated now but here is the update with a
sample of the SPECIFICATIONS.txt file:
=====================================================================

# This program compares two Timedate values, subtracts the two and
# converts the difference to seconds and hours.
#

# %A Monday # %a Mon # %B January # %b Jan
# %d 05 day # %m month as 01 # %Y 2020 # %y 20
# %H 24 # %I 12 # %M 30 min # %S Seconds

import time
import datetime
from time import gmtime, strftime ##define strftime as time/date right now
# ======================================================

def GetSpecByItem(GetThisOne): #get line by item in column 4 - 7
ItemValue = "--"

with open("SPECIFICATIONS.txt" , 'r') as infile:
for lineEQN in infile: # loop to find each line in the file for that
dose
if ((lineEQN[4:7]== GetThisOne)):
ItemValue = lineEQN[30:60].strip() # Just the Data
return(ItemValue)

"""
SPECIFICATIONS.txt

IYf HRB Humalog R Date (2018, 12, 4, 10, 7, 00) ##
IYf HRG Humulin R Date (2022, 12, 13, 5, 3, 30) ##
"""
# ====================== Main() ======================================
print()
Startt = "404"
Stopp = "404"

Answer = "Y"
Answer = input("Run test A? (" + Answer + ")" )

if Answer == "Y" or Answer == "y" or Answer == "":
print()
print(" Running Test A:")
# Year Mth Day Hour Min Sec
Startt = 2018, 12, 4, 10, 7, 00
Stopp = 2022, 12, 12, 1, 15, 30
NowTime = 2022, 12, 14, 21, 15, 30
else:
print(" Running Test B:")
Startt = GetSpecByItem("HRG")
Stopp = GetSpecByItem("HRB")
NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")

print()
print("55 NowTime = " + str(NowTime))
print("56 Startt = " + str(Startt))
print("57 Stopp = " + str(Stopp))
print()

NowTime = datetime.datetime(*NowTime)
Startt = datetime.datetime(*Startt)
Stopp = datetime.datetime(*Stopp)

#Start == Startt # True"
#print("Startt test = " + Start)
# =================================================
print()
c = NowTime - Stopp
minutes = c.total_seconds() / 60
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
minutes = minutes - 60
hours += 1
minutes = round(minutes)
print ("77 Hours = <" + str(hours) + ">")
print ("78 Minutes = <" + str(minutes) + ">")
if hours > 7:
print(" Time to inject Humulin R u500.")

pause = input("Pause")
# ======================================================


-----Original Message-----
From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org <mailto:python-list-bounces+gronicus=sga.ninja at python.org> > On
Behalf Of Thomas Passin
Sent: Tuesday, December 13, 2022 11:20 PM
To: python-list at python.org <mailto:python-list at python.org>
Subject: Re: Subtracting dates to get hours and minutes

Your problem is that datetime.datetime does not accept a tuple as an
argument. It expects an integer value for the first argument, but you
supplied a tuple. In Python, you can use a sequence (e.g., tuple or
list) the way you want by prefixing it with an asterisk. This causes the
sequence of items to be treated as individual arguments. So:

Startt = datetime.datetime(2022, 12, 13, 5, 3, 30)
st1 = (2022, 12, 13, 5, 3, 30)
dts1 = datetime.datetime(*st1) # NOT datetime.datetime(st1)
dts1 == Startt # True

On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja <mailto:Gronicus at SGA.Ninja>  wrote:


As is, Test A works.
Comment out Test A and uncomment Test B it fails.
In Test B, I move the data into a variable resulting with the report:
"TypeError: an integer is required (got type tuple)

How do I fix this?

#---------------------------------------------------------------------
--------
import datetime
#=================================================
# Test A Hard coded Date/Time
Startt = datetime.datetime(2022, 12, 13, 5, 3, 30) Stopp =
datetime.datetime(2022, 12, 12, 21, 15, 30)

# =================================================
# Test B Date/Time data as a variable
#Startt = (2022, 12, 13, 5, 3, 30)
#Stopp = (2022, 12, 12, 21, 15, 30)

#Startt = datetime.datetime(Startt)
#Stopp = datetime.datetime(Stopp)

# =================================================
c = Startt - Stopp
minutes = c.total_seconds() / 60
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
minutes = minutes - 60
hours += 1
minutes = round(minutes)
print()
print (" Hours = <" + str(hours) + ">")
print (" Minutes = <" + str(minutes) + ">")

#
----------------------------------------------------------------------
-------


--
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From Gronicus at SGA.Ninja  Thu Dec 15 17:49:23 2022
From: Gronicus at SGA.Ninja (Gronicus at SGA.Ninja)
Date: Thu, 15 Dec 2022 17:49:23 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <252f3f64.8d86.185171c7cb3.Webtop.120@btinternet.com>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
 <252f3f64.8d86.185171c7cb3.Webtop.120@btinternet.com>
Message-ID: <00ec01d910d7$7a9023a0$6fb06ae0$@SGA.Ninja>

Yes, it works like a charm. On the tupility of it all.
Special thanks for the explanation too?..

 

(Originally asked but I found the errors. All is working)

Now that the code no longer produces the errors, I see that the year and month not included in the calculation? How do I fix this?

 

From: anthony.flury <anthony.flury at btinternet.com> 
Sent: Thursday, December 15, 2022 1:47 PM
To: Gronicus at SGA.Ninja
Subject: RE: Subtracting dates to get hours and minutes

 

What is likely happening is that when you read the data from the file you are not reading a tuple, you are reading a 26 charcter string.

You have to convert that string into a tuple - the easiest way will be somthing like this : 

 

timet = tuple(int(x.strip()) for x in timestring[1:-1].split(','))

 

where timestring is the data you get from the file

The [1:-1] removes the () from the data

The .split(",") method creates a temporary list from the remaining string breaking the string where there are commas

The x.strip() removes spaces from each item in the temporary list.

 

Note that the * unpack operator doesn't just unpack tuples, it works on an iterable, so when you read the data from the file currently, and then use * on it, it will pass 26 separate characters to the function.

 



------ Original Message ------
From: Gronicus at SGA.Ninja <mailto:Gronicus at SGA.Ninja> 
To: "'Thomas Passin'" <list1 at tompassin.net <mailto:list1 at tompassin.net> >; python-list at python.org <mailto:python-list at python.org> 
Sent: Thursday, 15 Dec, 22 At 18:14
Subject: RE: Subtracting dates to get hours and minutes

So far so good , I can now use a variable in datetime.datetime but it only
works if I hard-code the time/date information. Now I want to have the code
read from a file but I get: TypeError: function takes at most 9 arguments
(26 given)

I figure that the structure in the file is incorrect. What should it be? The
entry in the file is (2022, 12, 13, 5, 3, 30) but when my program tries to
use it I get the error.

The program is a bit more sophisticated now but here is the update with a
sample of the SPECIFICATIONS.txt file:
=====================================================================

# This program compares two Timedate values, subtracts the two and
# converts the difference to seconds and hours.
#

# %A Monday # %a Mon # %B January # %b Jan
# %d 05 day # %m month as 01 # %Y 2020 # %y 20
# %H 24 # %I 12 # %M 30 min # %S Seconds

import time
import datetime
from time import gmtime, strftime ##define strftime as time/date right now
# ======================================================

def GetSpecByItem(GetThisOne): #get line by item in column 4 - 7
ItemValue = "--"

with open("SPECIFICATIONS.txt" , 'r') as infile:
for lineEQN in infile: # loop to find each line in the file for that
dose
if ((lineEQN[4:7]== GetThisOne)):
ItemValue = lineEQN[30:60].strip() # Just the Data
return(ItemValue)

"""
SPECIFICATIONS.txt

IYf HRB Humalog R Date (2018, 12, 4, 10, 7, 00) ##
IYf HRG Humulin R Date (2022, 12, 13, 5, 3, 30) ##
"""
# ====================== Main() ======================================
print()
Startt = "404"
Stopp = "404"

Answer = "Y"
Answer = input("Run test A? (" + Answer + ")" )

if Answer == "Y" or Answer == "y" or Answer == "":
print()
print(" Running Test A:")
# Year Mth Day Hour Min Sec
Startt = 2018, 12, 4, 10, 7, 00 
Stopp = 2022, 12, 12, 1, 15, 30
NowTime = 2022, 12, 14, 21, 15, 30
else:
print(" Running Test B:")
Startt = GetSpecByItem("HRG")
Stopp = GetSpecByItem("HRB")
NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")

print()
print("55 NowTime = " + str(NowTime))
print("56 Startt = " + str(Startt))
print("57 Stopp = " + str(Stopp))
print()

NowTime = datetime.datetime(*NowTime)
Startt = datetime.datetime(*Startt)
Stopp = datetime.datetime(*Stopp)

#Start == Startt # True" 
#print("Startt test = " + Start)
# =================================================
print()
c = NowTime - Stopp 
minutes = c.total_seconds() / 60 
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
minutes = minutes - 60
hours += 1
minutes = round(minutes)
print ("77 Hours = <" + str(hours) + ">")
print ("78 Minutes = <" + str(minutes) + ">")
if hours > 7:
print(" Time to inject Humulin R u500.")

pause = input("Pause") 
# ======================================================


-----Original Message-----
From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org <mailto:python-list-bounces+gronicus=sga.ninja at python.org> > On
Behalf Of Thomas Passin
Sent: Tuesday, December 13, 2022 11:20 PM
To: python-list at python.org <mailto:python-list at python.org> 
Subject: Re: Subtracting dates to get hours and minutes

Your problem is that datetime.datetime does not accept a tuple as an
argument. It expects an integer value for the first argument, but you
supplied a tuple. In Python, you can use a sequence (e.g., tuple or
list) the way you want by prefixing it with an asterisk. This causes the
sequence of items to be treated as individual arguments. So:

Startt = datetime.datetime(2022, 12, 13, 5, 3, 30)
st1 = (2022, 12, 13, 5, 3, 30)
dts1 = datetime.datetime(*st1) # NOT datetime.datetime(st1)
dts1 == Startt # True

On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja <mailto:Gronicus at SGA.Ninja>  wrote:

			
As is, Test A works.
Comment out Test A and uncomment Test B it fails.
In Test B, I move the data into a variable resulting with the report:
"TypeError: an integer is required (got type tuple)

How do I fix this?

#---------------------------------------------------------------------
--------
import datetime
#=================================================
# Test A Hard coded Date/Time
Startt = datetime.datetime(2022, 12, 13, 5, 3, 30) Stopp = 
datetime.datetime(2022, 12, 12, 21, 15, 30)

# =================================================
# Test B Date/Time data as a variable
#Startt = (2022, 12, 13, 5, 3, 30)
#Stopp = (2022, 12, 12, 21, 15, 30)

#Startt = datetime.datetime(Startt)
#Stopp = datetime.datetime(Stopp)

# =================================================
c = Startt - Stopp
minutes = c.total_seconds() / 60
minutes = c.seconds / 60
hours = 0

while (minutes > 59):
minutes = minutes - 60
hours += 1
minutes = round(minutes)
print()
print (" Hours = <" + str(hours) + ">")
print (" Minutes = <" + str(minutes) + ">")

# 
----------------------------------------------------------------------
-------


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

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


From list1 at tompassin.net  Thu Dec 15 17:35:26 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 15 Dec 2022 17:35:26 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <c8d190d9-f60c-1569-b438-4ae70a29f8e9@tompassin.net>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
 <c8d190d9-f60c-1569-b438-4ae70a29f8e9@tompassin.net>
Message-ID: <3d0dae98-1e5d-f185-74b7-d24b8e4fa8df@tompassin.net>

Oops,

"items = dstr[1:-2].split(',')"

should have read

"items = dstr[1:-1].split(',')".

On 12/15/2022 1:56 PM, Thomas Passin wrote:
> It's hard to be sure from what you have offered, but I suspect that you 
> are taking the string "(2022, 12, 13,? 5,? 3, 30)" from the file and 
> using it as is.? When you feed that in as a starred argument, the string 
> gets treated as a sequence where each item is a character in the string. 
>  ?Your example contains 26 characters, which matches the error message, 
> so that's probably what is going on.
> 
> You need to convert the string into the correct integers, because is the 
> datetime function expects to get integers, not strings.? It isn't going 
> to work with a string that looks like a tuple when it is printed.
> 
> Here is one way you could do this.? From the input file, extract the 
> string. Call it dstr.? Then you have to get rid of the parentheses and 
> separate out each item so you can convert it into an integer.? So:
> 
> items = dstr[1:-2].split(',')? # This creates a list of strings.
> # print(items) --> ['2022', ' 12', ' 13', '? 5', '? 3', ' 3']
> 
> # Create a tuple of integers from the string items
> seq = (int(n) for n in items)
> # or make it a list instead: seq = [int(n) for n in items]
> 
> # And here is the datetime object you wanted
> d1 = datetime.datetime(*seq)
> 
> 
> On 12/15/2022 1:14 PM, Gronicus at SGA.Ninja wrote:
>> So far so good , I can now use a variable in datetime.datetime but it 
>> only
>> works if I hard-code the time/date information. Now I want to have the 
>> code
>> read from a file but I get: TypeError: function takes at most 9 arguments
>> (26 given)
>>
>> I figure that the structure in the file is incorrect. What should it 
>> be? The
>> entry in the file is (2022, 12, 13,? 5,? 3, 30) but when my program 
>> tries to
>> use it I get the error.
>>
>> The program is a bit more sophisticated now but here is the update with a
>> sample of the SPECIFICATIONS.txt file:
>> =====================================================================
>>
>> # This program compares two Timedate values, subtracts the two and
>> # converts the difference to seconds and hours.
>> #
>>
>> #? %A Monday??? #? %a Mon?????????? #? %B January?? #? %b Jan
>> #? %d 05 day??? #? %m month as 01?? #? %Y 2020????? #? %y 20
>> #? %H 24??????? #? %I 12??????????? #? %M 30 min??? #? %S Seconds
>>
>> import time
>> import datetime
>> from time import gmtime, strftime ##define strftime as time/date right 
>> now
>> # ======================================================
>>
>> def GetSpecByItem(GetThisOne):? #get line by item in column 4 - 7
>> ???? ItemValue = "--"
>> ???? with open("SPECIFICATIONS.txt" , 'r') as infile:
>> ????? for lineEQN in infile: # loop to find each line in the file for 
>> that
>> dose
>> ???????? if ((lineEQN[4:7]== GetThisOne)):
>> ??????????? ItemValue = lineEQN[30:60].strip()?? # Just the Data
>> ???? return(ItemValue)
>>
>> """
>> SPECIFICATIONS.txt
>>
>> IYf HRB Humalog R Date?????????? (2018, 12, 4, 10,? 7, 00)?????????? ##
>> IYf HRG Humulin R Date?????????? (2022, 12, 13,? 5,? 3, 30)????????? ##
>> """
>> # ====================== Main() ======================================
>> print()
>> Startt = "404"
>> Stopp? = "404"
>>
>> Answer = "Y"
>> Answer = input("Run test A? (" + Answer + ")" )
>>
>> if Answer == "Y" or Answer == "y" or Answer == "":
>> ??? print()
>> ??? print("???? Running Test A:")
>> #?????????? Year? Mth Day Hour Min Sec
>> ??? Startt? =?? 2018, 12, 4, 10,? 7, 00
>> ??? Stopp?? =?? 2022, 12, 12, 1, 15, 30
>> ??? NowTime =?? 2022, 12, 14, 21, 15, 30
>> else:
>> ??? print("???? Running Test B:")
>> ??? Startt = GetSpecByItem("HRG")
>> ??? Stopp =? GetSpecByItem("HRB")
>> ??? NowTime = strftime("(%Y, %m, %d, %H, %M, %S)")
>> print()
>> print("55??? NowTime = " + str(NowTime))
>> print("56???? Startt = " + str(Startt))
>> print("57????? Stopp = " + str(Stopp))
>> print()
>>
>> NowTime =? datetime.datetime(*NowTime)
>> Startt =?? datetime.datetime(*Startt)
>> Stopp =??? datetime.datetime(*Stopp)
>>
>> #Start == Startt? # True"
>> #print("Startt test = " + Start)
>> # =================================================
>> print()
>> c = NowTime - Stopp
>> minutes = c.total_seconds() / 60
>> minutes = c.seconds / 60
>> hours = 0
>>
>> while (minutes > 59):
>> ???????? minutes = minutes - 60
>> ???????? hours += 1
>> minutes = round(minutes)
>> print ("77 Hours =???? <" + str(hours) + ">")
>> print ("78 Minutes =?? <" + str(minutes) + ">")
>> if hours > 7:
>> ???? print(" Time to inject Humulin R u500.")
>>
>> pause = input("Pause")
>> # ======================================================
>>
>>
>> -----Original Message-----
>> From: Python-list <python-list-bounces+gronicus=sga.ninja at python.org> On
>> Behalf Of Thomas Passin
>> Sent: Tuesday, December 13, 2022 11:20 PM
>> To: python-list at python.org
>> Subject: Re: Subtracting dates to get hours and minutes
>>
>> Your problem is that datetime.datetime does not accept a tuple as an
>> argument.? It expects an integer value for the first argument, but you
>> supplied a tuple.? In Python, you can use a sequence (e.g., tuple or
>> list) the way you want by prefixing it with an asterisk.? This causes the
>> sequence of items to be treated as individual arguments. So:
>>
>> Startt = datetime.datetime(2022, 12, 13,? 5,? 3, 30)
>> st1 = (2022, 12, 13,? 5,? 3, 30)
>> dts1 = datetime.datetime(*st1)? # NOT datetime.datetime(st1)
>> dts1 == Startt? # True
>>
>> On 12/13/2022 10:43 PM, Gronicus at SGA.Ninja wrote:
>>> ?? As is, Test A works.
>>> ?? Comment out Test A and uncomment Test B it fails.
>>> ?? In Test B, I move the data into a variable resulting with the report:
>>> ????????????? "TypeError: an integer is required (got type tuple)
>>>
>>> How do I fix this?
>>>
>>> #---------------------------------------------------------------------
>>> --------
>>> import datetime
>>> #=================================================
>>> #???????? Test A?? Hard coded Date/Time
>>> Startt = datetime.datetime(2022, 12, 13,? 5,? 3, 30) Stopp =
>>> datetime.datetime(2022, 12, 12, 21, 15, 30)
>>>
>>> # =================================================
>>> #???????? Test B?? Date/Time data as a variable
>>> #Startt = (2022, 12, 13,? 5,? 3, 30)
>>> #Stopp =? (2022, 12, 12, 21, 15, 30)
>>>
>>> #Startt = datetime.datetime(Startt)
>>> #Stopp =? datetime.datetime(Stopp)
>>>
>>> # =================================================
>>> c = Startt - Stopp
>>> minutes = c.total_seconds() / 60
>>> minutes = c.seconds / 60
>>> hours = 0
>>>
>>> while (minutes > 59):
>>> ????????? minutes = minutes - 60
>>> ????????? hours += 1
>>> minutes = round(minutes)
>>> print()
>>> print ("?????? Hours =? <" + str(hours) + ">")
>>> print ("???? Minutes =? <" + str(minutes) + ">")
>>>
>>> #
>>> ----------------------------------------------------------------------
>>> -------
>>>
>>
>> -- 
>> https://mail.python.org/mailman/listinfo/python-list
>>
> 


From python at mrabarnett.plus.com  Thu Dec 15 23:34:06 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Fri, 16 Dec 2022 04:34:06 +0000
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <00ec01d910d7$7a9023a0$6fb06ae0$@SGA.Ninja>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
 <252f3f64.8d86.185171c7cb3.Webtop.120@btinternet.com>
 <00ec01d910d7$7a9023a0$6fb06ae0$@SGA.Ninja>
Message-ID: <7420959b-1f58-5caa-ba7a-37dcbd676df4@mrabarnett.plus.com>

On 2022-12-15 22:49, Gronicus at SGA.Ninja wrote:
> Yes, it works like a charm. On the tupility of it all.
> Special thanks for the explanation too?..
> 
>   
> 
> (Originally asked but I found the errors. All is working)
> 
> Now that the code no longer produces the errors, I see that the year and month not included in the calculation? How do I fix this?
> 
>   
How long is a month? How many months are there until January 1? On 
December 25, many months will there be until January 1? And how many 
years are there until January 1?

[snip]


From list1 at tompassin.net  Fri Dec 16 00:25:22 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Fri, 16 Dec 2022 00:25:22 -0500
Subject: Subtracting dates to get hours and minutes
In-Reply-To: <7420959b-1f58-5caa-ba7a-37dcbd676df4@mrabarnett.plus.com>
References: <64B09923-9660-4E02-A5BA-E1F2FC453DAE@barrys-emacs.org>
 <Y5Zfk18S0Ji7PAf5@cskk.homeip.net>
 <003901d90def$36620a80$a3261f80$@SGA.Ninja>
 <da7849f9-1d54-5a82-a616-9683c12ba1c1@marcsnet.com>
 <016201d90f6e$3eae74a0$bc0b5de0$@SGA.Ninja>
 <503d15f0-18bb-409b-e911-e1c2de2ac90b@tompassin.net>
 <00c701d910b1$1b6a56f0$523f04d0$@SGA.Ninja>
 <252f3f64.8d86.185171c7cb3.Webtop.120@btinternet.com>
 <00ec01d910d7$7a9023a0$6fb06ae0$@SGA.Ninja>
 <7420959b-1f58-5caa-ba7a-37dcbd676df4@mrabarnett.plus.com>
Message-ID: <fb186c72-9ff9-20cc-d9b2-27bd79d5c962@tompassin.net>

On 12/15/2022 11:34 PM, MRAB wrote:
> On 2022-12-15 22:49, Gronicus at SGA.Ninja wrote:
>> Yes, it works like a charm. On the tupility of it all.
>> Special thanks for the explanation too?..
>>
>>
>> (Originally asked but I found the errors. All is working)
>>
>> Now that the code no longer produces the errors, I see that the year 
>> and month not included in the calculation? How do I fix this?

First you should read about the function you are using.  In this case, 
it is at

https://docs.python.org/3.10/library/datetime.html

I found this page using an internet search for "python datetime.datetime".

All Python functions, classes, and methods will normally be found in the 
documentation for the standard library, as this one is.

You should also look at datetime.timedelta, as various people have 
posted here.  Try to understand what is being described.  Then try to 
make simple examples that will show if you can get what you want, or if 
not, what more information you need.  Look through the rest of the 
documentation of (in this case) the datetime module and see if any of 
the other functionality looks like it will produce what you want.

It is important to understand clearly what your input data is like, and 
what results you need to achieve.  If you are not clear, or do not 
express yourself clearly, it will be hard and frustrating for others on 
the list to assist you.

For example, you wrote "I see that the year and month not included in 
the calculation".  I don't know what you mean.  You already include the 
month in the tuple that you feed to datetime.datetime().  That is, in 
the input string you showed, "(2022, 12, 13,  5,  3, 30)", it seems that 
"2022" represents a year, "12" represents a month, "13" represents a day 
of the month, and so forth.

So I don't understand how year and month not included.  I see that you 
do think that something is not coming out right, but you need to be more 
precise about what you mean so that others can understand too.

To succeed at programming, you need to be very precise about attending 
to details because the computer cannot know what you have in your mind. 
To succeed at getting help, you have to be precise and accurate about 
what you want to achieve and what is not coming out right, and describe 
those things simply and clearly to other people.

In other words, please help us to help you.

From kaiserarnhart at gmail.com  Fri Dec 16 11:07:21 2022
From: kaiserarnhart at gmail.com (Kaiser Arnhart)
Date: Fri, 16 Dec 2022 10:07:21 -0600
Subject: Download Not Working
In-Reply-To: <CAGVF70JB_V4fDOj=z3zvCJA-O7i8gW5Jm-wiC7ShvTwNR=8eFA@mail.gmail.com>
References: <CAGVF70JB_V4fDOj=z3zvCJA-O7i8gW5Jm-wiC7ShvTwNR=8eFA@mail.gmail.com>
Message-ID: <09FE50A0-578D-4DF3-BF5E-66B787ED5D4F@gmail.com>

> Good afternoon, 
> 
> I am unable to open Python 3 after downloading. For context, I uninstalled it due to not checking the "Add to Path" box and then I reinstalled after checking that box and now none of the downloads will open and run Python 3. Please help. 
> 
> Thanks, 


Kaiser Arnhart
Baylor University
Ashton Woods - Project Manager

> On Dec 16, 2022, at 9:14 AM, Kaiser Arnhart <kaiserarnhart at gmail.com> wrote:
> 
> ?
> Good afternoon, 
> 
> I am unable to open Python 3 after downloading. For context, I uninstalled it due to not checking the "Add to Path" box and then I reinstalled after checking that box and now none of the downloads will open and run Python 3. Please help. 
> 
> Thanks, 
> 
> -- 
> Kaiser Arnhart
> Baylor University
> Ashton Woods - Project Manager
> 
> 

From PythonList at DancesWithMice.info  Fri Dec 16 11:40:50 2022
From: PythonList at DancesWithMice.info (dn)
Date: Sat, 17 Dec 2022 05:40:50 +1300
Subject: Download Not Working
In-Reply-To: <09FE50A0-578D-4DF3-BF5E-66B787ED5D4F@gmail.com>
References: <CAGVF70JB_V4fDOj=z3zvCJA-O7i8gW5Jm-wiC7ShvTwNR=8eFA@mail.gmail.com>
 <09FE50A0-578D-4DF3-BF5E-66B787ED5D4F@gmail.com>
Message-ID: <a5255f55-d4a6-d296-624a-cc95ef0b02f8@DancesWithMice.info>

On 17/12/2022 05.07, Kaiser Arnhart wrote:
>> Good afternoon,
>>
>> I am unable to open Python 3 after downloading. For context, I uninstalled it due to not checking the "Add to Path" box and then I reinstalled after checking that box and now none of the downloads will open and run Python 3. Please help.
>>
>> Thanks,
> 
> 
> Kaiser Arnhart
> Baylor University
> Ashton Woods - Project Manager
> 
>> On Dec 16, 2022, at 9:14 AM, Kaiser Arnhart <kaiserarnhart at gmail.com> wrote:
>>
>> ?
>> Good afternoon,
>>
>> I am unable to open Python 3 after downloading. For context, I uninstalled it due to not checking the "Add to Path" box and then I reinstalled after checking that box and now none of the downloads will open and run Python 3. Please help.
>>
>> Thanks,
>>
>> -- 
>> Kaiser Arnhart
>> Baylor University
>> Ashton Woods - Project Manager

Please be advised that there are many download sources, and several 
operating systems which will run Python. Please provide more precise 
information, including what is visible in the Download folder "after 
downloading", and which command(s) are being used to "open and run 
Python 3".

Assuming MS-Windows, please review the documentation at: 
https://docs.python.org/3/using/windows.html
(or navigate from there to appropriate advice)

-- 
Regards,
=dn

From list1 at tompassin.net  Fri Dec 16 11:45:43 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Fri, 16 Dec 2022 11:45:43 -0500
Subject: Download Not Working
In-Reply-To: <09FE50A0-578D-4DF3-BF5E-66B787ED5D4F@gmail.com>
References: <CAGVF70JB_V4fDOj=z3zvCJA-O7i8gW5Jm-wiC7ShvTwNR=8eFA@mail.gmail.com>
 <09FE50A0-578D-4DF3-BF5E-66B787ED5D4F@gmail.com>
Message-ID: <52a16756-4e87-ce35-b22a-01b3e43f58d8@tompassin.net>

Please be more informative!  Is this on Windows?  Did Python 3 run as 
you expected, before you uninstalled it?  Exactly how did you try to 
launch Python? Exactly what did you observe when it appeared not to run? 
  Did you try any other ways to run it?  What version of Python are you 
talking about?  Did you install it for you only or for all users?  What 
did you expect to see when you tried to run it?

On 12/16/2022 11:07 AM, Kaiser Arnhart wrote:
>> Good afternoon,
>>
>> I am unable to open Python 3 after downloading. For context, I uninstalled it due to not checking the "Add to Path" box and then I reinstalled after checking that box and now none of the downloads will open and run Python 3. Please help.
>>
>> Thanks,
> 
> 
> Kaiser Arnhart
> Baylor University
> Ashton Woods - Project Manager
> 
>> On Dec 16, 2022, at 9:14 AM, Kaiser Arnhart <kaiserarnhart at gmail.com> wrote:
>>
>> ?
>> Good afternoon,
>>
>> I am unable to open Python 3 after downloading. For context, I uninstalled it due to not checking the "Add to Path" box and then I reinstalled after checking that box and now none of the downloads will open and run Python 3. Please help.
>>
>> Thanks,
>>
>> -- 
>> Kaiser Arnhart
>> Baylor University
>> Ashton Woods - Project Manager
>>
>>


From mats at wichmann.us  Fri Dec 16 14:45:03 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Fri, 16 Dec 2022 12:45:03 -0700
Subject: Download Not Working
In-Reply-To: <09FE50A0-578D-4DF3-BF5E-66B787ED5D4F@gmail.com>
References: <CAGVF70JB_V4fDOj=z3zvCJA-O7i8gW5Jm-wiC7ShvTwNR=8eFA@mail.gmail.com>
 <09FE50A0-578D-4DF3-BF5E-66B787ED5D4F@gmail.com>
Message-ID: <30b4be5c-63d1-bfa5-5aa7-8cb837ec3275@wichmann.us>

On 12/16/22 09:07, Kaiser Arnhart wrote:
>> Good afternoon,
>>
>> I am unable to open Python 3 after downloading. For context, I uninstalled it due to not checking the "Add to Path" box 

Others have already asked for more details.

On the above, though, note that you can fix many aspects of the install 
on Windows without uninstalling.

Open the Apps & Features applet.  Click on Python. Click on Modify.

follow the steps from there...

the path thin is on the Advanced Options page.




From romimarcov at gmail.com  Fri Dec 16 21:20:56 2022
From: romimarcov at gmail.com (Romina Marcovecchio)
Date: Fri, 16 Dec 2022 18:20:56 -0800 (PST)
Subject: Cannot import gdal in jupyter notebook
In-Reply-To: <efe58ac2-1959-42b3-946e-f69ce628a3c0n@googlegroups.com>
References: <c8f3fedc-8d73-4526-9cae-d030df8f4a99n@googlegroups.com>
 <e84f649b-c9f2-59f9-1ad5-dd0b9243698f@mrabarnett.plus.com>
 <ebc42eff-14b4-ed8f-81c4-12c6cbe3770c@tompassin.net>
 <mailman.658.1665520154.20444.python-list@python.org>
 <b40fc13d-8827-4e47-9ea3-e33ccf930200n@googlegroups.com>
 <efe58ac2-1959-42b3-946e-f69ce628a3c0n@googlegroups.com>
Message-ID: <88188f08-c00e-48d5-a550-8716bd11a7f2n@googlegroups.com>

El mi?rcoles, 12 de octubre de 2022 a las 10:18:23 UTC-3, Abdul Haseeb Azizi escribi?:
> On Wednesday, October 12, 2022 at 9:51:22 AM UTC+2, Abdul Haseeb Azizi wrote: 
> > On Tuesday, October 11, 2022 at 10:29:34 PM UTC+2, MRAB wrote: 
> > > On 2022-10-11 20:38, Thomas Passin wrote: 
> > > > On Windows, when I tried to install gdal using pip, it needed to compile 
> > > > part of it. I'm not set up with the Microsoft compiler and header 
> > > > files, so that failed. If you are on Windows, you will need to look for 
> > > > a binary wheel to install, or install and configure the compiler and 
> > > > header files. 
> > > > 
> > > The PyPI page at https://pypi.org/project/GDAL/ has this: 
> > > 
> > > """ 
> > > Conda 
> > > GDAL can be quite complex to build and install, particularly on Windows 
> > > and MacOS. Pre built binaries are provided for the conda system: 
> > > 
> > > https://docs.conda.io/en/latest/ 
> > > 
> > > By the conda-forge project: 
> > > 
> > > https://conda-forge.org/ 
> > > """ 
> > > 
> > > > On 10/11/2022 11:53 AM, Abdul Haseeb Azizi wrote: 
> > > >> Hi everyone, 
> > > >> I am new to python and I am trying to utilize this code "from osgeo import gdal". I installed python 3.10 and also I installed anaconda3 to solve this matter but I could not succeed. When I run that code I get the following error. 
> > > >> --------------------------------------------------------------------------- 
> > > >> ModuleNotFoundError Traceback (most recent call last) 
> > > >> Cell In [1], line 1 
> > > >> ----> 1 from osgeo import gdal 
> > > >> 
> > > >> ModuleNotFoundError: No module named 'osgeo' 
> > > >> 
> > > >> I also tried to create anaconda environment and enter the following codes: 
> > > >> conda crate --name pygdal 
> > > >> conda activate pygdal 
> > > >> conda install -c conda-forge gdal 
> > > >> 
> > > >> I don't what is the problem. Any help is appreciated to solve this matter. 
> > > >> Looking forward to hear from you. 
> > > >> 
> > > >> with regards 
> > > >> Abdul 
> > > > 
> > Thanks a lot for your recommendations. 
> > As I mentioned before I installed conda and also created conda environment using the following codes: 
> > Step 1: Create conda environment 
> > 
> > conda create --name venv 
> > 
> > After creating the virtual environment, by default it will install some of the packages. 
> > Step 2: Installation of gdal 
> > conda install -c conda-forge gdal 
> > Step 3: Installation of ipykernel 
> > 
> > conda install -c anaconda ipykernel 
> > 
> > Step 4: Add ipykernel and run jupyternotebook 
> > 
> > python -m ipykernel install --user --name=venv 
> > jupyter notebook 
> > 
> > 
> > still I get the following error: 
> > 
> > %pip install gdal 
> > 
> > Requirement already satisfied: gdal in c:\users\abdul\anaconda3\lib\site-packages (3.4.1) 
> > Note: you may need to restart the kernel to use updated packages. 
> > 
> > from osgeo import gdal 
> > 
> > 
> > --------------------------------------------------------------------------- 
> > ImportError Traceback (most recent call last) 
> > File ~\anaconda3\lib\site-packages\osgeo\__init__.py:29, in swig_import_helper() 
> > 28 try: 
> > ---> 29 return importlib.import_module(mname) 
> > 30 except ImportError: 
> > 
> > File ~\anaconda3\lib\importlib\__init__.py:127, in import_module(name, package) 
> > 126 level += 1 
> > --> 127 return _bootstrap._gcd_import(name[level:], package, level) 
> > 
> > File <frozen importlib._bootstrap>:1030, in _gcd_import(name, package, level) 
> > 
> > File <frozen importlib._bootstrap>:1007, in _find_and_load(name, import_) 
> > 
> > File <frozen importlib._bootstrap>:986, in _find_and_load_unlocked(name, import_) 
> > 
> > File <frozen importlib._bootstrap>:666, in _load_unlocked(spec) 
> > 
> > File <frozen importlib._bootstrap>:565, in module_from_spec(spec) 
> > 
> > File <frozen importlib._bootstrap_external>:1173, in create_module(self, spec) 
> > 
> > File <frozen importlib._bootstrap>:228, in _call_with_frames_removed(f, *args, **kwds) 
> > 
> > ImportError: DLL load failed while importing _gdal: The specified module could not be found. 
> > 
> > During handling of the above exception, another exception occurred: 
> > 
> > ImportError Traceback (most recent call last) 
> > Input In [1], in <cell line: 1>() 
> > ----> 1 from osgeo import gdal 
> > File ~\anaconda3\lib\site-packages\osgeo\__init__.py:45, in <module> 
> > 41 raise ImportError(traceback_string + '\n' + msg) 
> > 42 return importlib.import_module('_gdal') 
> > ---> 45 _gdal = swig_import_helper() 
> > 46 del swig_import_helper 
> > 48 __version__ = _gdal.__version__ = _gdal.VersionInfo("RELEASE_NAME") 
> > 
> > File ~\anaconda3\lib\site-packages\osgeo\__init__.py:41, in swig_import_helper() 
> > 39 import traceback 
> > 40 traceback_string = ''.join(traceback.format_exception(*sys.exc_info())) 
> > ---> 41 raise ImportError(traceback_string + '\n' + msg) 
> > 42 return importlib.import_module('_gdal') 
> > 
> > ImportError: Traceback (most recent call last): 
> > File "C:\Users\abdul\anaconda3\lib\site-packages\osgeo\__init__.py", line 29, in swig_import_helper 
> > return importlib.import_module(mname) 
> > File "C:\Users\abdul\anaconda3\lib\importlib\__init__.py", line 127, in import_module 
> > return _bootstrap._gcd_import(name[level:], package, level) 
> > File "<frozen importlib._bootstrap>", line 1030, in _gcd_import 
> > File "<frozen importlib._bootstrap>", line 1007, in _find_and_load 
> > File "<frozen importlib._bootstrap>", line 986, in _find_and_load_unlocked 
> > File "<frozen importlib._bootstrap>", line 666, in _load_unlocked 
> > File "<frozen importlib._bootstrap>", line 565, in module_from_spec 
> > File "<frozen importlib._bootstrap_external>", line 1173, in create_module 
> > File "<frozen importlib._bootstrap>", line 228, in _call_with_frames_removed 
> > ImportError: DLL load failed while importing _gdal: The specified module could not be found. 
> > 
> > On Windows, with Python >= 3.8, DLLs are no longer imported from the PATH. 
> > If gdalXXX.dll is in the PATH, then set the USE_PATH_FOR_GDAL_PYTHON=YES environment variable 
> > to feed the PATH into os.add_dll_directory(). 
> > 
> > I hope you could look at the errors and guide me to solve this problem. 
> > 
> > with regards 
> > Abdul
> Hi all, 
> I followed the instructions given in the following link and I could install gdal and it works perfectly now. 
> In case this might be of use for anyone of you. 
> https://www.quora.com/How-do-I-install-gdal-in-PyCharm 
> 
> thanks
Hola, no  he podido solucionar el problema gdal:
ImportError                               Traceback (most recent call last)
Cell In[4], line 1
----> 1 import rasterio

File ~\anaconda3\envs\myenv1\lib\site-packages\rasterio\__init__.py:9
      6 from logging import NullHandler
      7 from pathlib import Path
----> 9 from rasterio._base import gdal_version
     10 from rasterio.drivers import driver_from_extension, is_blacklisted
     11 from rasterio.dtypes import (
     12     bool_,
     13     ubyte,
   (...)
     25     check_dtype,
     26 )

ImportError: DLL load failed while importing _base: No se puede encontrar el m?dulo especificado.

From email at paulstgeorge.com  Sat Dec 17 06:51:17 2022
From: email at paulstgeorge.com (Paul St George)
Date: Sat, 17 Dec 2022 12:51:17 +0100
Subject: String to Float, without introducing errors
Message-ID: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>

I have a large/long array of numbers in an external file. The numbers look like this:

-64550.727
-64511.489
-64393.637
-64196.763
-63920.2
-63563.037
-63124.156
-62602.254
-61995.895
-61303.548
-60523.651
-59654.66
...

When I bring the numbers into my code, they are Strings. To use the numbers in my code, I want to change the Strings to Float type because the code will not work with Strings but I do not want to change the numbers in any other way.

So, I want my Strings (above) to be these numbers.

-64550.727
-64511.489
-64393.637
-64196.763
-63920.2
-63563.037
-63124.156
-62602.254
-61995.895
-61303.548
-60523.651
-59654.66
...

Please help!











From gweatherby at uchc.edu  Sat Dec 17 06:59:59 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Sat, 17 Dec 2022 11:59:59 +0000
Subject: String to Float, without introducing errors
In-Reply-To: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
Message-ID: <SA1PR14MB585573EF22DE708DF14E1F02B9E79@SA1PR14MB5855.namprd14.prod.outlook.com>

https://docs.python.org/3/library/decimal.html

Get Outlook for iOS<https://aka.ms/o0ukef>
________________________________
From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Paul St George <email at paulstgeorge.com>
Sent: Saturday, December 17, 2022 6:51:17 AM
To: python-list at python.org <python-list at python.org>
Subject: String to Float, without introducing errors

*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

I have a large/long array of numbers in an external file. The numbers look like this:

-64550.727
-64511.489
-64393.637
-64196.763
-63920.2
-63563.037
-63124.156
-62602.254
-61995.895
-61303.548
-60523.651
-59654.66
...

When I bring the numbers into my code, they are Strings. To use the numbers in my code, I want to change the Strings to Float type because the code will not work with Strings but I do not want to change the numbers in any other way.

So, I want my Strings (above) to be these numbers.

-64550.727
-64511.489
-64393.637
-64196.763
-63920.2
-63563.037
-63124.156
-62602.254
-61995.895
-61303.548
-60523.651
-59654.66
...

Please help!










--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!guE_zPsjxMW4k6nHIdOqZbrt8SdjUC9GELXgSHatARIr2PrAYr6tXCmixkZGNocjsf9SKLduQFjZjM7tOeaQ$

From learn2program at gmail.com  Sat Dec 17 07:11:37 2022
From: learn2program at gmail.com (Alan Gauld)
Date: Sat, 17 Dec 2022 12:11:37 +0000
Subject: String to Float, without introducing errors
In-Reply-To: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
Message-ID: <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>

On 17/12/2022 11:51, Paul St George wrote:
> I have a large/long array of numbers in an external file. The numbers look like this:
> 
> -64550.727
> -64511.489
> -64393.637
> -64196.763
> -63920.2

> When I bring the numbers into my code, they are Strings. To use the 
> numbers in my code, I want to change the Strings to Float type 
> because the code will not work with Strings but I do not want 
> to change the numbers in any other way.

That may be impossible. Float type is not exact and the conversion
will be the closest binary representation of your decimal number.
It will be very close but it may be slightly different when you
print it, for example. (You can usually deal with that by using
string formatting features.)

Another option is to use the decimal numeric type. That has other
compromises associated with it but, if retaining absolute decimal
accuracy is your primary goal, it might suit you better.


-- 
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 hjp-python at hjp.at  Sat Dec 17 07:39:56 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 17 Dec 2022 13:39:56 +0100
Subject: String to Float, without introducing errors
In-Reply-To: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
Message-ID: <20221217123956.epbpwrhrywl2u3ko@hjp.at>

On 2022-12-17 12:51:17 +0100, Paul St George wrote:
> I have a large/long array of numbers in an external file. The numbers
> look like this:
> 
> -64550.727
> -64511.489
> -64393.637
[...]
> 
> When I bring the numbers into my code, they are Strings. To use the
> numbers in my code, I want to change the Strings to Float type because
> the code will not work with Strings but I do not want to change the
> numbers in any other way.

>>> s = "-64550.727"
>>> f = float(s)
>>> f
-64550.727
>>> type(f)
<class 'float'>

(Contrary to the other people posting in this thread I don't think float
is the wrong type for the job. It might be, but you haven't given enough
details to tell whether the inevitable rounding error matters or not. In
my experience in almost all cases where people think it matters it
really doesn't.)

        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 list1 at tompassin.net  Sat Dec 17 09:15:58 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sat, 17 Dec 2022 09:15:58 -0500
Subject: String to Float, without introducing errors
In-Reply-To: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
Message-ID: <ecccc7dd-faed-bbd2-9e6a-14bb1c1dc160@tompassin.net>

You have strings, and you want to end up with numbers.  The numbers are 
not integers.  Other responders have gone directly to whether you should 
use float or decimal as the conversion, but that is a secondary matter.

If you have integers, convert with

integer = int(number_string)

If you don't have integers, convert with

number = float(number_string)

If the number is not an integer and you need to be extremely precise 
with the fractional part - for example, if you need to keep exact track 
of exact amounts of money - you can use decimal instead of float.  But 
in this example it seems unlikely that you need that.

The thing to be aware of that hasn't been mentioned so far is that the 
conversion might cause an exception if there is something wrong with one 
of the number strings.  If you don't handle it, your program will quit 
running when it hits the error.  That might not matter to you.  If it 
matters, you can handle the exception in the program, but first you will 
need to decide what to do about such an error: should that number be 
omitted, should it be replaced with a placeholder, should it be replaced 
with float("NaN"), or what else?

In your case here, I'd suggest not handling the error until you get the 
basics of your program working.  Then if you need to, figure out how you 
want to handle exceptions.


On 12/17/2022 6:51 AM, Paul St George wrote:
> I have a large/long array of numbers in an external file. The numbers look like this:
> 
> -64550.727
> -64511.489
> -64393.637
> -64196.763
> -63920.2
> -63563.037
> -63124.156
> -62602.254
> -61995.895
> -61303.548
> -60523.651
> -59654.66
> ...
> 
> When I bring the numbers into my code, they are Strings. To use the numbers in my code, I want to change the Strings to Float type because the code will not work with Strings but I do not want to change the numbers in any other way.
> 
> So, I want my Strings (above) to be these numbers.
> 
> -64550.727
> -64511.489
> -64393.637
> -64196.763
> -63920.2
> -63563.037
> -63124.156
> -62602.254
> -61995.895
> -61303.548
> -60523.651
> -59654.66
> ...
> 
> Please help!
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 


From mats at wichmann.us  Sat Dec 17 13:41:32 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Sat, 17 Dec 2022 11:41:32 -0700
Subject: String to Float, without introducing errors
In-Reply-To: <ecccc7dd-faed-bbd2-9e6a-14bb1c1dc160@tompassin.net>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <ecccc7dd-faed-bbd2-9e6a-14bb1c1dc160@tompassin.net>
Message-ID: <13bbe0c7-3fb1-6474-51fd-99cfb9fd0e88@wichmann.us>

On 12/17/22 07:15, Thomas Passin wrote:
> You have strings, and you want to end up with numbers.? The numbers are 
> not integers.? Other responders have gone directly to whether you should 
> use float or decimal as the conversion, but that is a secondary matter.
> 
> If you have integers, convert with
> 
> integer = int(number_string)
>> -64550.727

they pretty clearly aren't integers:

>> -64511.489
>> -64393.637
>> -64196.763
>> -63920.2
>> -63563.037
>> -63124.156
>> -62602.254
>> -61995.895
>> -61303.548
>> -60523.651
>> -59654.66

From list1 at tompassin.net  Sat Dec 17 14:09:45 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sat, 17 Dec 2022 14:09:45 -0500
Subject: String to Float, without introducing errors
In-Reply-To: <13bbe0c7-3fb1-6474-51fd-99cfb9fd0e88@wichmann.us>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <ecccc7dd-faed-bbd2-9e6a-14bb1c1dc160@tompassin.net>
 <13bbe0c7-3fb1-6474-51fd-99cfb9fd0e88@wichmann.us>
Message-ID: <9ca24bea-e012-e772-c70e-5eddc9180606@tompassin.net>

On 12/17/2022 1:41 PM, Mats Wichmann wrote:
> On 12/17/22 07:15, Thomas Passin wrote:
>> You have strings, and you want to end up with numbers.? The numbers 
>> are not integers.? Other responders have gone directly to whether you 
>> should use float or decimal as the conversion, but that is a secondary 
>> matter.
>>
>> If you have integers, convert with
>>
>> integer = int(number_string)
>>> -64550.727
> 
> they pretty clearly aren't integers:

Of course they aren't.  That's why I gave the line with float() too. 
It's useful to see that there is a basic pattern here:  Given a string, 
expect to need to convert it to what you actually want, int, float, 
decimal, whatever.

