bug#29608: python.el movement functions

[Glenn Morris <rgm@gnu.org>]

Alex Branham wrote:

> Python movement statements do not always result in the behavior I'd
> expect. Consider this python file (with (|) representing point):
>
> (|)for i in [1, 2, 3]:
>     print(i)
>
> I'd expect M-x python-nav-forward-statement to result in
>
> for i in [1, 2, 3]:
>     print(i)
> (|)
>
> but instead you wind up with
>
> for i in [1, 2, 3]:
>     (|)print(i)

The actual result seems reasonable to me?

> and python-nav-forward-block (bound to M-e) is even worse. It results
> in point not moving at all:
>
> (|)for i in [1, 2, 3]:
>     print(i)

It seems that you disagree with python.el's definition of "statement" and
"block". Eg the block definition seems to be:

(defconst python-rx-constituents
  `((block-start          . ,(rx symbol-start
                                 (or "def" "class" "if" "elif" "else" "try"
                                     "except" "finally" "for" "while" "with"
                                     ;; Python 3.5+ PEP492
                                     (and "async" (+ space)
                                          (or "def" "for" "with")))
                                 symbol-end))