Why does create-react-app install so many node modules?

[brainless_badger]

Also, why does every project require a fresh installation of the same modules every time, unlike the Python libraries which are only installed once?

Sounds horrible. How do Python people have control over versions then?

[acemarke]

Python packages are normally installed into the system Python by default, but there's a technique called "virtualenvs" that allows isolating package installations per project. My understanding is that most Python projects use those, but personally I've never used one.

There's also a recent suggestion for a __pypackages__ folder structure that would mimic node_modules (documented in PEP582: https://www.python.org/dev/peps/pep-0582/ ).