Help creating a pattern using the re module

[zulu_likuum]

You could replace (?: - flubber)?\.(?:mp|MP)4$ with .mp4

That worked great. Thanks a lot. I think it's making sense. But let me make sure I understand what I think I understand.

In this case when I compile a pattern and use patt.sub(repl, filename), I didn't need to capture the beginning of the string with (.+) because the entire string is already going to be returned with only the changes applied?

Thanks again.