>>> -64511.489
>>> -64393.637
>>> -64196.763
>>> -63920.2
>>> -63563.037
>>> -63124.156
>>> -62602.254
>>> -61995.895
>>> -61303.548
>>> -60523.651
>>> -59654.66


From rob.cliffe at btinternet.com  Thu Dec 15 08:30:39 2022
From: rob.cliffe at btinternet.com (Rob Cliffe)
Date: Thu, 15 Dec 2022 13:30:39 +0000
Subject: Single line if statement with a continue
In-Reply-To: <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
Message-ID: <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>



On 15/12/2022 04:35, Chris Angelico wrote:
> On Thu, 15 Dec 2022 at 14:41, Aaron P <transreductionist at gmail.com> wrote:
>> I occasionally run across something like:
>>
>> for idx, thing in enumerate(things):
>>      if idx == 103:
>>          continue
>>      do_something_with(thing)
>>
>> It seems more succinct and cleaner to use:
>>
>> if idx == 103: continue.
>>
>>
>> Nothing at all wrong with writing that on a single line. If you have
>> issues with Flake8 not accepting your choices, reconfigure Flake8 :)
>>
>> ChrisA
I'm so glad that Chris and others say this.? It (i.e. if plus 
break/continue/return on a single line) is something I have quite often 
done in my own code, albeit with a feeling of guilt that I was breaking 
a Python taboo.? Now I will do it with a clear conscience. ?
Best wishes
Rob Cliffe

From rob.cliffe at btinternet.com  Wed Dec 14 14:17:50 2022
From: rob.cliffe at btinternet.com (Rob Cliffe)
Date: Wed, 14 Dec 2022 19:17:50 +0000
Subject: Top level of a recursive function
In-Reply-To: <names-20221214144540@ram.dialup.fu-berlin.de>
References: <tna385$2hmog$1@dont-email.me>
 <rest-20221213160153@ram.dialup.fu-berlin.de> <tnan9a$2ja6s$1@dont-email.me>
 <names-20221214144540@ram.dialup.fu-berlin.de>
Message-ID: <f8cd8afe-d18c-fcf8-2709-ab9b053b15e8@btinternet.com>



On 14/12/2022 13:49, Stefan Ram wrote:
> I also found an example similar to what was discussed here
>    in pypy's library file "...\Lib\_tkinter\__init__.py":
>
> |def _flatten(item):
> |    def _flatten1(output, item, depth):
> |        if depth > 1000:
> |            raise ValueError("nesting too deep in _flatten")
> |        if not isinstance(item, (list, tuple)):
> |            raise TypeError("argument must be sequence")
> |        # copy items to output tuple
> |        for o in item:
> |            if isinstance(o, (list, tuple)):
> |                _flatten1(output, o, depth + 1)
> |            elif o is not None:
> |                output.append(o)
> |
> |    result = []
> |    _flatten1(result, item, 0)
> |    return tuple(result)
>
>    .
>
>
This presumably results in an (avoidable) run-time overhead from 
constructing _flatten1 every time _flatten is called (and having it 
garbage-collected later).
Best wishes
Rob Cliffe

From sjeik_appie at hotmail.com  Sat Dec 17 14:45:18 2022
From: sjeik_appie at hotmail.com (Albert-Jan Roskam)
Date: Sat, 17 Dec 2022 20:45:18 +0100
Subject: Keeping a list of records with named fields that can be updated
In-Reply-To: <9158537c-f561-e666-f60c-34d50f61d7b7@web.de>
Message-ID: <DB6PR01MB3895A0826921A51E4AE87D6A83E79@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>

   On Dec 15, 2022 10:21, Peter Otten <__peter__ at web.de> wrote:

     >>> from collections import namedtuple
     >>> Row = namedtuple("Row", "foo bar baz")
     >>> row = Row(1, 2, 3)
     >>> row._replace(bar=42)
     Row(foo=1, bar=42, baz=3)

   ====
   Ahh, I always thought these are undocumented methods, but: "In addition to
   the methods inherited from tuples, named tuples support three additional
   methods and two attributes. To prevent conflicts with field names, the
   method and attribute names start with an underscore."
   https://docs.python.org/3/library/collections.html#collections.somenamedtuple._make

From abdullahnafees23 at gmail.com  Sat Dec 17 14:22:42 2022
From: abdullahnafees23 at gmail.com (Abdullah Nafees)
Date: Sun, 18 Dec 2022 00:22:42 +0500
Subject: Single line if statement with a continue
In-Reply-To: <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
Message-ID: <CA+SQCwuzscCroLkn9HhgaVMGVTPuQ5gPLuGFpLCFLJ9fPUX_8A@mail.gmail.com>

Just wanted to say that a silent reader like me learnt more about PEP-8
solely from this thread than my mentor at work or any other course I have
taken earlier this year. Thank you so much.

On Sun, 18 Dec 2022, 00:16 Rob Cliffe via Python-list, <
python-list at python.org> wrote:

>
>
> On 15/12/2022 04:35, Chris Angelico wrote:
> > On Thu, 15 Dec 2022 at 14:41, Aaron P <transreductionist at gmail.com>
> wrote:
> >> I occasionally run across something like:
> >>
> >> for idx, thing in enumerate(things):
> >>      if idx == 103:
> >>          continue
> >>      do_something_with(thing)
> >>
> >> It seems more succinct and cleaner to use:
> >>
> >> if idx == 103: continue.
> >>
> >>
> >> Nothing at all wrong with writing that on a single line. If you have
> >> issues with Flake8 not accepting your choices, reconfigure Flake8 :)
> >>
> >> ChrisA
> I'm so glad that Chris and others say this.  It (i.e. if plus
> break/continue/return on a single line) is something I have quite often
> done in my own code, albeit with a feeling of guilt that I was breaking
> a Python taboo.  Now I will do it with a clear conscience. ?
> Best wishes
> Rob Cliffe
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From email at paulstgeorge.com  Sat Dec 17 15:45:06 2022
From: email at paulstgeorge.com (Paul St George)
Date: Sat, 17 Dec 2022 21:45:06 +0100
Subject: String to Float, without introducing errors
In-Reply-To: <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
Message-ID: <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>

Thanks to all!
It was the rounding rounding error that I needed to avoid (as Peter J. Holzer suggested). The use of decimal solved it and just in time. I was about to truncate the number, get each of the characters from the string mantissa, and then do something like this:

64550.727

64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)

Now I do not need to!





> On 17 Dec 2022, at 13:11, Alan Gauld <learn2program at gmail.com> wrote:
> 
> On 17/12/2022 11:51, Paul St George wrote:
>> I have a large/long array of numbers in an external file. The numbers look like this:
>> 
>> -64550.727
>> -64511.489
>> -64393.637
>> -64196.763
>> -63920.2
> 
>> When I bring the numbers into my code, they are Strings. To use the 
>> numbers in my code, I want to change the Strings to Float type 
>> because the code will not work with Strings but I do not want 
>> to change the numbers in any other way.
> 
> That may be impossible. Float type is not exact and the conversion
> will be the closest binary representation of your decimal number.
> It will be very close but it may be slightly different when you
> print it, for example. (You can usually deal with that by using
> string formatting features.)
> 
> Another option is to use the decimal numeric type. That has other
> compromises associated with it but, if retaining absolute decimal
> accuracy is your primary goal, it might suit you better.
> 
> 
> -- 
> 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 rosuav at gmail.com  Sat Dec 17 15:49:05 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Dec 2022 07:49:05 +1100
Subject: String to Float, without introducing errors
In-Reply-To: <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
Message-ID: <CAPTjJmofPSNV9kWZST151+9PFK3NTYtotRO2OgzANGN88JqnKA@mail.gmail.com>

On Sun, 18 Dec 2022 at 07:46, Paul St George <email at paulstgeorge.com> wrote:
>
> Thanks to all!
> It was the rounding rounding error that I needed to avoid (as Peter J. Holzer suggested). The use of decimal solved it and just in time. I was about to truncate the number, get each of the characters from the string mantissa, and then do something like this:
>
> 64550.727
>
> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
>
> Now I do not need to!

It sounds like fixed-point arithmetic might be a better fit for what
you're doing.

ChrisA

From grant.b.edwards at gmail.com  Sat Dec 17 16:21:34 2022
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Sat, 17 Dec 2022 13:21:34 -0800 (PST)
Subject: String to Float, without introducing errors
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
 <CAPTjJmofPSNV9kWZST151+9PFK3NTYtotRO2OgzANGN88JqnKA@mail.gmail.com>
Message-ID: <639e32de.020a0220.7add7.2f5b@mx.google.com>

On 2022-12-17, Chris Angelico <rosuav at gmail.com> wrote:

>> It was the rounding rounding error that I needed to avoid (as Peter
>> J. Holzer suggested). The use of decimal solved it and just in
>> time. I was about to truncate the number, get each of the
>> characters from the string mantissa, and then do something like
>> this:
>>
>> 64550.727
>>
>> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
>>
>> Now I do not need to!
>
> It sounds like fixed-point arithmetic might be a better fit for what
> you're doing.

Yes, fixed point (or decimal) is a better fit for what he's doing. but
I suspect that floating point would be a better fit for the problem
he's trying to solve.

--
Grant




From rosuav at gmail.com  Sat Dec 17 16:27:21 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Dec 2022 08:27:21 +1100
Subject: String to Float, without introducing errors
In-Reply-To: <639e32de.020a0220.7add7.2f5b@mx.google.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
 <CAPTjJmofPSNV9kWZST151+9PFK3NTYtotRO2OgzANGN88JqnKA@mail.gmail.com>
 <639e32de.020a0220.7add7.2f5b@mx.google.com>
Message-ID: <CAPTjJmpBqrz3qRpv00XAoy=9=M4ORf9aCFswStuJ-1ZTBrvJDg@mail.gmail.com>

On Sun, 18 Dec 2022 at 08:22, Grant Edwards <grant.b.edwards at gmail.com> wrote:
>
> On 2022-12-17, Chris Angelico <rosuav at gmail.com> wrote:
>
> >> It was the rounding rounding error that I needed to avoid (as Peter
> >> J. Holzer suggested). The use of decimal solved it and just in
> >> time. I was about to truncate the number, get each of the
> >> characters from the string mantissa, and then do something like
> >> this:
> >>
> >> 64550.727
> >>
> >> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
> >>
> >> Now I do not need to!
> >
> > It sounds like fixed-point arithmetic might be a better fit for what
> > you're doing.
>
> Yes, fixed point (or decimal) is a better fit for what he's doing. but
> I suspect that floating point would be a better fit for the problem
> he's trying to solve.
>

Hard to judge, given how little info we have on the actual problem.
Could go either way.

ChrisA

From hjp-python at hjp.at  Sat Dec 17 16:45:12 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Sat, 17 Dec 2022 22:45:12 +0100
Subject: String to Float, without introducing errors
In-Reply-To: <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
Message-ID: <20221217214512.wlm2htukxisij6v5@hjp.at>

On 2022-12-17 21:45:06 +0100, Paul St George wrote:
> It was the rounding rounding error that I needed to avoid (as Peter J.
> Holzer suggested). The use of decimal solved it and just in time. I
> was about to truncate the number, get each of the characters from the
> string mantissa, and then do something like this:
> 
> 64550.727
> 
> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)

That wouldn't have helped. In fact it would have made matters worse
because instead of a single rounding operation you now have nine!

        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 list1 at tompassin.net  Sat Dec 17 16:54:05 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sat, 17 Dec 2022 16:54:05 -0500
Subject: String to Float, without introducing errors
In-Reply-To: <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
Message-ID: <71d697b7-9f95-6136-a1ad-308093e5ef23@tompassin.net>

On 12/17/2022 3:45 PM, Paul St George wrote:
> Thanks to all!
> It was the rounding rounding error that I needed to avoid (as Peter J. Holzer suggested). The use of decimal solved it and just in time. I was about to truncate the number, get each of the characters from the string mantissa, and then do something like this:
> 
> 64550.727
> 
> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
> 
> Now I do not need to!

And that approach would not have helped you, because each of those 
calculations would be done as floating point, and you wouldn't have 
gotten any more precision (and maybe less) than simply doing 
float('64550.727').

Here is a small but interesting discussion thread about float vs Decimal:

https://stackoverflow.com/questions/32053647/comparing-python-decimals-created-from-float-and-string

Would you mind telling us why that degree of precision (that is, decimal 
vs float) matters for your problem?


>> On 17 Dec 2022, at 13:11, Alan Gauld <learn2program at gmail.com> wrote:
>>
>> On 17/12/2022 11:51, Paul St George wrote:
>>> I have a large/long array of numbers in an external file. The numbers look like this:
>>>
>>> -64550.727
>>> -64511.489
>>> -64393.637
>>> -64196.763
>>> -63920.2
>>
>>> When I bring the numbers into my code, they are Strings. To use the
>>> numbers in my code, I want to change the Strings to Float type
>>> because the code will not work with Strings but I do not want
>>> to change the numbers in any other way.
>>
>> That may be impossible. Float type is not exact and the conversion
>> will be the closest binary representation of your decimal number.
>> It will be very close but it may be slightly different when you
>> print it, for example. (You can usually deal with that by using
>> string formatting features.)
>>
>> Another option is to use the decimal numeric type. That has other
>> compromises associated with it but, if retaining absolute decimal
>> accuracy is your primary goal, it might suit you better.
>>
>>
>> -- 
>> 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 PythonList at DancesWithMice.info  Sat Dec 17 16:54:55 2022
From: PythonList at DancesWithMice.info (dn)
Date: Sun, 18 Dec 2022 10:54:55 +1300
Subject: String to Float, without introducing errors
In-Reply-To: <20221217123956.epbpwrhrywl2u3ko@hjp.at>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <20221217123956.epbpwrhrywl2u3ko@hjp.at>
Message-ID: <b8065807-95c1-77a4-c7e2-c39bca5f3b5f@DancesWithMice.info>

On 18/12/2022 01.39, Peter J. Holzer wrote:
> On 2022-12-17 12:51:17 +0100, Paul St George wrote:
>> I have a large/long array of numbers in an external file. The numbers
>> look like this:
>>
>> -64550.727
>> -64511.489
>> -64393.637
> [...]
>>
>> When I bring the numbers into my code, they are Strings. To use the
>> numbers in my code, I want to change the Strings to Float type because
>> the code will not work with Strings but I do not want to change the
>> numbers in any other way.
> 
>>>> s = "-64550.727"
>>>> f = float(s)
>>>> f
> -64550.727
>>>> type(f)
> <class 'float'>
> 
> (Contrary to the other people posting in this thread I don't think float
> is the wrong type for the job. It might be, but you haven't given enough
> details to tell whether the inevitable rounding error matters or not. In
> my experience in almost all cases where people think it matters it
> really doesn't.)

Agreed: (ultimately) insufficient information-provided.
(but that probably doesn't matter either - as the OP seems to have come 
to a decision)


Agreed: probably doesn't matter.


'The world' agrees with both, having decided that Numerical Analysis is 
no-longer a necessary ComSc study.

In the ?good, old, days Numerical Analysis included contemplation of the 
difficulties and differences between "precision" and "accuracy". Thus, 
the highly accurate calculation of less-than precise numbers - or was it 
precise values subject to less than accurate computation?
(rhetorical!)

Sort of like giving highly-accurate answers to a less-than precise 
(complete) question, by presuming can ignore the latter.

-- 
Regards,
=dn

From PythonList at DancesWithMice.info  Sat Dec 17 16:59:14 2022
From: PythonList at DancesWithMice.info (dn)
Date: Sun, 18 Dec 2022 10:59:14 +1300
Subject: Single line if statement with a continue
In-Reply-To: <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
Message-ID: <9db24918-e924-3c0a-9a84-d513c6efd51d@DancesWithMice.info>

On 16/12/2022 02.30, Rob Cliffe via Python-list wrote:
> On 15/12/2022 04:35, Chris Angelico wrote:
>> On Thu, 15 Dec 2022 at 14:41, Aaron P <transreductionist at gmail.com> 
>> wrote:
>>> I occasionally run across something like:
>>>
>>> for idx, thing in enumerate(things):
>>> ???? if idx == 103:
>>> ???????? continue
>>> ???? do_something_with(thing)
>>>
>>> It seems more succinct and cleaner to use:
>>>
>>> if idx == 103: continue.
>>>
>>>
>>> Nothing at all wrong with writing that on a single line. If you have
>>> issues with Flake8 not accepting your choices, reconfigure Flake8 :)
>>>
>>> ChrisA
> I'm so glad that Chris and others say this.? It (i.e. if plus 
> break/continue/return on a single line) is something I have quite often 
> done in my own code, albeit with a feeling of guilt that I was breaking 
> a Python taboo.? Now I will do it with a clear conscience. ?

Anxiety doesn't help anyone - least of all you.

Remember another Python mantra: "we're all adults here"!

(also (compulsory interjection) PEP-008 is not a set of rules for all 
Python code - see PEP-008)

-- 
Regards,
=dn

From annelmoeti at gmail.com  Sat Dec 17 17:45:21 2022
From: annelmoeti at gmail.com (Anne)
Date: Sun, 18 Dec 2022 00:45:21 +0200
Subject: Subject: problem activating python
In-Reply-To: <818D04E1-24EB-4C55-A5E6-AB2C7C46B8CB@hxcore.ol>
References: <818D04E1-24EB-4C55-A5E6-AB2C7C46B8CB@hxcore.ol>
Message-ID: <E8D3C2AA-FA6A-4538-8BD6-DED324EDF048@hxcore.ol>

   I tried several times to install and use python for youtube views with Tor
   using Youtube tutorials but I keep getting error after error. Please help
   me.
   regards Dimpho

   ?

   ?

   ?

   ?

From rosuav at gmail.com  Sat Dec 17 17:58:05 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Dec 2022 09:58:05 +1100
Subject: String to Float, without introducing errors
In-Reply-To: <float-20221217225423@ram.dialup.fu-berlin.de>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
 <CAPTjJmofPSNV9kWZST151+9PFK3NTYtotRO2OgzANGN88JqnKA@mail.gmail.com>
 <639e32de.020a0220.7add7.2f5b@mx.google.com>
 <mailman.1210.1671312099.20444.python-list@python.org>
 <float-20221217225423@ram.dialup.fu-berlin.de>
Message-ID: <CAPTjJmqWT4H=+pyxjVjytvWzG_6wwyK0rGbgoYYT0SGinvjPQA@mail.gmail.com>

On Sun, 18 Dec 2022 at 09:46, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>
> Grant Edwards <grant.b.edwards at gmail.com> writes:
> >Yes, fixed point (or decimal) is a better fit for what he's doing. but
> >I suspect that floating point would be a better fit for the problem
> >he's trying to solve.
>
>   I'd like to predict that within the next ten posts in this
>   thread someone will mention "What Every Computer Scientist
>   Should Know About Floating-Point Arithmetic".
>
> |>>> 0.1 + 0.2 - 0.3
> |5.551115123125783e-17
>

Looks like someone just did.

ChrisA

From avi.e.gross at gmail.com  Sat Dec 17 18:05:46 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Sat, 17 Dec 2022 18:05:46 -0500
Subject: String to Float, without introducing errors
In-Reply-To: <13bbe0c7-3fb1-6474-51fd-99cfb9fd0e88@wichmann.us>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <ecccc7dd-faed-bbd2-9e6a-14bb1c1dc160@tompassin.net>
 <13bbe0c7-3fb1-6474-51fd-99cfb9fd0e88@wichmann.us>
Message-ID: <005c01d9126c$191b2e80$4b518b80$@gmail.com>

As often seems to happen, someone asks something that may not be fully clear and others chime in and extend the question.

Was the original question how to read in a ingle column of numbers from a file that are all numeric and NOT integers and be able to use them?

If so, the answer was quite trivial using the conversion function of your choice. Handling errors or what to do with something like a blank or NA are nice ideas if asked about.

My answer would be to ask if this was an assignment where they are EXPECTED to do things a certain way to master a concept, or part of a serious attempt to get things done.

For the latter case, it may make plenty of sense considering a single column of text as just a special case for the kind of multi-column files often read in from formatted data files and use some functionality from add-on modules like numpy or pandas that also allow you to deal with many other concerns.

Note such utilities also often make a decent guess on what data type a column should be turned into and it is possible they may occasionally decide based on the data that the contents all HAPPEN to be integer or there is at least one that makes it choose character. So any such use may well require the subsequent use of functions that check the dtype and, if needed, do an explicit conversion to what you really really really want.



-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On Behalf Of Mats Wichmann
Sent: Saturday, December 17, 2022 1:42 PM
To: python-list at python.org
Subject: Re: String to Float, without introducing errors

On 12/17/22 07:15, Thomas Passin wrote:
> You have strings, and you want to end up with numbers.  The numbers 
> are not integers.  Other responders have gone directly to whether you 
> should use float or decimal as the conversion, but that is a secondary matter.
> 
> If you have integers, convert with
> 
> integer = int(number_string)
>> -64550.727

they pretty clearly aren't integers:

>> -64511.489
>> -64393.637
>> -64196.763
>> -63920.2
>> -63563.037
>> -63124.156
>> -62602.254
>> -61995.895
>> -61303.548
>> -60523.651
>> -59654.66
--
https://mail.python.org/mailman/listinfo/python-list


From mats at wichmann.us  Sat Dec 17 18:38:35 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Sat, 17 Dec 2022 16:38:35 -0700
Subject: Subject: problem activating python
In-Reply-To: <E8D3C2AA-FA6A-4538-8BD6-DED324EDF048@hxcore.ol>
References: <818D04E1-24EB-4C55-A5E6-AB2C7C46B8CB@hxcore.ol>
 <E8D3C2AA-FA6A-4538-8BD6-DED324EDF048@hxcore.ol>
Message-ID: <91cc6767-e54c-51e9-7208-c560cebdddae@wichmann.us>

On 12/17/22 15:45, Anne wrote:
>     I tried several times to install and use python for youtube views with Tor
>     using Youtube tutorials but I keep getting error after error. Please help
>     me.
>     regards Dimpho

Folks around here tend to be pretty helpful.  But only if you describe 
the problem in a way they can help with.  It's not clear what you're 
trying to do, and "I keep getting error after error" doesn't give anyone 
any information to work with.




From avi.e.gross at gmail.com  Sat Dec 17 18:57:47 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Sat, 17 Dec 2022 18:57:47 -0500
Subject: Single line if statement with a continue
In-Reply-To: <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
Message-ID: <006801d91273$5cfffe80$16fffb80$@gmail.com>

I happen to be of two schools here.

Is something sort of taboo when using something like a computer language to write a program? What if another language tells you to do it a different way or sort of the opposite? Is it based on the details of the language and implementation or the prejudices of the one trying to make rules?

If a compiler or interpreter HAPPILY (as happy as machines/code get) compiles or interprets your code without errors every time you use it a certain way, then it is not wrong to use it. Of course if it subject to change or already deprecated, ...

If people around you complain they do not like it, then the word "taboo" does apply but you can feel free to re-educate them or move on.

This reminds me too much of people who are taught some grammar such as some part of a sentence requiring a "noun-phrase" and later it explains that a non-phrase can be EITHER a noun accompanied by an assortment of other words that together form a phrase, or just a "noun" or just a "pronoun" or just a "nothing but an implied pronoun".

So which is it? The answer is all of them are legal, at least within bounds. A sentence like "Come over here" is an implied "You come over here" and works best if earlier sentences have laid some context on what is being talked about so the "you" is obvious or will be explained later but perhaps should be discouraged in other circumstances.

So back to computer languages. Many languages using grouping with something like "{...}" often do not care where you break your lines albeit some get touchy about an else statement placed improperly. It is perfectly legal to write:

If (condition) { first; second; third }

The grammar basically states that a "statement" or similar name can be a simple statement or a compound statement and anywhere one can go, within reason, so can the other.

Python has a twist here in that they discourage or outlaw some such things as they use mainly indentation rather than braces. This makes it hard to use multiple lines when the first line is way at the end as the others do not line up. It becomes all or ONE. I mean it allows a simple expression on the same line after the colon and then terminates the construct so a future indented line is seen as an indentation error. An experiment shows the following attempt to line up a second line way over below the first also fails:

if 5 > 3: a = a * 3
          b = b * 3

In a constant width font my second line is indented so "b is just below "a" and it fails because the interpreter does not measure the beginning column of the first line as being where the " a = a * 3" starts but at the "if" and that makes reasonable sense. I could imagine another design but since it is not what is done, the multi-line version MUST be done only on subsequent lines indented properly and identically.

So it is not really right or wrong to do one-liners. It is legal and often more readable. But if you ever want to extend your lines to be multi-line, it probably is best to use the multi-line approach regularly.

Still, using many editors, you will rapidly notice something is wrong when adding a line of code and seeing it is indented under the "if".

Is anyone really thrilled to read code in other languages that span so many lines:

If (condition)
  {
  var1 = 0
  }
else
  {
  var1 = 1
  }

It is a great way to get your line-of-code count up but the many briefer versions can be easier to read in one glance up to and including a bit murkier ones like

var1 =  (condition) ? 0 : 1

My view is that simple things that fit easily on a screen, and also held all at once in my mind, should be written fairly concisely. I do admit how much I can hold at once varies based on how well I can concentrate at that moment and have met people whose short-term memory for many things is larger or smaller than mine. But generally people can handle simple constructs like we are discussing.

Complicated things and ones that might need changes later should be written very cautiously and in detail including judicious use of comments around and within the code OR consider re-planning it into a less complicated form that calls on other fairly simple functions that can each  be decently understood based on naming and usage.

If you have a complicated calculation that eventually assigns values to a1, a2, a3, a4 then a language like Python makes a
One liner easy as in:

If (condition): 
  a1, a2, a3, a4 = func(args)

But now that four or more lines have been collapsed into one, maybe something like this works too and maybe is a tad more readable with parentheses:

If (condition): (a1, a2, a3, a4) = func(args)


I am not suggesting using something silly like this though:

if(1): (a, b, c, d) = (min(1,2), (1+2)/2, (1*2*2*3)/4, max(1,2))

That is so way beyond a one liner that it is best seen as multiple lines. It may be legal but is best used to obfuscate!

The problem with some RULES is that not only are they not real rules but sometimes have exceptions where they get in the way of getting things done.

- Avi

-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On Behalf Of Rob Cliffe via Python-list
Sent: Thursday, December 15, 2022 8:31 AM
To: python-list at python.org
Subject: Re: Single line if statement with a continue



On 15/12/2022 04:35, Chris Angelico wrote:
> On Thu, 15 Dec 2022 at 14:41, Aaron P <transreductionist at gmail.com> wrote:
>> I occasionally run across something like:
>>
>> for idx, thing in enumerate(things):
>>      if idx == 103:
>>          continue
>>      do_something_with(thing)
>>
>> It seems more succinct and cleaner to use:
>>
>> if idx == 103: continue.
>>
>>
>> Nothing at all wrong with writing that on a single line. If you have 
>> issues with Flake8 not accepting your choices, reconfigure Flake8 :)
>>
>> ChrisA
I'm so glad that Chris and others say this.  It (i.e. if plus break/continue/return on a single line) is something I have quite often done in my own code, albeit with a feeling of guilt that I was breaking a Python taboo.  Now I will do it with a clear conscience. ?
Best wishes
Rob Cliffe
--
https://mail.python.org/mailman/listinfo/python-list


From list1 at tompassin.net  Sat Dec 17 19:50:42 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sat, 17 Dec 2022 19:50:42 -0500
Subject: Single line if statement with a continue
In-Reply-To: <006801d91273$5cfffe80$16fffb80$@gmail.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
 <006801d91273$5cfffe80$16fffb80$@gmail.com>
Message-ID: <1bd05dac-6689-98a8-6d47-4df6925eba55@tompassin.net>

 >if 5 > 3: a = a * 3
 >          b = b * 3

That would be a fairly weird construction, neither one thing nor 
another.  But still, if you really want it that way, this is legal Python:

a = 2; b = 10
if 5 > 3: a = a * 3;\
           b = b * 3
print(a, b)  # 6 30

On 12/17/2022 6:57 PM, avi.e.gross at gmail.com wrote:
> I happen to be of two schools here.
> 
> Is something sort of taboo when using something like a computer language to write a program? What if another language tells you to do it a different way or sort of the opposite? Is it based on the details of the language and implementation or the prejudices of the one trying to make rules?
> 
> If a compiler or interpreter HAPPILY (as happy as machines/code get) compiles or interprets your code without errors every time you use it a certain way, then it is not wrong to use it. Of course if it subject to change or already deprecated, ...

That's not the point of using some consistent style. IMO, source code 
should be clear, compact, and easy for someone else to understand.  That 
someone might be you six months from now.

These objectives do not always align.  Consistency helps reduce mental 
effort by using constructions and formatting in a familiar way - 
basically, using a familiar programming idiom.  Compactness can help 
clarity, unless the code is too terse which can become a hindrance.  But 
too much verbosity can get in the way of grasping the essential processing.

Personal taste and familiarity also factor into assessing clarity and 
compactness.

It's always a balancing act.  Style guides can help by providing good 
basic idioms. There's no law** that says you *have* to follow them 
exactly all the time.  But it's helpful when you can.  If your own style 
guide i is similar to one used widely, so much the better.

**Except at some organizations

> If people around you complain they do not like it, then the word "taboo" does apply but you can feel free to re-educate them or move on.
> 
> This reminds me too much of people who are taught some grammar such as some part of a sentence requiring a "noun-phrase" and later it explains that a non-phrase can be EITHER a noun accompanied by an assortment of other words that together form a phrase, or just a "noun" or just a "pronoun" or just a "nothing but an implied pronoun".
> 
> So which is it? The answer is all of them are legal, at least within bounds. A sentence like "Come over here" is an implied "You come over here" and works best if earlier sentences have laid some context on what is being talked about so the "you" is obvious or will be explained later but perhaps should be discouraged in other circumstances.
> 
> So back to computer languages. Many languages using grouping with something like "{...}" often do not care where you break your lines albeit some get touchy about an else statement placed improperly. It is perfectly legal to write:
> 
> If (condition) { first; second; third }
> 
> The grammar basically states that a "statement" or similar name can be a simple statement or a compound statement and anywhere one can go, within reason, so can the other.
> 
> Python has a twist here in that they discourage or outlaw some such things as they use mainly indentation rather than braces. This makes it hard to use multiple lines when the first line is way at the end as the others do not line up. It becomes all or ONE. I mean it allows a simple expression on the same line after the colon and then terminates the construct so a future indented line is seen as an indentation error. An experiment shows the following attempt to line up a second line way over below the first also fails:
> 
> if 5 > 3: a = a * 3
>            b = b * 3
> 
> In a constant width font my second line is indented so "b is just below "a" and it fails because the interpreter does not measure the beginning column of the first line as being where the " a = a * 3" starts but at the "if" and that makes reasonable sense. I could imagine another design but since it is not what is done, the multi-line version MUST be done only on subsequent lines indented properly and identically.
> 
> So it is not really right or wrong to do one-liners. It is legal and often more readable. But if you ever want to extend your lines to be multi-line, it probably is best to use the multi-line approach regularly.
> 
> Still, using many editors, you will rapidly notice something is wrong when adding a line of code and seeing it is indented under the "if".
> 
> Is anyone really thrilled to read code in other languages that span so many lines:
> 
> If (condition)
>    {
>    var1 = 0
>    }
> else
>    {
>    var1 = 1
>    }
> 
> It is a great way to get your line-of-code count up but the many briefer versions can be easier to read in one glance up to and including a bit murkier ones like
> 
> var1 =  (condition) ? 0 : 1
> 
> My view is that simple things that fit easily on a screen, and also held all at once in my mind, should be written fairly concisely. I do admit how much I can hold at once varies based on how well I can concentrate at that moment and have met people whose short-term memory for many things is larger or smaller than mine. But generally people can handle simple constructs like we are discussing.
> 
> Complicated things and ones that might need changes later should be written very cautiously and in detail including judicious use of comments around and within the code OR consider re-planning it into a less complicated form that calls on other fairly simple functions that can each  be decently understood based on naming and usage.
> 
> If you have a complicated calculation that eventually assigns values to a1, a2, a3, a4 then a language like Python makes a
> One liner easy as in:
> 
> If (condition):
>    a1, a2, a3, a4 = func(args)
> 
> But now that four or more lines have been collapsed into one, maybe something like this works too and maybe is a tad more readable with parentheses:
> 
> If (condition): (a1, a2, a3, a4) = func(args)
> 
> 
> I am not suggesting using something silly like this though:
> 
> if(1): (a, b, c, d) = (min(1,2), (1+2)/2, (1*2*2*3)/4, max(1,2))
> 
> That is so way beyond a one liner that it is best seen as multiple lines. It may be legal but is best used to obfuscate!
> 
> The problem with some RULES is that not only are they not real rules but sometimes have exceptions where they get in the way of getting things done.
> 
> - Avi
> 
> -----Original Message-----
> From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On Behalf Of Rob Cliffe via Python-list
> Sent: Thursday, December 15, 2022 8:31 AM
> To: python-list at python.org
> Subject: Re: Single line if statement with a continue
> 
> 
> 
> On 15/12/2022 04:35, Chris Angelico wrote:
>> On Thu, 15 Dec 2022 at 14:41, Aaron P <transreductionist at gmail.com> wrote:
>>> I occasionally run across something like:
>>>
>>> for idx, thing in enumerate(things):
>>>       if idx == 103:
>>>           continue
>>>       do_something_with(thing)
>>>
>>> It seems more succinct and cleaner to use:
>>>
>>> if idx == 103: continue.
>>>
>>>
>>> Nothing at all wrong with writing that on a single line. If you have
>>> issues with Flake8 not accepting your choices, reconfigure Flake8 :)
>>>
>>> ChrisA
> I'm so glad that Chris and others say this.  It (i.e. if plus break/continue/return on a single line) is something I have quite often done in my own code, albeit with a feeling of guilt that I was breaking a Python taboo.  Now I will do it with a clear conscience. ?
> Best wishes
> Rob Cliffe
> --
> https://mail.python.org/mailman/listinfo/python-list
> 


From rosuav at gmail.com  Sat Dec 17 19:59:44 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 18 Dec 2022 11:59:44 +1100
Subject: Single line if statement with a continue
In-Reply-To: <006801d91273$5cfffe80$16fffb80$@gmail.com>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
 <006801d91273$5cfffe80$16fffb80$@gmail.com>
Message-ID: <CAPTjJmpZherAhc84GwxSvUFZYvbJS7efTvauQDfUVjO941KxjQ@mail.gmail.com>

On Sun, 18 Dec 2022 at 10:59, <avi.e.gross at gmail.com> wrote:
>
> If a compiler or interpreter HAPPILY (as happy as machines/code get) compiles or interprets your code without errors every time you use it a certain way, then it is not wrong to use it. Of course if it subject to change or already deprecated, ...
>

Source code is, first and foremost, for programmers to read. You're
confusing it with binary executables.

ChrisA

From torriem at gmail.com  Sat Dec 17 20:41:46 2022
From: torriem at gmail.com (Michael Torrie)
Date: Sat, 17 Dec 2022 18:41:46 -0700
Subject: Subject: problem activating python
In-Reply-To: <E8D3C2AA-FA6A-4538-8BD6-DED324EDF048@hxcore.ol>
References: <818D04E1-24EB-4C55-A5E6-AB2C7C46B8CB@hxcore.ol>
 <E8D3C2AA-FA6A-4538-8BD6-DED324EDF048@hxcore.ol>
Message-ID: <27d418c6-49e9-4df8-8b9a-b54326f0c0bb@gmail.com>

On 12/17/22 15:45, Anne wrote:
>    I tried several times to install and use python for youtube views with Tor
>    using Youtube tutorials but I keep getting error after error. Please help
>    me.
>    regards Dimpho

Given the lack of any information in your post, I can only assume you're
trying to get Python installed on Windows.  Please read this page and
post here if you have any questions:
https://docs.python.org/3/using/windows.html


From jimdaniellewis at gmail.com  Sun Dec 18 06:50:10 2022
From: jimdaniellewis at gmail.com (Jim Lewis)
Date: Sun, 18 Dec 2022 06:50:10 -0500
Subject: Fwd: Installation hell
In-Reply-To: <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
Message-ID: <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>

I'm an occasional user of Python and have a degree in computer science.
Almost every freaking time I use Python, I go through PSH (Python Setup
Hell). Sometimes a wrong version is installed. Sometimes it's a path issue.
Or exe naming confusion: python, python3, phthon311, etc. Or library
compatibility issues - took an hour to find out that pygame does not work
with the current version of python. Then the kludgy PIP app and using a DOS
box under Windows with command prompts which is ridiculous. God only knows
how many novice users of the language (or even intermediate users) were
lost in the setup process. Why not clean the infrastructure up and make a
modern environment or IDE or something better than it is now. Or at least
good error messages that explain exactly what to do. Even getting this
email to the list took numerous steps.

-- A frustrated user

From c.buhtz at posteo.jp  Sun Dec 18 10:38:57 2022
From: c.buhtz at posteo.jp (c.buhtz at posteo.jp)
Date: Sun, 18 Dec 2022 15:38:57 +0000
Subject: pip/setuptools: Entry points not visible from pkexec-root-environment
Message-ID: <4NZn7V1JFkz6tpJ@submission01.posteo.de>

Hello,

when I install a package on a GNU/Linux system via "sudo python3 -m pip
install -e ." that defines entry points in its pyproject.toml the entry
point starter scripts are located in /usr/locale/bin.

That folder is in PATH for "regular" root users and by "sudo su" roots
users.

But I need to start that entry points via "pkexec".
But in the environment started by "pkexec" the PATH does not contain
/usr/local/bin.

So what can I do?

I don't need a hack or workaround but an "elegant" solution.

From email at paulstgeorge.com  Sun Dec 18 14:00:37 2022
From: email at paulstgeorge.com (Paul St George)
Date: Sun, 18 Dec 2022 20:00:37 +0100
Subject: String to Float, without introducing errors
Message-ID: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>

So I am working on a physics paper with a colleague. We have a theory about Newtons Cradle. We answer the question why when you lift and drop balls 1 and 2, balls 4 and 5 rise up. I could say more, but ... (if you are interested please write to me).

We want to illustrate the paper with animations. The theory includes distortion of the balls and this distortion is very very small. So, I am sent data with locations and dimensions to 13 decimal places. Something strange is happening with the animations: the balls are not moving smoothly. I do not know (yet) where the problem lies so it is difficult to provide a clear narrative.

Because there is a problem, I am investigating in all areas. This brings me to the question I asked here. I am not expecting six decimal places or three decimal places to be as accurate as thirteen decimal places, but I would like to be in control of or fully aware of what goes on under the bonnet.

Here is a picture:
https://paulstgeorge.com/newton/cyclography.html?
Thanks,
Paul



 
>> On 17 Dec 2022, at 16:54:05 EST 2022, Thomas Passin wrote:
On 12/17/2022 3:45 PM, Paul St George wrote:
> Thanks to all!
> It was the rounding rounding error that I needed to avoid (as Peter J. Holzer suggested). The use of decimal solved it and just in time. I was about to truncate the number, get each of the characters from the string mantissa, and then do something like this:
> 
> 64550.727
> 
> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
> 
> Now I do not need to!

And that approach would not have helped you, because each of those 
calculations would be done as floating point, and you wouldn't have 
gotten any more precision (and maybe less) than simply doing 
float('64550.727').

Here is a small but interesting discussion thread about float vs Decimal:

https://stackoverflow.com/questions/32053647/comparing-python-decimals-created-from-float-and-string

Would you mind telling us why that degree of precision (that is, decimal 
vs float) matters for your problem?


>> On 17 Dec 2022, at 13:11, Alan Gauld <learn2program at gmail.com <https://mail.python.org/mailman/listinfo/python-list>> wrote:
>>
>> On 17/12/2022 11:51, Paul St George wrote:
>>> I have a large/long array of numbers in an external file. The numbers look like this:
>>>
>>> -64550.727
>>> -64511.489
>>> -64393.637
>>> -64196.763
>>> -63920.2
>>
>>> When I bring the numbers into my code, they are Strings. To use the
>>> numbers in my code, I want to change the Strings to Float type
>>> because the code will not work with Strings but I do not want
>>> to change the numbers in any other way.
>>
>> That may be impossible. Float type is not exact and the conversion
>> will be the closest binary representation of your decimal number.
>> It will be very close but it may be slightly different when you
>> print it, for example. (You can usually deal with that by using
>> string formatting features.)
>>
>> Another option is to use the decimal numeric type. That has other
>> compromises associated with it but, if retaining absolute decimal
>> accuracy is your primary goal, it might suit you better.
>>
>>
>> -- 
>> 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 gweatherby at uchc.edu  Sun Dec 18 13:45:39 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Sun, 18 Dec 2022 18:45:39 +0000
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
Message-ID: <SA1PR14MB585562533983664CF1A0BC10B9E49@SA1PR14MB5855.namprd14.prod.outlook.com>

"sudo python3 -m pip
install -e ."

You?ve already started down a problematic road. I recommend installing root level Python packages through your system package manager. (apt for debian, or whatever RedHat is using now).

If a package you need isn?t available from the system level virtual environments are your friend.

I?ve never used pkexec. Generally, just use sudo. There?s an -E flag to preserve the environment. We generally write bash wrappers that set whatever environment we need.


From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of c.buhtz at posteo.jp <c.buhtz at posteo.jp>
Date: Sunday, December 18, 2022 at 12:56 PM
To: Python-list at python.org <Python-list at python.org>
Subject: pip/setuptools: Entry points not visible from pkexec-root-environment
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Hello,

when I install a package on a GNU/Linux system via "sudo python3 -m pip
install -e ."

From mats at wichmann.us  Sun Dec 18 14:04:14 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Sun, 18 Dec 2022 12:04:14 -0700
Subject: Fwd: Installation hell
In-Reply-To: <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
Message-ID: <3d790e8f-9ade-d000-c0e6-4a12c27f6eee@wichmann.us>

On 12/18/22 04:50, Jim Lewis wrote:
> I'm an occasional user of Python and have a degree in computer science.
> Almost every freaking time I use Python, I go through PSH (Python Setup
> Hell). Sometimes a wrong version is installed. Sometimes it's a path issue.
> Or exe naming confusion: python, python3, phthon311, etc. Or library
> compatibility issues - took an hour to find out that pygame does not work
> with the current version of python. 

It's usually best to wait a bit after a new Python releases, until the 
myriad packages developed externally which depend on the binary ABI 
catch up. *Some* carefully follow the beta release cycle and are ready 
on or close to day 1, some feel like they have enough other work to do 
and are not. Can understand both viewpoints.  You can check - search for 
something that's important to you on pypi.org and see if binary wheels 
are available.

e.g. https://pypi.org/project/pygame/#files

New Python releases are only once a year, so this shouldn't be too huge 
a burden, Python 3.10 works just fine in the meantime.

> Then the kludgy PIP app and using a DOS
> box under Windows with command prompts which is ridiculous. 

Why? Python is a command-line tool to process a language, Similar to 
many other languages - Go, for example.  Or a C/C++ compiler.  *Or* you 
can choose to use someone's wrapping of that process inside an 
Integrated Development Environment. There are tons that support Python 
and let you run your code from within the editor environment without 
having to go open a cmd.exe or powershell box. Most of those are 
external, but the comes-with-Python IDLE works well, too.

> God only knows
> how many novice users of the language (or even intermediate users) were
> lost in the setup process. Why not clean the infrastructure up and make a
> modern environment or IDE or something better than it is now. Or at least
> good error messages that explain exactly what to do. Even getting this
> email to the list took numerous steps.
> 
> -- A frustrated user


From axy at declassed.art  Sun Dec 18 14:08:36 2022
From: axy at declassed.art (Axy)
Date: Sun, 18 Dec 2022 19:08:36 +0000
Subject: Fun with python string formatting
Message-ID: <7d8373d0-b0d0-da45-7316-537a99dc399f@declassed.art>

Hi all,

what do you see looking at format string syntax 
https://docs.python.org/3/library/string.html#formatstrings ?

In particular, at something like this:

{h[1].red.jumbo-header:Hello, World!}

Yes, this is syntactically correct statement and if we tweak Formatter 
methods, we can generate such an output:

<h1 class="red jumbo-header">Hello, World!</h1>

Someone might need a booze to catch sight of arguments and css classes 
in the source statement, okay: let it be Aligote markup.

Although I haven't implemented HTML rendering yet (my actual needs were 
reST and Markdown), this does generate plain text and Markdown now.

However, I'm discouraged at the moment. Without nested markup the 
implementation is very small and nice. With more or less complex 
formatting, such as nested lists, there's a need to analyse upper level 
statements and to enforce some rules. Also, there's a pain with 
indentation, but that's mainly because I was too lazy and based my 
implementation on previous work instead of writing a better one from 
scratch.

There are some undefined points such as how to render paragraphs. Use 
strict {p:text} directive or just split literal text by doubly newlines.

Can't decide whether to cut down all the complexity and revert recursion 
level to 2 or proceed with rich markup.

Anyway, below is the rendered specification in plain text. Here's the 
source code 
https://github.com/declassed-art/clabate/blob/main/clabate/extras/aligote.py 
and the specification 
https://github.com/declassed-art/clabate/blob/main/clabate/examples/aligote_spec.py

If this looks funny and you have any crazy ideas what can be added to or 
changed in the specification, let me know.

Axy.


