[rjprins]

Imho, (good) Python code is so easy to read and inspect, that it can be better than documentation. Documentation is less exact. I often find myself reading the libraries that I use, to see what it really does. Once you get into the habit of that, documentation is only useful as a starting point and you can discover a lot more useful functionality. (And also get a good feel of the quality of the library, and learn a lot in terms of patterns)

Of course, this habit comes with the risk that you might have to do more maintenance on your code on library updates.

As documentation takes effort to write and constitutes a sort of contract with your users, it makes sense for library writers to only document the truly essential.

[andreasvc]

I don't think this position of relying on code instead of documentation is tenable for non-trivial code. The amount of effort to understand code is generally much more than that of maintaining documentation of what a function does, meaning of arguments, and any assumptions made. Documentation can (and should) have a much higher signal-to-noise ratio.