code: def verify_file_signature(self, signature_url, file_url, filename):
          
  
          req = requests.get(signature_url, stream=True)
          if req.status_code is 200:
              sigfile = req.raw
          else:
              raise RepositoryMissingSignatureError(signature_url)
  
          verified = self.gpg.verify_file(sigfile, filename)
  
          if verified.valid is True:
              logger.debug("verified {0} against {1}".format(filename, signature_url))
          else:
              raise RepositorySignatureError(file_url, signature_url)
docs: Verify a local file against it's remote signature
  
          :type signature_url: str
          :param signature_url: remote path to signature for file_url
          :type file_url: str
          :param file_url: url from which file at filename was fetched
          :type filename: str
          :param filename: filename of local file downloaded from file_url