Aligote markup specification
============================

Headings
--------

{h1:heading}
============

{h2:heading}
------------

{h3:heading}
------------

{h4:heading}
------------

{h5:heading}
------------

{h6:heading}
------------

Styles
------

{b:bold text}

{i:italic text}

{b:bold and {i:italic} text}

{i:italic and {b:bold} text}

{u:underline text}

{s:strike-through text}

{sub:subscript text}

{sup:superscript text}

Links
-----

{link[optional text]:URL}

Examples:

{link:http://declassed.art}

{link[Declassed Art]:http://declassed.art}

Rendered as:

http://declassed.art

Declassed Art (http://declassed.art)


Lists
-----

Unordered lists
---------------

{ul:
 ??? {li:item one, can be markup}
 ??? {li:item two
 ??????? can be multi-line}
 ??? {li:etc}
}

Rendered as:

* item one, can be {b:markup}
* item two
 ? can be multi-line
* etc

Ordered lists
-------------

{ol:
 ??? {li:item one}
 ??? {li:item two}
 ??? {li:etc}
}

Rendered as:

1. item one
2. item two
3. etc

Nested lists
------------

{ul:
 ??? {li:item one}
 ??? {li:item two}
 ??? {ol:
 ??????? {li:item one,
 ??????????? multi-line}
 ??????? {li:item two}
 ??? }
 ??? {li:etc}
}

Rendered as:

* item one
* item two
 ??? 1. item one,
 ?????? multi-line
 ??? 2. item two
* etc

Optional arguments
------------------

XXX Markdown does not support arbitrary numbering, does it?

{ol:
 ??? {li[3]:item 3}
 ??? {li[5]:item 5
 ??????? {ol:
 ??????????? {li:ordinal is rendered as 5.1}
 ??????????? {li[3]:ordinal is rendered as 5.3}
 ??????????? {li[5][5]:ordinal is rendered as 5.5}
 ??????????? {li: ordinal is rendered as 5.6}
 ??????? }
 ??? }
}

Rendered as:

3. item 3
5. item 5
 ?? 5.1. ordinal is rendered as 5.1
 ?? 5.3. ordinal is rendered as 5.3
 ?? 5.5. ordinal is rendered as 5.5
 ?? 5.6. ordinal is rendered as 5.6

Optional argument for unordered list is the bullet character.
Default is `*`:
{ul:
 ??? {li:item 1}
 ??? {li[+]:item 2}
 ??? {li[-]:item 3}
}

Rendered as:

* item 1
+ item 2
- item 3

Quirks
------

{ol:
 ??? {li:item one}

 ??? Basically, lists may contain any literal text.
 ??? In terms of python formatting this is not an error,
 ??? but that's not good for rendering.

 ??? {li:item two}
}

Rendered as:

1. item one

Basically, lists may contain any literal text.
In terms of python formatting this is not an error,
but that's not good for rendering.

2. item two

Syntax highlighting
-------------------

{python:
 ??? print('Hello, world!')
}

Rendered as:


 ??? print('Hello, world!')

From c.buhtz at posteo.jp  Sun Dec 18 14:23:24 2022
From: c.buhtz at posteo.jp (c.buhtz at posteo.jp)
Date: Sun, 18 Dec 2022 19:23:24 +0000
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <SA1PR14MB585562533983664CF1A0BC10B9E49@SA1PR14MB5855.namprd14.prod.outlook.com>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <SA1PR14MB585562533983664CF1A0BC10B9E49@SA1PR14MB5855.namprd14.prod.outlook.com>
Message-ID: <f300669b3055150d19f6567cae9caca9@posteo.de>

Dear Gerard,
thank you for your reply.

Am 18.12.2022 19:45 schrieb Weatherby,Gerard:
> "sudo python3 -m pip
> install -e ."
> 
> You?ve already started down a problematic road. I recommend installing
> root level Python packages through your system package manager. (apt
> for debian, or whatever RedHat is using now).

I'm totally with you at this point.

It is clear for me that distro maintainers sometimes using different 
mechanics.
But I'm the upstream maintainer and before handing offer a release to 
the distro that thing need to run without a distro. And that is pip. I 
also know a quit old project using "make" for that.

This question is independent from distros.

> I?ve never used pkexec. Generally, just use sudo.

They are two very different things. There is a strict reason why I need 
to use pkexec here.


From rosuav at gmail.com  Sun Dec 18 14:25:31 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Dec 2022 06:25:31 +1100
Subject: Fwd: Installation hell
In-Reply-To: <3d790e8f-9ade-d000-c0e6-4a12c27f6eee@wichmann.us>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <3d790e8f-9ade-d000-c0e6-4a12c27f6eee@wichmann.us>
Message-ID: <CAPTjJmr4wNEGabyg0y=zmF9JG0mmKN7-0v7czpEGCAhSMGcuPQ@mail.gmail.com>

On Mon, 19 Dec 2022 at 06:10, Mats Wichmann <mats at wichmann.us> wrote:
> Why? Python is a command-line tool to process a language, Similar to
> many other languages - Go, for example.  Or a C/C++ compiler.  *Or* you
> can choose to use someone's wrapping of that process inside an
> Integrated Development Environment. There are tons that support Python
> and let you run your code from within the editor environment without
> having to go open a cmd.exe or powershell box. Most of those are
> external, but the comes-with-Python IDLE works well, too.

I wouldn't bother responding to these sorts of people. They have
already decided that it's impossible to find any sort of decent IDE
for Python (despite pretty much every editor out there having Python
support), are deathly afraid of command lines, and yet feel the need
to join a mailing list to tell us all that. You won't convince them of
anything.

ChrisA

From rosuav at gmail.com  Sun Dec 18 14:27:26 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Dec 2022 06:27:26 +1100
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
Message-ID: <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>

On Mon, 19 Dec 2022 at 04:56, <c.buhtz at posteo.jp> wrote:
>
> Hello,
>
> when I install a package on a GNU/Linux system via "sudo python3 -m pip
> install -e ." that defines entry points in its pyproject.toml the entry
> point starter scripts are located in /usr/locale/bin.
>
> That folder is in PATH for "regular" root users and by "sudo su" roots
> users.
>
> But I need to start that entry points via "pkexec".
> But in the environment started by "pkexec" the PATH does not contain
> /usr/local/bin.
>
> So what can I do?
>
> I don't need a hack or workaround but an "elegant" solution.

Does it have to be in path? Can't you say
/usr/local/bin/entrypointname? Not sure what constitutes an elegant
solution here.

ChrisA

From list1 at tompassin.net  Sun Dec 18 14:55:50 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sun, 18 Dec 2022 14:55:50 -0500
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <f300669b3055150d19f6567cae9caca9@posteo.de>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <SA1PR14MB585562533983664CF1A0BC10B9E49@SA1PR14MB5855.namprd14.prod.outlook.com>
 <f300669b3055150d19f6567cae9caca9@posteo.de>
Message-ID: <f207531a-b2b3-bb39-f5ae-c2c9ef55859c@tompassin.net>

Pip is fine for most packages, as it looks like you know.  Some distros 
put some packages in unusual places, and those are the ones that either 
are not or should not be installed via pip.  Which ones varies from 
distro to distro. (I just include this  information here for others who 
haven't discovered it yet).

You asked for something that's not a hack, but here's a hack anyway :). 
Worth reading for the caveats -

https://stackoverflow.com/questions/50783033/execute-pkexec-command-on-a-different-path

I think the most natural way is to launch it with a script that adds 
your desired path to the pkexec environment.  What I don't know is if 
that script needs elevated permissions itself, but you probably already 
know about that.

On 12/18/2022 2:23 PM, c.buhtz at posteo.jp wrote:
> Dear Gerard,
> thank you for your reply.
> 
> Am 18.12.2022 19:45 schrieb Weatherby,Gerard:
>> "sudo python3 -m pip
>> install -e ."
>>
>> You?ve already started down a problematic road. I recommend installing
>> root level Python packages through your system package manager. (apt
>> for debian, or whatever RedHat is using now).
> 
> I'm totally with you at this point.
> 
> It is clear for me that distro maintainers sometimes using different 
> mechanics.
> But I'm the upstream maintainer and before handing offer a release to 
> the distro that thing need to run without a distro. And that is pip. I 
> also know a quit old project using "make" for that.
> 
> This question is independent from distros.
> 
>> I?ve never used pkexec. Generally, just use sudo.
> 
> They are two very different things. There is a strict reason why I need 
> to use pkexec here.
> 


From list1 at tompassin.net  Sun Dec 18 15:06:35 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sun, 18 Dec 2022 15:06:35 -0500
Subject: String to Float, without introducing errors
In-Reply-To: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
Message-ID: <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>

Thanks for filling us in!  I wouldn't think the animations themselves 
would need such precision, though perhaps the calculations of the forces 
and motions do.  One way to check might be to perturb the initial 
conditions a bit and see if the changes in the motions seem to be 
correspondingly small.  That might help you work out if the problem is 
with the physics solution or the animation.  It would be easy to get 
some numerical instability in the calculations, for example if you are 
inverting matrices.

On 12/18/2022 2:00 PM, Paul St George wrote:
> So I am working on a physics paper with a colleague. We have a theory about Newtons Cradle. We answer the question why when you lift and drop balls 1 and 2, balls 4 and 5 rise up. I could say more, but ... (if you are interested please write to me).
> 
> We want to illustrate the paper with animations. The theory includes distortion of the balls and this distortion is very very small. So, I am sent data with locations and dimensions to 13 decimal places. Something strange is happening with the animations: the balls are not moving smoothly. I do not know (yet) where the problem lies so it is difficult to provide a clear narrative.
> 
> Because there is a problem, I am investigating in all areas. This brings me to the question I asked here. I am not expecting six decimal places or three decimal places to be as accurate as thirteen decimal places, but I would like to be in control of or fully aware of what goes on under the bonnet.
> 
> Here is a picture:
> https://paulstgeorge.com/newton/cyclography.html?
> Thanks,
> Paul
> 
> 
> 
>   
>>> On 17 Dec 2022, at 16:54:05 EST 2022, Thomas Passin wrote:
> On 12/17/2022 3:45 PM, Paul St George wrote:
>> Thanks to all!
>> It was the rounding rounding error that I needed to avoid (as Peter J. Holzer suggested). The use of decimal solved it and just in time. I was about to truncate the number, get each of the characters from the string mantissa, and then do something like this:
>>
>> 64550.727
>>
>> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
>>
>> Now I do not need to!
> 
> And that approach would not have helped you, because each of those
> calculations would be done as floating point, and you wouldn't have
> gotten any more precision (and maybe less) than simply doing
> float('64550.727').
> 
> Here is a small but interesting discussion thread about float vs Decimal:
> 
> https://stackoverflow.com/questions/32053647/comparing-python-decimals-created-from-float-and-string
> 
> Would you mind telling us why that degree of precision (that is, decimal
> vs float) matters for your problem?
> 
> 
>>> On 17 Dec 2022, at 13:11, Alan Gauld <learn2program at gmail.com <https://mail.python.org/mailman/listinfo/python-list>> wrote:
>>>
>>> On 17/12/2022 11:51, Paul St George wrote:
>>>> I have a large/long array of numbers in an external file. The numbers look like this:
>>>>
>>>> -64550.727
>>>> -64511.489
>>>> -64393.637
>>>> -64196.763
>>>> -63920.2
>>>
>>>> When I bring the numbers into my code, they are Strings. To use the
>>>> numbers in my code, I want to change the Strings to Float type
>>>> because the code will not work with Strings but I do not want
>>>> to change the numbers in any other way.
>>>
>>> That may be impossible. Float type is not exact and the conversion
>>> will be the closest binary representation of your decimal number.
>>> It will be very close but it may be slightly different when you
>>> print it, for example. (You can usually deal with that by using
>>> string formatting features.)
>>>
>>> Another option is to use the decimal numeric type. That has other
>>> compromises associated with it but, if retaining absolute decimal
>>> accuracy is your primary goal, it might suit you better.
>>>
>>>
>>> -- 
>>> 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 wlfraed at ix.netcom.com  Sun Dec 18 11:07:18 2022
From: wlfraed at ix.netcom.com (Dennis Lee Bieber)
Date: Sun, 18 Dec 2022 11:07:18 -0500
Subject: Single line if statement with a continue
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
Message-ID: <cbeuph57qc2u30a5l4pk2ij8t9l3cno9le@4ax.com>

On Wed, 14 Dec 2022 10:53:10 -0800 (PST), Aaron P
<transreductionist at gmail.com> declaimed the following:

	Late response here, and the concept may have been covered in
skimmed-over posts..

>I occasionally run across something like:
>
>for idx, thing in enumerate(things):
>    if idx == 103: 
>        continue
>    do_something_with(thing)
>

	For this example, I'd probably reverse the condition.

	if idx != 103:
		do_something_with(thing)

and hence completely drop the "continue" -- after all, if idx is 103, the
if statement falls through, and the end of the loop acts as an implicit
"continue"

	OTOH: if the "if/continue" is buried in four or five layers of
conditionals, it could be cleaner than trying to configure the conditionals
to have a chained exit.


-- 
	Wulfraed                 Dennis Lee Bieber         AF6VN
	wlfraed at ix.netcom.com    http://wlfraed.microdiversity.freeddns.org/

From songbird at anthive.com  Sun Dec 18 10:44:18 2022
From: songbird at anthive.com (songbird)
Date: Sun, 18 Dec 2022 10:44:18 -0500
Subject: Keeping a list of records with named fields that can be updated
References: <6gip6j-698.ln1@anthive.com>
 <9158537c-f561-e666-f60c-34d50f61d7b7@web.de>
 <mailman.1175.1671096336.20444.python-list@python.org>
Message-ID: <i3p37j-5c2.ln1@anthive.com>

Peter Otten wrote:
...
> While I think what you need is a database instead of the collection of
> csv files the way to alter namedtuples is to create  a new one:
>
> >>> from collections import namedtuple
> >>> Row = namedtuple("Row", "foo bar baz")
> >>> row = Row(1, 2, 3)
> >>> row._replace(bar=42)
> Row(foo=1, bar=42, baz=3)

  namedtuple is easier to use as that will use the csv and
csvreader and create the records without me having to do any
conversion or direct handling myself.  it's all automagically
done.  my initial version works, but i'd like it to be a bit
more elegant and handle descriptions it hasn't seen before
in a more robust manner.


> An alternative would be dataclasses where basic usage is just as easy:
>
> >>> from dataclasses import make_dataclass
> >>> Row = make_dataclass("Row", "foo bar baz".split())
> >>> row = Row(1, 2, 3)
> >>> row
> Row(foo=1, bar=2, baz=3)
> >>> row.bar = 42
> >>> row
> Row(foo=1, bar=42, baz=3)

  i do like that i can directly reference each field in a
dataclass and not have to specify a _replace for each change.

  is there an easy way to convert from namedtuple to dataclass?
i can see there is a _asdict converter, but don't really like
how that turns out as then i have to do a bunch of:
    rec['fieldname'] = blah

rec.fieldname is much easier to understand.


  songbird

From bowman at montana.com  Sun Dec 18 12:19:56 2022
From: bowman at montana.com (rbowman)
Date: 18 Dec 2022 17:19:56 GMT
Subject: String to Float, without introducing errors
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
 <CAPTjJmofPSNV9kWZST151+9PFK3NTYtotRO2OgzANGN88JqnKA@mail.gmail.com>
 <639e32de.020a0220.7add7.2f5b@mx.google.com>
 <mailman.1210.1671312099.20444.python-list@python.org>
 <float-20221217225423@ram.dialup.fu-berlin.de>
 <gueuph59r82gr8tc1scaubrfaugi18k8qu@4ax.com>
Message-ID: <k090drFk31qU1@mid.individual.net>

On Sun, 18 Dec 2022 11:14:28 -0500, Dennis Lee Bieber wrote:

> .. And maybe lament the days when a 3-digit result was acceptable in
> math class -- being the typical capability in reading a standard (10"
> scale) slide rule.

Arguably more thought was given to what those three digits meant in the 
real world. For example, is calculating a latitude to 6 decimal places 
meaningful when the data was gathered by a GPS receiver with 5m accuracy? 

From email at paulstgeorge.com  Sun Dec 18 12:35:47 2022
From: email at paulstgeorge.com (Paul St George)
Date: Sun, 18 Dec 2022 18:35:47 +0100
Subject: String to Float, without introducing errors
Message-ID: <414BA74A-525D-4923-A435-47DB61F78979@paulstgeorge.com>

So I am working on a physics paper with a colleague. We have a theory about Newtons Cradle. We answer the question why when you lift and drop balls 1 and 2, balls 4 and 5 rise up. I could say more, but ... (if you are interested please write to me).

We want to illustrate the paper with animations. The theory includes distortion of the balls and this distortion is very very small. So, I am sent data with locations and dimensions to 13 decimal places. Something strange is happening with the animations: the balls are not moving smoothly. I do not know (yet) where the problem lies so it is difficult to provide a clear narrative.

Because there is a problem, I am investigating in all areas. This brings me to the question I asked here. I am not expecting six decimal places or three decimal places to be as accurate as thirteen decimal places, but I would like to be in control of or fully aware of what goes on under the bonnet.


?




 
>> On 17 Dec 2022, at 16:54:05 EST 2022, Thomas Passin wrote:
On 12/17/2022 3:45 PM, Paul St George wrote:
> Thanks to all!
> It was the rounding rounding error that I needed to avoid (as Peter J. Holzer suggested). The use of decimal solved it and just in time. I was about to truncate the number, get each of the characters from the string mantissa, and then do something like this:
> 
> 64550.727
> 
> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
> 
> Now I do not need to!

And that approach would not have helped you, because each of those 
calculations would be done as floating point, and you wouldn't have 
gotten any more precision (and maybe less) than simply doing 
float('64550.727').

Here is a small but interesting discussion thread about float vs Decimal:

https://stackoverflow.com/questions/32053647/comparing-python-decimals-created-from-float-and-string

Would you mind telling us why that degree of precision (that is, decimal 
vs float) matters for your problem?


>> On 17 Dec 2022, at 13:11, Alan Gauld <learn2program at gmail.com <https://mail.python.org/mailman/listinfo/python-list>> wrote:
>>
>> On 17/12/2022 11:51, Paul St George wrote:
>>> I have a large/long array of numbers in an external file. The numbers look like this:
>>>
>>> -64550.727
>>> -64511.489
>>> -64393.637
>>> -64196.763
>>> -63920.2
>>
>>> When I bring the numbers into my code, they are Strings. To use the
>>> numbers in my code, I want to change the Strings to Float type
>>> because the code will not work with Strings but I do not want
>>> to change the numbers in any other way.
>>
>> That may be impossible. Float type is not exact and the conversion
>> will be the closest binary representation of your decimal number.
>> It will be very close but it may be slightly different when you
>> print it, for example. (You can usually deal with that by using
>> string formatting features.)
>>
>> Another option is to use the decimal numeric type. That has other
>> compromises associated with it but, if retaining absolute decimal
>> accuracy is your primary goal, it might suit you better.
>>
>>
>> -- 
>> 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 c.buhtz at posteo.jp  Sun Dec 18 16:07:38 2022
From: c.buhtz at posteo.jp (c.buhtz at posteo.jp)
Date: Sun, 18 Dec 2022 21:07:38 +0000
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>
Message-ID: <f886ccff4e3b451827636c3f6c0db264@posteo.de>

Dear Chris,

thank you for your reply.

Am 18.12.2022 20:27 schrieb Chris Angelico:
> Does it have to be in path? Can't you say
> /usr/local/bin/entrypointname? Not sure what constitutes an elegant
> solution here.

I asked that myself. My current solution do determine the full path of 
the entrypoint via "which entrypoint".
I also think this is to my current knowledge the best solution.

From barry at barrys-emacs.org  Sun Dec 18 16:33:22 2022
From: barry at barrys-emacs.org (Barry)
Date: Sun, 18 Dec 2022 21:33:22 +0000
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
Message-ID: <53296433-ED16-42C4-8F97-4408A8D6061E@barrys-emacs.org>



> On 18 Dec 2022, at 17:57, c.buhtz at posteo.jp wrote:
> 
> ?Hello,
> 
> when I install a package on a GNU/Linux system via "sudo python3 -m pip
> install -e ." that defines entry points in its pyproject.toml the entry
> point starter scripts are located in /usr/locale/bin.
> 
> That folder is in PATH for "regular" root users and by "sudo su" roots
> users.
> 
> But I need to start that entry points via "pkexec".
> But in the environment started by "pkexec" the PATH does not contain
> /usr/local/bin.
> 
> So what can I do?


Why are asking on this list and discuss.python.org?
Lots of people on this list are also on discuss.python.org.

Barry
> 
> I don't need a hack or workaround but an "elegant" solution.
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From mats at wichmann.us  Sun Dec 18 16:37:07 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Sun, 18 Dec 2022 14:37:07 -0700
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <f886ccff4e3b451827636c3f6c0db264@posteo.de>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>
 <f886ccff4e3b451827636c3f6c0db264@posteo.de>
Message-ID: <a9bb81c0-6cba-91ad-aa60-8354b6505928@wichmann.us>

On 12/18/22 14:07, c.buhtz at posteo.jp wrote:
> Dear Chris,
> 
> thank you for your reply.
> 
> Am 18.12.2022 20:27 schrieb Chris Angelico:
>> Does it have to be in path? Can't you say
>> /usr/local/bin/entrypointname? Not sure what constitutes an elegant
>> solution here.
> 
> I asked that myself. My current solution do determine the full path of 
> the entrypoint via "which entrypoint".
> I also think this is to my current knowledge the best solution.

the which command uses your PATH, so I'm not sure you're buying anything 
new there....


From PythonList at DancesWithMice.info  Sun Dec 18 16:45:34 2022
From: PythonList at DancesWithMice.info (dn)
Date: Mon, 19 Dec 2022 10:45:34 +1300
Subject: String to Float, without introducing errors
In-Reply-To: <float-20221217225423@ram.dialup.fu-berlin.de>
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
 <CAPTjJmofPSNV9kWZST151+9PFK3NTYtotRO2OgzANGN88JqnKA@mail.gmail.com>
 <639e32de.020a0220.7add7.2f5b@mx.google.com>
 <mailman.1210.1671312099.20444.python-list@python.org>
 <float-20221217225423@ram.dialup.fu-berlin.de>
Message-ID: <f34dbec7-658c-f57d-be87-3a28f3f76cad@DancesWithMice.info>

On 18/12/2022 10.55, Stefan Ram wrote:
> Grant Edwards <grant.b.edwards at gmail.com> writes:
>> Yes, fixed point (or decimal) is a better fit for what he's doing. but
>> I suspect that floating point would be a better fit for the problem
>> he's trying to solve.
> 
>    I'd like to predict that within the next ten posts in this
>    thread someone will mention "What Every Computer Scientist
>    Should Know About Floating-Point Arithmetic".


Thank you for doing-so.

More specific: https://docs.python.org/3/tutorial/floatingpoint.html


Perhaps in the rush to 'answer', the joke is on 'us' - that we might 
first need to more carefully-understand the OP's use-case, requirements, 
and constraints?


The joke sours when remembering that this 'mystery' generates frequent 
questions 'here' (and on other Python fora) - not as many as 'why don't 
I see a pretty-GUI when I fire-up Python on MS-Windows?' but it is a 
more sophisticated realisation and deserves a detailed response (such as 
the thought-provoking illustration-code appearing today).


Is it a consequence of Python lowering 'the barrier to entry'? Good 
thing? Bad thing?

(we first started noticing this sort of issue in our (non-Python) MOOCs, 
several pre-COVID years ago: when we first started, the trainee was 
typically recent post-grad; whereas today we enrol folk with a much 
wider range of ages and backgrounds. It is likely that more dev.work has 
gone into 'the bottom end', than into new/higher sophistications - even 
given IT's rate-of-change!)

-- 
-- 
Regards,
=dn

From cs at cskk.id.au  Sun Dec 18 16:53:56 2022
From: cs at cskk.id.au (Cameron Simpson)
Date: Mon, 19 Dec 2022 08:53:56 +1100
Subject: String to Float, without introducing errors
In-Reply-To: <414BA74A-525D-4923-A435-47DB61F78979@paulstgeorge.com>
References: <414BA74A-525D-4923-A435-47DB61F78979@paulstgeorge.com>
Message-ID: <Y5+L9DQVO7x2DDyS@cskk.homeip.net>

On 18Dec2022 18:35, Paul St George <email at paulstgeorge.com> wrote:
>So I am working on a physics paper with a colleague. We have a theory about Newtons Cradle. We answer the question why when you lift and drop balls 1 and 2, balls 4 and 5 rise up. I could say more, but ... (if you are interested please write to me).
>
>We want to illustrate the paper with animations. The theory includes distortion of the balls and this distortion is very very small. So, I am sent data with locations and dimensions to 13 decimal places. Something strange is happening with the animations: the balls are not moving smoothly. I do not know (yet) where the problem lies so it is difficult to provide a clear narrative.
>
>Because there is a problem, I am investigating in all areas. This brings me to the question I asked here. I am not expecting six decimal places or three decimal places to be as accurate as thirteen decimal places, but I would like to be in control of or fully aware of what goes on under the bonnet.

First the short take: your machine pobably is quite precise, and float 
is far more performant that the other numeric types available. Your 
source data seem to have more round off than the rounding in a float.

Under the bonnet:

A Python float is effectively a base-2 value in scientific notation.  
Internally it has a base-2 mantissa and base-2 exponent. This page:
https://docs.python.org/3/library/stdtypes.html#typesnumeric
says that CPython's float uses C's "double" floating point type
(you are almost certainly using the CPython implementation) and thus 
you're using the machine's floating point implemenetation.

I believe that almost all modern CPUs implement IEEE 754 floating point:
https://en.wikipedia.org/wiki/IEEE_754

Because they're base 2, various values in other bases will not be 
precisely representable as a float. For example, 1/3 (which you will 
know is _also_ not representable precisely as a base-10 value such as 
0.333).

You can get specifics of your Python's floating point from 
`sys.float_Info`, i.e:

     from sys import float_info

The look at float_info.epsilon etc. Details:
https://docs.python.org/3/library/sys.html#sys.float_info

Here's my machine:

     Python 3.10.6 (main, Aug 11 2022, 13:47:18) [Clang 12.0.0 
     (clang-1200.0.32.29)] on darwin
     Type "help", "copyright", "credits" or "license" for more 
     information.
     >>> from sys import float_info
     >>> float_info
     sys.float_info(max=1.7976931348623157e+308, max_exp=1024, 
     max_10_exp=308, min=2.2250738585072014e-308, min_exp=-1021, 
     min_10_exp=-307, dig=15, mant_dig=53, epsilon=2.220446049250313e-16, 
     radix=2, rounds=1)

Values of note: mant_dig=53 (53 base-2 bits), dig=15 (15 decimal digits 
of precision).

You might want to look at sys.float_repr_style here:
https://docs.python.org/3/library/sys.html#sys.float_repr_style
which affects how Python writes floats out. In particular this text:

      If the string has value 'short' then for a finite float x, repr(x) 
      aims to produce a short string with the property that 
      float(repr(x)) == x. This is the usual behaviour in Python 3.1 and 
      later.

Again, on my machine:

     >>> 64550.727
     64550.727
     >>> 64550.728
     64550.728
     >>> 64550.72701
     64550.72701
     >>> 64550.7270101
     64550.7270101
     >>> 64550.727010101
     64550.727010101
     >>> 64550.72701010101
     64550.72701010101
     >>> 64550.7270101010101
     64550.72701010101
     >>> 64550.727010101010101
     64550.72701010101
     >>> 64550.72701010101010101
     64550.72701010101

>>> On 17 Dec 2022, at 16:54:05 EST 2022, Thomas Passin wrote:
>On 12/17/2022 3:45 PM, Paul St George wrote:
>> Thanks to all!
>> It was the rounding rounding error that I needed to avoid (as Peter J. Holzer suggested). The use of decimal solved it and just in time. I was about to truncate the number, get each of the characters from the string mantissa, and then do something like this:
>>
>> 64550.727
>>
>> 64550 + (7 * 0.1) + (2 * 0.01) + (7 * 0.001)
>>
>> Now I do not need to!

Good, because if you do that using floats it will be less precise than 
float(64550.727). (Which I see Alan has already stated.)

Your source file contains strings like "64550.727". They look to already 
be less than 13 digits of precision as written i.e. some round off 
already took place when that file was written. Do you know the precision 
of the source data?

I suspect that rather than chasing a "perfect" representation of your 
source data, which is already rounded off, you:
- see if the source values can be obtained more precisely
- figure out which operations in your simulation contribute to the 
   motion roughness you see

I'm no expert on floating point coding for precision, but I believe that 
trying to work with values "close together" in magnitude is important 
because values of different scales inherently convert one of them to the 
other scale (i.e. similar sized exponent part) with corresponding loss 
of precision in the mantissa part. That may require you to form your 
calcutations carefully.

See if you can locate a source for the jerkiness (by printing 
intermediate results) and then maybe rephrase that step?

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

From rosuav at gmail.com  Sun Dec 18 17:25:17 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Dec 2022 09:25:17 +1100
Subject: String to Float, without introducing errors
In-Reply-To: <precision-20221218212316@ram.dialup.fu-berlin.de>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
Message-ID: <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>

On Mon, 19 Dec 2022 at 07:57, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> G = Decimal( 6.6743015E-11 )
> r = Decimal( 6.371E6 )
> M = Decimal( 5.9722E24 )

What's the point of using Decimal if you start with nothing more than
float accuracy?

ChrisA

From guinness.tony at gmail.com  Sun Dec 18 16:27:52 2022
From: guinness.tony at gmail.com (Tony Oliver)
Date: Sun, 18 Dec 2022 13:27:52 -0800 (PST)
Subject: Single line if statement with a continue
In-Reply-To: <mailman.1220.1671321471.20444.python-list@python.org>
References: <AQJI2jgjpoZjOo45TmZxO3GBPwt80gLd5Qc0AIkvxEStd+t1gA==>
 <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <CAPTjJmp7itCdQQ76UQttWg_A8f5Y=NHnSBe_t_BFWXiQEP0nUw@mail.gmail.com>
 <006801d91273$5cfffe80$16fffb80$@gmail.com>
 <4f21e136-dbec-3aed-60e2-c3908bebce71@btinternet.com>
 <mailman.1220.1671321471.20444.python-list@python.org>
Message-ID: <d14e4dc6-d785-4d3b-adb5-1be673bc93d7n@googlegroups.com>

On Saturday, 17 December 2022 at 23:58:11 UTC, avi.e... at gmail.com wrote:
> Is something sort of taboo when using something like a computer language to write a program?

With what else would you write a program?

From greg.ewing at canterbury.ac.nz  Sun Dec 18 16:35:39 2022
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 19 Dec 2022 10:35:39 +1300
Subject: String to Float, without introducing errors
In-Reply-To: <mailman.1235.1671396293.20444.python-list@python.org>
References: <414BA74A-525D-4923-A435-47DB61F78979@paulstgeorge.com>
 <mailman.1235.1671396293.20444.python-list@python.org>
Message-ID: <95fed732-8a8f-eb55-8e82-3061fd2d8359@canterbury.ac.nz>

On 19/12/22 6:35 am, Paul St George wrote:
> So I am working on a physics paper with a colleague. We have a theory about Newtons Cradle.
> 
> We want to illustrate the paper with animations.
> 
> Because there is a problem, I am investigating in all areas. ... I would like to be in control of or fully aware of what goes on under the bonnet.

When you convert a string to a float, you're already getting the closest
possible value in binary floating point.

For things like physics simulations, you need to design your algorithms
so that they're tolerant of small inaccuracies in the representation of
your numbers. If those are causing you problems, it sounds like there
is some kind of numerical instability in your algorithm that needs to
be addressed.

It's also possible that there is just a bug somewhere in your code, and
the problem really has nothing to do with floating point inaccuracies.

If you can post some code we might be able to help you further.

-- 
Greg

From cs at cskk.id.au  Sun Dec 18 19:41:13 2022
From: cs at cskk.id.au (Cameron Simpson)
Date: Mon, 19 Dec 2022 11:41:13 +1100
Subject: String to Float, without introducing errors
In-Reply-To: <Y5+L9DQVO7x2DDyS@cskk.homeip.net>
References: <Y5+L9DQVO7x2DDyS@cskk.homeip.net>
Message-ID: <Y5+zKfgd31eJkGrB@cskk.homeip.net>

On 19Dec2022 08:53, Cameron Simpson <cs at cskk.id.au> wrote:
>I'm no expert on floating point coding for precision, but I believe 
>that trying to work with values "close together" in magnitude is 
>important because values of different scales inherently convert one of 
>them to the other scale (i.e. similar sized exponent part) with 
>corresponding loss of precision in the mantissa part. That may require 
>you to form your calcutations carefully.

This depends on the operation. With addition/subtraction you'd see this 
directly. With multiplication etc it isn't really the case. But there 
are both more and less effective ways to arrange your floating point 
math in terms of preserving what precision you have.

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

From c.buhtz at posteo.jp  Mon Dec 19 01:29:10 2022
From: c.buhtz at posteo.jp (c.buhtz at posteo.jp)
Date: Mon, 19 Dec 2022 06:29:10 +0000
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <a9bb81c0-6cba-91ad-aa60-8354b6505928@wichmann.us>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>
 <f886ccff4e3b451827636c3f6c0db264@posteo.de>
 <a9bb81c0-6cba-91ad-aa60-8354b6505928@wichmann.us>
Message-ID: <8dab758ebb1071c7854bf4e714d76450@posteo.de>

Am 18.12.2022 22:37 schrieb Mats Wichmann:
> the which command uses your PATH, so I'm not sure you're buying
> anything new there....

I'm using which before entering pkexec. ;)

I'll show a demonstrator project later.

From c.buhtz at posteo.jp  Mon Dec 19 01:36:49 2022
From: c.buhtz at posteo.jp (c.buhtz at posteo.jp)
Date: Mon, 19 Dec 2022 06:36:49 +0000
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <53296433-ED16-42C4-8F97-4408A8D6061E@barrys-emacs.org>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <53296433-ED16-42C4-8F97-4408A8D6061E@barrys-emacs.org>
Message-ID: <d8a2651b3453bd8a0a9b826a99f61a18@posteo.de>

Dear Barry,
thanks for reply and asking back.

Am 18.12.2022 22:33 schrieb Barry:
> Why are asking on this list and discuss.python.org?

To be exact I'm asking in the "Packaging" section of 
"discuss.python.org". To my knowledge that section is the official 
channel of "pypa/pip" project pointed to from there own README.md [1].
To be complete. I also asked in in context of "pypa/setuptools" [2] and 
on the debian-python mailing list.

Not all questions are exactly the same but touching the same meta topic.
"pypa/setuptools" themselfs pointed me to the fact that they are not 
responsible for generating the entry-point-scripts but "pypa/pip" is. No 
matter both have "pypa/" in their names they seem technically different. 
This has reasons but is very confusing for "developers from the outside" 
like me. There are also alternative build-tools other then "setuptools". 
That is why I asked on that python-list here, too. The later was in the 
hope to maybe be pointed to alternative solutions away from setuptools 
and/or pip.

My apologize. When I decide for a solution I will point you to a 
demonstrator repository illustrating that solution.

[1] -- <https://github.com/pypa/pip#readme>
[2] -- <https://github.com/pypa/setuptools/discussions/3729>

From rosuav at gmail.com  Mon Dec 19 01:40:52 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Dec 2022 17:40:52 +1100
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <8dab758ebb1071c7854bf4e714d76450@posteo.de>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>
 <f886ccff4e3b451827636c3f6c0db264@posteo.de>
 <a9bb81c0-6cba-91ad-aa60-8354b6505928@wichmann.us>
 <8dab758ebb1071c7854bf4e714d76450@posteo.de>
Message-ID: <CAPTjJmp=hVm=q64SetJQQ+AdE9ZGbhgnpEE3wVLVouu++bVK1g@mail.gmail.com>

On Mon, 19 Dec 2022 at 17:30, <c.buhtz at posteo.jp> wrote:
>
> Am 18.12.2022 22:37 schrieb Mats Wichmann:
> > the which command uses your PATH, so I'm not sure you're buying
> > anything new there....
>
> I'm using which before entering pkexec. ;)
>
> I'll show a demonstrator project later.

Hmm, then I'm not sure what you're *losing* here. The problem, as I
understand it, is that the scripts are getting installed into
/usr/local/bin (which is on PATH at the time they're installed), but
pkexec has a restricted PATH. So if you use which before pkexec'ing,
wouldn't you find the scripts, and then be able to run them without
regard to PATH?

ChrisA

From c.buhtz at posteo.jp  Mon Dec 19 03:36:34 2022
From: c.buhtz at posteo.jp (c.buhtz at posteo.jp)
Date: Mon, 19 Dec 2022 08:36:34 +0000
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <CAPTjJmp=hVm=q64SetJQQ+AdE9ZGbhgnpEE3wVLVouu++bVK1g@mail.gmail.com>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>
 <f886ccff4e3b451827636c3f6c0db264@posteo.de>
 <a9bb81c0-6cba-91ad-aa60-8354b6505928@wichmann.us>
 <8dab758ebb1071c7854bf4e714d76450@posteo.de>
 <CAPTjJmp=hVm=q64SetJQQ+AdE9ZGbhgnpEE3wVLVouu++bVK1g@mail.gmail.com>
Message-ID: <ea8075e7ee2c907ebdf932934c20f0e3@posteo.de>

Dear Chris,
thanks for asking back and my apologize for being to broad in my way of 
asking (in a foreign language).

Am 19.12.2022 07:40 schrieb Chris Angelico:
> Hmm, then I'm not sure what you're *losing* here. The problem, as I
> understand it, is that the scripts are getting installed into
> /usr/local/bin (which is on PATH at the time they're installed), but
> pkexec has a restricted PATH. So if you use which before pkexec'ing,
> wouldn't you find the scripts, and then be able to run them without
> regard to PATH?

Absolut correct. This works.

The question is if this is a "good" or "elegant" way from the viewpoint 
of different communities/projects (e.g. Python, setuptools, pip, other 
build-systems, distros, something I forgot).

I assume that I'm not the first person with such a use case. So there 
could be solutions out there. Maybe they are standardized solutions out 
there; e.g. a magic feature of setuptools or pip I haven't noticed yet.

From rosuav at gmail.com  Mon Dec 19 06:17:26 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Mon, 19 Dec 2022 22:17:26 +1100
Subject: pip/setuptools: Entry points not visible from
 pkexec-root-environment
In-Reply-To: <ea8075e7ee2c907ebdf932934c20f0e3@posteo.de>
References: <4NZn7V1JFkz6tpJ@submission01.posteo.de>
 <CAPTjJmpvAXUqFw+mso6VD6OQCeUMh2Gou8mmfbdeBs63yfi0Gg@mail.gmail.com>
 <f886ccff4e3b451827636c3f6c0db264@posteo.de>
 <a9bb81c0-6cba-91ad-aa60-8354b6505928@wichmann.us>
 <8dab758ebb1071c7854bf4e714d76450@posteo.de>
 <CAPTjJmp=hVm=q64SetJQQ+AdE9ZGbhgnpEE3wVLVouu++bVK1g@mail.gmail.com>
 <ea8075e7ee2c907ebdf932934c20f0e3@posteo.de>
Message-ID: <CAPTjJmqMjJ386Q5jcJ2v4kTGXoN3Xp_yho-Bkuum+7W_a0E3iA@mail.gmail.com>

On Mon, 19 Dec 2022 at 19:38, <c.buhtz at posteo.jp> wrote:
>
> Dear Chris,
> thanks for asking back and my apologize for being to broad in my way of
> asking (in a foreign language).
>
> Am 19.12.2022 07:40 schrieb Chris Angelico:
> > Hmm, then I'm not sure what you're *losing* here. The problem, as I
> > understand it, is that the scripts are getting installed into
> > /usr/local/bin (which is on PATH at the time they're installed), but
> > pkexec has a restricted PATH. So if you use which before pkexec'ing,
> > wouldn't you find the scripts, and then be able to run them without
> > regard to PATH?
>
> Absolut correct. This works.
>
> The question is if this is a "good" or "elegant" way from the viewpoint
> of different communities/projects (e.g. Python, setuptools, pip, other
> build-systems, distros, something I forgot).
>

Ah! Then, my response is: Yes, it is definitely a good/elegant
solution. I've often created scripts that install into somewhere (eg
systemd, cron, ifupdown) by using 'which' to figure something out, and
then posting the full path into the corresponding file. It's a
convenient way to ensure that the exact same program would be used.

Notably, "which python3" will ensure that you run on the
currently-active Python interpreter; this includes virtual
environments. Very convenient.

ChrisA

From hjp-python at hjp.at  Mon Dec 19 07:01:41 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 19 Dec 2022 13:01:41 +0100
Subject: Single line if statement with a continue
In-Reply-To: <loop-20221218174906@ram.dialup.fu-berlin.de>
References: <af8635f1-30b9-4a0b-b9f8-d81f2c54960an@googlegroups.com>
 <cbeuph57qc2u30a5l4pk2ij8t9l3cno9le@4ax.com>
 <loop-20221218174906@ram.dialup.fu-berlin.de>
Message-ID: <20221219120141.4geegs2aq4or37b3@hjp.at>

On 2022-12-18 16:49:27 +0000, Stefan Ram wrote:
> Dennis Lee Bieber <wlfraed at ix.netcom.com> writes:
> >>for idx, thing in enumerate(things):
> >>    if idx == 103: 
> >>        continue
> >>    do_something_with(thing)
> >>
> >	For this example, I'd probably reverse the condition.
> >	if idx != 103:
> >		do_something_with(thing)
> 
>   The first four lines of the quotation above cannot be a
>   complete program as "do_something_with" is not defined
>   therein, so they must be part of a larger program.
>   If, in this larger program, something still follows
>   "do_something_with(thing)" in the loop, the new program
>   after the transformation might not show the same behavior.

?do_something_with(thing)? is obviously not intended to be a single
function call but as a shorthand for ?one or more lines of code which do
something with `thing`?. So there is nothing after it because it is
included in it.

That said, the "fail and bail" technique is often more readable than
putting the main incode inside of an if - especially if that code is
long and/or it is guarded by multiple conditions.

        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 hjp-python at hjp.at  Mon Dec 19 09:10:52 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 19 Dec 2022 15:10:52 +0100
Subject: String to Float, without introducing errors
In-Reply-To: <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
 <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>
Message-ID: <20221219141052.frflz6y2n6md7uvj@hjp.at>

On 2022-12-19 09:25:17 +1100, Chris Angelico wrote:
> On Mon, 19 Dec 2022 at 07:57, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> > G = Decimal( 6.6743015E-11 )
> > r = Decimal( 6.371E6 )
> > M = Decimal( 5.9722E24 )
> 
> What's the point of using Decimal if you start with nothing more than
> float accuracy?

Right. He also interpreted the notation "6.67430(15)E-11" wrong. The
digits in parentheses represent the uncertainty in the same number of
last digits. So "6.67430(15)E-11" means "something between 6.67430E-11 -
0.00015E-11 and 6.67430E-11 + 0.00015E-11". The r value has only a
precision of 1 km and I'm not sure how accurate the mass is. Let's just
assume (for the sake of the argument) that these are actually accurate in
all given digits.

So G is between 6.67415E-11 and 6.67445E-11, r is between 6.3705E6 and
6.3715E6 and M is between 5.97215E24 and 5.97225E24. If we compute the
time for those deviations you will find that the differences are many
orders of magnitude greater than the effect you wanted to show. And that
still ignores the fact that a vacuum won't be perfect (and collisions
with a few stray atoms might have a similarly tiny effect), that gravity
isn't constant while the weight falls (it's getting closer to the center
of the earth and it's moving past other masses on its way) that Newton's
law is only an approximation, etc. So while the effect is (almost
certainly) real, the numbers are garbage.

I think there's a basic numeracy problem here. This is unfortunately all
too common, even among scientists. The OP apparently rounded their
numbers to 8 significant digits (thereby introducing an error of about
1E-8) and then insisted that the additional error of 1E-15 introduced by
the decimal to float conversion was unacceptable, showing IMHO a
fundamental misunderstanding of the numbers they are working with.

        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 gweatherby at uchc.edu  Mon Dec 19 09:59:20 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Mon, 19 Dec 2022 14:59:20 +0000
Subject: Installation hell
In-Reply-To: <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
Message-ID: <SA1PR14MB5855F356810C84A910A571DDB9E59@SA1PR14MB5855.namprd14.prod.outlook.com>

Personally, I don?t use Windows and avoid it like the plague.  Python is easy to install on Linux and Mac.

I?d start here: https://learn.microsoft.com/en-us/visualstudio/python/overview-of-python-tools-for-visual-studio?view=vs-2022

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jim Lewis <jimdaniellewis at gmail.com>
Date: Sunday, December 18, 2022 at 12:56 PM
To: Python-list at python.org <Python-list at python.org>
Subject: Fwd: Installation hell
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

I'm an occasional user of Python and have a degree in computer science.
Almost every freaking time I use Python, I go through PSH (Python Setup
Hell). Sometimes a wrong version is installed. Sometimes it's a path issue.
Or exe naming confusion: python, python3, phthon311, etc. Or library
compatibility issues - took an hour to find out that pygame does not work
with the current version of python. Then the kludgy PIP app and using a DOS
box under Windows with command prompts which is ridiculous. God only knows
how many novice users of the language (or even intermediate users) were
lost in the setup process. Why not clean the infrastructure up and make a
modern environment or IDE or something better than it is now. Or at least
good error messages that explain exactly what to do. Even getting this
email to the list took numerous steps.

