Code 21: Magic Method: __call__

1. Create Tony_Counter Class

• Instance attribute .counter defaulted to zero.

• Instance method increment() increases .counter attribute by 1

• Magic Method __call__() calls instance method increment():

• In other words, when an instance calls itself with (), the instance.__call__() will be called:

  • In this case incrementing .counter by 1 each time.

class Tony_Counter():
    def __init__(self):
        self.counter: int = 0
        
    def increment(self):
        self.counter += 1
        
    def __call__(self):
        self.increment() 

ctr = Tony_Counter()
print(ctr.counter)

0

ctr.increment()
print(ctr.counter)

1

ctr.increment()
print(ctr.counter)

2