modulegraph.py 文件源码

def _namespace_package_path(fqname, pathnames, path=None):
    """
    Return the __path__ for the python package in *fqname*.

    This function uses setuptools metadata to extract information
    about namespace packages from installed eggs.
    """
    working_set = pkg_resources.WorkingSet(path)

    path = list(pathnames)

    for dist in working_set:
        if dist.has_metadata('namespace_packages.txt'):
            namespaces = dist.get_metadata(
                    'namespace_packages.txt').splitlines()
            if fqname in namespaces:
                nspath = os.path.join(dist.location, *fqname.split('.'))
                if nspath not in path:
                    path.append(nspath)

    return path