python - 从DoesNotExist异常实例获取查找参数

Question

Django tutorial有一个部分显示了一些引发 DoesNotExist 异常的代码:

# Request an ID that doesn't exist, this will raise an exception.
>>> Poll.objects.get(id=2)
Traceback (most recent call last):
    ...
DoesNotExist: Poll matching query does not exist. Lookup parameters were {'id': 2}

异常实例上的消息显示用于查找的参数。但我没有看到这些参数:

>>> django.get_version()
'1.5.6'
>>> Client.objects.get(pk=2)
Traceback (most recent call last):
    ...
DoesNotExist: Client matching query does not exist.

实际上，这些信息对于我的项目调试日志记录非常有帮助。为什么我们看不到它，如果可能的话如何重新打开它？

Answer 1

本教程是为 Django 1.5 编写的。当时异常比较详细，source :

raise self.model.DoesNotExist(
          "%s matching query does not exist. "
          "Lookup parameters were %s" %
          (self.model._meta.object_name, kwargs))

但是，在最新版本中，异常消息已更改，现在仅包含 source :

raise self.model.DoesNotExist(
          "%s matching query does not exist." %
          self.model._meta.object_name)

仅供引用，实际的changeset尝试修复Passing self to object query may cause infinite regression问题。