I don't know how well CPAN and PyPi compare. For the most part, if I need something, I just either install the Ubuntu package (if one exists and is adequately up-to-date) or sudo -H pip3 install <the thing>. That's about as much as I need to interface with the two package systems in this case.
There are various Python fora out there, including subreddits. I can't comment on how good they are because I never used any of them. I rarely have issues with Python or elements of its third-party ecosystem and when I do there has always been something on Stack Overflow to answer my questions.