Python: base class for all other classes

In Python, what is the base class for all other classe开发者_JS百科s (real Base), that all other classes inherit from?

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All new style classes inherit from object.

New-style classes were introduced in Python 2.2 to unify classes and types. Here there is a nice description of what a new style class is. – Paolo Moretti

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It is object. At least in 2.7 and 3.1.

>>> class A():
...     pass
... 
>>> isinstance(A, object)
True