-- A frustrated user
--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$>

From list1 at tompassin.net  Mon Dec 19 10:02:46 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 10:02:46 -0500
Subject: String to Float, without introducing errors
In-Reply-To: <20221219141052.frflz6y2n6md7uvj@hjp.at>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
 <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>
 <20221219141052.frflz6y2n6md7uvj@hjp.at>
Message-ID: <c18586b8-6228-3f33-b2a7-cecdb7c3585d@tompassin.net>

On 12/19/2022 9:10 AM, Peter J. Holzer wrote:
> On 2022-12-19 09:25:17 +1100, Chris Angelico wrote:
>> On Mon, 19 Dec 2022 at 07:57, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>>> G = Decimal( 6.6743015E-11 )
>>> r = Decimal( 6.371E6 )
>>> M = Decimal( 5.9722E24 )
>>
>> What's the point of using Decimal if you start with nothing more than
>> float accuracy?
> 
> Right. He also interpreted the notation "6.67430(15)E-11" wrong. The
> digits in parentheses represent the uncertainty in the same number of
> last digits. So "6.67430(15)E-11" means "something between 6.67430E-11 -
> 0.00015E-11 and 6.67430E-11 + 0.00015E-11". The r value has only a
> precision of 1 km and I'm not sure how accurate the mass is. Let's just
> assume (for the sake of the argument) that these are actually accurate in
> all given digits.
> 
> So G is between 6.67415E-11 and 6.67445E-11, r is between 6.3705E6 and
> 6.3715E6 and M is between 5.97215E24 and 5.97225E24. If we compute the
> time for those deviations you will find that the differences are many
> orders of magnitude greater than the effect you wanted to show. And that
> still ignores the fact that a vacuum won't be perfect (and collisions
> with a few stray atoms might have a similarly tiny effect), that gravity
> isn't constant while the weight falls (it's getting closer to the center
> of the earth and it's moving past other masses on its way) that Newton's
> law is only an approximation, etc. So while the effect is (almost
> certainly) real, the numbers are garbage.
> 
> I think there's a basic numeracy problem here. This is unfortunately all
> too common, even among scientists. The OP apparently rounded their
> numbers to 8 significant digits (thereby introducing an error of about
> 1E-8) and then insisted that the additional error of 1E-15 introduced by
> the decimal to float conversion was unacceptable, showing IMHO a
> fundamental misunderstanding of the numbers they are working with.
> 
>          hp

In a way, this example shows both things - the potential value of using 
Decimal numbers, and a degree of innumeracy.  It also misses a chance to 
illustrate how to approach a problem in the simplest and most 
informative way.  Here's what I mean -

We can imagine that the input numbers really are exact, with the 
remaining digits filled in with zeros.  Then it might really be the case 
that - if you wanted to do this computation with precision and could 
assume all those other effects could be neglected - using Decimals would 
be a good thing to do. So OK, let's say that's demonstrated.  No need to 
nit-pick it further.

As a physics problem, though, you would generally be interested in two 
kinds of things:

1. Could there be such an effect, and if so would it be large enough to 
be interesting, whether in theory or in practice?
2. Can there be any feasible way to demonstrate the proposed effect by 
measurements?

The first thing one should do is to find a way to estimate the magnitude 
of the effect so it can be compared with some of those other phenomena 
(non-constant gravity, etc) to see if it's worth doing a full 
computation at all, or even spending any more time on the matter.  There 
is likely to be a way to make such an estimate without needing to resort 
to extremely high precision - you would only need to get within perhaps 
an order of magnitude.  Your real task, then, is to find that way.

For example, you would probably be able to estimate the precision needed 
without actually doing the calculation.  That in itself might turn out 
to enough.




From python at mrabarnett.plus.com  Mon Dec 19 10:14:14 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Mon, 19 Dec 2022 15:14:14 +0000
Subject: String to Float, without introducing errors
In-Reply-To: <20221219141052.frflz6y2n6md7uvj@hjp.at>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
 <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>
 <20221219141052.frflz6y2n6md7uvj@hjp.at>
Message-ID: <d46a7e91-77fe-8883-eae0-237642d5df36@mrabarnett.plus.com>

On 2022-12-19 14:10, Peter J. Holzer wrote:
> On 2022-12-19 09:25:17 +1100, Chris Angelico wrote:
>> On Mon, 19 Dec 2022 at 07:57, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>> > G = Decimal( 6.6743015E-11 )
>> > r = Decimal( 6.371E6 )
>> > M = Decimal( 5.9722E24 )
>> 
>> What's the point of using Decimal if you start with nothing more than
>> float accuracy?
> 
> Right. He also interpreted the notation "6.67430(15)E-11" wrong. The
> digits in parentheses represent the uncertainty in the same number of
> last digits. So "6.67430(15)E-11" means "something between 6.67430E-11 -
> 0.00015E-11 and 6.67430E-11 + 0.00015E-11". The r value has only a
> precision of 1 km and I'm not sure how accurate the mass is. Let's just
> assume (for the sake of the argument) that these are actually accurate in
> all given digits.
> 
> So G is between 6.67415E-11 and 6.67445E-11, r is between 6.3705E6 and
> 6.3715E6 and M is between 5.97215E24 and 5.97225E24. If we compute the
> time for those deviations you will find that the differences are many
> orders of magnitude greater than the effect you wanted to show. And that
> still ignores the fact that a vacuum won't be perfect (and collisions
> with a few stray atoms might have a similarly tiny effect), that gravity
> isn't constant while the weight falls (it's getting closer to the center
> of the earth and it's moving past other masses on its way) that Newton's
> law is only an approximation, etc. So while the effect is (almost
> certainly) real, the numbers are garbage.
> 
> I think there's a basic numeracy problem here. This is unfortunately all
> too common, even among scientists. The OP apparently rounded their
> numbers to 8 significant digits (thereby introducing an error of about
> 1E-8) and then insisted that the additional error of 1E-15 introduced by
> the decimal to float conversion was unacceptable, showing IMHO a
> fundamental misunderstanding of the numbers they are working with.
> 
To be fair, I don't think I've never seen that notation either! I've 
only ever seen the form 6.67430E-11 ? 0.00015E-11, which is much clearer.

From list1 at tompassin.net  Mon Dec 19 10:55:52 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 10:55:52 -0500
Subject: Installation hell
In-Reply-To: <SA1PR14MB5855F356810C84A910A571DDB9E59@SA1PR14MB5855.namprd14.prod.outlook.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <SA1PR14MB5855F356810C84A910A571DDB9E59@SA1PR14MB5855.namprd14.prod.outlook.com>
Message-ID: <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>

On 12/19/2022 9:59 AM, Weatherby,Gerard wrote:
> Personally, I don?t use Windows and avoid it like the plague.  Python is easy to install on Linux and Mac.

That's not been my experience.  Windows installers for Python have 
worked well for me over many generations of Python releases.  It's Linux 
where I've found difficulties.  For example, if your distro's Python 
install didn't include tkinter (or even pip), how do you get it?  It's 
different for different Linux distros.  I generally have to use internet 
searches to find out.

For another example, when you use pip to install a package, it sometimes 
suggests that you install a newer version of pip itself. Should you do 
that?  On Linux, probably not, because the distro will have modified pip 
so it puts things in distro-specific places. Yet there is no newer 
version of pip available through the distro's package manager.  Will 
anything bad happen if you don't update pip?  Who knows?

I have a Linux VM that has several versions of Python3 on it.  Python3.8 
came installed with the distro, but for some programs I need Python 
3.9+.  If I forget which versions I have, how can I find out?  People 
say to use which, but that doesn't work - it only reports "python3". 
This does work, but it's not all that easy to remember (the grep "site" 
part is just to filter out uninformative result lines):

~$ find 2>/dev/null ~ -name python -type d |grep "site"
/home/tom/.local/lib/python3.9/site-packages/PyQt5/Qt5/qsci/api/python
/home/tom/.local/lib/python3.8/site-packages/pandas/_libs/src/ujson/python
/home/tom/.local/lib/python3.10/site-packages/PyQt5/Qt5/qsci/api/python

Not that this task is much easier to remember on Windows, but it's not 
harder.  One way: the "py" launcher will tell you:

py --list
-V:3.10 *        Python 3.10 (64-bit)
-V:3.9           Python 3.9 (64-bit)
-V:3.7           Python 3.7 (64-bit)
-V:2.7

This is not Linux-bashing, but there's no need for Windows-bashing either.

> I?d start here: https://learn.microsoft.com/en-us/visualstudio/python/overview-of-python-tools-for-visual-studio?view=vs-2022
> 
> From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jim Lewis <jimdaniellewis at gmail.com>
> Date: Sunday, December 18, 2022 at 12:56 PM
> To: Python-list at python.org <Python-list at python.org>
> Subject: Fwd: Installation hell
> *** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***
> 
> I'm an occasional user of Python and have a degree in computer science.
> Almost every freaking time I use Python, I go through PSH (Python Setup
> Hell). Sometimes a wrong version is installed. Sometimes it's a path issue.
> Or exe naming confusion: python, python3, phthon311, etc. Or library
> compatibility issues - took an hour to find out that pygame does not work
> with the current version of python. Then the kludgy PIP app and using a DOS
> box under Windows with command prompts which is ridiculous. God only knows
> how many novice users of the language (or even intermediate users) were
> lost in the setup process. Why not clean the infrastructure up and make a
> modern environment or IDE or something better than it is now. Or at least
> good error messages that explain exactly what to do. Even getting this
> email to the list took numerous steps.
> 
> -- A frustrated user
> --
> https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$>


From hjp-python at hjp.at  Mon Dec 19 11:23:38 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 19 Dec 2022 17:23:38 +0100
Subject: String to Float, without introducing errors
In-Reply-To: <d46a7e91-77fe-8883-eae0-237642d5df36@mrabarnett.plus.com>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
 <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>
 <20221219141052.frflz6y2n6md7uvj@hjp.at>
 <d46a7e91-77fe-8883-eae0-237642d5df36@mrabarnett.plus.com>
Message-ID: <20221219162338.u5aheuwh6vpjnjca@hjp.at>

On 2022-12-19 15:14:14 +0000, MRAB wrote:
> On 2022-12-19 14:10, Peter J. Holzer wrote:
> > He also interpreted the notation "6.67430(15)E-11" wrong. The
> > digits in parentheses represent the uncertainty in the same number of
> > last digits. So "6.67430(15)E-11" means "something between 6.67430E-11 -
> > 0.00015E-11 and 6.67430E-11 + 0.00015E-11".
[...]
> To be fair, I don't think I've never seen that notation either!

I've probably seen it first on Wikipedia, quite a few years ago. Since
then I've also encountered in in physical and astronomical papers (I'm
neither a physicist nor an astronomomer but I occasionally read the
original papers if what I read in the "mainstream media"[1] or hear on
youtube seems suspect).

> I've only ever seen the form 6.67430E-11 ? 0.00015E-11, which is much
> clearer.

Yeah, it's definitely not the pinnacle of inuitiveness. I freely admit
that I looked it up before posting just to make sure that I wasn't
confused about its meaning.

Another problem (but it shares that with the ? notation) is that it's
not clear what that number actually represents. Is it one sigma or two?
Or something else? Is the distribution even symmetric?

        hp

[1] I'm not quite happy with that term.

-- 
   _  | 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 rosuav at gmail.com  Mon Dec 19 11:36:55 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Dec 2022 03:36:55 +1100
Subject: Installation hell
In-Reply-To: <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
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On Tue, 20 Dec 2022 at 03:05, Thomas Passin <list1 at tompassin.net> wrote:
>
> That's not been my experience.  Windows installers for Python have
> worked well for me over many generations of Python releases.  It's Linux
> where I've found difficulties.  For example, if your distro's Python
> install didn't include tkinter (or even pip), how do you get it?  It's
> different for different Linux distros.  I generally have to use internet
> searches to find out.

If you want to use your distro's Python and add more stuff to it
globally, then yes, it depends on your distro. This is not really a
surprise.

> For another example, when you use pip to install a package, it sometimes
> suggests that you install a newer version of pip itself. Should you do
> that?  On Linux, probably not, because the distro will have modified pip
> so it puts things in distro-specific places. Yet there is no newer
> version of pip available through the distro's package manager.  Will
> anything bad happen if you don't update pip?  Who knows?

Virtual environments work the same way regardless of distro, including
allowing you to install an upgraded pip. As long as your distro
provides the venv package (on Debian, that's in python3-venv), you can
just:

$ python3 -m venv env
$ source env/bin/activate
$ pip install -U pip
$ pip install -r requirements.txt
$ pip install some-package-name
$ etc etc etc etc etc

This is also a recommended way to do things on Windows, so you don't
even need to do things differently.

> I have a Linux VM that has several versions of Python3 on it.  Python3.8
> came installed with the distro, but for some programs I need Python
> 3.9+.  If I forget which versions I have, how can I find out?  People
> say to use which, but that doesn't work - it only reports "python3".
> This does work, but it's not all that easy to remember (the grep "site"
> part is just to filter out uninformative result lines):

Use what your shell already offers you! If you have multiple Pythons
installed, type "python3" and hit tab twice. You should get a list of
options. The exact shell you're using will affect how they're shown,
but I'm pretty sure most shells (at least, the ones designed to be
interactive - /bin/dash might not) will give you some facility like
this.

rosuav at sikorsky:~$ python3
python3               python3.5-dbg-config  python3.8-config
python3.10            python3.5dm           python3.8m
python3.10-config     python3.5dm-config    python3.8m-config
python3.11            python3.5m            python3.9
python3.11-config     python3.5m-config     python3.9-config
python3.12            python3.6             python3.9d
python3.12-config     python3.6-config      python3.9-dbg
python3.4             python3.6m            python3.9-dbg-config
python3.4-config      python3.6m-config     python3.9d-config
python3.4m            python3.7             python3-config
python3.4m-config     python3.7-config      python3d
python3.5             python3.7m            python3-dbg
python3.5-config      python3.7m-config     python3-dbg-config
python3.5-dbg         python3.8             python3d-config
rosuav at sikorsky:~$ python3

Yes, this is a bit noisy in that it has the -config and -dbg-config
tools listed as well, but you can easily see all the variants that are
installed.

> ~$ find 2>/dev/null ~ -name python -type d |grep "site"
> /home/tom/.local/lib/python3.9/site-packages/PyQt5/Qt5/qsci/api/python
> /home/tom/.local/lib/python3.8/site-packages/pandas/_libs/src/ujson/python
> /home/tom/.local/lib/python3.10/site-packages/PyQt5/Qt5/qsci/api/python

Ugh, that's a horribly inefficient way to do it. All you need to do is
search $PATH. If tab completion isn't suitable, you could probably use
"whereis python3", though it's probably a bit noisy.

> Not that this task is much easier to remember on Windows, but it's not
> harder.  One way: the "py" launcher will tell you:
>
> py --list
> -V:3.10 *        Python 3.10 (64-bit)
> -V:3.9           Python 3.9 (64-bit)
> -V:3.7           Python 3.7 (64-bit)
> -V:2.7
>
> This is not Linux-bashing, but there's no need for Windows-bashing either.

There's no need for Linux-bashing when Linux isn't the problem. :)

And Windows wasn't the OP's problem. Nor was Python. The OP moaned
about a lack of IDEs, when pretty much every IDE and text editor out
there has Python support.

We're not here to bash anything. Well, except maybe the popular Unix
shell. I'll /bin/bash that every day of the week... ahem. Anyhow.
We're here to share tips and help everyone be more productive.

ChrisA

From hjp-python at hjp.at  Mon Dec 19 11:54:51 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 19 Dec 2022 17:54:51 +0100
Subject: Installation hell
In-Reply-To: <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <SA1PR14MB5855F356810C84A910A571DDB9E59@SA1PR14MB5855.namprd14.prod.outlook.com>
 <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>
Message-ID: <20221219165451.eezmne5revu6clrf@hjp.at>

On 2022-12-19 10:55:52 -0500, Thomas Passin wrote:
> On 12/19/2022 9:59 AM, Weatherby,Gerard wrote:
> > Personally, I don?t use Windows and avoid it like the plague.
> > Python is easy to install on Linux and Mac.
> 
> That's not been my experience.  Windows installers for Python have worked
> well for me over many generations of Python releases.

I haven't had any problem either despite being only an occasional
Windows user.

It is however, quite noticable that almost everyone who asks a question
about their Python installation on this list is using Windows. I don't
think this is just because there are more Windows users than Linux or
Mac Users.

> It's Linux where I've found difficulties.  For example, if your
> distro's Python install didn't include tkinter (or even pip), how do
> you get it?  It's different for different Linux distros.

Yes, but most Linux users don't use a dozen different distributions. And
if you've used one for a while you generaLLy know their general naming
conventions. So just guessing (with a little help from your shell's
expansion mechanism) the name will take you a long way.

So as a long-time Debian and Ubuntu user I just know that a Python
package foo will be packaged as python3-foo while a Perl package of the
same name would be packaged as libfoo-perl. Not exactly consistent, but
you get used to it. On RedHat (which I've also used for a long time) the
naming conventions are a bit different but also easy to find out.

> For another example, when you use pip to install a package, it sometimes
> suggests that you install a newer version of pip itself. Should you do that?
> On Linux, probably not, because the distro will have modified pip so it puts
> things in distro-specific places. Yet there is no newer version of pip
> available through the distro's package manager.  Will anything bad happen if
> you don't update pip?  Who knows?

If I use pip on Linux I almost always install into a virtual environment
(rule 1: Don't mess with the package manager). So year, I can install a
new version of pip into that virtual environment without affecting
anything else.


> I have a Linux VM that has several versions of Python3 on it.  Python3.8
> came installed with the distro, but for some programs I need Python 3.9+.
> If I forget which versions I have, how can I find out?

I type python and then ctrl-D. The shell will then show me all commands
starting with "python" in my path (your shell may have a different key
combination for that, maybe tab-tab).

> People say to use which, but that doesn't work - it only reports
> "python3".

More specifically it will report *where* the exact command you named is
installed. So "which python3" might report /usr/bin/python3 or
/usr/local/bin/python3 or maybe /opt/python3.9.2/bin/python3 but it will
never report the presence of any executable not named "python3" and even
if you have several it will only give you one of them.

> ~$ find 2>/dev/null ~ -name python -type d |grep "site"
> /home/tom/.local/lib/python3.9/site-packages/PyQt5/Qt5/qsci/api/python
> /home/tom/.local/lib/python3.8/site-packages/pandas/_libs/src/ujson/python
> /home/tom/.local/lib/python3.10/site-packages/PyQt5/Qt5/qsci/api/python
> 
> Not that this task is much easier to remember on Windows, but it's not
> harder.  One way: the "py" launcher will tell you:
> 
> py --list
> -V:3.10 *        Python 3.10 (64-bit)
> -V:3.9           Python 3.9 (64-bit)
> -V:3.7           Python 3.7 (64-bit)
> -V:2.7

But that works only for Python. Shell expansion works for any command.
If you use Linux, learn how to use your shell (and maybe learn different
shells - I personally prefer zsh, but I can also use bash, ksh, tcsh and
if necessary even sh).

        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 list1 at tompassin.net  Mon Dec 19 12:06:38 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 12:06:38 -0500
Subject: Installation hell
In-Reply-To: <CAPTjJmpdD+fOto+T7nwYD6qfvHG9Zyyg3hJwAZVQz695ruszRQ@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
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Message-ID: <4dec30dc-6598-d9c7-444f-ddbac2565ebd@tompassin.net>

On 12/19/2022 11:36 AM, Chris Angelico wrote:
> On Tue, 20 Dec 2022 at 03:05, Thomas Passin <list1 at tompassin.net> wrote:
>>
>> That's not been my experience.  Windows installers for Python have
>> worked well for me over many generations of Python releases.  It's Linux
>> where I've found difficulties.  For example, if your distro's Python
>> install didn't include tkinter (or even pip), how do you get it?  It's
>> different for different Linux distros.  I generally have to use internet
>> searches to find out.
> 
> If you want to use your distro's Python and add more stuff to it
> globally, then yes, it depends on your distro. This is not really a
> surprise.
> 
>> For another example, when you use pip to install a package, it sometimes
>> suggests that you install a newer version of pip itself. Should you do
>> that?  On Linux, probably not, because the distro will have modified pip
>> so it puts things in distro-specific places. Yet there is no newer
>> version of pip available through the distro's package manager.  Will
>> anything bad happen if you don't update pip?  Who knows?
> 
> Virtual environments work the same way regardless of distro, including
> allowing you to install an upgraded pip.

I have always disliked working with venvs and avoid it whenever 
possible.  But I suppose that's just me.

> As long as your distro
> provides the venv package (on Debian, that's in python3-venv), you can
> just:
> 
> $ python3 -m venv env
> $ source env/bin/activate
> $ pip install -U pip
> $ pip install -r requirements.txt
> $ pip install some-package-name
> $ etc etc etc etc etc
> 
> This is also a recommended way to do things on Windows, so you don't
> even need to do things differently.
> 
>> I have a Linux VM that has several versions of Python3 on it.  Python3.8
>> came installed with the distro, but for some programs I need Python
>> 3.9+.  If I forget which versions I have, how can I find out?  People
>> say to use which, but that doesn't work - it only reports "python3".
>> This does work, but it's not all that easy to remember (the grep "site"
>> part is just to filter out uninformative result lines):
> 
> Use what your shell already offers you! If you have multiple Pythons
> installed, type "python3" and hit tab twice. You should get a list of
> options. The exact shell you're using will affect how they're shown,
> but I'm pretty sure most shells (at least, the ones designed to be
> interactive - /bin/dash might not) will give you some facility like
> this.

Ah, that's nice.  Though it didn't report python3.10 on the VM I 
mentioned earlier.

> 
> rosuav at sikorsky:~$ python3
> python3               python3.5-dbg-config  python3.8-config
> python3.10            python3.5dm           python3.8m
> python3.10-config     python3.5dm-config    python3.8m-config
> python3.11            python3.5m            python3.9
> python3.11-config     python3.5m-config     python3.9-config
> python3.12            python3.6             python3.9d
> python3.12-config     python3.6-config      python3.9-dbg
> python3.4             python3.6m            python3.9-dbg-config
> python3.4-config      python3.6m-config     python3.9d-config
> python3.4m            python3.7             python3-config
> python3.4m-config     python3.7-config      python3d
> python3.5             python3.7m            python3-dbg
> python3.5-config      python3.7m-config     python3-dbg-config
> python3.5-dbg         python3.8             python3d-config
> rosuav at sikorsky:~$ python3
> 
> Yes, this is a bit noisy in that it has the -config and -dbg-config
> tools listed as well, but you can easily see all the variants that are
> installed.
> 
>> ~$ find 2>/dev/null ~ -name python -type d |grep "site"
>> /home/tom/.local/lib/python3.9/site-packages/PyQt5/Qt5/qsci/api/python
>> /home/tom/.local/lib/python3.8/site-packages/pandas/_libs/src/ujson/python
>> /home/tom/.local/lib/python3.10/site-packages/PyQt5/Qt5/qsci/api/python
> 
> Ugh, that's a horribly inefficient way to do it. All you need to do is
> search $PATH. If tab completion isn't suitable, you could probably use
> "whereis python3", though it's probably a bit noisy.

Sure is!

>> Not that this task is much easier to remember on Windows, but it's not
>> harder.  One way: the "py" launcher will tell you:
>>
>> py --list
>> -V:3.10 *        Python 3.10 (64-bit)
>> -V:3.9           Python 3.9 (64-bit)
>> -V:3.7           Python 3.7 (64-bit)
>> -V:2.7
>>
>> This is not Linux-bashing, but there's no need for Windows-bashing either.
> 
> There's no need for Linux-bashing when Linux isn't the problem. :)
> 
> And Windows wasn't the OP's problem. Nor was Python. The OP moaned
> about a lack of IDEs, when pretty much every IDE and text editor out
> there has Python support.

Yes, the OP's rant didn't make much sense to me, especially since it 
didn't line up with my experience at all.

> We're not here to bash anything. Well, except maybe the popular Unix
> shell. I'll /bin/bash that every day of the week... ahem. Anyhow.
> We're here to share tips and help everyone be more productive.
> 
> ChrisA


From rosuav at gmail.com  Mon Dec 19 12:15:07 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Dec 2022 04:15:07 +1100
Subject: Installation hell
In-Reply-To: <20221219165451.eezmne5revu6clrf@hjp.at>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
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 <20221219165451.eezmne5revu6clrf@hjp.at>
Message-ID: <CAPTjJmosGP0Rk4G0j5W0spJcXVH_2S83CQHKWLgffn3MXZe2Og@mail.gmail.com>

On Tue, 20 Dec 2022 at 03:56, Peter J. Holzer <hjp-python at hjp.at> wrote:
>
> It is however, quite noticable that almost everyone who asks a question
> about their Python installation on this list is using Windows. I don't
> think this is just because there are more Windows users than Linux or
> Mac Users.

Yes. I think there are a few reasons for that. One is that there are
many many lazy people in the world, and those people are likely to (a)
use the OS that came with their computers - usually Windows or Mac OS;
and (b) ask a question on a mailing list rather than spend some extra
minutes figuring things out with some web searches. An unrelated cause
might be a large number of student and/or novice programmers, who
simply don't have the groundwork knowledge to figure these things out;
and, again, they'll be using whatever OS their systems come with. Why
don't we see more Mac questions, then? No idea, and I'm not a Mac
person so I can't judge, but I would guess it's just a matter of
numbers - Windows outnumbers Mac OS (not counting iOS, which people
don't tend to be installing Python on) by a fairly significant factor.

> > I have a Linux VM that has several versions of Python3 on it.  Python3.8
> > came installed with the distro, but for some programs I need Python 3.9+.
> > If I forget which versions I have, how can I find out?
>
> I type python and then ctrl-D. The shell will then show me all commands
> starting with "python" in my path (your shell may have a different key
> combination for that, maybe tab-tab).

Ah, interesting. When I mentioned tab-tab I was aware that there are
others, but I'm not familiar with Ctrl-D. Normally that means "send
the command as it is", so I assume your shell is set up to take an
unfinished command and tab-complete it. Which shell is that?

(Also - what happens if you Ctrl-D in the middle of a line? Does that work?)

> But that works only for Python. Shell expansion works for any command.
> If you use Linux, learn how to use your shell (and maybe learn different
> shells - I personally prefer zsh, but I can also use bash, ksh, tcsh and
> if necessary even sh).

I agree, although I wouldn't recommend trying to get too much out of
sh as an interactive shell. It's best aimed at low-overhead script
running, and configured accordingly. Though it's sometimes good to
have some familiarity with a low-powered shell and the most basic of
input methods, just in case you're ever thrust into a situation where
a hard drive has crashed, /bin/bash is corrupted, you don't have
convenient access to external boot media, and you just want to get the
network interface up so you can do some basic fixes or data
recovery...

(Never been in precisely that situation, but I have had other key
programs unavailable for various reasons, and it's handy to know
alternatives!)

ChrisA

From rosuav at gmail.com  Mon Dec 19 12:24:46 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Dec 2022 04:24:46 +1100
Subject: Installation hell
In-Reply-To: <4dec30dc-6598-d9c7-444f-ddbac2565ebd@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
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 <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>
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Message-ID: <CAPTjJmrZn71EB_JWOvyuD671FCzt7o4NiMqH-=v68Zo9GNd=wg@mail.gmail.com>

On Tue, 20 Dec 2022 at 04:14, Thomas Passin <list1 at tompassin.net> wrote:
>
> On 12/19/2022 11:36 AM, Chris Angelico wrote:
> > On Tue, 20 Dec 2022 at 03:05, Thomas Passin <list1 at tompassin.net> wrote:
> >>
> >> That's not been my experience.  Windows installers for Python have
> >> worked well for me over many generations of Python releases.  It's Linux
> >> where I've found difficulties.  For example, if your distro's Python
> >> install didn't include tkinter (or even pip), how do you get it?  It's
> >> different for different Linux distros.  I generally have to use internet
> >> searches to find out.
> >
> > If you want to use your distro's Python and add more stuff to it
> > globally, then yes, it depends on your distro. This is not really a
> > surprise.
> >
> >> For another example, when you use pip to install a package, it sometimes
> >> suggests that you install a newer version of pip itself. Should you do
> >> that?  On Linux, probably not, because the distro will have modified pip
> >> so it puts things in distro-specific places. Yet there is no newer
> >> version of pip available through the distro's package manager.  Will
> >> anything bad happen if you don't update pip?  Who knows?
> >
> > Virtual environments work the same way regardless of distro, including
> > allowing you to install an upgraded pip.
>
> I have always disliked working with venvs and avoid it whenever
> possible.  But I suppose that's just me.
>

That's fine. You don't HAVE to use venvs - and in fact, I only use
them for a relatively small number of projects (eg those that get
deployed to Heroku - make a venv, match Python version to Heroku's
offering, and install packages into it, for maximum consistency).
There are a few ways to manage things:

1) Always use your package manager. Don't use pip at all.
2) Install pip from your package manager, but then do user
installations (~/.local).
3) Install venv from your package manager, use virtual environments everywhere.
4) Build Python from source, parallel to your system Python.
5) Some combination of the above.

As you saw from my tab-tab demo, I have a LOT of Pythons installed,
many of them alphas and betas. Right now, my 'python3' command is
3.12, but /usr/bin/python3 is the system Python (3.9.2) and has
packages managed by apt/dpkg. So when a system-installed script tries
to run, it finds the Python and packages that were curated by the
Debian folks; but if I, at the command line, type "python3
somescript.py", I get a newer Python with packages managed by pip.
Sometimes I'll install those with "sudo python3 -m pip install X", but
mostly without sudo, and they land in ~/.local. (Installing as root is
useful when I need other users to be able to run the script - it's a
pain to try to install something into the correct low-privilege user.)

You have options. There's nothing wrong with picking and choosing
according to what's convenient for you.

ChrisA

From rtm443x at googlemail.com  Mon Dec 19 12:28:48 2022
From: rtm443x at googlemail.com (j)
Date: Mon, 19 Dec 2022 17:28:48 +0000
Subject: Fwd: Installation hell
In-Reply-To: <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
Message-ID: <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>

I agree. Wasted too much time on last few installs.

It got to the point I downloaded python-embedded, unzipped it and set 
the path manually for my work (needed it as part of a compiler).

It ain't good enough. And I like python.

jan

On 18/12/2022 11:50, Jim Lewis wrote:
> I'm an occasional user of Python and have a degree in computer science.
> Almost every freaking time I use Python, I go through PSH (Python Setup
> Hell). Sometimes a wrong version is installed. Sometimes it's a path issue.
> Or exe naming confusion: python, python3, phthon311, etc. Or library
> compatibility issues - took an hour to find out that pygame does not work
> with the current version of python. Then the kludgy PIP app and using a DOS
> box under Windows with command prompts which is ridiculous. God only knows
> how many novice users of the language (or even intermediate users) were
> lost in the setup process. Why not clean the infrastructure up and make a
> modern environment or IDE or something better than it is now. Or at least
> good error messages that explain exactly what to do. Even getting this
> email to the list took numerous steps.
>
> -- A frustrated user

From list1 at tompassin.net  Mon Dec 19 12:55:32 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 12:55:32 -0500
Subject: Fwd: Installation hell
In-Reply-To: <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
Message-ID: <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>

On 12/19/2022 12:28 PM, j via Python-list wrote:
> I agree. Wasted too much time on last few installs.
> 
> It got to the point I downloaded python-embedded, unzipped it and set 
> the path manually for my work (needed it as part of a compiler).

I don't set those paths.  If you have several different versions 
installed, who knows which one the path will find first?  Probably not 
the one you want.  Without paths to the script files, I need to set them 
temporarily, navigate to to the right directory first, or create a 
dedicated batch file, but at least I get the right ones that way.

I don't find it to be a problem.

> It ain't good enough. And I like python.
> 
> jan
> 
> On 18/12/2022 11:50, Jim Lewis wrote:
>> I'm an occasional user of Python and have a degree in computer science.
>> Almost every freaking time I use Python, I go through PSH (Python Setup
>> Hell). Sometimes a wrong version is installed. Sometimes it's a path 
>> issue.
>> Or exe naming confusion: python, python3, phthon311, etc. Or library
>> compatibility issues - took an hour to find out that pygame does not work
>> with the current version of python. Then the kludgy PIP app and using 
>> a DOS
>> box under Windows with command prompts which is ridiculous. God only 
>> knows
>> how many novice users of the language (or even intermediate users) were
>> lost in the setup process. Why not clean the infrastructure up and make a
>> modern environment or IDE or something better than it is now. Or at least
>> good error messages that explain exactly what to do. Even getting this
>> email to the list took numerous steps.
>>
>> -- A frustrated user


From __peter__ at web.de  Mon Dec 19 12:42:43 2022
From: __peter__ at web.de (Peter Otten)
Date: Mon, 19 Dec 2022 18:42:43 +0100
Subject: Keeping a list of records with named fields that can be updated
In-Reply-To: <DB6PR01MB3895A0826921A51E4AE87D6A83E79@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
References: <9158537c-f561-e666-f60c-34d50f61d7b7@web.de>
 <DB6PR01MB3895A0826921A51E4AE87D6A83E79@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
Message-ID: <1b77a861-8855-f327-1c44-35af4e12879e@web.de>

On 17/12/2022 20:45, Albert-Jan Roskam wrote:
>     On Dec 15, 2022 10:21, Peter Otten <__peter__ at web.de> wrote:
>
>       >>> from collections import namedtuple
>       >>> Row = namedtuple("Row", "foo bar baz")
>       >>> row = Row(1, 2, 3)
>       >>> row._replace(bar=42)
>       Row(foo=1, bar=42, baz=3)
>
>     ====
>     Ahh, I always thought these are undocumented methods, but: "In addition to
>     the methods inherited from tuples, named tuples support three additional
>     methods and two attributes. To prevent conflicts with field names, the
>     method and attribute names start with an underscore."
>     https://docs.python.org/3/library/collections.html#collections.somenamedtuple._make

I've read somewhere that Raymond Hettinger regrets the naming and now
would favour a trailing underscore to avoid name conflicts.

From hjp-python at hjp.at  Mon Dec 19 13:14:47 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Mon, 19 Dec 2022 19:14:47 +0100
Subject: Installation hell
In-Reply-To: <CAPTjJmosGP0Rk4G0j5W0spJcXVH_2S83CQHKWLgffn3MXZe2Og@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <SA1PR14MB5855F356810C84A910A571DDB9E59@SA1PR14MB5855.namprd14.prod.outlook.com>
 <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>
 <20221219165451.eezmne5revu6clrf@hjp.at>
 <CAPTjJmosGP0Rk4G0j5W0spJcXVH_2S83CQHKWLgffn3MXZe2Og@mail.gmail.com>
Message-ID: <20221219181447.i3v5cu5r245h6j2o@hjp.at>

On 2022-12-20 04:15:07 +1100, Chris Angelico wrote:
> On Tue, 20 Dec 2022 at 03:56, Peter J. Holzer <hjp-python at hjp.at> wrote:
> > It is however, quite noticable that almost everyone who asks a question
> > about their Python installation on this list is using Windows. I don't
> > think this is just because there are more Windows users than Linux or
> > Mac Users.
> 
> Yes. I think there are a few reasons for that. One is that there are
> many many lazy people in the world, and those people are likely to (a)
> use the OS that came with their computers - usually Windows or Mac OS;

Yeah. But also on Linux you never have to set up Python. It's just
there, ready for use (a few years ago, when Python2 way still the
default, you might have had to "apt install python3"[1] but that's it).
So the lazy Linux users never run into these problems.

> > > I have a Linux VM that has several versions of Python3 on it.  Python3.8
> > > came installed with the distro, but for some programs I need Python 3.9+.
> > > If I forget which versions I have, how can I find out?
> >
> > I type python and then ctrl-D. The shell will then show me all commands
> > starting with "python" in my path (your shell may have a different key
> > combination for that, maybe tab-tab).
> 
> Ah, interesting. When I mentioned tab-tab I was aware that there are
> others, but I'm not familiar with Ctrl-D. Normally that means "send
> the command as it is",

It means that only in cooked mode. Since an interactive shell has to
switch the terminal into cbreak or even raw mode anyway, it can mean
whatever the the shell wants it to mean.

> so I assume your shell is set up to take an unfinished command and
> tab-complete it. Which shell is that?

zsh (with vi keybindings, although I think ctrl-D works the same with
emacs keybindings).

> (Also - what happens if you Ctrl-D in the middle of a line? Does that work?)

Yes. For example if I type "ls foo", dann move the cursor back after
"ls" and type " --co^D", I get:

% ls --co foo
--color    -- control use of color
--context  -- print any security context of each file

If I then type tab, it cycles through the options. If I select --color=
and type ^D again, I get

% ls --color= foo
always  auto    never

Etc.

Debian/Ubuntu contains a ton of predefined expansions for zsh. Many of
them are very context specific and invoke other commands to figure out
the actual options (I guess that it actually invokes ls --help to find
the options of help, and for psql it definitely checks which users or
databases a local postgres installation has to provide you with sensible
options at the appropriate position in the command line. There's also
remote filename expansion for scp and rsync, etc.)


> > But that works only for Python. Shell expansion works for any command.
> > If you use Linux, learn how to use your shell (and maybe learn different
> > shells - I personally prefer zsh, but I can also use bash, ksh, tcsh and
> > if necessary even sh).
> 
> I agree, although I wouldn't recommend trying to get too much out of
> sh as an interactive shell.

Yeah. If I happen to login to an account which has /bin/sh as the login
shell I'll invoke a different shell if I have to type more than 3 or 4
commands (and there is an alernative installed on the machine, which
these days is usually the case). But when I started to use Unix, the
Bourne shell was all there was. If you were lucky, there might have been
a csh, too, but that didn't use cursor keys either. At least it had a
history and you could use ! escapes to access it (I still use those in
zsh and bash).

        hp

[1] Or use yum or zypper or whatever, or your GUI package manager if
    that's your thing.

-- 
   _  | 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 salmodovar at ligumu.com  Sat Dec 17 19:40:34 2022
From: salmodovar at ligumu.com (=?UTF-8?Q?Sabrina_Almod=c3=b3var?=)
Date: Sat, 17 Dec 2022 21:40:34 -0300
Subject: String to Float, without introducing errors
References: <5BF45E45-9112-4680-9692-15AE936A56A3@paulstgeorge.com>
 <512a2101-ea59-29aa-753a-eafe0655fc32@yahoo.co.uk>
 <2C24114F-7CA3-4AE0-B76F-988B33517F93@paulstgeorge.com>
 <CAPTjJmofPSNV9kWZST151+9PFK3NTYtotRO2OgzANGN88JqnKA@mail.gmail.com>
 <639e32de.020a0220.7add7.2f5b@mx.google.com>
 <mailman.1210.1671312099.20444.python-list@python.org>
 <float-20221217225423@ram.dialup.fu-berlin.de>
Message-ID: <tnlni3$1uq7$1@gioia.aioe.org>

On 17/12/2022 18:55, Stefan Ram wrote:
> Grant Edwards <grant.b.edwards at gmail.com> writes:
>> Yes, fixed point (or decimal) is a better fit for what he's doing. but
>> I suspect that floating point would be a better fit for the problem
>> he's trying to solve.
> 
>   I'd like to predict that within the next ten posts in this
>   thread someone will mention "What Every Computer Scientist
>   Should Know About Floating-Point Arithmetic".

Lol!  Speaking of which, let us guide ourselves by

  https://floating-point-gui.de/basic/

and learn that calculations such as ``0.1 + 0.4 work correctly.''
That's the Internet.  You learn a thing on a Tuesday, and on a Wednesday
you're a teacher.  <sarcasm>That's why we need peer review.</sarcasm>

From greg.ewing at canterbury.ac.nz  Sun Dec 18 19:10:16 2022
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Mon, 19 Dec 2022 13:10:16 +1300
Subject: String to Float, without introducing errors
In-Reply-To: <precision-20221218212316@ram.dialup.fu-berlin.de>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
Message-ID: <k09of8FnsbpU1@mid.individual.net>

On 19/12/22 9:24 am, Stefan Ram wrote:
>  So what's the time until a mass of one gram
>  arrives at the ground versus a mass of ten grams? I think
>  one needs "Decimal" to calculate this!

Or you can be smarter about how you calculate it.

Differentiating t with respect to m gives

dt/dm = -0.5 * sqrt(2 * s * r**2 / (G * (M + m)**3))

which, since m is much smaller than M, is approximately

    -0.5 * sqrt(2 * s * r**2 / (G * M**3))

So

 >>> G = 6.6743015E-11
 >>> r = 6.371E6
 >>> M = 5.9722E24
 >>> dtdm = -0.5 * sqrt(2*s*(r**2) / (G * M**3))
 >>> dtdm * (1/1000 - 10/1000)
3.4004053539917275e-28

which agrees with your Decimal calculation to 3 digits,
and should be as precise as the input numbers (about
4 digits in this case).

This is a good example of why it's important to choose
an appropriate numerical algorithm!

-- 
Greg

From michael.stemper at gmail.com  Mon Dec 19 12:29:24 2022
From: michael.stemper at gmail.com (Michael F. Stemper)
Date: Mon, 19 Dec 2022 11:29:24 -0600
Subject: String to Float, without introducing errors
In-Reply-To: <mailman.1252.1671463042.20444.python-list@python.org>
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
 <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>
 <20221219141052.frflz6y2n6md7uvj@hjp.at>
 <d46a7e91-77fe-8883-eae0-237642d5df36@mrabarnett.plus.com>
 <mailman.1252.1671463042.20444.python-list@python.org>
Message-ID: <tnq720$d7tk$1@dont-email.me>

On 19/12/2022 09.14, MRAB wrote:
> On 2022-12-19 14:10, Peter J. Holzer wrote:
>> On 2022-12-19 09:25:17 +1100, Chris Angelico wrote:
>>> On Mon, 19 Dec 2022 at 07:57, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>>> > G = Decimal( 6.6743015E-11 )
>>> > r = Decimal( 6.371E6 )
>>> > M = Decimal( 5.9722E24 )
>>>
>>> What's the point of using Decimal if you start with nothing more than
>>> float accuracy?
>>
>> Right. He also interpreted the notation "6.67430(15)E-11" wrong. The
>> digits in parentheses represent the uncertainty in the same number of
>> last digits. So "6.67430(15)E-11" means "something between 6.67430E-11 -
>> 0.00015E-11 and 6.67430E-11 + 0.00015E-11". The r value has only a
>> precision of 1 km and I'm not sure how accurate the mass is. Let's just
>> assume (for the sake of the argument) that these are actually accurate in
>> all given digits.

ntal misunderstanding of the numbers they are working with.
>>
> To be fair, I don't think I've never seen that notation either! I've only ever seen the form 6.67430E-11 ? 0.00015E-11, which is much clearer.

See, for instance:
<https://www.physics.nist.gov/cgi-bin/cuu/Value?bg>
In particular, the "concise form".

For more detail, see:
<https://en.wikipedia.org/wiki/Uncertainty#Measurements>

-- 
Michael F. Stemper
Isaiah 58:6-7

From __peter__ at web.de  Mon Dec 19 13:29:20 2022
From: __peter__ at web.de (Peter Otten)
Date: Mon, 19 Dec 2022 19:29:20 +0100
Subject: Keeping a list of records with named fields that can be updated
In-Reply-To: <i3p37j-5c2.ln1@anthive.com>
References: <6gip6j-698.ln1@anthive.com>
 <9158537c-f561-e666-f60c-34d50f61d7b7@web.de>
 <mailman.1175.1671096336.20444.python-list@python.org>
 <i3p37j-5c2.ln1@anthive.com>
Message-ID: <2ede4582-0bd9-fec3-421d-24239e2eb144@web.de>

On 18/12/2022 16:44, songbird wrote:
> Peter Otten wrote:
> ...
>> While I think what you need is a database instead of the collection of
>> csv files the way to alter namedtuples is to create  a new one:
>>
>>>>> from collections import namedtuple
>>>>> Row = namedtuple("Row", "foo bar baz")
>>>>> row = Row(1, 2, 3)
>>>>> row._replace(bar=42)
>> Row(foo=1, bar=42, baz=3)
>
>    namedtuple is easier to use as that will use the csv and
> csvreader and create the records without me having to do any
> conversion or direct handling myself.  it's all automagically
> done.  my initial version works, but i'd like it to be a bit
> more elegant and handle descriptions it hasn't seen before
> in a more robust manner.
>
>
>> An alternative would be dataclasses where basic usage is just as easy:
>>
>>>>> from dataclasses import make_dataclass
>>>>> Row = make_dataclass("Row", "foo bar baz".split())
>>>>> row = Row(1, 2, 3)
>>>>> row
>> Row(foo=1, bar=2, baz=3)
>>>>> row.bar = 42
>>>>> row
>> Row(foo=1, bar=42, baz=3)
>
>    i do like that i can directly reference each field in a
> dataclass and not have to specify a _replace for each change.
>
>    is there an easy way to convert from namedtuple to dataclass?
> i can see there is a _asdict converter, but don't really like
> how that turns out as then i have to do a bunch of:
>      rec['fieldname'] = blah
>
> rec.fieldname is much easier to understand.

I recommend that you use a dataclass /instead/ of a namedtuple, not
both. However, for a dataclass with the same fields in the same order as
in your namedtuple the conversion is trivial:

Create compatible namedtuple and dataclass types:

 >>> NTRow = namedtuple("NTRow", ["alpha", "beta", "gamma"])
 >>> DCRow = make_dataclass("DCRow", NTRow._fields)

Build the namedtuple:

 >>> ntrow = NTRow(1, "two", 3.0)
 >>> ntrow
NTRow(alpha=1, beta='two', gamma=3.0)

Convert to dataclass:

 >>> dcrow = DCRow(*ntrow)
 >>> dcrow
DCRow(alpha=1, beta='two', gamma=3.0)


From nospam at dfs.com  Mon Dec 19 13:57:41 2022
From: nospam at dfs.com (DFS)
Date: Mon, 19 Dec 2022 13:57:41 -0500
Subject: Fwd: Installation hell
In-Reply-To: <mailman.1224.1671386086.20444.python-list@python.org>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <mailman.1224.1671386086.20444.python-list@python.org>
Message-ID: <Du2oL.7368$ZhSc.2371@fx38.iad>

On 12/18/2022 6:50 AM, Jim Lewis wrote:
> I'm an occasional user of Python and have a degree in computer science.
> Almost every freaking time I use Python, I go through PSH (Python Setup
> Hell). Sometimes a wrong version is installed. Sometimes it's a path issue.
> Or exe naming confusion: python, python3, phthon311, etc. Or library
> compatibility issues - took an hour to find out that pygame does not work
> with the current version of python. Then the kludgy PIP app and using a DOS
> box under Windows with command prompts which is ridiculous. God only knows
> how many novice users of the language (or even intermediate users) were
> lost in the setup process. Why not clean the infrastructure up and make a
> modern environment or IDE or something better than it is now. Or at least
> good error messages that explain exactly what to do. Even getting this
> email to the list took numerous steps.
> 
> -- A frustrated user


Issues installing python and sending an email?

Ask for a refund on your compsci degree.

