What is the difference between old style and new style classes in Python?

Question

What is the difference between old style and new style classes in Python? When should I use one or the other?

Answer 1

Declaration-wise:

New-style classes inherit from object, or from another new-style class.

class NewStyleClass(object):
    pass

class AnotherNewStyleClass(NewStyleClass):
    pass

Old-style classes don't.

class OldStyleClass():
    pass

Python 3 Note:

Python 3 doesn't support old style classes, so either form noted above results in a new-style class.