code: def of_text(self, text, encoding="utf-8"):
          
          m = self.hash_algo()
          m.update(text.encode(encoding))
          if self.return_int:
              return int(m.hexdigest(), 16)
          else:
              return m.hexdigest()
docs: Use default hash method to return hash value of a piece of string
          default setting use 'utf-8' encoding.