bpo-32397: new option for TextWrapper to allow stable wrapping

[akulakov]

The new option fold_space_newline performs a more natural whitespace replacement for newlines, e.g.

'foo\n bar' => 'foo bar'
instead of
'foo\n bar' => 'foo  bar'
(with two spaces).

More importantly, it allows for "stable" wrapping when combined with drop_whitespace=False, i.e. wrap() can be applied multiple times producing the same output (see the Issue).

https://bugs.python.org/issue32397

[MaxwellDupre]

Could you re-target whatsnew for 3.12?

[akulakov]

@MaxwellDupre moved the what's new note from 3.11 to 3.12.

[MaxwellDupre]

Built fresh with
./configure --with-pydebug
make -s -j

But fails:
./python /home/me/PycharmProjects/TestingPy/32397-textwrap.py
original: 'xxxx xxxx xxxx xxxx xxxx. xxxx'
wrapped: 'xxxx xxxx xxxx xxxx xxxx.\nxxxx'
wrapped twice: 'xxxx xxxx xxxx xxxx xxxx. xxxx'

Traceback (most recent call last):
File "/home/me/PycharmProjects/TestingPy/32397-textwrap.py", line 27, in
assert wrapped == wrapped2
^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError
!  ~/D/G/cpython   32397-Add-textwrap-arg-for-stable-wrapping $

Im on Fedora 5.18.6-200.fc36.x86_64

[github-actions]

This PR is stale because it has been open for 30 days with no activity.