Then I realized I looked for it because I saw a module name in some code and I didn’t know which package it came from. There are other ways of finding that!
You can set up your editor so that you can “go to definition” on anything, including things from packages. You can see the package name in the file path.
You can search in the installed packages folder (if you know the module must come from an installed package). For example, using ripgrep (assumes a non-Windows environment):