Pygettext: Support translator comments

[tomasr8]

Feature or enhancement

Proposal:

Most gettext extraction tools such as xgettext or pybabel allow one to extract additional comments written by
the programmer which are meant to be read by the translator. These are prefixed with #. in the PO file.

The comments typically look something like this:

# i18n: Translator comment
_('foo')

This can be extracted with e.g. xgettext using xgettext --add-comments=i18n:

#. i18n: Translator comment
msgid "foo"
msgstr ""

Since this is a pretty widely used feature I propose we add this to pygettext as well.

Has this already been discussed elsewhere?

This is a minor feature, which does not need previous discussion elsewhere

Links to previous discussion of this feature:

No response

Linked PRs

• gh-130057: Pygettext: Support translator comments #130061