code: def validate(self, value):
          
          if value in list(self.choices.keys()):
              self._choice = value
              return True
          try:
              self._choice = list(self.choices.keys())[int(value)]
              return True
          except (ValueError, IndexError):
              self.error_message = '%s is not a valid choice.' % value
              return False
docs: Return a boolean if the choice is a number in the enumeration