Perl is a good example where most third-party modules have good documentation. Or at least a SYNOPSIS you can poke, some DESCRIPTION of what the module does, and a few hundred lines of code in the t/ directory that test all the features of the modules.
The one thing I miss in Python is the inability to click "view source" in my web browser to see how a core Python library is implemented. PHP also has this problem. (Code is the best documentation. Learn to read it.)
There's high variation in quality amongst third-party modules, but the "modern" python community takes documentation quite seriously, there's even a complete site dedicated to nothing but hosting compiled documentation. Projects like Django, Flask, SQLAlchemy or Flask have rather good documentation sets.