code: def score_url(self, url):
          
          t = urlparse(url)
          basename = posixpath.basename(t.path)
          compatible = True
          is_wheel = basename.endswith('.whl')
          is_downloadable = basename.endswith(self.downloadable_extensions)
          if is_wheel:
              compatible = is_compatible(Wheel(basename), self.wheel_tags)
          return (t.scheme == 'https', 'pypi.python.org' in t.netloc,
                  is_downloadable, is_wheel, compatible, basename)
docs: Give an url a score which can be used to choose preferred URLs
          for a given project release.