Hi! How can I add a method to an object. This code does not work: class Foo: def __init__(self): self.counter=0 f=Foo() def incr(self): self.counter+=1 f.incr=incr f.incr() ===> python extend.py Traceback (most recent call last): File "extend.py", line 12, in ? f.incr() TypeError: incr() takes exactly 1 argument (0 given)