def _get_index_urls_locations(self, project_name):

        def mkurl_pypi_url(url):
            loc = posixpath.join(
                url,
                urllib_parse.quote(canonicalize_name(project_name)))
            # For maximum compatibility with easy_install, ensure the path
            # ends in a trailing slash.  Although this isn't in the spec
            # (and PyPI can handle it without the slash) some other index
            # implementations might break if they relied on easy_install's
            # behavior.
            if not loc.endswith('/'):
                loc = loc + '/'
            return loc

        return [mkurl_pypi_url(url) for url in self.index_urls]
Returns the locations found via self.index_urls
dataset/ETHPy150Open pypa/pip/pip/index.py/PackageFinder._get_index_urls_locations