Returns first level namespace (package import name) of a setuptools distribution

release_info.py

#! /usr/bin/env python2.7

'''
http://stackoverflow.com/questions/7184375/how-to-find-import-name-of-any-package-in-python
'''

import distutils.core
import sys
import os


def get_release_namespace(setup_file):
    '''
    Returns first level namespace (package import name)
    of a setuptools distribution
    '''
    # setup wrapper
    def _fake_setup(*args, **kwargs):
        global dist
        dist = _real['setup'](*args, **kwargs)

    distutils.core._setup_stop_after = 'config'
    # backup
    _real = {
        'argv': sys.argv,
        'setup': distutils.core.setup,
        '__file__': __file__,
        '__path__': __path__,
        'cwd': os.getcwd(),
    }
    # fake
    sys.argv = [setup_file]
    __file__ = setup_file
    __path__ = os.path.dirname(__file__)
    os.chdir(os.path.dirname(setup_file))
    sys.path.append(__path__)
    distutils.core.setup = _fake_setup
    # run
    execfile(os.path.basename(setup_file))
    # get release info
    cat = lambda *seq: sum((i for i in seq if i is not None), [])
    pkgs = set(package.split('.')[0] for package
               in cat(dist.packages,
                      dist.py_modules,
                      [m.name for m in cat(dist.ext_modules)],
                      [m.name for m in cat(dist.ext_package)]))
    # restore
    sys.argv = _real['argv']
    distutils.core.setup = _real['setup']
    os.chdir(_real['cwd'])
    sys.path = sys.path[:-1]
    # return only existing directories from "pkgs"
    (package_dir, setup_py) = os.path.split(setup_file)
    return [d for d in pkgs if d in os.listdir(package_dir)]


if __name__ == '__main__':
    setup_file = sys.argv[1]
    print get_release_namespace(setup_file)