I can honestly say that all I've ever learned about python has come either from calibre's codebase, contributors to (Kindle|Mobi)Unpack here at MR, or friends of a certain Apprentice (with maybe a bit of Stack Overflow on the side).
You've given me several pointers along the way (and I've stolen countless more pointers you've given others) -- for which I'm eternally greatful.
True "proficiency" may be a pipe-dream for me. But I'm perfectly content with tweaking and debugging in the meantime.
