How to extract dependencies from a PyPi package without downloading it?

Question

I want to get the dependency of a PyPi package remotely without needing to download it completely.

I seem to understand (reading the pip code) that pip when resolving dependencies seems to read the egg once the package has been downloaded.

Is there any other way?

Answer 1

I've just needed to find a way to do this and this is what I came up with (stolen from pip).

def dist_metadata(setup_py):
    '''Get the dist object for setup.py file'''

    with open(setup_py) as f:
        d = f.read()

    try:
        # we have to do this with current globals else
        # imports will fail. secure? not really. A
        # problem? not really if your setup.py sources are 
        # trusted
        exec d in globals(), globals()
    except SystemExit:
        pass

    return distutils.core._setup_distribution

https://stackoverflow.com/a/12505166/3332282 answers why the exec incantation is subtle and hard to get right.