Python 2:
>>> class X(): pass
...
>>> x = X()
>>> type(x)
<type 'instance'>
>>> x.__class__
<class __main__.X at
0xb743144c>
>>> class X(object):
>>> pass
...
>>> x = X()
>>> type(x)
<class '__main__.X'>
>>> x.__class__
<class '__main__.X'>
Python 3:
>>> class X(): pass
...
>>> x = X()
>>> type(x)
<class '__main__.X'>
>>>
>>> x.__class__
<class '__main__.X'>
>>> class X(object):
>>> pass
...
>>> type(x)
<class '__main__.X'>
>>> x.__class__
<class '__main__.X'>
Old-style
class
New-style
class
Python 3 only knows
New Style Classes