There're tons of apps/widgets for PHP function reference and even for Ruby but I'm shocked to find there is nothing available for a popular language like Python (besides the official online documentation ofcourse). 
Is there really not a single handy reference widget/app available for Python? I have 'Pocket Reference' book, but a dashboard widget would be so handy!
Python libraries have (or should have) built in documentation through docstrings. Also, python code is (mostly) very readable, and reading the source (.py or even .c) is actually the preferred way for many developers to get the information they're looking for, especially since some corner cases may not even be documented.
I've caught myself looking through the source now and then, as if it's a natural step in looking up functionality, either because I'm curious how they solve the problem, or because I reckon it's faster than googling obscure problems and reading SO questions.
Python Function Reference