Severity: minor
Tags: patch

At the time of https://bugs.gnu.org/57184 python-ts-mode did not yet
exist, so the completion-predicates added to python.el as part of that
report understandably assumed only python-mode exists.

Here's what that means in practice:

0. emacs -Q
1. (setq read-extended-command-predicate
         #'command-completion-default-include-p)
2. C-x C-e
3. M-x python-ts-mode RET
4. M-x python-sort TAB
   => [No match]

And yet python-sort-imports is present in the local map:

5. C-g
6. C-h f python-sort-imports RET
   => It is bound to C-c TAB s.

By contrast, in python-mode:

7. M-x python-mode RET
8. M-x python-sort TAB
   => Completes to python-sort-imports

The following patch fixes this by associating M-x completion with
python-base-mode rather than python-mode: