bug#25753: 25.2; Python mode shell interaction not working 100%

[Carlos Pita <carlosjosepita@gmail.com>]

Hi Augusto,

> Unfortunately, this package is free of bugs and hasn't seen much
> development lately, so I prefer to live with the issues of the good old
> Python shell.

Just to be clear, I'm not saying python.el should move to jupyter or
anything like that. On the contrary, I believe it should provide a
solid focused basis for other modules (elpy, lsp, emacs-jupyter, etc)
and perhaps it's already somewhat at odds with that goal. Especially
regarding native completion I don't see much to be gained vs. directly
calling the readline completer (which is now considered the fallback
case) and OTOH there is something to be lost: at least in my
experience this has often been the non "just works" factor. Moreover,
the mechanism is far from perfect (it interferes with prompt
numbering, it's potentially blocking) and native completions solve
none of its issues. So I feel like getting rid of it. My point
regarding Jupyter, LSP and the emacs frameworks around them is that to
some extent they relieve python.el of having to be that smart.

Best regards,
Carlos