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Next: Instance objects Up: A first look Previous: Class definition syntax

Class objects

Class objects support two kinds of operations: attribute references and instantiation.

Attribute references use the standard syntax used for all attribute references in Python: obj.name. Valid attribute names are all the names that were in the class's name space when the class object was created. So, if the class definition looked like this:

        class MyClass:
                i = 12345
                def f(x):
                        return 'hello world'

then MyClass.i and MyClass.f are valid attribute references, returning an integer and a function object, respectively. Class attributes can also be assigned to, so you can change the value of MyClass.i by assignment.

Class instantiation uses function notation. Just pretend that the class object is a parameterless function that returns a new instance of the class. For example, (assuming the above class):

        x = MyClass()

creates a new instance of the class and assigns this object to the local variable x.



guido@cwi.nl