How do I get a Python REPL in Eshell on M$ Windows?

How do I get a Python REPL in Eshell on M$ Windows?

[Eduardo Ochs]

Hi list,

I have many students who sort of "want to learn GNU/Linux when they
grow up", but usually they take years between the "want to" stage and
the stage in which they have some kind of GNU/Linux installed in their
machines - either in a VM or in a partition - and several more years
between that stage and the stage in which they become minimally
proficient with a shell...

I'm trying to change that. The details are not important to my
question, but here is a link to them, for the sake of completeness:

  http://angg.twu.net/eev-wconfig.html

Anyway, here is my question.

When my students try to run Python in a buffer created with M-x shell
or M-x eshell they don't get an interactive REPL - they get something
that _looks like_ a REPL that is stuck because of bad terminal
settings. In Lua we were able to fix that by running "lua52.exe -i"
instead of just "lua52.exe"... anyone knows how to do something
similar for Python?

Here is what one student got in his *eshell* buffer:

  Welcome to the Emacs shell

  ~ $ ~/eev-wconfig/lua52.exe -i
  Lua 5.2.4  Copyright (C) 1994-2015 Lua.org, PUC-Rio
  > print(2+3)
  5
  > os.exit()
  ~ $
  ~ $ py
  print(2+3)
  print(2+3)

He sent me a photo of what he got when he ran "py" in a "normal"
terminal running PowerShell. It was something like this:

  Windows PowerShell
  Copyright (C) Microsoft Corporation. Todos os direitos reservados.

  Experimente a nova plataforma cruzada PowerShell https://aka.ms/pscore6

  PS C:\Users\ferob> py
  Python 3.10.4 [etc etc etc]
  >>> print(2+3)
  5
  >>>

Thanks in advance!

  Eduardo Ochs
  http://angg.twu.net/#eev

Re: How do I get a Python REPL in Eshell on M$ Windows?

[Eli Zaretskii]

> From: Eduardo Ochs <eduardoochs@gmail.com>
> Date: Sat, 4 Jun 2022 20:08:17 -0300
> 
> When my students try to run Python in a buffer created with M-x shell
> or M-x eshell they don't get an interactive REPL - they get something
> that _looks like_ a REPL that is stuck because of bad terminal
> settings. In Lua we were able to fix that by running "lua52.exe -i"
> instead of just "lua52.exe"... anyone knows how to do something
> similar for Python?
> 
> Here is what one student got in his *eshell* buffer:
> 
>   Welcome to the Emacs shell
> 
>   ~ $ ~/eev-wconfig/lua52.exe -i
>   Lua 5.2.4  Copyright (C) 1994-2015 Lua.org, PUC-Rio
>   > print(2+3)
>   5
>   > os.exit()
>   ~ $
>   ~ $ py
>   print(2+3)
>   print(2+3)
> 
> He sent me a photo of what he got when he ran "py" in a "normal"
> terminal running PowerShell. It was something like this:
> 
>   Windows PowerShell
>   Copyright (C) Microsoft Corporation. Todos os direitos reservados.
> 
>   Experimente a nova plataforma cruzada PowerShell https://aka.ms/pscore6
> 
>   PS C:\Users\ferob> py
>   Python 3.10.4 [etc etc etc]
>   >>> print(2+3)
>   5
>   >>>

I believe the buffering of Python interpreter's stdout can also be
controlled.  Search the Internet for "how to make python standard
output unbuffered", and you will find the answers.

Re: How do I get a Python REPL in Eshell on M$ Windows?

[Bruno Barbier]

Hi Eduardo,

Eli Zaretskii <eliz@gnu.org> writes:
>
> I believe the buffering of Python interpreter's stdout can also be
> controlled.  Search the Internet for "how to make python standard
> output unbuffered", and you will find the answers.

Yes, outputs are buffered by default, plus, python tries to detect if it's an
interactive shell.

So, with Emacs 'shell', I'm using:

   python -i -u

   '-i'  to force an interactive python
   
   '-u'  to force unbuffered outputs


Bruno