bug#28580: python.el: native completion setup failed

[Noam Postavsky <npostavs@users.sourceforge.net>]

Андрей Парамонов <cmr.pent@gmail.com> writes:

> Hello!
>
> I'm on Windows, using Python3 from Anaconda distrib. I've set option
>  '(python-shell-interpreter "py")
>
> When doing
> M-x run-python
> I get
> Warning (python): Your ‘python-shell-interpreter’ doesn’t seem to
> support readline, yet ‘python-shell-completion-native-enable’ was t
> and "py" is not part of the
> ‘python-shell-completion-native-disabled-interpreters’ list.  Native
> completions have been disabled locally. 
>
> Python 3.6.1 |Anaconda 4.4.0 (64-bit)| (default, May 11 2017,
> 13:25:24) [MSC v.1900 64 bit (AMD64)] on win32
> Type "help", "copyright", "credits" or "license" for more
> information.
>>>> python.el: native completion setup failed
>>>>
>
> It is expected that Python completion works out-of-the-box, without
> warnings.

Seems to be impossible, unfortunately.  Does this commentary from
python.el help?

;; If your Python installation lacks readline (like CPython for
;; Windows), installing pyreadline (URL
;; `http://ipython.org/pyreadline.html') should suffice.  To
;; troubleshoot why you are not getting any completions, you can try the
;; following in your Python shell:

;; >>> import readline, rlcompleter

;; If you see an error, then you need to either install pyreadline or
;; setup custom code that avoids that dependency.