Why does pip install requirements.txt install extra packages?

Question

I have a repository with an inflated requirements.tx that I\'d like to clean up. Using pipreqs I\'ve set my requirements.txt to be a minimal set of packages need for my reposito

Answer 1

Yes. The packages are dependencies of your dependencies​.

But no, you should not specify them directly. Automatic tools know to download dependencies recursively and it would significantly add to maintenance overhead.

Answer 2

This might have been because of the dependencies of your written libs in requirements.txt. For ex: if you have written scipy as requirement numpy will also be installed because scipy is dependent on numpy.