customizable entries

[Strandinator]

Hi there.
For our use case we have specific formatting of the occurrences section in .po files.
So i made POEntry and _BaseEntry easier to customize

With these adjustments i can define a custom POFile that creates custom POEntry elements.
(I am no python expert. Not sure if I could write this in one line)

class CustomPOFile(polib.POFile):

    def append(self, entry: polib.POEntry) -> None:
        custom = CustomPOEntry(wrapwidth=self.wrapwidth)

        custom.msgid = entry.msgid
        custom.msgstr = entry.msgstr
        custom.msgid_plural = entry.msgid_plural
        custom.msgstr_plural = entry.msgstr_plural
        custom.msgctxt = entry.msgctxt
        custom.obsolete = entry.obsolete
        custom.encoding = entry.encoding
        custom.comment = entry.comment
        custom.tcomment = entry.tcomment
        custom.occurrences = entry.occurrences
        custom.flags = entry.flags
        custom.previous_msgctxt = entry.previous_msgctxt
        custom.previous_msgid = entry.previous_msgid
        custom.previous_msgid_plural = entry.previous_msgid_plural
        custom.linenum = entry.linenum

        return super().append(custom)

And in my custom POEntry i can overwrite methods with my custom implementation:

class CustomPOEntry(polib.POEntry):

    def _unicode_occurrences(self, ret, **kwargs):
        # custom stuff
        # ret += [...]
        pass

Let me know if you would do something else. (also naming)
As I said: not a python expert.

[Strandinator]

To be clear. I could use this approach before. I just had replace the whole POEntry.__unicode__ implementation