From angel.gutierrez.rodriguez at gmail.com  Mon Dec 19 13:58:11 2022
From: angel.gutierrez.rodriguez at gmail.com (=?UTF-8?B?w4FuZ2VsIEdS?=)
Date: Mon, 19 Dec 2022 19:58:11 +0100
Subject: String to Float, without introducing errors
References: <CA9B7C97-E99C-4015-8960-8FBE81868396@paulstgeorge.com>
 <1de4633b-b6c4-14af-7463-8a57527cf0be@tompassin.net>
 <mailman.1234.1671394007.20444.python-list@python.org>
 <precision-20221218212316@ram.dialup.fu-berlin.de>
 <CAPTjJmoD1_6uyWmVGyrY8yS+6S4pOkNyNiKpj2nVaUqf1Hr4nQ@mail.gmail.com>
 <20221219141052.frflz6y2n6md7uvj@hjp.at>
 <d46a7e91-77fe-8883-eae0-237642d5df36@mrabarnett.plus.com>
 <mailman.1252.1671463042.20444.python-list@python.org>
Message-ID: <tnqc83$1l1q$1@gioia.aioe.org>

On 2022-12-19 16:14, MRAB wrote:
> To be fair, I don't think I've never seen that notation either! I've 
> only ever seen the form 6.67430E-11 ? 0.00015E-11, which is much clearer.

We use it regularly in our experimental data: 6.3(4), 15.002(10). Things 
would become complex using exponential forms for errors, specially when 
starting to play with exponents: 6.67430E-11 ? 1.5E-15.
-- 
?ngel GR


From songbird at anthive.com  Mon Dec 19 14:22:34 2022
From: songbird at anthive.com (songbird)
Date: Mon, 19 Dec 2022 14:22:34 -0500
Subject: Keeping a list of records with named fields that can be updated
References: <6gip6j-698.ln1@anthive.com>
 <9158537c-f561-e666-f60c-34d50f61d7b7@web.de>
 <mailman.1175.1671096336.20444.python-list@python.org>
 <i3p37j-5c2.ln1@anthive.com> <2ede4582-0bd9-fec3-421d-24239e2eb144@web.de>
 <mailman.1264.1671474780.20444.python-list@python.org>
Message-ID: <q8q67j-uob.ln1@anthive.com>

Peter Otten wrote:
...
> I recommend that you use a dataclass /instead/ of a namedtuple, not
> both. However, for a dataclass with the same fields in the same order as
> in your namedtuple the conversion is trivial:
>
> Create compatible namedtuple and dataclass types:
>
> >>> NTRow = namedtuple("NTRow", ["alpha", "beta", "gamma"])
> >>> DCRow = make_dataclass("DCRow", NTRow._fields)
>
> Build the namedtuple:
>
> >>> ntrow = NTRow(1, "two", 3.0)
> >>> ntrow
> NTRow(alpha=1, beta='two', gamma=3.0)
>
> Convert to dataclass:
>
> >>> dcrow = DCRow(*ntrow)
> >>> dcrow
> DCRow(alpha=1, beta='two', gamma=3.0)

  thanks, once i get the data in from the file i only have
to reference it, but for the rest of the code i can use
the dataclass instead and that will be easier to read than
dicts.  :)

  your help is appreciated.  :)


  songbird

From jschwar at sbcglobal.net  Mon Dec 19 15:34:42 2022
From: jschwar at sbcglobal.net (Jim Schwartz)
Date: Mon, 19 Dec 2022 14:34:42 -0600
Subject: Fwd: Installation hell
In-Reply-To: <Du2oL.7368$ZhSc.2371@fx38.iad>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <mailman.1224.1671386086.20444.python-list@python.org>
 <Du2oL.7368$ZhSc.2371@fx38.iad>
Message-ID: <003a01d913e9$53feb750$fbfc25f0$@sbcglobal.net>

This type of response is not called for.  I thought this list was designed
to help people.  That's not what this person was doing.  Everyone has
different experience levels and backgrounds.  Help them learn.  Don't berate
them.

Here's what was said:

Issues installing python and sending an email?

Ask for a refund on your compsci degree.

-----Original Message-----
From: Python-list <python-list-bounces+jschwar=sbcglobal.net at python.org> On
Behalf Of DFS
Sent: Monday, December 19, 2022 12:58 PM
To: python-list at python.org
Subject: Re: Fwd: Installation hell

On 12/18/2022 6:50 AM, Jim Lewis wrote:
> I'm an occasional user of Python and have a degree in computer science.
> Almost every freaking time I use Python, I go through PSH (Python 
> Setup Hell). Sometimes a wrong version is installed. Sometimes it's a path
issue.
> Or exe naming confusion: python, python3, phthon311, etc. Or library 
> compatibility issues - took an hour to find out that pygame does not 
> work with the current version of python. Then the kludgy PIP app and 
> using a DOS box under Windows with command prompts which is 
> ridiculous. God only knows how many novice users of the language (or 
> even intermediate users) were lost in the setup process. Why not clean 
> the infrastructure up and make a modern environment or IDE or 
> something better than it is now. Or at least good error messages that 
> explain exactly what to do. Even getting this email to the list took
numerous steps.
> 
> -- A frustrated user


Issues installing python and sending an email?

Ask for a refund on your compsci degree.
--
https://mail.python.org/mailman/listinfo/python-list


From rtm443x at googlemail.com  Mon Dec 19 15:34:54 2022
From: rtm443x at googlemail.com (j)
Date: Mon, 19 Dec 2022 20:34:54 +0000
Subject: Fwd: Installation hell
In-Reply-To: <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
Message-ID: <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>

I was unclear. I use the full path to the folder with the unzipped 
python-embedded. I shouldn't have said 'set'.

I have complained on here before about broken installs but got 
indifference. An installer should install stuff correctly (leaving a 
working environment). If it won't then give clear instructions on how to 
install manually then let us do it. A broken installer is like a road 
that just runs out.

Dismissals about 'lazy people' (for example) aren't helpful if you are 
trying to get some actual work done.

jan


On 19/12/2022 17:55, Thomas Passin wrote:
> On 12/19/2022 12:28 PM, j via Python-list wrote:
>> I agree. Wasted too much time on last few installs.
>>
>> It got to the point I downloaded python-embedded, unzipped it and set 
>> the path manually for my work (needed it as part of a compiler).
>
> I don't set those paths.? If you have several different versions 
> installed, who knows which one the path will find first?? Probably not 
> the one you want.? Without paths to the script files, I need to set 
> them temporarily, navigate to to the right directory first, or create 
> a dedicated batch file, but at least I get the right ones that way.
>
> I don't find it to be a problem.
>
>> It ain't good enough. And I like python.
>>
>> jan
>>
>> On 18/12/2022 11:50, Jim Lewis wrote:
>>> I'm an occasional user of Python and have a degree in computer science.
>>> Almost every freaking time I use Python, I go through PSH (Python Setup
>>> Hell). Sometimes a wrong version is installed. Sometimes it's a path 
>>> issue.
>>> Or exe naming confusion: python, python3, phthon311, etc. Or library
>>> compatibility issues - took an hour to find out that pygame does not 
>>> work
>>> with the current version of python. Then the kludgy PIP app and 
>>> using a DOS
>>> box under Windows with command prompts which is ridiculous. God only 
>>> knows
>>> how many novice users of the language (or even intermediate users) were
>>> lost in the setup process. Why not clean the infrastructure up and 
>>> make a
>>> modern environment or IDE or something better than it is now. Or at 
>>> least
>>> good error messages that explain exactly what to do. Even getting this
>>> email to the list took numerous steps.
>>>
>>> -- A frustrated user
>

From mats at wichmann.us  Mon Dec 19 15:47:42 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Mon, 19 Dec 2022 13:47:42 -0700
Subject: Fwd: Installation hell
In-Reply-To: <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
Message-ID: <10644030-2c9e-8be2-e42d-a80c445f062e@wichmann.us>

On 12/19/22 13:34, j via Python-list wrote:
> I was unclear. I use the full path to the folder with the unzipped 
> python-embedded. I shouldn't have said 'set'.
> 
> I have complained on here before about broken installs but got 
> indifference. An installer should install stuff correctly (leaving a 
> working environment). If it won't then give clear instructions on how to 
> install manually then let us do it. A broken installer is like a road 
> that just runs out.
> 
> Dismissals about 'lazy people' (for example) aren't helpful if you are 
> trying to get some actual work done.
> 
> jan

I don't think there was an intent to be dismissive, just to point out 
that this list, and the tutor list, and other places *do* get questions 
from people who haven't tried very much, and don't tell their readers 
what they've tried, jrather ust go "it's broken, please fix it for me". 
You can call that lazy or not (I personally would not throw out that 
term); it does happen.

The Python installer has a few specific people working on it, most of us 
here aren't in a position to make changes to it - complaining here can 
get sympathy, or not, but probably not action.  It does seem to work out 
for a lot of people, so it's always a bit of a surprise when it doesn't. 
  I'd say you ought to file an issue on it if it's broken for you - not 
to say you haven't tried that already.


From gweatherby at uchc.edu  Mon Dec 19 15:51:10 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Mon, 19 Dec 2022 20:51:10 +0000
Subject: Installation hell
In-Reply-To: <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <SA1PR14MB5855F356810C84A910A571DDB9E59@SA1PR14MB5855.namprd14.prod.outlook.com>
 <37be6b3c-fb22-83ad-16d1-25ed8ade3e76@tompassin.net>
Message-ID: <SA1PR14MB58550801EEC0AD80CDE0B23AB9E59@SA1PR14MB5855.namprd14.prod.outlook.com>

I was suggesting a possible resource while making it clear I am not Windows savvy. My avoidance of Windows has nothing to do with Python, so there is no need to discuss it here.

If I don?t care which Python I?m using, I?ll type python3. If I want3.9,  python3.9. python3 -V tells me the default on that system. (It varies across our servers).

If a Python package isn?t available in the mainline Ubuntu repository (python3-whatever), I?m creating a virtual environment. It just saves trouble in the long run. I have this in ~/bin to create an environment. I?m slowly moving projects to the pyproject.toml because pip is complaining about the setup.py installs.


#!/bin/bash
VERS=3.8 #default version
VENV=venv #default environment name
if [ $# -gt 0 ]; then
                VERS=$1
fi
if [ $# -gt 1 ]; then
                VENV=$2
fi
PYTHON=python$VERS
echo $PYTHON
$PYTHON -m venv $VENV
./$VENV/bin/pip install -U pip ipython
if [ -e requirements.txt ]; then
                ./$VENV/bin/pip install -r requirements.txt
fi
if [ -e setup.py ]; then
                ./$VENV/bin/python setup.py install
fi
if [ -e pyproject.toml ]; then
                ./$VENV/bin/pip install -e .
fi

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Thomas Passin <list1 at tompassin.net>
Date: Monday, December 19, 2022 at 11:05 AM
To: python-list at python.org <python-list at python.org>
Subject: Re: Installation hell
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

On 12/19/2022 9:59 AM, Weatherby,Gerard wrote:
> Personally, I don?t use Windows and avoid it like the plague.  Python is easy to install on Linux and Mac.

That's not been my experience.  Windows installers for Python have
worked well for me over many generations of Python releases.  It's Linux
where I've found difficulties.  For example, if your distro's Python
install didn't include tkinter (or even pip), how do you get it?  It's
different for different Linux distros.  I generally have to use internet
searches to find out.

For another example, when you use pip to install a package, it sometimes
suggests that you install a newer version of pip itself. Should you do
that?  On Linux, probably not, because the distro will have modified pip
so it puts things in distro-specific places. Yet there is no newer
version of pip available through the distro's package manager.  Will
anything bad happen if you don't update pip?  Who knows?

I have a Linux VM that has several versions of Python3 on it.  Python3.8
came installed with the distro, but for some programs I need Python
3.9+.  If I forget which versions I have, how can I find out?  People
say to use which, but that doesn't work - it only reports "python3".
This does work, but it's not all that easy to remember (the grep "site"
part is just to filter out uninformative result lines):

~$ find 2>/dev/null ~ -name python -type d |grep "site"
/home/tom/.local/lib/python3.9/site-packages/PyQt5/Qt5/qsci/api/python
/home/tom/.local/lib/python3.8/site-packages/pandas/_libs/src/ujson/python
/home/tom/.local/lib/python3.10/site-packages/PyQt5/Qt5/qsci/api/python

Not that this task is much easier to remember on Windows, but it's not
harder.  One way: the "py" launcher will tell you:

py --list
-V:3.10 *        Python 3.10 (64-bit)
-V:3.9           Python 3.9 (64-bit)
-V:3.7           Python 3.7 (64-bit)
-V:2.7

This is not Linux-bashing, but there's no need for Windows-bashing either.

> I?d start here: https://learn.microsoft.com/en-us/visualstudio/python/overview-of-python-tools-for-visual-studio?view=vs-2022
>
> From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Jim Lewis <jimdaniellewis at gmail.com>
> Date: Sunday, December 18, 2022 at 12:56 PM
> To: Python-list at python.org <Python-list at python.org>
> Subject: Fwd: Installation hell
> *** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***
>
> I'm an occasional user of Python and have a degree in computer science.
> Almost every freaking time I use Python, I go through PSH (Python Setup
> Hell). Sometimes a wrong version is installed. Sometimes it's a path issue.
> Or exe naming confusion: python, python3, phthon311, etc. Or library
> compatibility issues - took an hour to find out that pygame does not work
> with the current version of python. Then the kludgy PIP app and using a DOS
> box under Windows with command prompts which is ridiculous. God only knows
> how many novice users of the language (or even intermediate users) were
> lost in the setup process. Why not clean the infrastructure up and make a
> modern environment or IDE or something better than it is now. Or at least
> good error messages that explain exactly what to do. Even getting this
> email to the list took numerous steps.
>
> -- A frustrated user
> --
> https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$><https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$%3chttps:/urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!gdOs-oC1JZcmvMXy1G4irRpzHCUmF565UXVdCjzSWNGZKpmZ04I_llDX4WUeob3asBCjLe6TIthAAhmwFgbph9u1m9A$%3e>

--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!jE6AjIj87dxZUxuKQ6JNejqfM89fMIn9dCawvy3MAsC1Y9K1LVekL9Vxn1dNntu2VNPzdvehOKAEpOjyhEQ$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!jE6AjIj87dxZUxuKQ6JNejqfM89fMIn9dCawvy3MAsC1Y9K1LVekL9Vxn1dNntu2VNPzdvehOKAEpOjyhEQ$>

From nntp.mbourne at spamgourmet.com  Mon Dec 19 15:48:49 2022
From: nntp.mbourne at spamgourmet.com (Mark Bourne)
Date: Mon, 19 Dec 2022 20:48:49 +0000
Subject: How to enter escape character in a positional string argument
 from the command line?
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
Message-ID: <tnqinh$l03$1@gioia.aioe.org>

Jach Feng wrote:
> I have a script using the argparse module. I want to enter the string "step\x0A" as one of its positional arguments. I expect this string has a length of 5, but it gives 8. Obviously the escape character didn't function correctly. How to do it?

That depends on the command-line shell you're calling your script from.

In bash, you can include a newline in a quoted string:
./your_script 'step
'
(the closing quote is on the next line)

Or if you want to do it on a single line (or use other escape 
sequences), you can use e.g.:
./your_script $'step\x0a'
(dollar sign before a single-quoted string which contains escape sequences)

-- 
Mark.

From eryksun at gmail.com  Mon Dec 19 16:47:30 2022
From: eryksun at gmail.com (Eryk Sun)
Date: Mon, 19 Dec 2022 15:47:30 -0600
Subject: Installation hell
In-Reply-To: <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
Message-ID: <CACL+1auM1pVLzY0J-A_X9R3CePomDnr2_XXLbJm4Ae_UhevqCw@mail.gmail.com>

On 12/18/22, Jim Lewis <jimdaniellewis at gmail.com> wrote:
>
> Sometimes it's a path issue.

For whatever reason, Python installations on Windows lack versioned
executable names (except for the Microsoft Store distribution). Thus
adding multiple installations to PATH doesn't help unless "python.exe"
is manually linked or copied to versioned names, e.g. "python3.11.exe"
-> "python.exe" and "python3.exe" -> "python.exe". In this case, the
first installation in PATH is the default for running "python" and
"python3".

Using the "py.exe" launcher is the more general and preferred
solution. It allows running any registered Python installation. It's
also the installed handler for the ".py" file type, and it supports
Unix-style shebangs.

> Or exe naming confusion: python, python3, phthon311, etc.

I don't understand what's supposedly confusing here. Here are some
commands to help discover what "py" or "python" commands and
installations are available.

* CMD: where py*.exe
* PowerShell: get-command py*.exe
* Python launcher: py --list-paths

> Or library compatibility issues - took an hour to find out that
> pygame does not work with the current version of python.

It should be a trivial task to discover that wheel packages for pygame
aren't currently available for Python 3.11. It is not unreasonable to
expect Python developers to familiarize themselves with pip and PyPI.

If you search a bit deeper, you'll find a site with unofficial Windows
builds of many packages, including pygame for Python 3.11:

https://www.lfd.uci.edu/~gohlke/pythonlibs/#pygame

Otherwise, while building some packages from source can be quite
involved and difficult, I'd expect anyone with a degree in computer
science to be able to build pygame if necessary. They even provide a
simple guide:

https://www.pygame.org/wiki/CompileWindows

> Then the kludgy PIP app and using a DOS box under Windows with
> command prompts which is ridiculous.

How is pip "kludgy" (i.e. sloppy, hasty, shoddy, or inelegant)? How is
using a command-line interface "ridiculous"? Many programmers and
system administrators actually prefer using command-line interfaces
and text user interfaces (TUI) for many if not most development and
administration tasks. It's a matter of opinion.

---

Nerdy operating system discussion...

> using a DOS box under Windows

The term "DOS box" refers to a virtual machine running 16-bit MS-DOS
in virtual 8086 (v86) mode under Windows 3.1 or Windows 9x, with the
MS-DOS keyboard and display drivers hooked to redirect I/O to a
desktop window. There is no "DOS box" in Windows NT systems. Windows
client systems switched to NT starting with Windows XP. Thus the term
"DOS box" is about two decades out of date.

Also, "DOS" is not synonymous with a command-line interface shell
(e.g. the 16-bit MS-DOS shell, "COMMAND.COM"). A "Disk Operating
System" is one that supports disk drives and filesystems, which
includes most operating systems from the late 1960s onward (e.g.
DOS/360 from 1966). There were several DOS systems for personal
computers in the 1980s, such as Apple ProDOS, Atari DOS, Tandy TRSDOS,
Commodore DOS, and Microsoft MS-DOS. A DOS system can use a graphical
shell, such as running Windows 1.0 (1985) on MS-DOS.

The "python.exe" executable is a Windows application that's flagged to
require a console session. If it doesn't inherit a console session,
then the system allocates one automatically. However, any Windows
application can allocate, attach to, and detach from a console session
via AllocConsole(), AttachConsole(), and FreeConsole().

Prior to Windows 7, each console session in the current NT session is
hosted on threads in the subsystem process for Windows, "csrss.exe".
Starting with Windows 7, console sessions are hosted by instances of
"conhost.exe". The console host also implements a builtin terminal
window for command-line interface (CLI) and text user interface (TUI)
applications. (A console session can be allocated without a terminal
window if a console application is spawned with the creation flag
CREATE_NO_WINDOW.)

Prior to Windows 10, the connection between a console session and its
terminal is hardwired in the console host. This makes it difficult to
implement an alternate terminal, though some alternate terminals have
managed to do so in creative ways (e.g. ConEmu). Starting with Windows
10, alternate terminals can use an open source implementation of the
console host, named "openconsole.exe". The most important example is
Microsoft's "Windows Terminal". Starting with Windows 11, an alternate
terminal can also register as the default terminal for console
applications. For example, if Windows Terminal is set as the default
terminal, then running "python.exe" from Explorer opens a new tab in
Terminal.

From list1 at tompassin.net  Mon Dec 19 16:54:18 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 16:54:18 -0500
Subject: Fwd: Installation hell
In-Reply-To: <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
Message-ID: <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>

On 12/19/2022 3:34 PM, j wrote:
> I was unclear. I use the full path to the folder with the unzipped 
> python-embedded. I shouldn't have said 'set'.
> 
> I have complained on here before about broken installs but got 
> indifference. An installer should install stuff correctly (leaving a 
> working environment). If it won't then give clear instructions on how to 
> install manually then let us do it. A broken installer is like a road 
> that just runs out.

Yes, I've had a few of those, just not with Python so far.  One problem 
with a list like this is that if other people don't have the problem or 
can't make it happen, then they don't have any suggestions based on 
personal experience.  So they can't be helpful.  In this issue, I'm in 
that category.

In that situation, we (the list-people, I mean) need good information to 
have a chance of being helpful.  But I've observed that many requestors 
for help like this - especially installation issues - don't provide any 
useful particulars.  That makes it seem like they don't understand what 
they are doing, and folks would like them to do their homework and think 
about what it would take for other people to have a chance of helping.

Would you try to cook a meal, and then say "I followed the recipe and it 
didn't work, please help"?  It's impossible.  But I've seen this kind of 
question over and over on this list.

I did once have a Python installation problem.  The installed Python 
executable worked, but later I ran into some permissions problem.  I had 
installed for "everyone", so it installed into Program Files, and 
apparently somewhere along the way I had done something odd to the 
permissions for that directory.  I was never sure what.  I uninstalled, 
and since then I have always installed new versions for just one user 
(me). Never a problem since.

I'm sorry to say that I have never tried an embedded install, and I 
don't know what's different about one.  Maybe I'll try one now, just to 
know.

> Dismissals about 'lazy people' (for example) aren't helpful if you are 
> trying to get some actual work done.

Yes, that's true. Lack of clear information isn't helpful, either.

Well this is getting too long, and not directly helping with any of your 
problems.  I hope it may be informative for others who want to ask for 
help. To be able to help someone, I have to understand just what they 
were trying to do, what they did, what happened that caused them to 
think their efforts failed, and what error messages the system emitted. 
That may not be enough either, but it's a required starting point. 
Without this kind of information, people who want to help feel frustrated.

> jan
> 
> 
> On 19/12/2022 17:55, Thomas Passin wrote:
>> On 12/19/2022 12:28 PM, j via Python-list wrote:
>>> I agree. Wasted too much time on last few installs.
>>>
>>> It got to the point I downloaded python-embedded, unzipped it and set 
>>> the path manually for my work (needed it as part of a compiler).
>>
>> I don't set those paths.? If you have several different versions 
>> installed, who knows which one the path will find first?? Probably not 
>> the one you want.? Without paths to the script files, I need to set 
>> them temporarily, navigate to to the right directory first, or create 
>> a dedicated batch file, but at least I get the right ones that way.
>>
>> I don't find it to be a problem.
>>
>>> It ain't good enough. And I like python.
>>>
>>> jan
>>>
>>> On 18/12/2022 11:50, Jim Lewis wrote:
>>>> I'm an occasional user of Python and have a degree in computer science.
>>>> Almost every freaking time I use Python, I go through PSH (Python Setup
>>>> Hell). Sometimes a wrong version is installed. Sometimes it's a path 
>>>> issue.
>>>> Or exe naming confusion: python, python3, phthon311, etc. Or library
>>>> compatibility issues - took an hour to find out that pygame does not 
>>>> work
>>>> with the current version of python. Then the kludgy PIP app and 
>>>> using a DOS
>>>> box under Windows with command prompts which is ridiculous. God only 
>>>> knows
>>>> how many novice users of the language (or even intermediate users) were
>>>> lost in the setup process. Why not clean the infrastructure up and 
>>>> make a
>>>> modern environment or IDE or something better than it is now. Or at 
>>>> least
>>>> good error messages that explain exactly what to do. Even getting this
>>>> email to the list took numerous steps.
>>>>
>>>> -- A frustrated user
>>


From list1 at tompassin.net  Mon Dec 19 17:01:28 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 17:01:28 -0500
Subject: Fwd: Installation hell
In-Reply-To: <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
Message-ID: <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>

On 12/19/2022 4:54 PM, Thomas Passin wrote:
> On 12/19/2022 3:34 PM, j wrote:
>> I was unclear. I use the full path to the folder with the unzipped 
>> python-embedded. I shouldn't have said 'set'.
>>
>> I have complained on here before about broken installs but got 
>> indifference. An installer should install stuff correctly (leaving a 
>> working environment). If it won't then give clear instructions on how 
>> to install manually then let us do it. A broken installer is like a 
>> road that just runs out.
> 
> Yes, I've had a few of those, just not with Python so far.? One problem 
> with a list like this is that if other people don't have the problem or 
> can't make it happen, then they don't have any suggestions based on 
> personal experience.? So they can't be helpful.? In this issue, I'm in 
> that category.
> 
> In that situation, we (the list-people, I mean) need good information to 
> have a chance of being helpful.? But I've observed that many requestors 
> for help like this - especially installation issues - don't provide any 
> useful particulars.? That makes it seem like they don't understand what 
> they are doing, and folks would like them to do their homework and think 
> about what it would take for other people to have a chance of helping.
> 
> Would you try to cook a meal, and then say "I followed the recipe and it 
> didn't work, please help"?? It's impossible.? But I've seen this kind of 
> question over and over on this list.
> 
> I did once have a Python installation problem.? The installed Python 
> executable worked, but later I ran into some permissions problem.? I had 
> installed for "everyone", so it installed into Program Files, and 
> apparently somewhere along the way I had done something odd to the 
> permissions for that directory.? I was never sure what.? I uninstalled, 
> and since then I have always installed new versions for just one user 
> (me). Never a problem since.
> 
> I'm sorry to say that I have never tried an embedded install, and I 
> don't know what's different about one.? Maybe I'll try one now, just to 
> know.

FWIW, I once set up a Python installation so that it could run from a 
USB stick (Windows only).  My launcher was a batch file that contained 
the following:

@echo off
setlocal
: Find effective drive for this file.
set ed=%~d0
path %ed%\python37\Scripts;%ed%\python37;%PATH%
set PYTHONUSERBASE=%ed%\user\python
set HOME=%ed%\user\python
call python %*
endlocal

I suppose anyone trying to use an embedded version of Python would have 
to set up some environmental variables in a similar way.  Note that I 
used the "user" directory on the USB stick as a home directory for the 
installation.



From rosuav at gmail.com  Mon Dec 19 17:16:24 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Dec 2022 09:16:24 +1100
Subject: Fwd: Installation hell
In-Reply-To: <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
 <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
Message-ID: <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>

On Tue, 20 Dec 2022 at 09:12, Thomas Passin <list1 at tompassin.net> wrote:
> FWIW, I once set up a Python installation so that it could run from a
> USB stick (Windows only).  My launcher was a batch file that contained
> the following:
>
> @echo off
> setlocal
> : Find effective drive for this file.
> set ed=%~d0
> path %ed%\python37\Scripts;%ed%\python37;%PATH%
> set PYTHONUSERBASE=%ed%\user\python
> set HOME=%ed%\user\python
> call python %*
> endlocal
>

So much easier to do on a Unix-like system, where you don't need to
concern yourself with "effective drive" and can simply use relative
paths. I know we're not here to bash Windows, but... drive letters
really need to just die already.

ChrisA

From mats at wichmann.us  Mon Dec 19 17:28:12 2022
From: mats at wichmann.us (Mats Wichmann)
Date: Mon, 19 Dec 2022 15:28:12 -0700
Subject: Installation hell
In-Reply-To: <CACL+1auM1pVLzY0J-A_X9R3CePomDnr2_XXLbJm4Ae_UhevqCw@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <CACL+1auM1pVLzY0J-A_X9R3CePomDnr2_XXLbJm4Ae_UhevqCw@mail.gmail.com>
Message-ID: <19527ace-b516-cdb3-8715-0a38aafaaa3a@wichmann.us>

On 12/19/22 14:47, Eryk Sun wrote:

> If you search a bit deeper, you'll find a site with unofficial Windows
> builds of many packages, including pygame for Python 3.11:
> 
> https://www.lfd.uci.edu/~gohlke/pythonlibs/#pygame
Semi-OT: that's been a superb resource, but apparently it's no longer 
maintained - internet scuttlebutt suggests the project which let it 
exist has lost funding.  The link above is a mirror, marked "Archived", 
and I can't see there's been any addition since July 1. (sadly... I 
happen to need an lxml build for experimenting with 3.12 alphas, and 
that's an absolute bear to build for WIndows - I've never cracked it)

From list1 at tompassin.net  Mon Dec 19 17:53:16 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 17:53:16 -0500
Subject: Fwd: Installation hell
In-Reply-To: <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
 <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
 <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
Message-ID: <7f169067-a750-1ee2-d341-1089f746b81c@tompassin.net>

On 12/19/2022 5:16 PM, Chris Angelico wrote:
> On Tue, 20 Dec 2022 at 09:12, Thomas Passin <list1 at tompassin.net> wrote:
>> FWIW, I once set up a Python installation so that it could run from a
>> USB stick (Windows only).  My launcher was a batch file that contained
>> the following:
>>
>> @echo off
>> setlocal
>> : Find effective drive for this file.
>> set ed=%~d0
>> path %ed%\python37\Scripts;%ed%\python37;%PATH%
>> set PYTHONUSERBASE=%ed%\user\python
>> set HOME=%ed%\user\python
>> call python %*
>> endlocal
>>
> 
> So much easier to do on a Unix-like system, where you don't need to
> concern yourself with "effective drive" and can simply use relative
> paths. I know we're not here to bash Windows, but... drive letters
> really need to just die already.

Considering that this was for a removable drive, the launcher needed to 
know its own location, which might change from one instance to another. 
If you look at the code above, you won't find an obvious drive letter. 
You would need to do the equivalent on Linux. The Windows drive letter 
is just not relevant here.

(and I thought we weren't going keep on bashing non-preferred operating 
systems).


From grant.b.edwards at gmail.com  Mon Dec 19 18:01:40 2022
From: grant.b.edwards at gmail.com (Grant Edwards)
Date: Mon, 19 Dec 2022 15:01:40 -0800 (PST)
Subject: Fwd: Installation hell
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
 <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
 <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
Message-ID: <63a0ed54.050a0220.9ee4e.5a12@mx.google.com>

On 2022-12-19, Chris Angelico <rosuav at gmail.com> wrote:

> So much easier to do on a Unix-like system, where you don't need to
> concern yourself with "effective drive" and can simply use relative
> paths. I know we're not here to bash Windows, but... drive letters
> really need to just die already.

They needed to "die already" 40 years ago. I was a Unix user before
MS-DOS came out, and I was rather stunned by the whole drive letter
thing. It seemed like such a giant step backwards. I figured that once
hard drives became common, drive letters would die. Nope, they're
still failing strong!

--
Grant



From rosuav at gmail.com  Mon Dec 19 18:20:57 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 20 Dec 2022 10:20:57 +1100
Subject: Fwd: Installation hell
In-Reply-To: <7f169067-a750-1ee2-d341-1089f746b81c@tompassin.net>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
 <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
 <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
 <7f169067-a750-1ee2-d341-1089f746b81c@tompassin.net>
Message-ID: <CAPTjJmpFEO_DPGitnpuBOQUF15=K8kiyg9=uAsFeExWGLfTtqw@mail.gmail.com>

On Tue, 20 Dec 2022 at 10:01, Thomas Passin <list1 at tompassin.net> wrote:
>
> On 12/19/2022 5:16 PM, Chris Angelico wrote:
> > On Tue, 20 Dec 2022 at 09:12, Thomas Passin <list1 at tompassin.net> wrote:
> >> FWIW, I once set up a Python installation so that it could run from a
> >> USB stick (Windows only).  My launcher was a batch file that contained
> >> the following:
> >>
> >> @echo off
> >> setlocal
> >> : Find effective drive for this file.
> >> set ed=%~d0
> >> path %ed%\python37\Scripts;%ed%\python37;%PATH%
> >> set PYTHONUSERBASE=%ed%\user\python
> >> set HOME=%ed%\user\python
> >> call python %*
> >> endlocal
> >>
> >
> > So much easier to do on a Unix-like system, where you don't need to
> > concern yourself with "effective drive" and can simply use relative
> > paths. I know we're not here to bash Windows, but... drive letters
> > really need to just die already.
>
> Considering that this was for a removable drive, the launcher needed to
> know its own location, which might change from one instance to another.
> If you look at the code above, you won't find an obvious drive letter.
> You would need to do the equivalent on Linux. The Windows drive letter
> is just not relevant here.

The only thing that's relevant is the *path*. Everything can be made
relative to a single directory. On Unix-like systems, any relative
path can be made absolute with reference to a single directory - most
commonly the current working directory, of which there is precisely
one. On Windows, there is the current working directory, plus
twenty-six ADDITIONAL reference directories, plus a current drive (I'm
not certain whether "current working directory" is the same as
"current drive + current directory on that drive", so maybe there's
one fewer than this).

If you create a Python virtual environment without symlinks (eg
"python3 -m venv env --copies"), you can run Python scripts using that
environment simply by invoking the corresponding Python interpreter,
regardless of the actual path. Trivially easy, because it's simply
relative paths.

On Tue, 20 Dec 2022 at 10:03, Grant Edwards <grant.b.edwards at gmail.com> wrote:
>
> On 2022-12-19, Chris Angelico <rosuav at gmail.com> wrote:
>
> > So much easier to do on a Unix-like system, where you don't need to
> > concern yourself with "effective drive" and can simply use relative
> > paths. I know we're not here to bash Windows, but... drive letters
> > really need to just die already.
>
> They needed to "die already" 40 years ago. I was a Unix user before
> MS-DOS came out, and I was rather stunned by the whole drive letter
> thing. It seemed like such a giant step backwards. I figured that once
> hard drives became common, drive letters would die. Nope, they're
> still failing strong!

They feel like part of an old style of concrete identifiers, like
working with direct memory addresses (as opposed to virtual memory
pages), until you realise that even MS-DOS had a special hack that let
a single physical drive behave as both A: and B: with system-provided
prompts "please insert disk for drive A/B" when needed. And with the
SUBST and JOIN commands, you could - again, even in MS-DOS - mount
directories as drives or drives as directories. (I don't remember what
happened if you tried to use both at once to have a directory appear
in a different location - the equivalent of a bind mount. Might have
worked.) People could have destroyed drive letters by just always
turning them into directories, and then comfortably moving to a
Unix-like mount system, but since that didn't happen, generations of
Windows users have grown up with the expectation that drive letters
are a thing.

And that leads to myriad problems. Until Steve Dower got involved with
the Python installers, there were periodic issues resulting from
certain combinations of (a) installing Python somewhere other than the
C: drive, (b) using pip from somewhere other than the C: drive to
install packages, and (c) attempting to use those packages from
somewhere other than C:. I don't remember exactly what the solutions
were (I want to say that "use explicit paths" was part of it, but this
was a while ago and my memory of other people's problems isn't the
greatest), but it was often a mess.

Chrsia

From miked at dewhirst.com.au  Mon Dec 19 20:28:25 2022
From: miked at dewhirst.com.au (Mike Dewhirst)
Date: Tue, 20 Dec 2022 12:28:25 +1100
Subject: OT: ~gohlke [Was: Installation hell]
In-Reply-To: <19527ace-b516-cdb3-8715-0a38aafaaa3a@wichmann.us>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <CACL+1auM1pVLzY0J-A_X9R3CePomDnr2_XXLbJm4Ae_UhevqCw@mail.gmail.com>
 <19527ace-b516-cdb3-8715-0a38aafaaa3a@wichmann.us>
Message-ID: <b6093e42-4bd4-da5e-70ed-11768d0eb255@dewhirst.com.au>

On 20/12/2022 9:28 am, Mats Wichmann wrote:
> On 12/19/22 14:47, Eryk Sun wrote:
>
>> If you search a bit deeper, you'll find a site with unofficial Windows
>> builds of many packages, including pygame for Python 3.11:
>>
>> https://www.lfd.uci.edu/~gohlke/pythonlibs/#pygame
> Semi-OT: that's been a superb resource, but apparently it's no longer 
> maintained - internet scuttlebutt suggests the project which let it 
> exist has lost funding.? The link above is a mirror, marked 
> "Archived", and I can't see there's been any addition since July 1. 
> (sadly... I happen to need an lxml build for experimenting with 3.12 
> alphas, and that's an absolute bear to build for WIndows - I've never 
> cracked it)

That is dreadful news! Windows as a dev platform is dead without it. 
That is serious.

Back on topic - Installation hell

I use Windows for historic reasons related to needing to support 99% of 
my customers/dependents who also use it. I'm the only one who also uses 
Linux - but only non-GUI Linux.

Windows works for me as a dev platform because there are so many 
talented Python people out there who make it work. It would be 
impossible otherwise. I would be forced to to learn two GUIs if I had to 
develop on Linux.

I'm here to tell you that dev and production on different OSs works 
without a hitch! For me.

Whoever wrote the installation docs for Windows did a great job. All the 
bases and options are covered. Absolutely no-one could complain that any 
pertinent detail has been omitted.

Some marketing research is indicated. The OP who started this thread 
could define themself in exquisite detail so that installation 
infrastructure including documentation can be developed to suit that 
market exemplar.

I think there are several separate markets. Eg., for someone like me ... 
locked into Windows (but not Microsoft otherwise) and needing to target 
Linux web servers. That would allow a branching of the installation docs 
to home in, say, on virtual envs and multiple Python installations in 
the root of drive C: (well away from "Program files") and so on.

If the OP says they are an educated computer scientist they could become 
a hero and write up a tightly focused set of docs (extracted from the 
comprehensive canonical docs) which assume their particular "market", 
for want of a better term.

The PSF might recognise the effort and be able to promote such a high 
interest from Windows Python devs into funding for Chris Gohlke.

Cheers

Mike


-- 
Signed email is an absolute defence against phishing. This email has
been signed with my private key. If you import my public key you can
automatically decrypt my signature and be sure it came from me. Just
ask and I'll send it to you. Your email software can handle signing.

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From jfong at ms4.hinet.net  Mon Dec 19 21:24:49 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Mon, 19 Dec 2022 18:24:49 -0800 (PST)
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <tnqinh$l03$1@gioia.aioe.org>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
Message-ID: <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>

Mark Bourne ? 2022?12?20? ?????4:49:13 [UTC+8] ??????
> Jach Feng wrote: 
> > I have a script using the argparse module. I want to enter the string "step\x0A" as one of its positional arguments. I expect this string has a length of 5, but it gives 8. Obviously the escape character didn't function correctly. How to do it?
> That depends on the command-line shell you're calling your script from. 
> 
> In bash, you can include a newline in a quoted string: 
> ./your_script 'step 
> ' 
> (the closing quote is on the next line) 
> 
> Or if you want to do it on a single line (or use other escape 
> sequences), you can use e.g.: 
> ./your_script $'step\x0a' 
> (dollar sign before a single-quoted string which contains escape sequences) 
> 
> -- 
> Mark.
That's really good for Linux user! How about Windows?

From list1 at tompassin.net  Mon Dec 19 22:36:10 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Mon, 19 Dec 2022 22:36:10 -0500
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
 <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
Message-ID: <c2d88e02-718e-330b-a752-57b4e257be58@tompassin.net>

On 12/19/2022 9:24 PM, Jach Feng wrote:
> Mark Bourne ? 2022?12?20? ?????4:49:13 [UTC+8] ??????
>> Jach Feng wrote:
>>> I have a script using the argparse module. I want to enter the string "step\x0A" as one of its positional arguments. I expect this string has a length of 5, but it gives 8. Obviously the escape character didn't function correctly. How to do it?
>> That depends on the command-line shell you're calling your script from.
>>
>> In bash, you can include a newline in a quoted string:
>> ./your_script 'step
>> '
>> (the closing quote is on the next line)
>>
>> Or if you want to do it on a single line (or use other escape
>> sequences), you can use e.g.:
>> ./your_script $'step\x0a'
>> (dollar sign before a single-quoted string which contains escape sequences)
>>
>> -- 
>> Mark.
> That's really good for Linux user! How about Windows?

One way is to process the argument after it gets into Python rather than 
before. How hard that will be depends on how general you need the 
argument to be.  For your actual example, the argument comes into Python 
as if it were

arg1 = r"step\x0A"  # or "step\\x0a"

You can see if there is an "\\x":

pos = arg1.find('\\x')  # 4

Replace or use a regex to replace it:

arg1_fixed = arg1.replace('\\x0A', '\n')

Naturally, if "\\x0A" is only a special case and other combinations are 
possible, you will need to figure out what you need and do some more 
complicated processing.


From eryksun at gmail.com  Mon Dec 19 23:35:27 2022
From: eryksun at gmail.com (Eryk Sun)
Date: Mon, 19 Dec 2022 22:35:27 -0600
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
 <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
Message-ID: <CACL+1au_PQiVXi4XW892gphT=+HnTTaFwTxTuN4xjW_OJCmuwQ@mail.gmail.com>

On 12/19/22, Jach Feng <jfong at ms4.hinet.net> wrote:
>
> That's really good for Linux user! How about Windows?

In CMD, typing the "^" escape character at the end of a line ignores
the newline and prompts for "more" input. If you press enter again,
you'll get another "more" prompt in which you can write the rest of
the command line. Command-line arguments are separated by spaces, so
you have to start the next line with a space if you want it to be a
new argument. Also, "^" is a literal character when it's in a
double-quoted string, which requires careful use of quotes. For
example:

    C:\>py -c "import sys; print(sys.orig_argv[3:])" spam^
    More?
    More?  eggs^
    More?
    More? " and spam"
    ['spam\n', 'eggs\n and spam']

The above is easier in PowerShell, which supports entering multiline
strings without having to escape the newline. The second-level prompt
is ">> ". For example:

    > py -c "import sys; print(sys.orig_argv[3:])" spam"
    >> " eggs"
    >>  and spam"
    ['spam\n', 'eggs\n and spam']

From eryksun at gmail.com  Tue Dec 20 08:11:00 2022
From: eryksun at gmail.com (Eryk Sun)
Date: Tue, 20 Dec 2022 07:11:00 -0600
Subject: Fwd: Installation hell
In-Reply-To: <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
 <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
 <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
Message-ID: <CACL+1au1LpHP1WsT6tyoxNTng4AWW1xGY12awqiumeSKjF5zWA@mail.gmail.com>

On 12/19/22, Chris Angelico <rosuav at gmail.com> wrote:
> On Tue, 20 Dec 2022 at 09:12, Thomas Passin <list1 at tompassin.net> wrote:
>
>> @echo off
>> setlocal
>> : Find effective drive for this file.
>> set ed=%~d0
>> path %ed%\python37\Scripts;%ed%\python37;%PATH%

For reference, in case not everyone on the list knows what "%~d0"
means, the CMD shell supports extracting the drive (d), path (p), name
(n), and extension (x) components of a path name that's stored in a
parameter such as "%0". The full path (f) is resolved beforehand. For
example:

    C:\Temp>set var=spam\eggs.py

    C:\Temp>for %c in (%var%) do @echo drive: "%~dc"
    drive: "C:"

    C:\Temp>for %c in (%var%) do @echo path: "%~pc"
    path: "\Temp\spam\"

    C:\Temp>for %c in (%var%) do @echo name: "%~nc"
    name: "eggs"

    C:\Temp>for %c in (%var%) do @echo extension: "%~xc"
    extension: ".py"

    C:\Temp>for %c in (%var%) do @echo full path: "%~dpnxc"
    full path: "C:\Temp\spam\eggs.py"

    C:\Temp>for %c in (%var%) do @echo full path: "%~fc"
    full path: "C:\Temp\spam\eggs.py"

 > So much easier to do on a Unix-like system, where you don't need to
> concern yourself with "effective drive" and can simply use relative
> paths.

A relative path in the PATH environment variable would depend on the
current working directory. Surely the added paths need to be absolute.
However, Thomas didn't have to reference the drive explicitly. The
expression "%~dp0" is the fully-qualified directory of the executing
batch script, and an absolute path can reference its ancestor
directories using ".." components.

> I know we're not here to bash Windows, but... drive letters
> really need to just die already.

I don't foresee drive-letter names getting phased out of Windows. And
Windows itself is unlikely to get phased out as long as Microsoft
continues to profit from it, as it has for the past 37 years.

The drive concept is deeply ingrained in the design of NT, the Windows
API, shells, and applications. While assigning drive names "A:", "B:",
and "D:" to "Z:" can be avoided, the system volume, i.e. drive "C:",
still has to be accessed in the normal way, or using another one of
its persistent names, such as r"\\?\BootPartition".

The latter still uses the filesystem mount point on the root path of
the device (e.g. "\\\\?\\BootPartition\\"), which you probably take
issue with. That's a deeply ingrained aspect of Windows. Even mount
points set on filesystem directories are actually bind mount points
that ultimately resolve to the root path on the volume device (e.g.
"\\Device\\HarddiskVolume4\\").  This differs from how regular mount
points work on Unix, for which a path like "/dev/sda1/etc" is
gibberish.

Below I've outlined the underlying details of how logical drives (e.g.
"C:"), UNC shares (e.g. r"\\server\share"), other device names, and
filesystem mount points are implemented on NT.

---

NT Device Names

In contrast to Unix, NT is organized around an object namespace, not a
root filesystem. Instances of many object types can be named. Some
named object types also support a parse routine for paths in the
namespace of an object (e.g. the configuration manager's registry
"Key" type and the I/O manager's "Device" type).

The object manager uses two object types to define the object
namespace: Directory and Symbolic Link. Directory objects form the
hierarchical tree. At the base of the tree is the anonymous root
directory object (i.e. "\\"). A directory is implemented as a hashmap
of named objects. A directory can be set as the shadow of another
directory, creating a union directory for name lookups.

Unless otherwise stated, the following discussion uses "directory" and
"symlink" to refer to a directory object and a symbolic-link object,
respectively -- not to a filesystem directory or filesystem symlink.

A canonical NT device name (e.g. "C:", "PIPE", "UNC") is implemented
in the object namespace as a symlink that targets the path of a real
device object. The real device is typically in the r"\Device"
directory. A canonical device name might be a persistent name for an
enumerated device (e.g. "C:" -> r"\Device\HarddiskVolume2"). In some
cases the real device name is persistent, but it's different from the
canonical name (e.g. "PIPE" -> r"\Device\NamedPipe", or "UNC" ->
r"\Device\Mup").

