Fix Python – Should all Python classes extend object? [duplicate]


Asked By – Kara

I have found that both of the following work:

class Foo():
    def a(self):
        print "hello"

class Foo(object):
    def a(self):
        print "hello"

Should all Python classes extend object? Are there any potential problems with not extending object?

Now we will see solution for issue: Should all Python classes extend object? [duplicate]


In Python 2, not inheriting from object will create an old-style class, which, amongst other effects, causes type to give different results:

>>> class Foo: pass
>>> type(Foo())
<type 'instance'>


>>> class Bar(object): pass
>>> type(Bar())
<class '__main__.Bar'>

Also the rules for multiple inheritance are different in ways that I won’t even try to summarize here. All good documentation that I’ve seen about MI describes new-style classes.

Finally, old-style classes have disappeared in Python 3, and inheritance from object has become implicit. So, always prefer new style classes unless you need backward compat with old software.

This question is answered By – Fred Foo

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