'NoneType' 和 'NoneType' 重叠检查实例之间不支持“>”

Question

您好，我在验证检查中遇到了这个错误

def sefl(clean):

  start_number=self.cleaned_data.get("start_number",None)
  end_number=self.cleaned_data.get("end_number",None)
  latest_start=max(start_number, end_number)
  earliest_end = min(start_number, end_number)
  delta = (earliest_end - latest_start) + 1
  if delta is None:
        raise ValidationError("overlap not allowed")

Answer 1

您需要捕获正在创建的 none 值，如下所示：

def sefl(clean):
  start_number = self.cleaned_data.get("start_number", None)
  end_number = self.cleaned_data.get("end_number", None)
  if start_number is not None and end_number is not None:
      latest_start=max(start_number, end_number)
      earliest_end = min(start_number, end_bbch)
      delta = (earliest_end - latest_start) + 1
      if delta is None:
            raise ValidationError("overlap not allowed")
  else:
      raise ValidationError("start_number and end_number are required")

这是因为您将两个变量的默认值定义为 None。如果在 max 或 min 进行比较时，其中至少有一个实际上是 None，则会出现您遇到的问题。

如果您有兴趣，有几种解决方法。例如，如果有合适的值，您可以使用不同的默认值而不是 None。

'NoneType' 和 'NoneType' 重叠检查实例之间不支持“>”

'>' not supported between instances of 'NoneType' and 'NoneType' Overlapping Check

python

django

django-models

django-forms