The symlink that implements a canonical device name is created either
in the r"\Global??" directory or in a directory that's used for local
device names in a given logon session (e.g.
r"\Sessions\0\DosDevices\<logon session id>"). The global device
directory generally contains system devices. Mapped drives and
substitute drives typically use a local device directory, so users
don't have to worry about conflicting drive assignments in these
cases.

The global device directory is the shadow of each local device
directory, forming a union for name lookups. If the same device name
is defined in both the local and global directories, the local device
name takes precedence. However, each local device directory also
contains a symlink named "Global" to explicitly reference the global
device directory.

In NT 5.1+, the object path r"\??" is implemented as a virtual
directory. It always references the local device directory of the
current thread's logon session. For example, r"\??\Z:" is probably a
mapped drive in the current logon session, while r"\??\C:" is the
global "C:" drive, which can be written more explicitly as
r"\??\Global\C:".

The target of a symlink can be any path, including a directory in a
filesystem. The latter is the case for mapped drives (e.g. "Z:" ->
r"\Device\Mup\server\share") and substitute drives (e.g. "W:" ->
r"\??\C:\Windows"). Note that drive names that target a filesystem
directory instead of a device are peculiar. API functions generally
special case mapped drives, which target a path on r"\Device\Mup".
Substitute drives, on the other hand, may cause some API functions to
misbehave, such as GetVolumePathNameW().

The Windows API reserves two UNC path prefixes that translate to the
"\\??\\" virtual directory path in NT. The prefix "\\\\?\\"
(backslashes only) begins a path that opens literally, and the prefix
"\\\\.\\" (any mix of forward slashes and backslashes) begins a path
that opens normalized. The normalization of a path replaces forward
slashes with backlashes, collapses repeated slashes, resolves "." and
".." components, and strips trailing spaces and dots.

For example, "//./C:/spam/foo/..///eggs. . ." opens normalized as the
NT path r"\??\C:\spam\eggs", while r"\\?\C:\spam\eggs. . ." opens
literally as the NT path r"\??\C:\spam\eggs. . .". Literal paths have
to be used carefully, else one might create filenames such as "eggs. .
." that can't be accessed normally.

Finally, the global device directory contains a symlink named
"GlobalRoot" that targets the root directory in the object namespace.
It's not particularly useful in the NT API, which can directly access
the root directory. The Windows API, however, requires defining a new
device via DefineDosDeviceW(), if not for the "GlobalRoot" symlink.
For example, the NT path r"\Device\ConDrv\Output" can be opened in the
Windows API as r"\\?\GlobalRoot\Device\ConDrv\Output".

---

NT Mount Points

The primary mount point for a filesystem is usually the root path of
the device that contains the filesystem (e.g. "\\??\\PIPE\\"). For a
volume device, it's called a volume mount point (e.g. "\\??\\C:\\").
This is automatic by default. As soon as a volume device comes online,
an existing filesystem on the device gets recognized and mounted on
the root path of the device.

A common exception is the r"\??\UNC" device, which virtually mounts
UNC shares such as r"\??\UNC\server\share". A UNC share is the root
directory of a redirected filesystem or virtual filesystem. When a new
share path is encountered, the "UNC" device (really r"\Device\Mup")
sends it simultaneously to a prioritized list of providers in order to
determine which providers handle it, if any.

A bind mount point (i.e. a filesystem junction) can be set on an empty
filesystem directory. The target must be a path on a local volume
device. This is basically like the result of the JOIN command in
MS-DOS, except it's generalized to allow grafting a subtree instead of
an entire volume, and the joined volume isn't required to have a
logical drive name.  A junction can also be used instead of a
substitute drive (e.g. a drive created by subst.exe), either of which
makes working with a long base path more convenient.

A junction that targets the root path of a volume name can be
registered with the mount-point manager as the volume's canonical
mount point. A volume name is based on the volume's persistent GUID.
For example, the target path will look like
"\\??\\Volume{12345678-1234-1234-1234-123456781234}\\".

UNC paths can't be mounted on a filesystem directory. However, a
filesystem symlink can target a UNC path. This can be used in place of
a mapped drive. That said, the canonical mount point for a UNC share
is always of the form r"\??\UNC\server\share". It's never a mapped
drive, and it's definitely never a filesystem symlink.

From list1 at tompassin.net  Tue Dec 20 08:59:56 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Tue, 20 Dec 2022 08:59:56 -0500
Subject: Fwd: Installation hell
In-Reply-To: <CACL+1au1LpHP1WsT6tyoxNTng4AWW1xGY12awqiumeSKjF5zWA@mail.gmail.com>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
 <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
 <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
 <CACL+1au1LpHP1WsT6tyoxNTng4AWW1xGY12awqiumeSKjF5zWA@mail.gmail.com>
Message-ID: <a4b5eeb1-30fc-9a9a-157e-93f2912b147d@tompassin.net>

On 12/20/2022 8:11 AM, Eryk Sun wrote:
[snipped]
>> I know we're not here to bash Windows, but... drive letters
>> really need to just die already.
> I don't foresee drive-letter names getting phased out of Windows. And
> Windows itself is unlikely to get phased out as long as Microsoft
> continues to profit from it, as it has for the past 37 years.

Microsoft won't get rid of them for backwards compatibility reasons, 
aside from the sheer difficulty of changing all that code.  The company 
has always been very industrious about keeping backwards compatibility 
for Windows.  I have compiled Delphi Windows GUI code from 2003 and even 
earlier that still runs, as one example.


From edmondo.giovannozzi at gmail.com  Tue Dec 20 04:51:53 2022
From: edmondo.giovannozzi at gmail.com (Edmondo Giovannozzi)
Date: Tue, 20 Dec 2022 01:51:53 -0800 (PST)
Subject: Fwd: Installation hell
In-Reply-To: <mailman.1276.1671492070.20444.python-list@python.org>
References: <mailman.16182.1671363747.6178.python-list@python.org>
 <CANAua_0w=+AaOvFp5iKg+0DXS71Dwqt0KbPy92-Aus6aQxR-YA@mail.gmail.com>
 <CANAua_0DcJr6yqCsFsJ+W0+xA_-qgq6RDisoTqTAY9RHEnbbBA@mail.gmail.com>
 <ab22b6db-bd51-cdaa-6ab3-c169d33b15a2@gmail.com>
 <ad22650a-17bd-fe1c-d23d-fb273f99203d@tompassin.net>
 <8a0665e8-c968-ade1-4530-657bca739fde@gmail.com>
 <9a5c8d2c-7be3-d9c0-0e22-b16fdcbc955f@tompassin.net>
 <657c8d6c-fac2-9973-fdce-7b1515aa0a23@tompassin.net>
 <CAPTjJmrMBK+VQAM6Biv0d7RK7G7=561wvNGesxpBgsDNBAHmQw@mail.gmail.com>
 <CAPTjJmpFEO_DPGitnpuBOQUF15=K8kiyg9=uAsFeExWGLfTtqw@mail.gmail.com>
 <7f169067-a750-1ee2-d341-1089f746b81c@tompassin.net>
 <mailman.1276.1671492070.20444.python-list@python.org>
Message-ID: <50880739-c06c-434f-aa6f-b1f6ee3a9267n@googlegroups.com>

Personally I use winpython: https://winpython.github.io/
That have all the scientific packages already available.
It can run without being installed and uses spyder as an IDE (for small projects it's ok).
And,  I can import pygame (even though I have not tested if everything works) in python 3.11.
As I'm using it for science projects I find it perfect.

From marce at dziban.net  Tue Dec 20 16:09:37 2022
From: marce at dziban.net (Marce Coll)
Date: Tue, 20 Dec 2022 22:09:37 +0100
Subject: ContextVars in async context
Message-ID: <7eadba8f-bf67-4086-b0d3-b85119b43623@app.fastmail.com>

Hi python people, hope this is the correct place to ask this!

For a transactional async decorator I'm building I am using contextvars in order to know when a transaction is open in my current context.

My understanding is that if given the following call stack

A
|- B
|  |- C
|- D
   |- E

If you set a context var at A with value 1, and then override it at B with value 2, then A, D and E will see value 1 and B and C will se value 2. Very similar (although a bit more manual) than dynamic scopes in common lisp.

Now, back to the transactional decorator, from the little documentation there is about this I would imagine that something like this:

@asynccontextmanager
async def transactional(
        endpoint: _base.Endpoint,
        isolation_level: IsolationLevel = IsolationLevel.READ_COMMITTED,
):
    session = TRANSACTION_VAR.get()
    if not session:
        async with endpoint.session() as session, session.begin():
            tok = TRANSACTION_VAR.set(session)
            try:
                await session.execute(text(f"SET TRANSACTION ISOLATION LEVEL {isolation_level.value}"))
                yield session
            finally:
                TRANSACTION_VAR.reset(tok)
    else:
        yield session

should work automatically, and with some preliminary tests it seems it works, but, I don't understand why I need the manual reset. I thought just setting the variable would change it downstream the callstack and reset it when leaving the current context, as seen in the asyncio example in the documentation https://docs.python.org/3/library/contextvars.html#asyncio-support

Now the final question, while the current setup works, when trying to use this as a context manager inside an async generator and then wrapping that with like `asyncio.wait_for`. To illustrate this: 

--
async def gen():
    with transactional():
        ...
        yield data

g = gen()
asyncio.wait_for(g.__anext__(), 1)  # ValueError: <Token ...> was created in a different Context
--

As far as I understand, that moves the awaitable into a new task and when trying to reset tok, it complains that tok was created in a different context. This is unfortunate as sometimes you want to be able to add a timeout using wait_for, particularly in tests. Is there anything I could do to my code to make it more reliable and robust when working with contextvars in an async context?

Sorry for the wall of text, hope it's understandable

Thanks in advance,
-- 
  Marce Coll
  marce at dziban.net

From ethan at stoneleaf.us  Tue Dec 20 16:23:51 2022
From: ethan at stoneleaf.us (Ethan Furman)
Date: Tue, 20 Dec 2022 13:23:51 -0800
Subject: Friendly Reminder
Message-ID: <9f12edcf-2f0f-d125-d36c-d42a91db4c6a@stoneleaf.us>

Greetings, all!

I know our stress levels can be higher than normal around the holidays, but let's please be patient with each other. 
Both conversations and debates will be smoother if we assume other posters are asking/debating in good faith (at least, 
until proven otherwise).

Happy Pythoning, and happy holidays!

--
~Ethan~
Moderator

From jfong at ms4.hinet.net  Tue Dec 20 22:10:46 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Tue, 20 Dec 2022 19:10:46 -0800 (PST)
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <mailman.1278.1671507379.20444.python-list@python.org>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
 <c2d88e02-718e-330b-a752-57b4e257be58@tompassin.net>
 <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
 <mailman.1278.1671507379.20444.python-list@python.org>
Message-ID: <e5b9a0c4-143e-411f-a779-58c30a32ca99n@googlegroups.com>

Thomas Passin ? 2022?12?20? ?????11:36:41 [UTC+8] ??????
> On 12/19/2022 9:24 PM, Jach Feng wrote: 
> > Mark Bourne ? 2022?12?20? ?????4:49:13 [UTC+8] ?????? 
> >> Jach Feng wrote: 
> >>> I have a script using the argparse module. I want to enter the string "step\x0A" as one of its positional arguments. I expect this string has a length of 5, but it gives 8. Obviously the escape character didn't function correctly. How to do it? 
> >> That depends on the command-line shell you're calling your script from. 
> >> 
> >> In bash, you can include a newline in a quoted string: 
> >> ./your_script 'step 
> >> ' 
> >> (the closing quote is on the next line) 
> >> 
> >> Or if you want to do it on a single line (or use other escape 
> >> sequences), you can use e.g.: 
> >> ./your_script $'step\x0a' 
> >> (dollar sign before a single-quoted string which contains escape sequences) 
> >> 
> >> -- 
> >> Mark. 
> > That's really good for Linux user! How about Windows?
> One way is to process the argument after it gets into Python rather than 
> before. How hard that will be depends on how general you need the 
> argument to be. For your actual example, the argument comes into Python 
> as if it were 
> 
> arg1 = r"step\x0A" # or "step\\x0a" 
> 
> You can see if there is an "\\x": 
> 
> pos = arg1.find('\\x') # 4 
> 
> Replace or use a regex to replace it: 
> 
> arg1_fixed = arg1.replace('\\x0A', '\n') 
> 
> Naturally, if "\\x0A" is only a special case and other combinations are 
> possible, you will need to figure out what you need and do some more 
> complicated processing.
That's what I am taking this path under Windows now, the ultimate solution before Windows has shell similar to bash:-)

From jfong at ms4.hinet.net  Tue Dec 20 22:19:05 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Tue, 20 Dec 2022 19:19:05 -0800 (PST)
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <mailman.1279.1671510931.20444.python-list@python.org>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
 <CACL+1au_PQiVXi4XW892gphT=+HnTTaFwTxTuN4xjW_OJCmuwQ@mail.gmail.com>
 <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
 <mailman.1279.1671510931.20444.python-list@python.org>
Message-ID: <fa17a3d4-5762-4c0c-a341-8cb819d8275dn@googlegroups.com>

ery... at gmail.com ? 2022?12?20? ?????12:35:52 [UTC+8] ??????
> On 12/19/22, Jach Feng <jf... at ms4.hinet.net> wrote: 
> > 
> > That's really good for Linux user! How about Windows?
> In CMD, typing the "^" escape character at the end of a line ignores 
> the newline and prompts for "more" input. If you press enter again, 
> you'll get another "more" prompt in which you can write the rest of 
> the command line. Command-line arguments are separated by spaces, so 
> you have to start the next line with a space if you want it to be a 
> new argument. Also, "^" is a literal character when it's in a 
> double-quoted string, which requires careful use of quotes. For 
> example: 
> 
> C:\>py -c "import sys; print(sys.orig_argv[3:])" spam^ 
> More? 
> More? eggs^ 
> More? 
> More? " and spam" 
> ['spam\n', 'eggs\n and spam'] 
> 
> The above is easier in PowerShell, which supports entering multiline 
> strings without having to escape the newline. The second-level prompt 
> is ">> ". For example: 
> 
> > py -c "import sys; print(sys.orig_argv[3:])" spam" 
> >> " eggs" 
> >> and spam" 
> ['spam\n', 'eggs\n and spam']
Thanks for the information. No idea Windows CMD can take such a trick to enter "\n" :-)

From rosuav at gmail.com  Wed Dec 21 00:01:25 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Wed, 21 Dec 2022 16:01:25 +1100
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <e5b9a0c4-143e-411f-a779-58c30a32ca99n@googlegroups.com>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
 <c2d88e02-718e-330b-a752-57b4e257be58@tompassin.net>
 <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
 <mailman.1278.1671507379.20444.python-list@python.org>
 <e5b9a0c4-143e-411f-a779-58c30a32ca99n@googlegroups.com>
Message-ID: <CAPTjJmr2ecsGH=eNR+PTDOZg5LSu-JyteGVqi+RqVgKHSJBk+g@mail.gmail.com>

On Wed, 21 Dec 2022 at 15:28, Jach Feng <jfong at ms4.hinet.net> wrote:
> That's what I am taking this path under Windows now, the ultimate solution before Windows has shell similar to bash:-)

Technically, Windows DOES have a shell similar to bash. It's called
bash. :) The trouble is, most people use cmd.exe instead.

ChrisA

From sjeik_appie at hotmail.com  Wed Dec 21 07:15:58 2022
From: sjeik_appie at hotmail.com (Albert-Jan Roskam)
Date: Wed, 21 Dec 2022 13:15:58 +0100
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <CAPTjJmr2ecsGH=eNR+PTDOZg5LSu-JyteGVqi+RqVgKHSJBk+g@mail.gmail.com>
Message-ID: <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>

   On Dec 21, 2022 06:01, Chris Angelico <rosuav at gmail.com> wrote:

     On Wed, 21 Dec 2022 at 15:28, Jach Feng <jfong at ms4.hinet.net> wrote:
     > That's what I am taking this path under Windows now, the ultimate
     solution before Windows has shell similar to bash:-)

     Technically, Windows DOES have a shell similar to bash. It's called
     bash. :) The trouble is, most people use cmd.exe instead.

   =====
   I use Git Bash quite a lot:?https://gitforwindows.org/
   Is that the one you're referring to?

From lal at solute.de  Wed Dec 21 07:50:02 2022
From: lal at solute.de (Lars Liedtke)
Date: Wed, 21 Dec 2022 13:50:02 +0100
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
References: <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
Message-ID: <9889d5d4-3a41-4b7c-f709-b1810a09880e@solute.de>

Or you could have "native" bash ($SHELL) with WSL. But I assume not everyone is using it.

Cheers

Lars


Lars Liedtke
Software Entwickler

[Tel.]  +49 721 98993-
[Fax]   +49 721 98993-
[E-Mail]        lal at solute.de<mailto:lal at solute.de>


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Am 21.12.22 um 13:15 schrieb Albert-Jan Roskam:

   On Dec 21, 2022 06:01, Chris Angelico <rosuav at gmail.com><mailto:rosuav at gmail.com> wrote:

     On Wed, 21 Dec 2022 at 15:28, Jach Feng <jfong at ms4.hinet.net><mailto:jfong at ms4.hinet.net> wrote:
     > That's what I am taking this path under Windows now, the ultimate
     solution before Windows has shell similar to bash:-)

     Technically, Windows DOES have a shell similar to bash. It's called
     bash. :) The trouble is, most people use cmd.exe instead.

   =====
   I use Git Bash quite a lot: https://gitforwindows.org/
   Is that the one you're referring to?


From rosuav at gmail.com  Wed Dec 21 09:29:01 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Dec 2022 01:29:01 +1100
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
References: <CAPTjJmr2ecsGH=eNR+PTDOZg5LSu-JyteGVqi+RqVgKHSJBk+g@mail.gmail.com>
 <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
Message-ID: <CAPTjJmr3Kjzw7n8O=uPE2RqrzxqyrJtQqmMX768OyLzePDMGGQ@mail.gmail.com>

On Wed, 21 Dec 2022 at 23:16, Albert-Jan Roskam <sjeik_appie at hotmail.com> wrote:
>
>
>
> On Dec 21, 2022 06:01, Chris Angelico <rosuav at gmail.com> wrote:
>
> On Wed, 21 Dec 2022 at 15:28, Jach Feng <jfong at ms4.hinet.net> wrote:
> > That's what I am taking this path under Windows now, the ultimate solution before Windows has shell similar to bash:-)
>
> Technically, Windows DOES have a shell similar to bash. It's called
> bash. :) The trouble is, most people use cmd.exe instead.
>
>
> =====
>
> I use Git Bash quite a lot: https://gitforwindows.org/
>
> Is that the one you're referring to?
>

Yeah, that's probably the easiest way to get hold of it.

ChrisA

From jfong at ms4.hinet.net  Wed Dec 21 00:40:13 2022
From: jfong at ms4.hinet.net (Jach Feng)
Date: Tue, 20 Dec 2022 21:40:13 -0800 (PST)
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <mailman.1284.1671598898.20444.python-list@python.org>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
 <c2d88e02-718e-330b-a752-57b4e257be58@tompassin.net>
 <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
 <mailman.1278.1671507379.20444.python-list@python.org>
 <CAPTjJmr2ecsGH=eNR+PTDOZg5LSu-JyteGVqi+RqVgKHSJBk+g@mail.gmail.com>
 <e5b9a0c4-143e-411f-a779-58c30a32ca99n@googlegroups.com>
 <mailman.1284.1671598898.20444.python-list@python.org>
Message-ID: <9e965167-3e8c-418c-bafa-598d4e1de99cn@googlegroups.com>

Chris Angelico ? 2022?12?21? ?????1:02:01 [UTC+8] ??????
> On Wed, 21 Dec 2022 at 15:28, Jach Feng <jf... at ms4.hinet.net> wrote: 
> > That's what I am taking this path under Windows now, the ultimate solution before Windows has shell similar to bash:-)
> Technically, Windows DOES have a shell similar to bash. It's called 
> bash. :) The trouble is, most people use cmd.exe instead. 
> 
> ChrisA
Really? Where? I can't find it in my Windows 8.1

From rosuav at gmail.com  Wed Dec 21 11:12:50 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Dec 2022 03:12:50 +1100
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <9e965167-3e8c-418c-bafa-598d4e1de99cn@googlegroups.com>
References: <6b7f0c6d-f745-4745-aa5f-2012ec8ed906n@googlegroups.com>
 <tnqinh$l03$1@gioia.aioe.org>
 <c2d88e02-718e-330b-a752-57b4e257be58@tompassin.net>
 <c108a398-fd82-44fc-ae82-f4464faccf9dn@googlegroups.com>
 <mailman.1278.1671507379.20444.python-list@python.org>
 <CAPTjJmr2ecsGH=eNR+PTDOZg5LSu-JyteGVqi+RqVgKHSJBk+g@mail.gmail.com>
 <e5b9a0c4-143e-411f-a779-58c30a32ca99n@googlegroups.com>
 <mailman.1284.1671598898.20444.python-list@python.org>
 <9e965167-3e8c-418c-bafa-598d4e1de99cn@googlegroups.com>
Message-ID: <CAPTjJmpzJjvuB3aMjOAP5UV1Uv+mBv_o2w5DWnP4b1O+fz4LSw@mail.gmail.com>

On Thu, 22 Dec 2022 at 03:11, Jach Feng <jfong at ms4.hinet.net> wrote:
>
> Chris Angelico ? 2022?12?21? ?????1:02:01 [UTC+8] ??????
> > On Wed, 21 Dec 2022 at 15:28, Jach Feng <jf... at ms4.hinet.net> wrote:
> > > That's what I am taking this path under Windows now, the ultimate solution before Windows has shell similar to bash:-)
> > Technically, Windows DOES have a shell similar to bash. It's called
> > bash. :) The trouble is, most people use cmd.exe instead.
> >
> > ChrisA
> Really? Where? I can't find it in my Windows 8.1

Ah, I didn't mean "ships with"; bash for Windows is very much
available, but you'd have to go fetch it. Try the Windows app store
first, and if not, a quick web search will find it. Or install Git for
Windows, which comes with bash.

ChrisA

From rosuav at gmail.com  Wed Dec 21 11:19:18 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Dec 2022 03:19:18 +1100
Subject: How to enter escape character in a positional string argument
 from the command line?
In-Reply-To: <cmd-20221221143358@ram.dialup.fu-berlin.de>
References: <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
 <9889d5d4-3a41-4b7c-f709-b1810a09880e@solute.de>
 <mailman.1286.1671627449.20444.python-list@python.org>
 <cmd-20221221143358@ram.dialup.fu-berlin.de>
Message-ID: <CAPTjJmpLfbwVCczJzOGKsEUR9RmT4qd4VUgsCL9JAC=Hkd8h-A@mail.gmail.com>

On Thu, 22 Dec 2022 at 03:11, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>
> Lars Liedtke <lal at solute.de> writes:
> >Or you could have "native" bash ($SHELL) with WSL.
>
>   In this newsgroup, it would actually be obvious to use Python.

Less obvious than you might think - partly because bash is just so
dang good that it's really really hard to outdo it :) Sure, bash has a
lot of weird and wonky edge cases, but it's an incredibly practical
shell to use.

>   When commands are typed manually, this might be a bit verbose,
>   though. I mean
>
> os.chdir( r'C:\EXAMPLE' )
>
>   versus
>
> CD C:\EXAMPLE

Exactly. What's good for a programming language is often not good for a shell.

> class PythonShell( cmd.Cmd ):
>
>     intro = 'Welcome to the Python shell. Type help or ? to list commands.\n'
>     prompt = '(Python) '
>     file = None
>
>     def do_cd( self, arg ):
>         'change directory:  CD C:\EXAMPLE'
>         os.chdir( *parse( arg ))
>
>     def do_bye( self, arg ):
>         'Exit:  BYE'
>         print( 'Thank you for using the Python Shell!' )
>         return True

Sure, you can always create your own shell. But I think you'll find
that, as you start expanding on this, you'll end up leaning more
towards "implementing bash-like and/or cmd-like semantics in Python"
rather than "creating a Python shell". Shells, in general, try to
execute programs as easily and conveniently as possible. Programming
languages try to stay inside themselves and do things, with subprocess
spawning being a much less important task.

Fun challenge: see how much you can do in bash without ever forking to
another program. And by "fun", I mean extremely difficult, and by
"challenge" I really mean "something you might have to do when your
system is utterly hosed and all you have available is one root shell".

It's amazing how far you can go when your hard drive has crashed and
you desperately need to get one crucial login key that you thought you
had saved elsewhere but hadn't.

ChrisA

From gheskett at shentel.net  Wed Dec 21 11:55:54 2022
From: gheskett at shentel.net (gene heskett)
Date: Wed, 21 Dec 2022 11:55:54 -0500
Subject: How to enter escape character in a positional string argumentfrom
 the command line?
In-Reply-To: <CAPTjJmpLfbwVCczJzOGKsEUR9RmT4qd4VUgsCL9JAC=Hkd8h-A@mail.gmail.com>
References: <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
 <9889d5d4-3a41-4b7c-f709-b1810a09880e@solute.de>
 <mailman.1286.1671627449.20444.python-list@python.org>
 <cmd-20221221143358@ram.dialup.fu-berlin.de>
 <CAPTjJmpLfbwVCczJzOGKsEUR9RmT4qd4VUgsCL9JAC=Hkd8h-A@mail.gmail.com>
Message-ID: <1d7e4fd3-2cdb-e1df-ed18-d2d79b727dc4@shentel.net>

On 12/21/22 11:22, Chris Angelico wrote:
> On Thu, 22 Dec 2022 at 03:11, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>>
>> Lars Liedtke <lal at solute.de> writes:
>>> Or you could have "native" bash ($SHELL) with WSL.
>>
>>    In this newsgroup, it would actually be obvious to use Python.
> 
> Less obvious than you might think - partly because bash is just so
> dang good that it's really really hard to outdo it :) Sure, bash has a
> lot of weird and wonky edge cases, but it's an incredibly practical
> shell to use.
> 
When you make a statement like that, Chris, you should also note that 
every single one of those "wonky edge cases" is documented down to the 
last dotted i. Bash's docs will kill a good sized pulp tree, needing 
around a ream of paper to print on a duplex printer. I know, I did it 
around a decade ago. If you like to write scripts, having a dead tree 
copy of the docs at your elbow in incredibly useful.  That huge man page 
does not cover it like the printed docs do.

>>    When commands are typed manually, this might be a bit verbose,
>>    though. I mean
>>
>> os.chdir( r'C:\EXAMPLE' )
>>
>>    versus
>>
>> CD C:\EXAMPLE
> 
> Exactly. What's good for a programming language is often not good for a shell.
> 
>> class PythonShell( cmd.Cmd ):
>>
>>      intro = 'Welcome to the Python shell. Type help or ? to list commands.\n'
>>      prompt = '(Python) '
>>      file = None
>>
>>      def do_cd( self, arg ):
>>          'change directory:  CD C:\EXAMPLE'
>>          os.chdir( *parse( arg ))
>>
>>      def do_bye( self, arg ):
>>          'Exit:  BYE'
>>          print( 'Thank you for using the Python Shell!' )
>>          return True
> 
> Sure, you can always create your own shell. But I think you'll find
> that, as you start expanding on this, you'll end up leaning more
> towards "implementing bash-like and/or cmd-like semantics in Python"
> rather than "creating a Python shell". Shells, in general, try to
> execute programs as easily and conveniently as possible. Programming
> languages try to stay inside themselves and do things, with subprocess
> spawning being a much less important task.
> 
> Fun challenge: see how much you can do in bash without ever forking to
> another program. And by "fun", I mean extremely difficult, and by
> "challenge" I really mean "something you might have to do when your
> system is utterly hosed and all you have available is one root shell".
> 
> It's amazing how far you can go when your hard drive has crashed and
> you desperately need to get one crucial login key that you thought you
> had saved elsewhere but hadn't.
> 
> ChrisA

Cheers, Gene Heskett.
-- 
"There are four boxes to be used in defense of liberty:
  soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
  - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/>


From rosuav at gmail.com  Wed Dec 21 12:00:44 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Dec 2022 04:00:44 +1100
Subject: How to enter escape character in a positional string argumentfrom
 the command line?
In-Reply-To: <1d7e4fd3-2cdb-e1df-ed18-d2d79b727dc4@shentel.net>
References: <DB6PR01MB3895C71E48173D3AE6993D5883EB9@DB6PR01MB3895.eurprd01.prod.exchangelabs.com>
 <9889d5d4-3a41-4b7c-f709-b1810a09880e@solute.de>
 <mailman.1286.1671627449.20444.python-list@python.org>
 <cmd-20221221143358@ram.dialup.fu-berlin.de>
 <CAPTjJmpLfbwVCczJzOGKsEUR9RmT4qd4VUgsCL9JAC=Hkd8h-A@mail.gmail.com>
 <1d7e4fd3-2cdb-e1df-ed18-d2d79b727dc4@shentel.net>
Message-ID: <CAPTjJmqySfY-Bq1K7c29330KTFHTjwD=gKkKEcRavYtMU2LZQA@mail.gmail.com>

On Thu, 22 Dec 2022 at 03:58, gene heskett <gheskett at shentel.net> wrote:
>
> On 12/21/22 11:22, Chris Angelico wrote:
> > On Thu, 22 Dec 2022 at 03:11, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
> >>
> >> Lars Liedtke <lal at solute.de> writes:
> >>> Or you could have "native" bash ($SHELL) with WSL.
> >>
> >>    In this newsgroup, it would actually be obvious to use Python.
> >
> > Less obvious than you might think - partly because bash is just so
> > dang good that it's really really hard to outdo it :) Sure, bash has a
> > lot of weird and wonky edge cases, but it's an incredibly practical
> > shell to use.
> >
> When you make a statement like that, Chris, you should also note that
> every single one of those "wonky edge cases" is documented down to the
> last dotted i. Bash's docs will kill a good sized pulp tree, needing
> around a ream of paper to print on a duplex printer. I know, I did it
> around a decade ago. If you like to write scripts, having a dead tree
> copy of the docs at your elbow in incredibly useful.  That huge man page
> does not cover it like the printed docs do.
>

Oh yes, absolutely true. Its wonkiness is dependable and consistent;
but it is definitely quirky (look at all the different ways to embed
arguments into things, and the ways that $*, $@, "$*, and "$@" behave
when put into variables). Not usually a problem, but it does sometimes
leave you thinking "wow, wouldn't it be easier to just use something
like Python?". And in the complicated cases, yeah, it can be. But in
the simple cases? Bash rocks.

ChrisA

From rosuav at gmail.com  Wed Dec 21 12:16:47 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Thu, 22 Dec 2022 04:16:47 +1100
Subject: How to enter escape character in a positional string argumentfrom
 the command line?
In-Reply-To: <775B6DA0-165A-484F-99F2-D9A3255A649F@barrys-emacs.org>
References: <CAPTjJmqySfY-Bq1K7c29330KTFHTjwD=gKkKEcRavYtMU2LZQA@mail.gmail.com>
 <775B6DA0-165A-484F-99F2-D9A3255A649F@barrys-emacs.org>
Message-ID: <CAPTjJmrie2y3ccW7_QPdQn4w7T2GkSyR8H_9iNGEiPf2ffxJYw@mail.gmail.com>

On Thu, 22 Dec 2022 at 04:12, Barry <barry at barrys-emacs.org> wrote:
> I see bash scripts that are 1000?s of line of code at work and its a maintenance nightmare.
>
> Knowing when to make the move from ?handy bash script? to ?this is a production application? and needs to be python is what I see people miss.
>
> After a certain point in complexity the python code wins on maintenance.
> Personally i set a low bar to move from bash to python.

Agreed 100%. However, how many commands do you type a day at the bash
prompt? *Every one of those* is a simple case that doesn't need
Python. That's what makes bash such a great shell. You can type
simple, convenient commands, and they *just work*. Need something a
bit more complicated? You can do that too. Want to automate a short
sequence of commands? Don't have to translate them into another system
(like Python subprocess calls), just copy/paste them into a shell
script.

Yes, there absolutely is a point beyond which it's better to translate
everything. But the vast number of commands executed every day? Most
of them are fine with bash. And that's why Python will never replace
bash as a shell.

ChrisA

From barry at barrys-emacs.org  Wed Dec 21 12:12:47 2022
From: barry at barrys-emacs.org (Barry)
Date: Wed, 21 Dec 2022 17:12:47 +0000
Subject: How to enter escape character in a positional string argumentfrom
 the command line?
In-Reply-To: <CAPTjJmqySfY-Bq1K7c29330KTFHTjwD=gKkKEcRavYtMU2LZQA@mail.gmail.com>
References: <CAPTjJmqySfY-Bq1K7c29330KTFHTjwD=gKkKEcRavYtMU2LZQA@mail.gmail.com>
Message-ID: <775B6DA0-165A-484F-99F2-D9A3255A649F@barrys-emacs.org>



> On 21 Dec 2022, at 17:06, Chris Angelico <rosuav at gmail.com> wrote:
> 
> ?On Thu, 22 Dec 2022 at 03:58, gene heskett <gheskett at shentel.net> wrote:
>> 
>>> On 12/21/22 11:22, Chris Angelico wrote:
>>> On Thu, 22 Dec 2022 at 03:11, Stefan Ram <ram at zedat.fu-berlin.de> wrote:
>>>> 
>>>> Lars Liedtke <lal at solute.de> writes:
>>>>> Or you could have "native" bash ($SHELL) with WSL.
>>>> 
>>>>   In this newsgroup, it would actually be obvious to use Python.
>>> 
>>> Less obvious than you might think - partly because bash is just so
>>> dang good that it's really really hard to outdo it :) Sure, bash has a
>>> lot of weird and wonky edge cases, but it's an incredibly practical
>>> shell to use.
>>> 
>> When you make a statement like that, Chris, you should also note that
>> every single one of those "wonky edge cases" is documented down to the
>> last dotted i. Bash's docs will kill a good sized pulp tree, needing
>> around a ream of paper to print on a duplex printer. I know, I did it
>> around a decade ago. If you like to write scripts, having a dead tree
>> copy of the docs at your elbow in incredibly useful.  That huge man page
>> does not cover it like the printed docs do.
>> 
> 
> Oh yes, absolutely true. Its wonkiness is dependable and consistent;
> but it is definitely quirky (look at all the different ways to embed
> arguments into things, and the ways that $*, $@, "$*, and "$@" behave
> when put into variables). Not usually a problem, but it does sometimes
> leave you thinking "wow, wouldn't it be easier to just use something
> like Python?". And in the complicated cases, yeah, it can be. But in
> the simple cases? Bash rocks.

I see bash scripts that are 1000?s of line of code at work and its a maintenance nightmare.

Knowing when to make the move from ?handy bash script? to ?this is a production application? and needs to be python is what I see people miss.

After a certain point in complexity the python code wins on maintenance.
Personally i set a low bar to move from bash to python.

Barry


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


From dieter at handshake.de  Wed Dec 21 12:16:14 2022
From: dieter at handshake.de (Dieter Maurer)
Date: Wed, 21 Dec 2022 18:16:14 +0100
Subject: ContextVars in async context
In-Reply-To: <7eadba8f-bf67-4086-b0d3-b85119b43623@app.fastmail.com>
References: <7eadba8f-bf67-4086-b0d3-b85119b43623@app.fastmail.com>
Message-ID: <25507.16222.156662.41602@ixdm.fritz.box>

Marce Coll wrote at 2022-12-20 22:09 +0100:
>Hi python people, hope this is the correct place to ask this!
>
>For a transactional async decorator I'm building I am using contextvars in order to know when a transaction is open in my current context.
>
>My understanding is that if given the following call stack
>
>A
>|- B
>|  |- C
>|- D
>   |- E
>
>If you set a context var at A with value 1, and then override it at B with value 2, then A, D and E will see value 1 and B and C will se value 2. Very similar (although a bit more manual) than dynamic scopes in common lisp.

This is not the way I understand context variables.
In my view (--> PEP 0567), the context is the coroutine not the call stack.
This means: all calls in the same coroutine share the same context
variables. In your example, if `B` overrides the context variable, then
all later calls in this coroutine will see the overridden value.

From pegloff at gmail.com  Wed Dec 21 16:32:28 2022
From: pegloff at gmail.com (Patrick EGLOFF)
Date: Wed, 21 Dec 2022 22:32:28 +0100
Subject: pygame.midi input/output not working
Message-ID: <CA+Q=Bo=Scjg7w9JQjJbXLBQxsz7PQsbkuHn6h7Jt88cE6CgQRQ@mail.gmail.com>

HI,
Some time ago I wrote a small software using pygame.midi
It worked just fine with Win10/ python 3.9 / SDL 2.0.14 / pygame 2.0.1

I had to change my computer and now I installed Win10 / Python 3.11.1 / SDL
2.0.18 / pygame 2.1.2

The following instructions don't work anymore, making the IDE stop
execution :

my_input = pygame.midi.Input(MidiDeviceIn)
midi_out = pygame.midi.Output(MidiDeviceOut)

Does someone have a suggestion?

Thanks,

-- 
Patrick Egloff
email : pegloff at gmail.com
Web page : http://www.egloff.eu

From list1 at tompassin.net  Wed Dec 21 17:23:47 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Wed, 21 Dec 2022 17:23:47 -0500
Subject: pygame.midi input/output not working
In-Reply-To: <CA+Q=Bo=Scjg7w9JQjJbXLBQxsz7PQsbkuHn6h7Jt88cE6CgQRQ@mail.gmail.com>
References: <CA+Q=Bo=Scjg7w9JQjJbXLBQxsz7PQsbkuHn6h7Jt88cE6CgQRQ@mail.gmail.com>
Message-ID: <1ded41e3-3551-fed8-f836-ee8c60aea5af@tompassin.net>

On 12/21/2022 4:32 PM, Patrick EGLOFF wrote:
> HI,
> Some time ago I wrote a small software using pygame.midi
> It worked just fine with Win10/ python 3.9 / SDL 2.0.14 / pygame 2.0.1
> 
> I had to change my computer and now I installed Win10 / Python 3.11.1 / SDL
> 2.0.18 / pygame 2.1.2
> 
> The following instructions don't work anymore, making the IDE stop
> execution :
> 
> my_input = pygame.midi.Input(MidiDeviceIn)
> midi_out = pygame.midi.Output(MidiDeviceOut)
> 
> Does someone have a suggestion?

The pygame web site says this:

"Pygame still does not run on Python 3.11"

Also from the same page:

"Make sure you install python with the "Add python to PATH" option 
selected. This means that python, and pip will work for you from the 
command line."

See https://www.pygame.org/wiki/GettingStarted#Pygame%20Installation

So what to do until pygame runs in Python 3.11?  I'd install an earlier 
version of Python.  You can have several versions on your machine at the 
same time.  Remember, you have to install all the required packages with 
each version of Python - they don't use each other's code or libraries.

From pegloff at gmail.com  Thu Dec 22 00:33:07 2022
From: pegloff at gmail.com (Patrick EGLOFF)
Date: Thu, 22 Dec 2022 06:33:07 +0100
Subject: Fwd: pygame.midi input/output not working
In-Reply-To: <CA+Q=BonvK7LPae1f9Kf+uzv2s_hbq_tQM+Bz=ZzW1ODC8uBayg@mail.gmail.com>
References: <CA+Q=Bo=Scjg7w9JQjJbXLBQxsz7PQsbkuHn6h7Jt88cE6CgQRQ@mail.gmail.com>
 <1ded41e3-3551-fed8-f836-ee8c60aea5af@tompassin.net>
 <CA+Q=BonvK7LPae1f9Kf+uzv2s_hbq_tQM+Bz=ZzW1ODC8uBayg@mail.gmail.com>
Message-ID: <CA+Q=BomYhY6L24ARM92hc30-iXi5hQHqSHxsqUf9=E8c5ejH+g@mail.gmail.com>

Hi Thomas,

Thanks for the answer AND solution !
That was it... shame on me, I didn't notice this warning.

I uninstalled 3.11.1 and installed 3.10.9, and my software is back to live
!

Now I have to figure out another problem. I will make another post about
this serial weird behavior.

Thanks for making my day !
Patrick

Le mer. 21 d?c. 2022 ? 23:27, Thomas Passin <list1 at tompassin.net> a ?crit :

> On 12/21/2022 4:32 PM, Patrick EGLOFF wrote:
> > HI,
> > Some time ago I wrote a small software using pygame.midi
> > It worked just fine with Win10/ python 3.9 / SDL 2.0.14 / pygame 2.0.1
> >
> > I had to change my computer and now I installed Win10 / Python 3.11.1 /
> SDL
> > 2.0.18 / pygame 2.1.2
> >
> > The following instructions don't work anymore, making the IDE stop
> > execution :
> >
> > my_input = pygame.midi.Input(MidiDeviceIn)
> > midi_out = pygame.midi.Output(MidiDeviceOut)
> >
> > Does someone have a suggestion?
>
> The pygame web site says this:
>
> "Pygame still does not run on Python 3.11"
>
> Also from the same page:
>
> "Make sure you install python with the "Add python to PATH" option
> selected. This means that python, and pip will work for you from the
> command line."
>
> See https://www.pygame.org/wiki/GettingStarted#Pygame%20Installation
>
> So what to do until pygame runs in Python 3.11?  I'd install an earlier
> version of Python.  You can have several versions on your machine at the
> same time.  Remember, you have to install all the required packages with
> each version of Python - they don't use each other's code or libraries.
> --
> https://mail.python.org/mailman/listinfo/python-list
>


-- 
Patrick Egloff
email : pegloff at gmail.com
Web page : http://www.egloff.eu


-- 
Patrick Egloff
email : pegloff at gmail.com
Web page : http://www.egloff.eu

From hjp-python at hjp.at  Thu Dec 22 05:04:22 2022
From: hjp-python at hjp.at (Peter J. Holzer)
Date: Thu, 22 Dec 2022 11:04:22 +0100
Subject: pygame.midi input/output not working
In-Reply-To: <1ded41e3-3551-fed8-f836-ee8c60aea5af@tompassin.net>
References: <CA+Q=Bo=Scjg7w9JQjJbXLBQxsz7PQsbkuHn6h7Jt88cE6CgQRQ@mail.gmail.com>
 <1ded41e3-3551-fed8-f836-ee8c60aea5af@tompassin.net>
Message-ID: <20221222100422.bsbyubmjw3y7gn6c@hjp.at>

On 2022-12-21 17:23:47 -0500, Thomas Passin wrote:
> The pygame web site says this:
> 
> "Pygame still does not run on Python 3.11"

This doesn't sound like "we haven't got around to preparing packages
yet" and more like "there's a serious incompatibility we haven't solved
yet".

Does anybody know what the issue is?

        hp

-- 
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"
-------------- next part --------------
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From gweatherby at uchc.edu  Thu Dec 22 08:08:55 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Thu, 22 Dec 2022 13:08:55 +0000
Subject: pygame.midi input/output not working
In-Reply-To: <20221222100422.bsbyubmjw3y7gn6c@hjp.at>
References: <CA+Q=Bo=Scjg7w9JQjJbXLBQxsz7PQsbkuHn6h7Jt88cE6CgQRQ@mail.gmail.com>
 <1ded41e3-3551-fed8-f836-ee8c60aea5af@tompassin.net>
 <20221222100422.bsbyubmjw3y7gn6c@hjp.at>
Message-ID: <SA1PR14MB5855CA2BFFF1A30595976948B9E89@SA1PR14MB5855.namprd14.prod.outlook.com>

https://github.com/pygame/pygame/issues/3522

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Peter J. Holzer <hjp-python at hjp.at>
Date: Thursday, December 22, 2022 at 5:06 AM
To: python-list at python.org <python-list at python.org>
Subject: Re: pygame.midi input/output not working
On 2022-12-21 17:23:47 -0500, Thomas Passin wrote:
> The pygame web site says this:
>
> "Pygame still does not run on Python 3.11"

This doesn't sound like "we haven't got around to preparing packages
yet" and more like "there's a serious incompatibility we haven't solved
yet".

Does anybody know what the issue is?

        hp

--
   _  | Peter J. Holzer    | Story must make more sense than reality.
|_|_) |                    |
| |   | hjp at hjp.at         |    -- Charles Stross, "Creative writing
__/   | http://www.hjp.at/ |       challenge!"

From list1 at tompassin.net  Thu Dec 22 08:45:11 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 22 Dec 2022 08:45:11 -0500
Subject: pygame.midi input/output not working
In-Reply-To: <20221222100422.bsbyubmjw3y7gn6c@hjp.at>
References: <CA+Q=Bo=Scjg7w9JQjJbXLBQxsz7PQsbkuHn6h7Jt88cE6CgQRQ@mail.gmail.com>
 <1ded41e3-3551-fed8-f836-ee8c60aea5af@tompassin.net>
 <20221222100422.bsbyubmjw3y7gn6c@hjp.at>
Message-ID: <0e418681-6ebd-f385-a122-10947cd39c4b@tompassin.net>

This issue thread on Github says that everyone is waiting on the 
packaging maintainer, but nothing from him for some time.

On 12/22/2022 5:04 AM, Peter J. Holzer wrote:
> On 2022-12-21 17:23:47 -0500, Thomas Passin wrote:
>> The pygame web site says this:
>>
>> "Pygame still does not run on Python 3.11"
> 
> This doesn't sound like "we haven't got around to preparing packages
> yet" and more like "there's a serious incompatibility we haven't solved
> yet".
> 
> Does anybody know what the issue is?
> 
>          hp
> 
> 


From pegloff at gmail.com  Thu Dec 22 06:01:44 2022
From: pegloff at gmail.com (Patrick EGLOFF)
Date: Thu, 22 Dec 2022 12:01:44 +0100
Subject: Pyserial problem
Message-ID: <CA+Q=BomOwwTSXJCv5XXaB9O-ZKJM44hjNBB=vBEK0wkU4iqVpA@mail.gmail.com>

Hi all,

I use Python 3.10.9 and Pyserial 3.5 on a Win10 machine.

I'm sending datas via an USB port to a device that accept commands in the
form of  : cmd;
The device receives and reacts to the commands sent, and it should reply
with an ACK of the same kind.

But looking with a COM port sniffer, nothing is sent back.

I checked that everything is working with PUTTY and even MINITERM, and
everything is just fine, the device is responding correctly.

I have set the flow control to different values, as well as setting the RTS
and DTR high or low with no change.
Normally, the device works without any flow control, and CTS + DTR high.

I checked with MINITERM, that the flow control and control lines have the
same state.

