如何在Python2中了解Mro

Question

在python3中，我们可以使用 '__mro__'获得如下：

>>> class a:
...     pass
...  
>>> a.__mro__
(<class '__main__.a'>, <class 'object'>)
>>> 

Python2是否有另一种方法？我试图找到一个但失败。

>>> class a:
...     pass
... 
>>> dir(a)
['__doc__', '__module__']
>>> class a(object):
...     pass
... 
>>> dir(a)
['__class__', '__delattr__', '__dict__', '__doc__', '__format__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__']

Answer 1

mro()可用，因为Python 2.2（https://www.python.org/download/releases/2.3/mro/）

但是，该类必须是一个新样式类。

>>> class A: pass
>>> A.mro()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: class A has no attribute 'mro'
>>> class A(object): pass
>>> A.mro()
[<class '__main__.A'>, <type 'object'>]