Daniel Holth writes:

When you are using setuptools, setup.py can be used to generate declarative metadata with the command "python setup.py egg_info". You can add --egg-base <dir> to put the static metadata in a different directory. Setuptools even makes it easy to add new metadata files to the .egg-info folder by using a plugin to write each file. The majority of the sdists on pypi contain pre-built versions of this static metadata in .egg-info folders.

Can it be correctly said that all of the metadata passed to setup() is in .egg-info? How far can we rely on the accuracy of the content of .egg-info dirs in sdists on PyPI? I have found hundreds of projects where even basic metadata is missing or incorrect - for example, the version.

Unfortunately setup.py is used to build not one, but many different dists (the most common difference of course being different requirements) depending on any number of factors, so pip rebuilds the static metadata before using it. Metadata 1.2+ of course allow us to put the most common "reasons for different dependencies" conditions in the static metadata itself.

Unfortunately, that doesn't help with nearly all the stuff currently on PyPI. Regards, Vinay Sajip