Hi,

Completion in Python mode buffer fails when the point in Python shell
buffer is before the last prompt:

1. emacs -Q
2. Open the following Python file.

#+begin_src python
import sys
#+end_src

3. C-u -1 M-x eldoc-mode (Disable ElDoc mode. This step can be skipped
   if the fix for #58389 is applied.)
4. C-c C-p (M-x run-python)
5. M-< (M-x beginning-of-buffer)
6. C-x o (Back to the Python mode buffer)
7. C-c C-c (M-x python-shell-send-buffer)
8. C-n (M-x next-line)
9. Type "sys."
10. C-M-i (M-x completion-at-point)
11. "No match" is shown in the minibuffer.

In `python-shell-completion-at-point', current point in the shell
buffer is checked if it is after the last prompt.  However, I think
there is no reason to do this check when
`python-shell-completion-at-point' is used to complete in Python mode
buffer (not Inferior Python Shell buffer).

Attached is a patch to fix this issue.

Best Regards,

--

In GNU Emacs 29.0.50 (build 5, x86_64-pc-linux-gnu, X toolkit, cairo
 version 1.16.0, Xaw scroll bars) of 2022-10-09 built on ubuntu
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