I program a lot of Python using PyCharm, and one of my favorite features of this combination of language and IDE is how easy it is to hop into the source of your dependencies. Anything you have imported into your code you can bring up the context menu for and click "go to declaration" (or use the relevant keyboard shortcut).

Python dependencies are source code, not compiled blobs, and the import syntax makes it very explicit where definitions come from.

If I'm unsure how to do something with the library I usually look at the source of the relevant module before looking up online docs.