I'm a bit surprised and stucked.
Can someone help ?
Thanks,
-- 
Patrick Egloff
email : pegloff at gmail.com
Web page : http://www.egloff.eu

From hongyi.zhao at gmail.com  Thu Dec 22 08:35:04 2022
From: hongyi.zhao at gmail.com (hongy...@gmail.com)
Date: Thu, 22 Dec 2022 05:35:04 -0800 (PST)
Subject: =?UTF-8?Q?Extract_the_=E2=80=9CMatrix_form=E2=80=9D_dataset_from_BCS_websi?=
 =?UTF-8?Q?te=2E?=
Message-ID: <2c0b55d0-202a-47ed-ae4f-697a1342bf34n@googlegroups.com>

I want to extract / scrape the ?Matrix form? dataset from the BCS website [1], a.k.a., the data appeared in the 3rd column.

I tried with the following python code snippet, but still failed to figure out the trick:

import requests
from bs4 import BeautifulSoup
import re

proxies = {
    'http': 'socks5h://127.0.0.1:18888',
    'https': 'socks5h://127.0.0.1:18888'
}

requests.packages.urllib3.disable_warnings()
r = requests.get('https://www.cryst.ehu.es/cgi-bin/plane/programs/nph-plane_getgen?gnum=17&type=plane', proxies=proxies, verify=False)
soup = BeautifulSoup(r.content, features="lxml")

table = soup.find('table')
id = table.find_all('id')

My python environment is as follows:

werner at X10DAi:~$ pyenv shell datasci 
(datasci) werner at X10DAi:~$ python --version
Python 3.11.1

Any tips will be appreciated.

[1] https://www.cryst.ehu.es/cgi-bin/plane/programs/nph-plane_getgen?gnum=17&type=plane

Regards,
Zhao

From phd at phdru.name  Thu Dec 22 11:41:38 2022
From: phd at phdru.name (Oleg Broytman)
Date: Thu, 22 Dec 2022 19:41:38 +0300
Subject: SQLObject 3.10.1
Message-ID: <Y6SIwgAOB6jIcNZo@phdru.name>

Hello!

I'm pleased to announce version 3.10.1, the first minor feature release of
branch 3.10 of SQLObject.


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

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

* Use ``module_loader.exec_module(module_loader.create_module())``
  instead of ``module_loader.load_module()`` when available.

Drivers
-------

* Added ``mysql-connector-python``.

Tests
-----

* Run tests with Python 3.11.

CI
--

* Ubuntu >= 22 and ``setup-python`` dropped Pythons < 3.7.
  Use ``conda`` via ``s-weigand/setup-conda`` instead of ``setup-python``
  to install older Pythons on Linux.

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


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

SQLObject is a free and open-source (LGPL) Python object-relational
mapper.  Your database tables are described as classes, and rows are
instances of those classes.  SQLObject is meant to be easy to use and
quick to get started with.

SQLObject supports a number of backends: MySQL/MariaDB (with a number of
DB API drivers: ``MySQLdb``, ``mysqlclient``, ``mysql-connector``,
``PyMySQL``, ``mariadb``), PostgreSQL (``psycopg2``, ``PyGreSQL``,
partially ``pg8000`` and ``py-postgresql``), SQLite (builtin ``sqlite``,
``pysqlite``, partially ``supersqlite``); connections to other backends
- Firebird, Sybase, MSSQL and MaxDB (also known as SAPDB) - are less
debugged).

Python 2.7 or 3.4+ is required.


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

Site:
http://sqlobject.org

Download:
https://pypi.org/project/SQLObject/3.10.1

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

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

Mailing lists:
https://sourceforge.net/p/sqlobject/mailman/

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

Developer Guide:
http://sqlobject.org/DeveloperGuide.html


Example
=======

Install::

  $ pip install sqlobject

Create a simple class that wraps a table::

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

Use the object::

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

Queries::

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

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

From list1 at tompassin.net  Thu Dec 22 12:34:05 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Thu, 22 Dec 2022 12:34:05 -0500
Subject: =?UTF-8?Q?Re=3a_Extract_the_=e2=80=9cMatrix_form=e2=80=9d_dataset_f?=
 =?UTF-8?Q?rom_BCS_website=2e?=
In-Reply-To: <2c0b55d0-202a-47ed-ae4f-697a1342bf34n@googlegroups.com>
References: <2c0b55d0-202a-47ed-ae4f-697a1342bf34n@googlegroups.com>
Message-ID: <39dfb3d6-0e51-e94a-539d-ef114d380e2d@tompassin.net>

On 12/22/2022 8:35 AM, hongy... at gmail.com wrote:
> I want to extract / scrape the ?Matrix form? dataset from the BCS website [1], a.k.a., the data appeared in the 3rd column.
> 
> I tried with the following python code snippet, but still failed to figure out the trick:

Tell what you observed, and what you expected.  For example, does the 
data get downloaded?  Do you get error messages, and if so what are 
they?  Does the id variable contain anything at all? Etc.

> import requests
> from bs4 import BeautifulSoup
> import re
> 
> proxies = {
>      'http': 'socks5h://127.0.0.1:18888',
>      'https': 'socks5h://127.0.0.1:18888'
> }
> 
> requests.packages.urllib3.disable_warnings()
> r = requests.get('https://www.cryst.ehu.es/cgi-bin/plane/programs/nph-plane_getgen?gnum=17&type=plane', proxies=proxies, verify=False)
> soup = BeautifulSoup(r.content, features="lxml")
> 
> table = soup.find('table')
> id = table.find_all('id')
> 
> My python environment is as follows:
> 
> werner at X10DAi:~$ pyenv shell datasci
> (datasci) werner at X10DAi:~$ python --version
> Python 3.11.1
> 
> Any tips will be appreciated.
> 
> [1] https://www.cryst.ehu.es/cgi-bin/plane/programs/nph-plane_getgen?gnum=17&type=plane
> 
> Regards,
> Zhao


From barry at barrys-emacs.org  Thu Dec 22 12:37:25 2022
From: barry at barrys-emacs.org (Barry)
Date: Thu, 22 Dec 2022 17:37:25 +0000
Subject: Pyserial problem
In-Reply-To: <CA+Q=BomOwwTSXJCv5XXaB9O-ZKJM44hjNBB=vBEK0wkU4iqVpA@mail.gmail.com>
References: <CA+Q=BomOwwTSXJCv5XXaB9O-ZKJM44hjNBB=vBEK0wkU4iqVpA@mail.gmail.com>
Message-ID: <DC381360-5A8D-4412-BDF6-F5943B657F44@barrys-emacs.org>



> On 22 Dec 2022, at 17:09, Patrick EGLOFF <pegloff at gmail.com> wrote:
> 
> ?Hi all,
> 
> I use Python 3.10.9 and Pyserial 3.5 on a Win10 machine.
> 
> I'm sending datas via an USB port to a device that accept commands in the
> form of  : cmd;
> The device receives and reacts to the commands sent, and it should reply
> with an ACK of the same kind.
> 
> But looking with a COM port sniffer, nothing is sent back.
> 
> I checked that everything is working with PUTTY and even MINITERM, and
> everything is just fine, the device is responding correctly.
> 
> I have set the flow control to different values, as well as setting the RTS
> and DTR high or low with no change.
> Normally, the device works without any flow control, and CTS + DTR high.
> 
> I checked with MINITERM, that the flow control and control lines have the
> same state.
> 
> I'm a bit surprised and stucked.
> Can someone help ?

Please post tour code that you are using to talk to the device.

Barry

> Thanks,
> -- 
> Patrick Egloff
> email : pegloff at gmail.com
> Web page : http://www.egloff.eu
> -- 
> https://mail.python.org/mailman/listinfo/python-list
> 


From phd at phdru.name  Sun Dec 25 11:18:22 2022
From: phd at phdru.name (Oleg Broytman)
Date: Sun, 25 Dec 2022 19:18:22 +0300
Subject: CheetahTemplate 3.3.1
Message-ID: <Y6h3ziyPIVTB51Hv@phdru.name>

Hello!

I'm pleased to announce version 3.3.1, the 1st bugfix release
of branch 3.3 of CheetahTemplate3.


What's new in CheetahTemplate3
==============================

Bug fixes:

  - Fixed ``ImportHooks`` under PyPy3.

Tests:

  - Run tests with PyPy3.

CI:

  - Use ``conda`` to install older Pythons

    Ubuntu >= 22 and ``setup-python`` dropped Pythons < 3.7.
    Use ``s-weigand/setup-conda`` instead of ``setup-python``.


What is CheetahTemplate3
========================

Cheetah3 is a free and open source (MIT) Python template engine.
It's a fork of the original CheetahTemplate library.

Python 2.7 or 3.4+ is required.


Where is CheetahTemplate3
=========================

Site:
https://cheetahtemplate.org/

Download:
https://pypi.org/project/CT3/3.3.1

News and changes:
https://cheetahtemplate.org/news.html

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

Mailing lists:
https://sourceforge.net/p/cheetahtemplate/mailman/

Development:
https://github.com/CheetahTemplate3

Developer Guide:
https://cheetahtemplate.org/dev_guide/


Example
=======

Install::

    $ pip install CT3 # (or even "ct3")

Below is a simple example of some Cheetah code, as you can see it's practically
Python. You can import, inherit and define methods just like in a regular Python
module, since that's what your Cheetah templates are compiled to :) ::

    #from Cheetah.Template import Template
    #extends Template

    #set $people = [{'name' : 'Tom', 'mood' : 'Happy'}, {'name' : 'Dick',
                            'mood' : 'Sad'}, {'name' : 'Harry', 'mood' : 'Hairy'}]

    <strong>How are you feeling?</strong>
    <ul>
        #for $person in $people
            <li>
                $person['name'] is $person['mood']
            </li>
        #end for
    </ul>

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

From antoon.pardon at vub.be  Tue Dec 27 05:27:29 2022
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 27 Dec 2022 11:27:29 +0100
Subject: How make your module substitute a python stdlib module.
Message-ID: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>

OK, I am writing an alternative for the threading module. What I would 
like to know is how I can get some library modules call my alternative 
instead of the threading module.

For instance there is the logging module, it can log the thread name. So 
I would like to know how I can get the logging module to call the 
function from my module to get the current_thread, instead of it calling 
"current_thread" from the threading module.

-- 
Antoon Pardon

From rosuav at gmail.com  Tue Dec 27 05:37:29 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 27 Dec 2022 21:37:29 +1100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
Message-ID: <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>

On Tue, 27 Dec 2022 at 21:29, Antoon Pardon <antoon.pardon at vub.be> wrote:
>
> OK, I am writing an alternative for the threading module. What I would
> like to know is how I can get some library modules call my alternative
> instead of the threading module.
>
> For instance there is the logging module, it can log the thread name. So
> I would like to know how I can get the logging module to call the
> function from my module to get the current_thread, instead of it calling
> "current_thread" from the threading module.

Easy: make sure your module is called "threading.py" and is earlier in
the path than the standard library. In fact, it's so easy that people
do it unintentionally all the time... Generally, the current directory
(or the script directory) is the first entry in sys.path, so that's a
good place to put it.

ChrisA

From antoon.pardon at vub.be  Tue Dec 27 06:12:16 2022
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 27 Dec 2022 12:12:16 +0100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
Message-ID: <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>



Op 27/12/2022 om 11:37 schreef Chris Angelico:
> On Tue, 27 Dec 2022 at 21:29, Antoon Pardon <antoon.pardon at vub.be> wrote:
>> OK, I am writing an alternative for the threading module. What I would
>> like to know is how I can get some library modules call my alternative
>> instead of the threading module.
>>
>> For instance there is the logging module, it can log the thread name. So
>> I would like to know how I can get the logging module to call the
>> function from my module to get the current_thread, instead of it calling
>> "current_thread" from the threading module.
> Easy: make sure your module is called "threading.py" and is earlier in
> the path than the standard library. In fact, it's so easy that people
> do it unintentionally all the time... Generally, the current directory
> (or the script directory) is the first entry in sys.path, so that's a
> good place to put it.

Well I had hope for a somewhat more selective solution. The intention is
to have a number of modules collected in a package where this module is
one of and the package is available via the "installed" search path.

So the programmer should just be able to choose to write his code with
either:

 ??? from threading import Thread

or

 ??? from QYZlib.threaders import Thread

-- 
Antoon Pardon

From rosuav at gmail.com  Tue Dec 27 06:28:32 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 27 Dec 2022 22:28:32 +1100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
Message-ID: <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>

On Tue, 27 Dec 2022 at 22:13, Antoon Pardon <antoon.pardon at vub.be> wrote:
>
>
>
> Op 27/12/2022 om 11:37 schreef Chris Angelico:
> > On Tue, 27 Dec 2022 at 21:29, Antoon Pardon <antoon.pardon at vub.be> wrote:
> >> OK, I am writing an alternative for the threading module. What I would
> >> like to know is how I can get some library modules call my alternative
> >> instead of the threading module.
> >>
> >> For instance there is the logging module, it can log the thread name. So
> >> I would like to know how I can get the logging module to call the
> >> function from my module to get the current_thread, instead of it calling
> >> "current_thread" from the threading module.
> > Easy: make sure your module is called "threading.py" and is earlier in
> > the path than the standard library. In fact, it's so easy that people
> > do it unintentionally all the time... Generally, the current directory
> > (or the script directory) is the first entry in sys.path, so that's a
> > good place to put it.
>
> Well I had hope for a somewhat more selective solution. The intention is
> to have a number of modules collected in a package where this module is
> one of and the package is available via the "installed" search path.
>
> So the programmer should just be able to choose to write his code with
> either:
>
>      from threading import Thread
>
> or
>
>      from QYZlib.threaders import Thread
>

How do you intend to distinguish one from the other? How should the
logging module know which threading module to use?

ChrisA

From antoon.pardon at vub.be  Tue Dec 27 07:04:53 2022
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 27 Dec 2022 13:04:53 +0100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
Message-ID: <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>



Op 27/12/2022 om 12:28 schreef Chris Angelico:
> On Tue, 27 Dec 2022 at 22:13, Antoon Pardon<antoon.pardon at vub.be>  wrote:
>>
>>
>> Op 27/12/2022 om 11:37 schreef Chris Angelico:
>>> On Tue, 27 Dec 2022 at 21:29, Antoon Pardon<antoon.pardon at vub.be>  wrote:
>>>> OK, I am writing an alternative for the threading module. What I would
>>>> like to know is how I can get some library modules call my alternative
>>>> instead of the threading module.
>>>>
>>>> For instance there is the logging module, it can log the thread name. So
>>>> I would like to know how I can get the logging module to call the
>>>> function from my module to get the current_thread, instead of it calling
>>>> "current_thread" from the threading module.
>>> Easy: make sure your module is called "threading.py" and is earlier in
>>> the path than the standard library. In fact, it's so easy that people
>>> do it unintentionally all the time... Generally, the current directory
>>> (or the script directory) is the first entry in sys.path, so that's a
>>> good place to put it.
>> Well I had hope for a somewhat more selective solution. The intention is
>> to have a number of modules collected in a package where this module is
>> one of and the package is available via the "installed" search path.
>>
>> So the programmer should just be able to choose to write his code with
>> either:
>>
>>       from threading import Thread
>>
>> or
>>
>>       from QYZlib.threaders import Thread
>>
> How do you intend to distinguish one from the other? How should the
> logging module know which threading module to use?

That is my question! How can I get the logging module to use my module.I was hoping the logging module would allow some kind of dependency 
injection, so you can tell it what threading module to use. An other 
option might be to manipulate sys.modules. -- Antoon Pardon

From rosuav at gmail.com  Tue Dec 27 07:09:37 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 27 Dec 2022 23:09:37 +1100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
Message-ID: <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>

On Tue, 27 Dec 2022 at 23:06, Antoon Pardon <antoon.pardon at vub.be> wrote:
> > How do you intend to distinguish one from the other? How should the
> > logging module know which threading module to use?
>
> That is my question! How can I get the logging module to use my module.I was hoping the logging module would allow some kind of dependency
> injection, so you can tell it what threading module to use. An other
> option might be to manipulate sys.modules. -- Antoon Pardon

But presumably you want OTHER modules to continue using the vanilla
threading module? This is likely to end up somewhat hacky. Yes, you
can manipulate sys.modules, but there's only one threading module at a
time, so you need a way to distinguish between modules that should use
the changed one and modules that shouldn't.

TBH this is starting to sound like something where you want
unittest-type facilities, actually.

ChrisA

From antoon.pardon at vub.be  Tue Dec 27 07:26:37 2022
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 27 Dec 2022 13:26:37 +0100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
 <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
Message-ID: <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>



Op 27/12/2022 om 13:09 schreef Chris Angelico:
> On Tue, 27 Dec 2022 at 23:06, Antoon Pardon<antoon.pardon at vub.be>  wrote:
>>> How do you intend to distinguish one from the other? How should the
>>> logging module know which threading module to use?
>> That is my question! How can I get the logging module to use my module.I was hoping the logging module would allow some kind of dependency
>> injection, so you can tell it what threading module to use. An other
>> option might be to manipulate sys.modules. -- Antoon Pardon
> But presumably you want OTHER modules to continue using the vanilla
> threading module? This is likely to end up somewhat hacky. Yes, you
> can manipulate sys.modules, but there's only one threading module at a
> time, so you need a way to distinguish between modules that should use
> the changed one and modules that shouldn't.

But don't these caveats also apply with your original answer of having a
local threading.py file?

At the moment I am happy with a solution that once the programmer has
imported from QYZlib.threaders that module will used as the threading
module.

-- 
Antoon Pardon.

From rosuav at gmail.com  Tue Dec 27 07:46:09 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Tue, 27 Dec 2022 23:46:09 +1100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
 <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
 <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>
Message-ID: <CAPTjJmpm-+GQTRYnT=N_6asxCgPvfg+wpccJf4gfv=w-EUZw-Q@mail.gmail.com>

On Tue, 27 Dec 2022 at 23:28, Antoon Pardon <antoon.pardon at vub.be> wrote:
>
>
>
> Op 27/12/2022 om 13:09 schreef Chris Angelico:
> > On Tue, 27 Dec 2022 at 23:06, Antoon Pardon<antoon.pardon at vub.be>  wrote:
> >>> How do you intend to distinguish one from the other? How should the
> >>> logging module know which threading module to use?
> >> That is my question! How can I get the logging module to use my module.I was hoping the logging module would allow some kind of dependency
> >> injection, so you can tell it what threading module to use. An other
> >> option might be to manipulate sys.modules. -- Antoon Pardon
> > But presumably you want OTHER modules to continue using the vanilla
> > threading module? This is likely to end up somewhat hacky. Yes, you
> > can manipulate sys.modules, but there's only one threading module at a
> > time, so you need a way to distinguish between modules that should use
> > the changed one and modules that shouldn't.
>
> But don't these caveats also apply with your original answer of having a
> local threading.py file?
>
> At the moment I am happy with a solution that once the programmer has
> imported from QYZlib.threaders that module will used as the threading
> module.
>

Oh! If that's all you need, then yes, a simple patch of sys.modules
will work. You'll have to make sure you get your module imported
before anything else pulls up the vanilla one, though. Otherwise, your
only option is to keep the existing module object and monkeypatch it
with whatever changes you need.

But a simple "sys.modules['threading'] = QYZlib.threaders" will work.
Of course, how *well* this works depends also on how well that module
manages to masquerade as the threading module, but I'm sure you've
figured that part out :)

ChrisA

From antoon.pardon at vub.be  Tue Dec 27 08:25:00 2022
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Tue, 27 Dec 2022 14:25:00 +0100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <CAPTjJmpm-+GQTRYnT=N_6asxCgPvfg+wpccJf4gfv=w-EUZw-Q@mail.gmail.com>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
 <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
 <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>
 <CAPTjJmpm-+GQTRYnT=N_6asxCgPvfg+wpccJf4gfv=w-EUZw-Q@mail.gmail.com>
Message-ID: <302d8b3c-86b2-ebb7-84ff-8d290b30af35@vub.be>



Op 27/12/2022 om 13:46 schreef Chris Angelico:
> On Tue, 27 Dec 2022 at 23:28, Antoon Pardon<antoon.pardon at vub.be>  wrote:
>> At the moment I am happy with a solution that once the programmer has
>> imported from QYZlib.threaders that module will used as the threading
>> module.
>>
> Oh! If that's all you need, then yes, a simple patch of sys.modules
> will work. You'll have to make sure you get your module imported
> before anything else pulls up the vanilla one, though. Otherwise, your
> only option is to keep the existing module object and monkeypatch it
> with whatever changes you need.
>
> But a simple "sys.modules['threading'] = QYZlib.threaders" will work.
> Of course, how *well* this works depends also on how well that module
> manages to masquerade as the threading module, but I'm sure you've
> figured that part out :)

Well it is what will work for the moment. Thanks for the confirmation
this will indeed work.

-- 
Antoon Pardon.

From nntp.mbourne at spamgourmet.com  Tue Dec 27 08:37:08 2022
From: nntp.mbourne at spamgourmet.com (Mark Bourne)
Date: Tue, 27 Dec 2022 13:37:08 +0000
Subject: How make your module substitute a python stdlib module.
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <mailman.1308.1672139542.20444.python-list@python.org>
Message-ID: <toese5$1meo$1@gioia.aioe.org>

Antoon Pardon wrote:
> 
> 
> Op 27/12/2022 om 11:37 schreef Chris Angelico:
>> On Tue, 27 Dec 2022 at 21:29, Antoon Pardon <antoon.pardon at vub.be> wrote:
>>> OK, I am writing an alternative for the threading module. What I would
>>> like to know is how I can get some library modules call my alternative
>>> instead of the threading module.
>>>
>>> For instance there is the logging module, it can log the thread name. So
>>> I would like to know how I can get the logging module to call the
>>> function from my module to get the current_thread, instead of it calling
>>> "current_thread" from the threading module.
>> Easy: make sure your module is called "threading.py" and is earlier in
>> the path than the standard library. In fact, it's so easy that people
>> do it unintentionally all the time... Generally, the current directory
>> (or the script directory) is the first entry in sys.path, so that's a
>> good place to put it.
> 
> Well I had hope for a somewhat more selective solution. The intention is
> to have a number of modules collected in a package where this module is
> one of and the package is available via the "installed" search path.
> 
> So the programmer should just be able to choose to write his code with
> either:
> 
>  ??? from threading import Thread
> 
> or
> 
>  ??? from QYZlib.threaders import Thread 

In that case, it sounds like you don't want to always replace the 
logging module's behaviour, since code might use the standard threading 
module.  You might also need to consider that a mix of both the standard 
threading module and yours might be used (particularly if using other 
libraries which create their own threads using the standard module).

It might be better for your module to provide a custom `logging.Filter` 
subclass, which replaces the `thread` and `threadName` attributes of the 
`LogRecord` with your threading module's idea of the thread ID.  Then 
applications using your threading module would configure the `logging` 
module to use your filter, while code using the standard threading 
module can continue as normal.  Despite the name, logging filters can 
also modify log records, not just filter whether or not they're logged.

It might even be desirable to leave the original `thread` and 
`threadName` attributes unchanged and add new attributes to the 
`LogRecord` for your module's idea of threads (e.g. `myThread` and 
`myThreadName`).  I think using `%(myThread)d` and `%(myThreadName)s` in 
the log format string would use those attributes, without needing a 
custom formatter.  That would allow both thread IDs to be logged, in 
case a mix of standard threads and your threads is used.

-- 
Mark.

From dieter at handshake.de  Tue Dec 27 13:46:38 2022
From: dieter at handshake.de (Dieter Maurer)
Date: Tue, 27 Dec 2022 19:46:38 +0100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <302d8b3c-86b2-ebb7-84ff-8d290b30af35@vub.be>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
 <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
 <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>
 <CAPTjJmpm-+GQTRYnT=N_6asxCgPvfg+wpccJf4gfv=w-EUZw-Q@mail.gmail.com>
 <302d8b3c-86b2-ebb7-84ff-8d290b30af35@vub.be>
Message-ID: <25515.15758.806652.162959@ixdm.fritz.box>

Antoon Pardon wrote at 2022-12-27 14:25 +0100:
> ...
>> But a simple "sys.modules['threading'] = QYZlib.threaders" will work.
>> Of course, how *well* this works depends also on how well that module
>> manages to masquerade as the threading module, but I'm sure you've
>> figured that part out :)
>
>Well it is what will work for the moment. Thanks for the confirmation
>this will indeed work.

If you need to change a module in minor ways (e.g. only
provide a custom `thread_ident` function), you can use
a technique called "monkey patching" (which is patching at runtime).

You can usually assign new values to module variables.
Thus, you yould try `threading.thread_ident = <your function>`.

This would affect most uses of the function -- which may not be
a good idea.
Alternatively, you could monkey patch the `logging` module.
Look at its code and find out whether it accesses the function
directly or indirectly via `threading`. In the first case,
you would monkey patch the function, in the second the `threading`
variable.

You could also use `dm.reuse` (a package maintained on PyPI)
to override the method using the function. This way, your
change would be even more localized.

From list1 at tompassin.net  Tue Dec 27 10:49:45 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Tue, 27 Dec 2022 10:49:45 -0500
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <302d8b3c-86b2-ebb7-84ff-8d290b30af35@vub.be>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
 <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
 <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>
 <CAPTjJmpm-+GQTRYnT=N_6asxCgPvfg+wpccJf4gfv=w-EUZw-Q@mail.gmail.com>
 <302d8b3c-86b2-ebb7-84ff-8d290b30af35@vub.be>
Message-ID: <f796a72c-70b8-5b6b-a45c-cd63b9fa58d2@tompassin.net>

On 12/27/2022 8:25 AM, Antoon Pardon wrote:
> 
> 
> Op 27/12/2022 om 13:46 schreef Chris Angelico:
>> On Tue, 27 Dec 2022 at 23:28, Antoon Pardon<antoon.pardon at vub.be>? wrote:
>>> At the moment I am happy with a solution that once the programmer has
>>> imported from QYZlib.threaders that module will used as the threading
>>> module.
>>>
>> Oh! If that's all you need, then yes, a simple patch of sys.modules
>> will work. You'll have to make sure you get your module imported
>> before anything else pulls up the vanilla one, though. Otherwise, your
>> only option is to keep the existing module object and monkeypatch it
>> with whatever changes you need.
>>
>> But a simple "sys.modules['threading'] = QYZlib.threaders" will work.
>> Of course, how *well* this works depends also on how well that module
>> manages to masquerade as the threading module, but I'm sure you've
>> figured that part out :)
> 
> Well it is what will work for the moment. Thanks for the confirmation
> this will indeed work.


What you **should not** do is to make other modules use your code when 
they think they are using the standard library.  Raymond Chen in The Old 
New Thing blog often writes about users who want to do a basically 
similar thing. He always asks "What if some other program wants to do 
the same thing?"  One case was when a developer wanted his program's 
icon to force itself to be at the top position in the Windows task bar. 
"What if another program tried this too?"  The two would keep trying to 
displace each other at the top position.

If you set the PYTHONPATH environmental variable, you can put any 
directory you like to be at the start of the module search path after 
the current directory.  Perhaps this would be enough for your use case?

From antoon.pardon at vub.be  Wed Dec 28 05:39:08 2022
From: antoon.pardon at vub.be (Antoon Pardon)
Date: Wed, 28 Dec 2022 11:39:08 +0100
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <f796a72c-70b8-5b6b-a45c-cd63b9fa58d2@tompassin.net>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
 <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
 <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>
 <CAPTjJmpm-+GQTRYnT=N_6asxCgPvfg+wpccJf4gfv=w-EUZw-Q@mail.gmail.com>
 <302d8b3c-86b2-ebb7-84ff-8d290b30af35@vub.be>
 <f796a72c-70b8-5b6b-a45c-cd63b9fa58d2@tompassin.net>
Message-ID: <a39b3b78-6a8e-e635-6dac-e9eb5462d36b@vub.be>

Op 27/12/2022 om 16:49 schreef Thomas Passin:
> On 12/27/2022 8:25 AM, Antoon Pardon wrote:
>>
>>
>> Op 27/12/2022 om 13:46 schreef Chris Angelico:
>>> On Tue, 27 Dec 2022 at 23:28, Antoon Pardon<antoon.pardon at vub.be>? 
>>> wrote:
>>>> At the moment I am happy with a solution that once the programmer has
>>>> imported from QYZlib.threaders that module will used as the threading
>>>> module.
>>>>
>>> Oh! If that's all you need, then yes, a simple patch of sys.modules
>>> will work. You'll have to make sure you get your module imported
>>> before anything else pulls up the vanilla one, though. Otherwise, your
>>> only option is to keep the existing module object and monkeypatch it
>>> with whatever changes you need.
>>>
>>> But a simple "sys.modules['threading'] = QYZlib.threaders" will work.
>>> Of course, how *well* this works depends also on how well that module
>>> manages to masquerade as the threading module, but I'm sure you've
>>> figured that part out :)
>>
>> Well it is what will work for the moment. Thanks for the confirmation
>> this will indeed work.
>
>
> What you **should not** do is to make other modules use your code when 
> they think they are using the standard library. Raymond Chen in The 
> Old New Thing blog often writes about users who want to do a basically 
> similar thing. He always asks "What if some other program wants to do 
> the same thing?"? One case was when a developer wanted his program's 
> icon to force itself to be at the top position in the Windows task 
> bar. "What if another program tried this too?"? The two would keep 
> trying to displace each other at the top position.
>
> If you set the PYTHONPATH environmental variable, you can put any 
> directory you like to be at the start of the module search path after 
> the current directory.? Perhaps this would be enough for your use case?

But if I put a threading.py file in that directory, it would make other 
modules use my code when they "think" they are using the standard library.

The problem is that the logging module uses threading, but doesn't allow 
you to specify which threading module to use. So if you want to use an 
alternative, you either have to do things like this, or copy the logging 
packages into your project and adapt it to use your alternative.



From list1 at tompassin.net  Wed Dec 28 10:55:51 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Wed, 28 Dec 2022 10:55:51 -0500
Subject: How make your module substitute a python stdlib module.
In-Reply-To: <a39b3b78-6a8e-e635-6dac-e9eb5462d36b@vub.be>
References: <9ac8fb4f-b998-e7cd-6499-e3427e42e420@vub.be>
 <CAPTjJmovVh4w87k1RzqFaZ02-AjVcWoBJR5B8NAYJY0kdO-4uw@mail.gmail.com>
 <909b8fd7-de13-1945-63a5-f71d286a78a4@vub.be>
 <CAPTjJmq38bd-EGAv+pS2mbS1N_BzgvWzYyR0-2sDjUt-LLKLmg@mail.gmail.com>
 <20a11b92-c2c9-e06f-07e9-44a42391ee3f@vub.be>
 <CAPTjJmog8T7gVUFx_0FG77xfmifeJEMdiqtKQpLH=gUqkpcSbQ@mail.gmail.com>
 <ab0f6f2c-7bec-b50e-ec66-633c82954af9@vub.be>
 <CAPTjJmpm-+GQTRYnT=N_6asxCgPvfg+wpccJf4gfv=w-EUZw-Q@mail.gmail.com>
 <302d8b3c-86b2-ebb7-84ff-8d290b30af35@vub.be>
 <f796a72c-70b8-5b6b-a45c-cd63b9fa58d2@tompassin.net>
 <a39b3b78-6a8e-e635-6dac-e9eb5462d36b@vub.be>
Message-ID: <46619686-a011-f7e9-b7d5-b8b9790fb7b0@tompassin.net>

On 12/28/2022 5:39 AM, Antoon Pardon wrote:
> Op 27/12/2022 om 16:49 schreef Thomas Passin:
>> On 12/27/2022 8:25 AM, Antoon Pardon wrote:
>>>
>>>
>>> Op 27/12/2022 om 13:46 schreef Chris Angelico:
>>>> On Tue, 27 Dec 2022 at 23:28, Antoon Pardon<antoon.pardon at vub.be> 
>>>> wrote:
>>>>> At the moment I am happy with a solution that once the programmer has
>>>>> imported from QYZlib.threaders that module will used as the threading
>>>>> module.
>>>>>
>>>> Oh! If that's all you need, then yes, a simple patch of sys.modules
>>>> will work. You'll have to make sure you get your module imported
>>>> before anything else pulls up the vanilla one, though. Otherwise, your
>>>> only option is to keep the existing module object and monkeypatch it
>>>> with whatever changes you need.
>>>>
>>>> But a simple "sys.modules['threading'] = QYZlib.threaders" will work.
>>>> Of course, how *well* this works depends also on how well that module
>>>> manages to masquerade as the threading module, but I'm sure you've
>>>> figured that part out :)
>>>
>>> Well it is what will work for the moment. Thanks for the confirmation
>>> this will indeed work.
>>
>>
>> What you **should not** do is to make other modules use your code when 
>> they think they are using the standard library. Raymond Chen in The 
>> Old New Thing blog often writes about users who want to do a basically 
>> similar thing. He always asks "What if some other program wants to do 
>> the same thing?"? One case was when a developer wanted his program's 
>> icon to force itself to be at the top position in the Windows task 
>> bar. "What if another program tried this too?"? The two would keep 
>> trying to displace each other at the top position.
>>
>> If you set the PYTHONPATH environmental variable, you can put any 
>> directory you like to be at the start of the module search path after 
>> the current directory.? Perhaps this would be enough for your use case?
> 
> But if I put a threading.py file in that directory, it would make other 
> modules use my code when they "think" they are using the standard library.
> 
> The problem is that the logging module uses threading, but doesn't allow 
> you to specify which threading module to use. So if you want to use an 
> alternative, you either have to do things like this, or copy the logging 
> packages into your project and adapt it to use your alternative.

In that case, I think your best bet would be to write wrappers for the 
threading classes or functions you want to use.  Your wrappers would 
import from the threading module and could then produce the behavior you 
want.


From alexander.richert at noaa.gov  Wed Dec 28 13:42:29 2022
From: alexander.richert at noaa.gov (Alexander Richert - NOAA Affiliate)
Date: Wed, 28 Dec 2022 10:42:29 -0800
Subject: Possible re bug when using ".*"
Message-ID: <CAGzSPDAF-=xywBvHbs_XEfCYRQyGb=3kQKcNaQfBhLsHHL-5Vg@mail.gmail.com>

 In a couple recent versions of Python (including 3.8 and 3.10), the
following code:
import re
print(re.sub(".*", "replacement", "pattern"))
yields the output "replacementreplacement".

This behavior does not occur in 3.6.

Which behavior is the desired one? Perhaps relatedly, I noticed that even
in 3.6, the code
print(re.findall(".*","pattern"))
yields ['pattern',''] which is not what I was expecting.

Thanks,
Alex Richert

-- 
Alexander Richert, PhD
*RedLine Performance Systems*

From roel at roelschroeven.net  Wed Dec 28 13:59:09 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Wed, 28 Dec 2022 19:59:09 +0100
Subject: Possible re bug when using ".*"
In-Reply-To: <CAGzSPDAF-=xywBvHbs_XEfCYRQyGb=3kQKcNaQfBhLsHHL-5Vg@mail.gmail.com>
References: <CAGzSPDAF-=xywBvHbs_XEfCYRQyGb=3kQKcNaQfBhLsHHL-5Vg@mail.gmail.com>
Message-ID: <2be03a38-87af-a064-1c67-69ba627f7c4f@roelschroeven.net>

Alexander Richert - NOAA Affiliate via Python-list schreef op 28/12/2022 
om 19:42:
>   In a couple recent versions of Python (including 3.8 and 3.10), the
> following code:
> import re
> print(re.sub(".*", "replacement", "pattern"))
> yields the output "replacementreplacement".
>
> This behavior does not occur in 3.6.
>
> Which behavior is the desired one? Perhaps relatedly, I noticed that even
> in 3.6, the code
> print(re.findall(".*","pattern"))
> yields ['pattern',''] which is not what I was expecting.
The documentation for re.sub() and re.findall() has these notes: 
"Changed in version 3.7: Empty matches for the pattern are replaced when 
adjacent to a previous non-empty match." and "Changed in version 3.7: 
Non-empty matches can now start just after a previous empty match."
That's probably describes the behavior you're seeing. ".*" first matches 
"pattern", which is a non-empty match; then it matches the empty string 
at the end, which is an empty match but is replaced because it is 
adjacent to a non-empty match.

Seems somewhat counter-intuitive to me, but AFAICS it's the intended 
behavior.

-- 
"Programming today is a race between software engineers striving to build bigger
and better idiot-proof programs, and the Universe trying to produce bigger and
better idiots. So far, the Universe is winning."
         -- Douglas Adams

From roel at roelschroeven.net  Wed Dec 28 14:03:04 2022
From: roel at roelschroeven.net (Roel Schroeven)
Date: Wed, 28 Dec 2022 20:03:04 +0100
Subject: Possible re bug when using ".*"
In-Reply-To: <2be03a38-87af-a064-1c67-69ba627f7c4f@roelschroeven.net>
References: <CAGzSPDAF-=xywBvHbs_XEfCYRQyGb=3kQKcNaQfBhLsHHL-5Vg@mail.gmail.com>
 <2be03a38-87af-a064-1c67-69ba627f7c4f@roelschroeven.net>
Message-ID: <f428ad65-3151-05bb-d1b2-b765bccc7ed9@roelschroeven.net>

Roel Schroeven schreef op 28/12/2022 om 19:59:
> Alexander Richert - NOAA Affiliate via Python-list schreef op 
> 28/12/2022 om 19:42:
>>   In a couple recent versions of Python (including 3.8 and 3.10), the
>> following code:
>> import re
>> print(re.sub(".*", "replacement", "pattern"))
>> yields the output "replacementreplacement".
>>
>> This behavior does not occur in 3.6.
>>
>> Which behavior is the desired one? Perhaps relatedly, I noticed that even
>> in 3.6, the code
>> print(re.findall(".*","pattern"))
>> yields ['pattern',''] which is not what I was expecting.
> The documentation for re.sub() and re.findall() has these notes: 
> "Changed in version 3.7: Empty matches for the pattern are replaced 
> when adjacent to a previous non-empty match." and "Changed in version 
> 3.7: Non-empty matches can now start just after a previous empty match."
> That's probably describes the behavior you're seeing. ".*" first 
> matches "pattern", which is a non-empty match; then it matches the 
> empty string at the end, which is an empty match but is replaced 
> because it is adjacent to a non-empty match.
>
> Seems somewhat counter-intuitive to me, but AFAICS it's the intended 
> behavior.
For what it's worth, there's some discussion about this in this Github 
issue: https://github.com/python/cpython/issues/76489

-- 
"Je ne suis pas d?accord avec ce que vous dites, mais je me battrai jusqu??
la mort pour que vous ayez le droit de le dire."
         -- Attribu? ? Voltaire
"I disapprove of what you say, but I will defend to the death your right to
say it."
         -- Attributed to Voltaire
"Ik ben het niet eens met wat je zegt, maar ik zal je recht om het te zeggen
tot de dood toe verdedigen"
         -- Toegeschreven aan Voltaire

From python at mrabarnett.plus.com  Wed Dec 28 14:07:06 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Wed, 28 Dec 2022 19:07:06 +0000
Subject: Possible re bug when using ".*"
In-Reply-To: <CAGzSPDAF-=xywBvHbs_XEfCYRQyGb=3kQKcNaQfBhLsHHL-5Vg@mail.gmail.com>
References: <CAGzSPDAF-=xywBvHbs_XEfCYRQyGb=3kQKcNaQfBhLsHHL-5Vg@mail.gmail.com>
Message-ID: <014c86f6-d181-ec5c-3908-88dabd52a966@mrabarnett.plus.com>

On 2022-12-28 18:42, Alexander Richert - NOAA Affiliate via Python-list 
wrote:
>   In a couple recent versions of Python (including 3.8 and 3.10), the
> following code:
> import re
> print(re.sub(".*", "replacement", "pattern"))
> yields the output "replacementreplacement".
> 
> This behavior does not occur in 3.6.
> 
> Which behavior is the desired one? Perhaps relatedly, I noticed that even
> in 3.6, the code
> print(re.findall(".*","pattern"))
> yields ['pattern',''] which is not what I was expecting.
> 
It's not a bug, it's a change in behaviour to bring it more into line 
with other regex implementations in other languages.

From ethan at stoneleaf.us  Wed Dec 28 15:37:20 2022
From: ethan at stoneleaf.us (Ethan Furman)
Date: Wed, 28 Dec 2022 12:37:20 -0800
Subject: Possible re bug when using ".*"
In-Reply-To: <014c86f6-d181-ec5c-3908-88dabd52a966@mrabarnett.plus.com>
References: <CAGzSPDAF-=xywBvHbs_XEfCYRQyGb=3kQKcNaQfBhLsHHL-5Vg@mail.gmail.com>
 <014c86f6-d181-ec5c-3908-88dabd52a966@mrabarnett.plus.com>
Message-ID: <e0479542-9749-7c38-dd9a-5ba7fbbf8bc4@stoneleaf.us>

On 12/28/22 11:07, MRAB wrote:
> On 2022-12-28 18:42, Alexander Richert - NOAA Affiliate via Python-list wrote:
>> ? In a couple recent versions of Python (including 3.8 and 3.10), the
>> following code:
>> import re
>> print(re.sub(".*", "replacement", "pattern"))
>> yields the output "replacementreplacement".
>>
>> This behavior does not occur in 3.6.
>>
>> Which behavior is the desired one? Perhaps relatedly, I noticed that even
>> in 3.6, the code
>> print(re.findall(".*","pattern"))
>> yields ['pattern',''] which is not what I was expecting.
>>
> It's not a bug, it's a change in behaviour to bring it more into line with other regex implementations in other languages.

The new behavior makes no sense to me, but better to be consistent with the other regex engines than not -- I still get 
thrown off by vim's regex.

--
~Ethan~

From barry at barrys-emacs.org  Thu Dec 29 08:17:34 2022
From: barry at barrys-emacs.org (Barry Scott)
Date: Thu, 29 Dec 2022 13:17:34 +0000
Subject: Possible re bug
In-Reply-To: <re-20221228195100@ram.dialup.fu-berlin.de>
References: <re-20221228195100@ram.dialup.fu-berlin.de>
Message-ID: <07801d28-76c1-a8dc-1c5c-c74d5fff2a84@barrys-emacs.org>

Please please fix you email client so that your replies stay with the
emails you are replying to.

Barry


On 28/12/2022 19:09, Stefan Ram wrote:
> Alexander Richert writes:
> |print(re.findall(".*","pattern"))
> |yields ['pattern',''] which is not what I was expecting.
>
>    The asterisk is "greedy", so I agree that it should consume
>    /everything/ including all the empty strings at the end.
>    To work around this, one can use '^.*' (no smiley intended).
>
>

From supersellerninja at gmail.com  Fri Dec 30 02:55:36 2022
From: supersellerninja at gmail.com (Mor yosef)
Date: Fri, 30 Dec 2022 09:55:36 +0200
Subject: help
Message-ID: <CAJQsdgj2QJiRApW-e81BuYt-UZRVxBxF+NT6qjFvVcYA2oQoGg@mail.gmail.com>

Hello guys,
i install python 3.11.1, and i have google chrome so i download the
Webdriver Chrome
and i just add it on my c:// driver and when i add some script on my
desktop i try to run it from the terminal and all the time i receive this
error message : maybe you guys can help me with this one?
when i add some random code the terminal like "python -m webbrowser
https://www.google.com" it's just works (it's open the website in new tab)
Regards
Mor yosef

From boblatest at yahoo.com  Fri Dec 30 08:48:01 2022
From: boblatest at yahoo.com (Robert Latest)
Date: 30 Dec 2022 13:48:01 GMT
Subject: Why can't the pointer in a PyCapsule be NULL?
Message-ID: <k188ghFdnulU1@mid.individual.net>

Hi all,

the question is in the subject. I'd like the pointer to be able to be NULL
because that would make my code slightly cleaner. No big deal though.

From boblatest at yahoo.com  Fri Dec 30 12:59:10 2022
From: boblatest at yahoo.com (Robert Latest)
Date: 30 Dec 2022 17:59:10 GMT
Subject: Why can't the pointer in a PyCapsule be NULL?
References: <k188ghFdnulU1@mid.individual.net>
 <NULL-20221230152003@ram.dialup.fu-berlin.de>
Message-ID: <k18n7eFg18gU1@mid.individual.net>

Stefan Ram wrote:
> Robert Latest <boblatest at yahoo.com> writes:
>>the question is in the subject. I'd like the pointer to be able to be NULL
>>because that would make my code slightly cleaner. No big deal though.
>
>   In Usenet, it is considered good style to have all relevant
>   content in the body.

Makes sense.

>   . On a superficial level, the answer is: "Because
>   PyCapsule_GetPointer uses NULL to indicate failure."

Makes sense, too. Thanks.

From arequipeno at gmail.com  Fri Dec 30 16:41:19 2022
From: arequipeno at gmail.com (Ian Pilcher)
Date: Fri, 30 Dec 2022 15:41:19 -0600
Subject: set.add() doesn't replace equal element
Message-ID: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>

I just discovered this behavior, which is problematic for my particular
use.  Is there a different set API (or operator) that can be used to
add an element to a set, and replace any equal element?

If not, am I correct that I should call set.discard() before calling
set.add() to achieve the behavior that I want?

-- 
========================================================================
Google                                      Where SkyNet meets Idiocracy
========================================================================

From pbryan at anode.ca  Fri Dec 30 16:47:59 2022
From: pbryan at anode.ca (Paul Bryan)
Date: Fri, 30 Dec 2022 13:47:59 -0800
Subject: set.add() doesn't replace equal element
In-Reply-To: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
References: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
Message-ID: <ZJ4QNR.MRMQX7HA6XKF1@anode.ca>

What kind of elements are being added to the set? Can you show 
reproducible sample code?

