I've been programming in python for almost 15 years and I don't know all the functions/classes/attributes of any module in the standard library probably. What I do know is that if I'm on a vanilla python shell I can type `help(module)` and I'll get that list in the shell directly, and even `help(module.function)` will give me enough context most of the time that I won't need to go online either.
However, as my daily shell, I use IPython, on which I have smart autocomplete that inspects the modules for me by just typing `module.`, hit tab and BAM! All the things inside the module pop up before me to explore. Something looks about what I need? I add a ? at the end an press enter, so `module.function?` will show me the docstring, nicely formatted with the signture (the same thing the built-in `help()` does).
So the online docs, for python, rest on an entirely different level. But sure, coming from other languages it may be weird not having what you're used to. It's part of the languages culture.