Packages would be useless without an organized way to store, upload, and download them. Python Package Index is the main source of open source packages in the Python community. Anyone can freely upload new packages and the only requirement is to register on the PyPI site: https://pypi.python.org/pypi.
You are not, of course, limited to only this index and all Python packaging tools support the usage of alternative package repositories. This is especially useful for distributing closed source code among internal organizations or for deployment purposes. Details of such packaging usage with instructions on how to create your own package index will be explained in the next chapter. Here we focus mainly on open source uploads to PyPI, with only little mention on how to specify alternative repositories.