How to extend Class instance

Question

MyClass is defined in module.py. There is no way we can modify it. But we do know the Class definition looks like this:

class MyCla         


        

Answer 1

You could subclass it as well:

class MyClass:
    def method(self, msg):
        print 'from method:', msg

def function(msg):
    print 'from function:', msg

class MyNewClass(MyClass):
    def method(self, msg):
        function(msg)
        MyClass.method(self, msg)

And use it like:

>>> a = MyNewClass()
>>> a.method("test")
from function: test
from method: test

Or, if you want to make your class a "new-style" class (for Python 2 - judging by your print statements) - just have MyClass inherit from object and then you can user super:

class MyClass(object):  # object added here
    def method(self, msg):
        print 'from method:', msg

def function(msg):
    print 'from function:', msg

class MyNewClass(MyClass):
    def method(self, msg):
        function(msg)
        super(self.__class__, self).method(msg)  # super added here