with M-q resp. fill-paragraph it's fine here too.
python-fill-paragraph displays the bug.
[...]
AFAIS bug basically might reside in
fill-paragraph, where
If calling fill-paragraph works while python-fill-paragraph doesn't, it
would rather seem to indicate that the bug is in python-fill-paragraph
(maybe the bug is that python-fill-paragraph should never be called
directly as a command, for example).
;; 2. Try fill-paragraph-function.
(and (not (eq fill-paragraph-function t))
(or fill-paragraph-function
(and (minibufferp (current-buffer))
(= 1 (point-min))))
(let ((function (or fill-paragraph-function
should be written like
(cond (fill-paragraph-function
DTRT)
(t everything else
No, the current definition is on purpose.