code: def _make_boundary(self):
          
          if self.PY2:
              return '===============%s==' % uuid.uuid4().get_hex()
          elif self.PY3:
              return '===============%s==' % uuid.uuid4().hex
          else:
              from random import choice
              digits = "0123456789"
              letters = "abcdefghijklmnopqrstuvwxyz"
              return '===============%s==' % ''.join(choice(letters + digits) \
                                                     for i in range(15))
docs: creates a boundary for multipart post (form post)