How to fake type with Python

Question

I recently developed a class named DocumentWrapper around some ORM document object in Python to transparently add some features to it without changing its inter

Answer 1

Override __class__ in your wrapper class DocumentWrapper:

class DocumentWrapper(object):

  @property
  def __class__(self):
    return User

>>> isinstance(DocumentWrapper(), User)
True

This way no modifications to the wrapped class User are needed.

Python Mock does the same (see mock.py:612 in mock-2.0.0, couldn't find sources online to link to, sorry).