EDIT I was being stupid. Just type help('package_name'.'pyb_name') which worked.
I would like to find out what is actually in a python package I have locally downloaded and installed with pip. 
Typing help(package_name) just lists NAME, FILE (where the init.py is) and PACKAGE CONTENTS which is just one .pyd file.
I can't open the .pyd file to check what's inside(tbh not all that familiar with .pyds). These two with a 159byte init.pyc are the only files in the package. 
I need to use this (not widely available) package for some university work. 
Thanks.
You can't know what a python package does unless it is stated in its docs (on PyPI or in the repository) or without reading the code. A Python package can be anything that has a setup.py and either a single module or multiple files under a folder with a __init__.py file in it.
The fact that the __init__.py is empty doesn't mean anything other than the fact that its existence means there's a python package involved.
Any specific package you want to know about, you should look up for documentation or read the code to get a sense of its purpose.
How to find out what a python package does