Overloading standard parantheses (“()”) in Python

Question

This should be very simple but I failed to google it: How (if at all) can I overload the parantheses operator in Python? So that this code will make sense:

my_new_object = my_new_class()
x = my_new_object(5)

Answer 1

You need to define __call__ on your class.

For example

>>> class Multiplier(object):
...    def __init__(self, num):
...        self.num = num
...    def __call__(self, other):
...        return self.num*other
...
>>> mul5 = Multiplier(5)
>>> mul5(6)
30

Answer 2

Define __call__() on your class:

class MyNewClass(object):
    def __call__(self, x):
        return x

Answer 3

You should look at the "Callable types" section of this document . In particular, your class could implement __call__ .