There are (at least) two ways to determine the type of something in Python:
type(obj) obj.__class__ By design, they are not guaranteed to give the same result. Is there a definitive explanation given by the docs for the difference and which you should use under different circumstances? In Python 2, the type() of classic classes is always the same thing: py> class A: # classic class ... def spam(self): return "from A" ... py> class B: ... def spam(self): return "from B" ... py> a = A() py> b = B() py> a.__class__ is b.__class__ False py> type(a) is type(b) # a special type "instance" True Writing to __class__ lets you modify the behaviour of the instance: py> a.spam() 'from A' py> a.__class__ = B py> a.spam() 'from B' New-style classes are different: py> class C(object): # new-style class ... def spam(self): ... return "from C" ... py> class D(object): ... def spam(self): ... return "from D" ... py> c = C() py> d = D() py> c.__class__ is d.__class__ False py> type(c) is type(d) False Like classic classes, you can override the __class__ attribute on instances, and change their behaviour: py> c.spam() 'from C' py> c.__class__ = D py> c.spam() 'from D' Any other differences? -- Steven -- https://mail.python.org/mailman/listinfo/python-list