On Fri, Dec 30 2022 at 03:41:19 PM -0600, Ian Pilcher 
<arequipeno at gmail.com> wrote:
> I just discovered this behavior, which is problematic for my 
> particular
> use.  Is there a different set API (or operator) that can be used to
> add an element to a set, and replace any equal element?
> 
> If not, am I correct that I should call set.discard() before calling
> set.add() to achieve the behavior that I want?
> 
> --
> ========================================================================
> Google                                      Where SkyNet meets 
> Idiocracy
> ========================================================================
> --
> <https://mail.python.org/mailman/listinfo/python-list>


From rosuav at gmail.com  Fri Dec 30 16:58:20 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 31 Dec 2022 08:58:20 +1100
Subject: set.add() doesn't replace equal element
In-Reply-To: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
References: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
Message-ID: <CAPTjJmp8=hdECMzMWFK7iSbZtenK+YBBWtLY6wd=Z4gM4C3UeA@mail.gmail.com>

On Sat, 31 Dec 2022 at 08:42, Ian Pilcher <arequipeno at gmail.com> wrote:
>
> I just discovered this behavior, which is problematic for my particular
> use.  Is there a different set API (or operator) that can be used to
> add an element to a set, and replace any equal element?
>
> If not, am I correct that I should call set.discard() before calling
> set.add() to achieve the behavior that I want?
>

Use a dictionary. Initially, map everything to itself. You can then
replace things with the new keys:

>>> stuff = {}
>>> stuff[1] = 1
>>> stuff[4] = 4
>>> stuff[True] = True
>>> stuff[2] = 2
>>> stuff[4.0] = 4.0
>>> stuff
{1: True, 4: 4.0, 2: 2}

To see what's in your set, look at the dictionary's values. They will
replace any equal elements, leaving the keys unchanged.

ChrisA

From avi.e.gross at gmail.com  Fri Dec 30 17:03:54 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Fri, 30 Dec 2022 17:03:54 -0500
Subject: set.add() doesn't replace equal element
In-Reply-To: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
References: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
Message-ID: <002b01d91c9a$9be04d90$d3a0e8b0$@gmail.com>

Ian,

Do you have some examples of things you can put in a set that you consider
equal but want to store in the set INSTEAD of any current element?

What follows is some thoughts on some methods you could build yourself.
Others re possible and someone else may present you with a module that does
what you want.

In principle, if you had a function that produced a canonical version of an
argument as a sort of FIRST choice, you might still have to do some serious
work.

Assuming alpha, beta and gamma are all what you define as equal, such as if
you consider the value of a string like "32.00" to be equal to
"32.000000000" or even to "64/2", then you can get ALL elements of the set
and call your function on it and  compare it to the function applied to your
new proposed set addition. So f(alpha)and f(beta) and f(gamma) would by
definition return the same result, albeit that might be an integer like 32,
or a string of "32.0" or whatever you need. 

Now are you sure the set has no "duplicates" already per your algorithm?

If you are, your algorithm would need to loop on all keys and if a key
matches using f() and the newer version is not otherwise identical, remove
the old and insert the new. You can break out of the loop at that point BUT
if there is no uniqueness guarantee, you need to process all keys every
time.

A possible improvement would be to consider various mixed approaches. You
could use a dictionary where the keys are f(whatever) and the values are the
current "whatever" as one example. The "set" then would be the values of the
dictionary when you need  that view, and the dictionary as a whole when you
want to add or delete. If you needed operations like union and intersect, it
may take more work.

And, of course, you can maintain two sets. The other set would contain only
f(whatever) while the first would contain the "whatever"s.

What you are describing may have been implemented with a concept like
partitions. An example might be the partitioning of numbers modulo N so that
numbers are considered "equal" if they leave the same remainder when divided
by N. Rather than use a set directly, this could be better done by creating
an object that manages internal data structures so asking it to add a new
number results in it calculating the remainder, seeing if it is in use, and
replacing it with the latest if needed.

Avi


-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
Behalf Of Ian Pilcher
Sent: Friday, December 30, 2022 4:41 PM
To: python-list at python.org
Subject: set.add() doesn't replace equal element

I just discovered this behavior, which is problematic for my particular use.
Is there a different set API (or operator) that can be used to add an
element to a set, and replace any equal element?

If not, am I correct that I should call set.discard() before calling
set.add() to achieve the behavior that I want?

--
========================================================================
Google                                      Where SkyNet meets Idiocracy
========================================================================
--
https://mail.python.org/mailman/listinfo/python-list


From cgrace.chris at gmail.com  Fri Dec 30 17:13:48 2022
From: cgrace.chris at gmail.com (Chris Grace)
Date: Fri, 30 Dec 2022 17:13:48 -0500
Subject: help
In-Reply-To: <CAJQsdgj2QJiRApW-e81BuYt-UZRVxBxF+NT6qjFvVcYA2oQoGg@mail.gmail.com>
References: <CAJQsdgj2QJiRApW-e81BuYt-UZRVxBxF+NT6qjFvVcYA2oQoGg@mail.gmail.com>
Message-ID: <CA+vPKvkuw7X8bVQJSVx+nQBrPq=FmA+X38ZHDubyWAPmR2dN_A@mail.gmail.com>

Hello,

The mailing list strips all images. We cannot see the error you posted. I'd
recommend posting it in text form.

What is the script you are running?

What do you expect your script to do?

On Fri, Dec 30, 2022, 3:14 PM Mor yosef <supersellerninja at gmail.com> wrote:

> Hello guys,
> i install python 3.11.1, and i have google chrome so i download the
> Webdriver Chrome
> and i just add it on my c:// driver and when i add some script on my
> desktop i try to run it from the terminal and all the time i receive this
> error message : maybe you guys can help me with this one?
> when i add some random code the terminal like "python -m webbrowser
> https://www.google.com" it's just works (it's open the website in new tab)
> Regards
> Mor yosef
> --
> https://mail.python.org/mailman/listinfo/python-list
>

From arequipeno at gmail.com  Fri Dec 30 17:27:56 2022
From: arequipeno at gmail.com (Ian Pilcher)
Date: Fri, 30 Dec 2022 16:27:56 -0600
Subject: set.add() doesn't replace equal element
In-Reply-To: <ZJ4QNR.MRMQX7HA6XKF1@anode.ca>
References: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
 <ZJ4QNR.MRMQX7HA6XKF1@anode.ca>
Message-ID: <b8790bfa-f952-85eb-8ad3-b49c55048055@gmail.com>

On 12/30/22 15:47, Paul Bryan wrote:
> What kind of elements are being added to the set? Can you show 
> reproducible sample code?

The objects in question are DHCP leases.  I consider them "equal" if
the lease address (or IPv6 prefix) is equal, even if the timestamps have
changed.  That code is not small, but it's easy to demonstrate the
behavior.

 >>> import datetime
 >>> class Foo(object):
...     def __init__(self, index):
...         self.index = index
...         self.timestamp = datetime.datetime.now()
...     def __eq__(self, other):
...         return type(other) is Foo and other.index == self.index
...     def __hash__(self):
...         return hash(self.index)
...     def __repr__(self):
...         return f'Foo({self.index}) created at {str(self.timestamp)}'
...
 >>> f1 = Foo(1)
 >>> s = { f1 }
 >>> s
{Foo(1) created at 2022-12-30 16:24:12.352908}
 >>> f2 = Foo(1)
 >>> f2
Foo(1) created at 2022-12-30 16:24:35.489208
 >>> s.add(f2)
 >>> s
{Foo(1) created at 2022-12-30 16:24:12.352908}

-- 
========================================================================
Google                                      Where SkyNet meets Idiocracy
========================================================================


From rosuav at gmail.com  Fri Dec 30 17:46:45 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sat, 31 Dec 2022 09:46:45 +1100
Subject: set.add() doesn't replace equal element
In-Reply-To: <b8790bfa-f952-85eb-8ad3-b49c55048055@gmail.com>
References: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
 <ZJ4QNR.MRMQX7HA6XKF1@anode.ca>
 <b8790bfa-f952-85eb-8ad3-b49c55048055@gmail.com>
Message-ID: <CAPTjJmrx06j8LYWsmX7VrVVhFHLL5xoyJtBNu36secwVDvWSaQ@mail.gmail.com>

On Sat, 31 Dec 2022 at 09:29, Ian Pilcher <arequipeno at gmail.com> wrote:
>
> On 12/30/22 15:47, Paul Bryan wrote:
> > What kind of elements are being added to the set? Can you show
> > reproducible sample code?
>
> The objects in question are DHCP leases.  I consider them "equal" if
> the lease address (or IPv6 prefix) is equal, even if the timestamps have
> changed.  That code is not small, but it's easy to demonstrate the
> behavior.

Seems the more logical approach would be to use a dictionary mapping
the lease address/prefix to the timestamp? The part that contributes
to the equality check is the key, and everything else is the value.

ChrisA

From pbryan at anode.ca  Fri Dec 30 18:00:15 2022
From: pbryan at anode.ca (Paul Bryan)
Date: Fri, 30 Dec 2022 15:00:15 -0800
Subject: set.add() doesn't replace equal element
In-Reply-To: <b8790bfa-f952-85eb-8ad3-b49c55048055@gmail.com>
References: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
 <ZJ4QNR.MRMQX7HA6XKF1@anode.ca>
 <b8790bfa-f952-85eb-8ad3-b49c55048055@gmail.com>
Message-ID: <FW7QNR.87MNNZRX4DPR@anode.ca>

It seems to me like you have to ideas of what "equal" means. You want 
to update a "non-equal/equal" value in the set (because of a different 
time stamp). If you truly considered them equal, the time stamp would 
be irrelevant and updating the value in the set would be unnecessary.

I would:

a) /not/ consider two different leases with two different time stamps 
to be equal, and
b) as already mentioned, store them in another data structure like a 
dictionary.

Not knowing the specifics of the DHCP object structure, if a DHCP lease 
object has some immutable key or other durable immutable attribute, I 
would be inclined to make that the dictionary key, and store the DHCP 
object as the value.


On Fri, Dec 30 2022 at 04:27:56 PM -0600, Ian Pilcher 
<arequipeno at gmail.com> wrote:
> On 12/30/22 15:47, Paul Bryan wrote:
>> What kind of elements are being added to the set? Can you show 
>> reproducible sample code?
> 
> The objects in question are DHCP leases.  I consider them "equal" if
> the lease address (or IPv6 prefix) is equal, even if the timestamps 
> have
> changed.  That code is not small, but it's easy to demonstrate the
> behavior.
> 
> >>> import datetime
> >>> class Foo(object):
> ...     def __init__(self, index):
> ...         self.index = index
> ...         self.timestamp = datetime.datetime.now()
> ...     def __eq__(self, other):
> ...         return type(other) is Foo and other.index == self.index
> ...     def __hash__(self):
> ...         return hash(self.index)
> ...     def __repr__(self):
> ...         return f'Foo({self.index}) created at 
> {str(self.timestamp)}'
> ...
> >>> f1 = Foo(1)
> >>> s = { f1 }
> >>> s
> {Foo(1) created at 2022-12-30 16:24:12.352908}
> >>> f2 = Foo(1)
> >>> f2
> Foo(1) created at 2022-12-30 16:24:35.489208
> >>> s.add(f2)
> >>> s
> {Foo(1) created at 2022-12-30 16:24:12.352908}
> 
> --
> ========================================================================
> Google                                      Where SkyNet meets 
> Idiocracy
> ========================================================================
> 


From goranikac65 at gmail.com  Sat Dec 31 00:45:40 2022
From: goranikac65 at gmail.com (Goran Ikac)
Date: Sat, 31 Dec 2022 06:45:40 +0100
Subject: NoneType List
Message-ID: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>

Happy New Year, everybody!
I'm new in the Python List, new in Python world, and new in coding.
A few days (weeks?) ago, I faced a problem trying to write a program for an
exercise. I asked for help and nobody answered.
In the meantime, I found a part of the solution, but a part still remains a
mystery for me. Please run this small snippet, and help.
Thanks

a = [1, 2]
print()

print("a ==", a)
print("type(a) is", type(a))

b = a.append(3)
print("\nb =", "a.append(3)")
print("b ==", b)
print("type(b) is", type(b))

c = ['1', '2']
print("\nc ==", c)
print("type(c) is", type(c))

d = c.append('3')
print("\nd =", "c.append('3')")
print("d ==", d)
print("type(d) is", type(d))

"""
I mean: why b = a.append(something) is the None type, and how to make a new
list
that contains all the items from a and some new items?
I wasn't able to solve it in a few hours :(
Now I know:
"""

crta = '='
print('\n', 4 * ' ', crta * (len('The solution:')), sep='')
print(3 * ' ', 'The solution:')
print(4 * ' ', crta * (len('The solution:')), sep='')
print('\nThe solution is the slice, an element of Python syntax that
allows')
print('to make a brand new copy of a list, or parts of a list.')
print('The slice actually copies the list\'s contents, not the list\'s
name:')

print()
a = [1, 2]
print("a ==", a)
print("type(a) is", type(a))

b = a[:]
print("\nb = a[:]")
print("b ==", b)
b.append(3)
print("\nb =", "b.append(3)")
print("b ==", b)
print("type(b) is", type(b))
print("\na ==", a)

print('But I still don't know why "b = a.append(something)" is the None
type.')
print('Is there anybody out there?!')

From PythonList at DancesWithMice.info  Sat Dec 31 03:58:05 2022
From: PythonList at DancesWithMice.info (dn)
Date: Sat, 31 Dec 2022 21:58:05 +1300
Subject: NoneType List
In-Reply-To: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
Message-ID: <b05ca8b3-6dad-c110-7f01-254ba95634c1@DancesWithMice.info>

On 31/12/2022 18.45, Goran Ikac wrote:
> Happy New Year, everybody!
> I'm new in the Python List, new in Python world, and new in coding.
> A few days (weeks?) ago, I faced a problem trying to write a program for an
> exercise. I asked for help and nobody answered.
> In the meantime, I found a part of the solution, but a part still remains a
> mystery for me. Please run this small snippet, and help.
> Thanks
> 
> a = [1, 2]
> print()
> 
> print("a ==", a)
> print("type(a) is", type(a))
> 
> b = a.append(3)
> 
> print("b ==", b)
> print("type(b) is", type(b))

Please review https://docs.python.org/3/tutorial/datastructures.html

It is not immediately obvious to people who are not used to 
object-oriented programming.

As observed, "a" is a list. The list contains a pair of numeric-values.

The append is a "method". Methods are functions which belong to classes 
(let's say). Accordingly, the operation is performed on that class, ie 
the appending is to the "a" list.

This can be proven by adding to the above:

print( "\na (appended) =", a )
[1, 2, 3]

As far as the expression on the right-hand side of (the equals sign) 
there is no output-value, hence b == None.


For comparison, try:

b = a + [ 4 ]

and understand why the answer is different, and thus why the first 
'problem' behavior works the way it does...


print( 'Happy new year!' )


PS are you aware of the Python-Tutor Discussion List? It may be more 
suited to assisting your learning intentions...
-- 
Regards,
=dn

From learn2program at gmail.com  Sat Dec 31 04:09:04 2022
From: learn2program at gmail.com (Alan Gauld)
Date: Sat, 31 Dec 2022 09:09:04 +0000
Subject: NoneType List
In-Reply-To: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
Message-ID: <da443c21-c812-ca0e-6ead-06455c8f00e8@yahoo.co.uk>

On 31/12/2022 05:45, Goran Ikac wrote:

> b = a.append(3)


> I mean: why b = a.append(something) is the None type, and how to make a new
> list that contains all the items from a and some new items?

append() like many other collection methods in Python works
in place and returns None. But the action has succeeded
and 3 will have been appended to list 'a'.

So, to create a new list that contains all the old items you could do:

newlist = []   # an empty list
for item in oldlist:
    newlist.append(item)

This is so common Python has a shorthand form to do this:

newlist = [item for item in oldlist]

called a list comprehension.

And there is an even shorter way using something called slicing:

newlist = oldlist[:]    # copy oldlist to new.


However, as an ex-Smalltalk programmer, I do wish that Python
returned self from these methods rather than None so that
we could chain them. But sadly it doesn't.

-- 
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 chris_roysmith at internode.on.net  Sat Dec 31 02:09:07 2022
From: chris_roysmith at internode.on.net (Chris Roy-Smith)
Date: Sat, 31 Dec 2022 18:09:07 +1100
Subject: NoneType List
In-Reply-To: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
Message-ID: <143a64ee-8c85-3f34-1d95-44e93f705c25@internode.on.net>

On 31/12/22 16:45, Goran Ikac wrote:
> Happy New Year, everybody!
> I'm new in the Python List, new in Python world, and new in coding.
> A few days (weeks?) ago, I faced a problem trying to write a program for an
> exercise. I asked for help and nobody answered.
> In the meantime, I found a part of the solution, but a part still remains a
> mystery for me. Please run this small snippet, and help.
> Thanks
> 
> a = [1, 2]
> print()
> 
> print("a ==", a)
> print("type(a) is", type(a))
> 
> b = a.append(3)
append is not used that way, append is a method, not a function.

have a look at https://www.w3schools.com/python/ref_list_append.asp.

regards, Chris



> print("\nb =", "a.append(3)")
> print("b ==", b)
> print("type(b) is", type(b))
> 
> c = ['1', '2']
> print("\nc ==", c)
> print("type(c) is", type(c))
> 
> d = c.append('3')
> print("\nd =", "c.append('3')")
> print("d ==", d)
> print("type(d) is", type(d))
> 
> """
> I mean: why b = a.append(something) is the None type, and how to make a new
> list
> that contains all the items from a and some new items?
> I wasn't able to solve it in a few hours :(
> Now I know:
> """
> 
> crta = '='
> print('\n', 4 * ' ', crta * (len('The solution:')), sep='')
> print(3 * ' ', 'The solution:')
> print(4 * ' ', crta * (len('The solution:')), sep='')
> print('\nThe solution is the slice, an element of Python syntax that
> allows')
> print('to make a brand new copy of a list, or parts of a list.')
> print('The slice actually copies the list\'s contents, not the list\'s
> name:')
> 
> print()
> a = [1, 2]
> print("a ==", a)
> print("type(a) is", type(a))
> 
> b = a[:]
> print("\nb = a[:]")
> print("b ==", b)
> b.append(3)
> print("\nb =", "b.append(3)")
> print("b ==", b)
> print("type(b) is", type(b))
> print("\na ==", a)
> 
> print('But I still don't know why "b = a.append(something)" is the None
> type.')
> print('Is there anybody out there?!')


From gweatherby at uchc.edu  Sat Dec 31 10:33:31 2022
From: gweatherby at uchc.edu (Weatherby,Gerard)
Date: Sat, 31 Dec 2022 15:33:31 +0000
Subject: NoneType List
In-Reply-To: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
Message-ID: <SJ0PR14MB5864A6BD600367966C4B1072B9F19@SJ0PR14MB5864.namprd14.prod.outlook.com>

Just use the addition operator:

a = [1,2]

a = a + [3,4]

a is now [1, 2, 3, 4]

From: Python-list <python-list-bounces+gweatherby=uchc.edu at python.org> on behalf of Goran Ikac <goranikac65 at gmail.com>
Date: Saturday, December 31, 2022 at 1:53 AM
To: python-list at python.org <python-list at python.org>
Subject: NoneType List
*** Attention: This is an external email. Use caution responding, opening attachments or clicking on links. ***

Happy New Year, everybody!
I'm new in the Python List, new in Python world, and new in coding.
A few days (weeks?) ago, I faced a problem trying to write a program for an
exercise. I asked for help and nobody answered.
In the meantime, I found a part of the solution, but a part still remains a
mystery for me. Please run this small snippet, and help.
Thanks

a = [1, 2]
print()

print("a ==", a)
print("type(a) is", type(a))

b = a.append(3)
print("\nb =", "a.append(3)")
print("b ==", b)
print("type(b) is", type(b))

c = ['1', '2']
print("\nc ==", c)
print("type(c) is", type(c))

d = c.append('3')
print("\nd =", "c.append('3')")
print("d ==", d)
print("type(d) is", type(d))

"""
I mean: why b = a.append(something) is the None type, and how to make a new
list
that contains all the items from a and some new items?
I wasn't able to solve it in a few hours :(
Now I know:
"""

crta = '='
print('\n', 4 * ' ', crta * (len('The solution:')), sep='')
print(3 * ' ', 'The solution:')
print(4 * ' ', crta * (len('The solution:')), sep='')
print('\nThe solution is the slice, an element of Python syntax that
allows')
print('to make a brand new copy of a list, or parts of a list.')
print('The slice actually copies the list\'s contents, not the list\'s
name:')

print()
a = [1, 2]
print("a ==", a)
print("type(a) is", type(a))

b = a[:]
print("\nb = a[:]")
print("b ==", b)
b.append(3)
print("\nb =", "b.append(3)")
print("b ==", b)
print("type(b) is", type(b))
print("\na ==", a)

print('But I still don't know why "b = a.append(something)" is the None
type.')
print('Is there anybody out there?!')
--
https://urldefense.com/v3/__https://mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!mv_VSTDWgnB7T16IHcBh7TaT3whji-SsPeUtaBmHdSsIJknJZ16qeALOSjCkjCmqheE1pJ-47P_mwAauV-0TjQo$<https://urldefense.com/v3/__https:/mail.python.org/mailman/listinfo/python-list__;!!Cn_UX_p3!mv_VSTDWgnB7T16IHcBh7TaT3whji-SsPeUtaBmHdSsIJknJZ16qeALOSjCkjCmqheE1pJ-47P_mwAauV-0TjQo$>

From list1 at tompassin.net  Sat Dec 31 10:50:13 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sat, 31 Dec 2022 10:50:13 -0500
Subject: NoneType List
Message-ID: <8f6d265a-c484-b566-2e13-c1c791b20ebf@tompassin.net>

Happy New Year, everybody!
I'm new in the Python List, new in Python world, and new in coding.
A few days (weeks?) ago, I faced a problem trying to write a program for an
exercise. I asked for help and nobody answered.
In the meantime, I found a part of the solution, but a part still remains a
mystery for me. Please run this small snippet, and help.
Thanks

a = [1, 2]
print()

print("a ==", a)
print("type(a) is", type(a))

b = a.append(3)
print("\nb =", "a.append(3)")
print("b ==", b)
print("type(b) is", type(b))

c = ['1', '2']
print("\nc ==", c)
print("type(c) is", type(c))

d = c.append('3')
print("\nd =", "c.append('3')")
print("d ==", d)
print("type(d) is", type(d))

"""
I mean: why b = a.append(something) is the None type, and how to make a new
list
that contains all the items from a and some new items?
I wasn't able to solve it in a few hours :(
Now I know:
"""

crta = '='
print('\n', 4 * ' ', crta * (len('The solution:')), sep='')
print(3 * ' ', 'The solution:')
print(4 * ' ', crta * (len('The solution:')), sep='')
print('\nThe solution is the slice, an element of Python syntax that
allows')
print('to make a brand new copy of a list, or parts of a list.')
print('The slice actually copies the list\'s contents, not the list\'s
name:')

print()
a = [1, 2]
print("a ==", a)
print("type(a) is", type(a))

b = a[:]
print("\nb = a[:]")
print("b ==", b)
b.append(3)
print("\nb =", "b.append(3)")
print("b ==", b)
print("type(b) is", type(b))
print("\na ==", a)

print('But I still don't know why "b = a.append(something)" is the None
type.')
print('Is there anybody out there?!')
-- 
https://mail.python.org/mailman/listinfo/python-list

From arequipeno at gmail.com  Sat Dec 31 11:41:32 2022
From: arequipeno at gmail.com (Ian Pilcher)
Date: Sat, 31 Dec 2022 10:41:32 -0600
Subject: set.add() doesn't replace equal element
In-Reply-To: <FW7QNR.87MNNZRX4DPR@anode.ca>
References: <b3e4102c-c503-2579-ccac-285ce01d0f74@gmail.com>
 <ZJ4QNR.MRMQX7HA6XKF1@anode.ca>
 <b8790bfa-f952-85eb-8ad3-b49c55048055@gmail.com>
 <FW7QNR.87MNNZRX4DPR@anode.ca>
Message-ID: <07e467b1-630d-51d9-f811-257ea21f02d1@gmail.com>

On 12/30/22 17:00, Paul Bryan wrote:
> It seems to me like you have to ideas of what "equal" means. You want to 
> update a "non-equal/equal" value in the set (because of a different time 
> stamp). If you truly considered them equal, the time stamp would be 
> irrelevant and updating the value in the set would be unnecessary.
> 
> I would:
> 
> a) /not/ consider two different leases with two different time stamps to 
> be equal, and
> b) as already mentioned, store them in another data structure like a 
> dictionary.
> 
> Not knowing the specifics of the DHCP object structure, if a DHCP lease 
> object has some immutable key or other durable immutable attribute, I 
> would be inclined to make that the dictionary key, and store the DHCP 
> object as the value.

I have come to the conclusion that you are correct.  Thanks!

-- 
========================================================================
Google                                      Where SkyNet meets Idiocracy
========================================================================


From list1 at tompassin.net  Sat Dec 31 12:07:25 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sat, 31 Dec 2022 12:07:25 -0500
Subject: NoneType List
In-Reply-To: <8f6d265a-c484-b566-2e13-c1c791b20ebf@tompassin.net>
References: <8f6d265a-c484-b566-2e13-c1c791b20ebf@tompassin.net>
Message-ID: <3eb7480c-88f7-72cf-af66-c0072928bf3f@tompassin.net>

Oops, my reply got lost somehow.  Here it is:

Everyone's answer to date has been too complicated.  What is going on is 
that list.append() changes the list in place.  It returns nothing.  If 
you want to append an item and then assign the result to a new list, you 
have to do just that:

l1.append(item)
# If we want a *copy* of the appended list:
l2 = l1[:]  # Changes to l2 will not change l1

# If we want another name for the appended list:
l2 = l1  # Changes to l2 will change l1 since they are the same object

list.sort() also operates in place.  There is a function sorted() that 
returns the sorted list (without changing the original list).

The same thing is true of set.add(). The set is changed in place, and 
nothing is returned.

On 12/31/2022 10:50 AM, Thomas Passin wrote:
> Happy New Year, everybody!
> I'm new in the Python List, new in Python world, and new in coding.
> A few days (weeks?) ago, I faced a problem trying to write a program for an
> exercise. I asked for help and nobody answered.
> In the meantime, I found a part of the solution, but a part still remains a
> mystery for me. Please run this small snippet, and help.
> Thanks
> 
> a = [1, 2]
> print()
> 
> print("a ==", a)
> print("type(a) is", type(a))
> 
> b = a.append(3)
> print("\nb =", "a.append(3)")
> print("b ==", b)
> print("type(b) is", type(b))
> 
> c = ['1', '2']
> print("\nc ==", c)
> print("type(c) is", type(c))
> 
> d = c.append('3')
> print("\nd =", "c.append('3')")
> print("d ==", d)
> print("type(d) is", type(d))
> 
> """
> I mean: why b = a.append(something) is the None type, and how to make a new
> list
> that contains all the items from a and some new items?
> I wasn't able to solve it in a few hours :(
> Now I know:
> """
> 
> crta = '='
> print('\n', 4 * ' ', crta * (len('The solution:')), sep='')
> print(3 * ' ', 'The solution:')
> print(4 * ' ', crta * (len('The solution:')), sep='')
> print('\nThe solution is the slice, an element of Python syntax that
> allows')
> print('to make a brand new copy of a list, or parts of a list.')
> print('The slice actually copies the list\'s contents, not the list\'s
> name:')
> 
> print()
> a = [1, 2]
> print("a ==", a)
> print("type(a) is", type(a))
> 
> b = a[:]
> print("\nb = a[:]")
> print("b ==", b)
> b.append(3)
> print("\nb =", "b.append(3)")
> print("b ==", b)
> print("type(b) is", type(b))
> print("\na ==", a)
> 
> print('But I still don't know why "b = a.append(something)" is the None
> type.')
> print('Is there anybody out there?!')


From python at mrabarnett.plus.com  Sat Dec 31 12:37:39 2022
From: python at mrabarnett.plus.com (MRAB)
Date: Sat, 31 Dec 2022 17:37:39 +0000
Subject: NoneType List
In-Reply-To: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
Message-ID: <2321d9bc-5eb3-c1b9-0425-020b54dd39e8@mrabarnett.plus.com>

On 2022-12-31 05:45, Goran Ikac wrote:
> Happy New Year, everybody!
> I'm new in the Python List, new in Python world, and new in coding.
> A few days (weeks?) ago, I faced a problem trying to write a program for an
> exercise. I asked for help and nobody answered.
> In the meantime, I found a part of the solution, but a part still remains a
> mystery for me. Please run this small snippet, and help.
> Thanks
> 
> a = [1, 2]
> print()
> 
> print("a ==", a)
> print("type(a) is", type(a))
> 
> b = a.append(3)
> print("\nb =", "a.append(3)")
> print("b ==", b)
> print("type(b) is", type(b))
> 
> c = ['1', '2']
> print("\nc ==", c)
> print("type(c) is", type(c))
> 
> d = c.append('3')
> print("\nd =", "c.append('3')")
> print("d ==", d)
> print("type(d) is", type(d))
> 
> """
> I mean: why b = a.append(something) is the None type, and how to make a new
> list
> that contains all the items from a and some new items?
> I wasn't able to solve it in a few hours :(
> Now I know:
> """
> 
> crta = '='
> print('\n', 4 * ' ', crta * (len('The solution:')), sep='')
> print(3 * ' ', 'The solution:')
> print(4 * ' ', crta * (len('The solution:')), sep='')
> print('\nThe solution is the slice, an element of Python syntax that
> allows')
> print('to make a brand new copy of a list, or parts of a list.')
> print('The slice actually copies the list\'s contents, not the list\'s
> name:')
> 
> print()
> a = [1, 2]
> print("a ==", a)
> print("type(a) is", type(a))
> 
> b = a[:]
> print("\nb = a[:]")
> print("b ==", b)
> b.append(3)
> print("\nb =", "b.append(3)")
> print("b ==", b)
> print("type(b) is", type(b))
> print("\na ==", a)
> 
> print('But I still don't know why "b = a.append(something)" is the None
> type.')
> print('Is there anybody out there?!')

Methods that modify in-place usually return None. "a.append(something)" 
modifies (appends to) the list 'a' and returns None.

If you want to a new line with something at the end try "b = a + 
[something]".


From PythonList at DancesWithMice.info  Sat Dec 31 15:58:35 2022
From: PythonList at DancesWithMice.info (dn)
Date: Sun, 1 Jan 2023 09:58:35 +1300
Subject: NoneType List
In-Reply-To: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
Message-ID: <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>

On 31/12/2022 18.45, Goran Ikac wrote:
...
> A few days (weeks?) ago, I faced a problem trying to write a program for an
> exercise. I asked for help and nobody answered.

Looking back over the last six months of List-Archives, your name does 
not appear against a single post. This may explain why "nobody answered".

However, ten hours after the above/first message, you posted again. This 
time as "Thomas Passin". That was followed an hour-or-so later, with a 
reply-to-self saying: "Everyone's answer to date has been too 
complicated", and then basically repeating the information 
previously-provided by a number of contributors.

It then goes on to talk about copying, sorting, adding, and even sets. 
Much of which you had earlier said: "I know". Was there a further 
question in there?

Which part of which answer did you find "too complicated"?

Did you try the experiments suggested, and read the references-provided?

Please ask a further question detailing what you have understood, and 
what is still mystifying. Folk here endeavor to be helpful (see also, 
earlier reference to the Python-Tutor list).

When asking a question here, please try to reduce the problem to its 
simplest form, so that you're not asking volunteers to read 
multiple-screens of irrelevant code. It will help to ask one question at 
a time, or to carefully separate multiple questions.

Yes, this can be difficult when one is learning. That said, we all 
started somewhere and are happy to help you to become a valued colleague!

-- 
Regards,
=dn

From avi.e.gross at gmail.com  Sat Dec 31 17:36:59 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Sat, 31 Dec 2022 17:36:59 -0500
Subject: NoneType List
In-Reply-To: <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
 <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
Message-ID: <006501d91d68$6538dd10$2faa9730$@gmail.com>

It depends on what people consider too complicated.

I find it a tad complicated when someone posts using two different ID, and
then wonders ...

The question related to taking a list and extending it and using the result
in an assignment statement.

There were several inter-related questions people responded to.

One was asking why something did not work as expected. Several answers
pointed out it was because it was not designed the way expected and reading
the manual page or other reference material would help explain that you need
to use code the way it was intended and not as you wish it. Other aspects of
similar code that do what you expect were shown and you could pick any you
liked.

A second question some were answering is various ways to get the
functionality wanted. Some were simple enough like using "+" and others did
seem complex as they showed many variations on copying an object or how to
make a subclass that effectively substitutes a method that returns the
internally changed object.

And, of course, we had the philosophical question of why the feature was
designed to not return anything (well, NULL) rather than return the changed
object. Returning nothing is arguably slightly more efficient in the many
cases where the return value is simply ignored and thus tossed. But as
mentioned, it would be nice for some purposes, including chaining, to be
able to write something like 

result = lst.add_ret("item").sort_ret()

As mentioned, this can still be easily done using something like:

result = sorted(lst + "item") 

-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
Behalf Of dn
Sent: Saturday, December 31, 2022 3:59 PM
To: python-list at python.org
Subject: Re: NoneType List

On 31/12/2022 18.45, Goran Ikac wrote:
...
> A few days (weeks?) ago, I faced a problem trying to write a program 
> for an exercise. I asked for help and nobody answered.

Looking back over the last six months of List-Archives, your name does not
appear against a single post. This may explain why "nobody answered".

However, ten hours after the above/first message, you posted again. This
time as "Thomas Passin". That was followed an hour-or-so later, with a
reply-to-self saying: "Everyone's answer to date has been too complicated",
and then basically repeating the information previously-provided by a number
of contributors.

It then goes on to talk about copying, sorting, adding, and even sets. 
Much of which you had earlier said: "I know". Was there a further question
in there?

Which part of which answer did you find "too complicated"?

Did you try the experiments suggested, and read the references-provided?

Please ask a further question detailing what you have understood, and what
is still mystifying. Folk here endeavor to be helpful (see also, earlier
reference to the Python-Tutor list).

When asking a question here, please try to reduce the problem to its
simplest form, so that you're not asking volunteers to read multiple-screens
of irrelevant code. It will help to ask one question at a time, or to
carefully separate multiple questions.

Yes, this can be difficult when one is learning. That said, we all started
somewhere and are happy to help you to become a valued colleague!

--
Regards,
=dn
--
https://mail.python.org/mailman/listinfo/python-list


From list1 at tompassin.net  Sat Dec 31 18:32:04 2022
From: list1 at tompassin.net (Thomas Passin)
Date: Sat, 31 Dec 2022 18:32:04 -0500
Subject: NoneType List
In-Reply-To: <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
 <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
Message-ID: <11625e0f-8975-b929-a2ca-e14ed74a19b0@tompassin.net>

On 12/31/2022 3:58 PM, dn wrote:
> On 31/12/2022 18.45, Goran Ikac wrote:
> ...
>> A few days (weeks?) ago, I faced a problem trying to write a program 
>> for an
>> exercise. I asked for help and nobody answered.
> 
> Looking back over the last six months of List-Archives, your name does 
> not appear against a single post. This may explain why "nobody answered".
> 
> However, ten hours after the above/first message, you posted again. This 
> time as "Thomas Passin". 

That message was probably a mistaken one from me.  I had composed a 
reply but through some mental glitch had to re-do it.  I managed to send 
it with the only quoted thread but not the reply I had wanted to 
include.  So I added my reply and sent it again.  It was probably 
confusing, and I'm sorry about that.

> That was followed an hour-or-so later, with a 
> reply-to-self saying: "Everyone's answer to date has been too 
> complicated", and then basically repeating the information 
> previously-provided by a number of contributors.
> 
> It then goes on to talk about copying, sorting, adding, and even sets. 
> Much of which you had earlier said: "I know". Was there a further 
> question in there?
> 
> Which part of which answer did you find "too complicated"?
> 
> Did you try the experiments suggested, and read the references-provided?
> 
> Please ask a further question detailing what you have understood, and 
> what is still mystifying. Folk here endeavor to be helpful (see also, 
> earlier reference to the Python-Tutor list).
> 
> When asking a question here, please try to reduce the problem to its 
> simplest form, so that you're not asking volunteers to read 
> multiple-screens of irrelevant code. It will help to ask one question at 
> a time, or to carefully separate multiple questions.
> 
> Yes, this can be difficult when one is learning. That said, we all 
> started somewhere and are happy to help you to become a valued colleague!
> 


From greg.ewing at canterbury.ac.nz  Sat Dec 31 19:21:05 2022
From: greg.ewing at canterbury.ac.nz (Greg Ewing)
Date: Sun, 1 Jan 2023 13:21:05 +1300
Subject: NoneType List
In-Reply-To: <mailman.1344.1672526224.20444.python-list@python.org>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
 <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
 <006501d91d68$6538dd10$2faa9730$@gmail.com>
 <mailman.1344.1672526224.20444.python-list@python.org>
Message-ID: <k1c1vkF15cmU1@mid.individual.net>

On 1/01/23 11:36 am, avi.e.gross at gmail.com wrote:
> And, of course, we had the philosophical question of why the feature was
> designed to not return anything ... rather than return the changed
> object.

My understanding is that Guido designed it that way to keep a
clear separation between mutating and non-mutating methods, and
to help catch mistakes resulting from mixing them up.

-- 
Greg

From avi.e.gross at gmail.com  Sat Dec 31 22:17:56 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Sat, 31 Dec 2022 22:17:56 -0500
Subject: NoneType List
In-Reply-To: <k1c1vkF15cmU1@mid.individual.net>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
 <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
 <006501d91d68$6538dd10$2faa9730$@gmail.com>
 <mailman.1344.1672526224.20444.python-list@python.org>
 <k1c1vkF15cmU1@mid.individual.net>
Message-ID: <00e601d91d8f$a4e59b20$eeb0d160$@gmail.com>

Agreed, there are lots of pro/con arguments and the feature is what it  is
historically and not trivial to change. Inline changes to an object make
sense to just be done "silently" and if there are errors, they propagate the
usual way.

As Guido was a major influence at that time,  one view was seen as more
important and prevailed.

Had a language like that been created today, I wonder if some designs might
have looked a bit different so that some functions could be called with
optional arguments that specified what the user wanted returned.

In particular, besides a function where you add a value returning
nothing/None, there may be room for other choices and any choice hard-wired
in would eleicit complaints from others.

lst.add("Value") 

could also return one of several other things such as a pointer to the
upgraded object but also of  a pointer to the object as it looked before the
change (not a serious proposal) or a True/False value specifying if the
change was able to be completed (such as running out of memory, or the
addition not being something you can put in the object) or even return what
was added or how many objects are now in the object at the top level, or how
many times the method was called so far!

I suspect, at the expense of some overhead, you could just add an argument
to many kinds of methods or even functions such as returning='option' that
guides what you want returned, with the default often being what Guido and
others currently have set.

Python already allows functions to return anything they feel like, so this
probably would not break many things.

Of course there are other paths in that direction, such as setting an
attribute of the list/object first that affects how things get returned but
that seems more cumbersome and makes all kinds of errors more likely. Still,
that is a path often used by some Python modules where objects are created
and then tweaked to behave in various ways when later methods are invoked.

But is any of it needed? The current system generally works fine and we have
seen many ways to get other results without tampering with the current
implementation.

This may be yet another example of people who come to python with
pre-existing bias, such as insisting it work like another language they have
used, or wanting the computer to do what they MEANT rather than what they
explicitly or implicitly programmed!


-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
Behalf Of Greg Ewing
Sent: Saturday, December 31, 2022 7:21 PM
To: python-list at python.org
Subject: Re: NoneType List

On 1/01/23 11:36 am, avi.e.gross at gmail.com wrote:
> And, of course, we had the philosophical question of why the feature 
> was designed to not return anything ... rather than return the changed 
> object.

My understanding is that Guido designed it that way to keep a clear
separation between mutating and non-mutating methods, and to help catch
mistakes resulting from mixing them up.

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


From rosuav at gmail.com  Sat Dec 31 22:23:13 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 1 Jan 2023 14:23:13 +1100
Subject: NoneType List
In-Reply-To: <00e601d91d8f$a4e59b20$eeb0d160$@gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
 <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
 <006501d91d68$6538dd10$2faa9730$@gmail.com>
 <mailman.1344.1672526224.20444.python-list@python.org>
 <k1c1vkF15cmU1@mid.individual.net> <00e601d91d8f$a4e59b20$eeb0d160$@gmail.com>
Message-ID: <CAPTjJmq=n0=B7fHvtydTwe0eZ+GVxTzGH-3TJDX6E9PyVHsEnQ@mail.gmail.com>

On Sun, 1 Jan 2023 at 14:19, <avi.e.gross at gmail.com> wrote:
> Had a language like that been created today, I wonder if some designs might
> have looked a bit different so that some functions could be called with
> optional arguments that specified what the user wanted returned.

Frankly, I doubt it. While you can argue "returning self is more
useful" vs "returning None is more clear if you get it wrong", having
options does NOT improve things, and just makes everything more
complicated, slower, harder to comprehend, and generally worse to work
with.

A language should have some sort of consistent behaviour and stick to
it. If that's not possible, an object type should at least have that.

ChrisA

From avi.e.gross at gmail.com  Sat Dec 31 23:16:10 2022
From: avi.e.gross at gmail.com (avi.e.gross at gmail.com)
Date: Sat, 31 Dec 2022 23:16:10 -0500
Subject: NoneType List
In-Reply-To: <CAPTjJmq=n0=B7fHvtydTwe0eZ+GVxTzGH-3TJDX6E9PyVHsEnQ@mail.gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
 <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
 <006501d91d68$6538dd10$2faa9730$@gmail.com>
 <mailman.1344.1672526224.20444.python-list@python.org>
 <k1c1vkF15cmU1@mid.individual.net>
 <00e601d91d8f$a4e59b20$eeb0d160$@gmail.com>
 <CAPTjJmq=n0=B7fHvtydTwe0eZ+GVxTzGH-3TJDX6E9PyVHsEnQ@mail.gmail.com>
Message-ID: <00fd01d91d97$c78994d0$569cbe70$@gmail.com>

Chris,

There is much to say about consistent behavior as compared to flexibility
and convenience.

 I have seen other languages provide functions for example, where the result
can vary and often cause confusion. R had a function that would sometimes
notice the result could be simplified and return that. Guess what? It caused
lots of problems and an option was added that said it should NOT simplify
and always return the same kind of thing.

Consider what happens if a calculation that returned a matrix would decide
that is there was only one columns, it would return a vector/array/whatever
as a one-dimensional result and if the calculation produced a 1 by 1 matrix,
it would simply return a scalar value!

But it may be a feature you want in some cases, albeit rarely when the
results of the function are fed into something that is not expecting it.
Various forms of polymorphism can be helpful but can also be very confusing.

Some solutions are what I have described in earlier messages and some
languages blur distinctions. Again, in R, there may not be a scalar as all
you have is a vector of length one. But matrices even of 1-D are not vectors
and I have had to interconvert between them to make some code run.

I am not making comparisons in the sense that nothing other languages choose
to do is binding on what Python should do. Still, I think it is wrong to
suggest that it does not often do partially ambiguous things from some
perspective. Many functions will take a variety of arguments and return
something reasonable but different each time. 

As a dumb example, what does a simple function like max() return if fed just
integers, just floating point or a combination of both? It seems to return
whatever type the maximum indicates. But it also accepts characters and
sorts them appropriately returning type 'str' and probably accepts and
returns  all kinds of objects if you specify a key function.

Is that so much different than we are discussing in that there isn't any
absolute consistency and things can go various ways in terms of return
value? Heck, I can even make max() return None!


-----Original Message-----
From: Python-list <python-list-bounces+avi.e.gross=gmail.com at python.org> On
Behalf Of Chris Angelico
Sent: Saturday, December 31, 2022 10:23 PM
To: python-list at python.org
Subject: Re: NoneType List

On Sun, 1 Jan 2023 at 14:19, <avi.e.gross at gmail.com> wrote:
> Had a language like that been created today, I wonder if some designs 
> might have looked a bit different so that some functions could be 
> called with optional arguments that specified what the user wanted
returned.

Frankly, I doubt it. While you can argue "returning self is more useful" vs
"returning None is more clear if you get it wrong", having options does NOT
improve things, and just makes everything more complicated, slower, harder
to comprehend, and generally worse to work with.

A language should have some sort of consistent behaviour and stick to it. If
that's not possible, an object type should at least have that.

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


From rosuav at gmail.com  Sat Dec 31 23:23:59 2022
From: rosuav at gmail.com (Chris Angelico)
Date: Sun, 1 Jan 2023 15:23:59 +1100
Subject: NoneType List
In-Reply-To: <00fd01d91d97$c78994d0$569cbe70$@gmail.com>
References: <CAM53q1S0NbOZG5QUHN7GX69L8203wDFRYzDi4Sq490-ZksN4Ow@mail.gmail.com>
 <2b238dce-3e9f-9bee-27a0-d163cb6c7cef@DancesWithMice.info>
 <006501d91d68$6538dd10$2faa9730$@gmail.com>
 <mailman.1344.1672526224.20444.python-list@python.org>
 <k1c1vkF15cmU1@mid.individual.net> <00e601d91d8f$a4e59b20$eeb0d160$@gmail.com>
 <CAPTjJmq=n0=B7fHvtydTwe0eZ+GVxTzGH-3TJDX6E9PyVHsEnQ@mail.gmail.com>
 <00fd01d91d97$c78994d0$569cbe70$@gmail.com>
Message-ID: <CAPTjJmqqGLqE=FepRMM1P95E3eGv5Qnq_=BfsGJNXuucLH6wMg@mail.gmail.com>

On Sun, 1 Jan 2023 at 15:16, <avi.e.gross at gmail.com> wrote:
>
> Chris,
>
> There is much to say about consistent behavior as compared to flexibility
> and convenience.
>
>  I have seen other languages provide functions for example, where the result
> can vary and often cause confusion. R had a function that would sometimes
> notice the result could be simplified and return that. Guess what? It caused
> lots of problems and an option was added that said it should NOT simplify
> and always return the same kind of thing.

The option was presumably added because backward compatibility is
important, but it would have been better to not need the option in the
first place.

> As a dumb example, what does a simple function like max() return if fed just
> integers, just floating point or a combination of both? It seems to return
> whatever type the maximum indicates. But it also accepts characters and
> sorts them appropriately returning type 'str' and probably accepts and
> returns  all kinds of objects if you specify a key function.
>
> Is that so much different than we are discussing in that there isn't any
> absolute consistency and things can go various ways in terms of return
> value? Heck, I can even make max() return None!
>

... yes? So? It still always returns the largest item in the list, for
some definition of "largest". You'll never have that value returned
wrapped up in a single-element list, though.

ChrisA