Introduction to Magic Methods in Python

If you’ve learnt Python for a while, chances are that you’ve come across the term magic method at some point. Simply put, magic methods belong in classes, has 2 underscore characters in front of and behind its name eg. __init__, __str__ & __add__, and are invoked when we perform certain actions in Python.

The __init__ Method

The __init__ method is invoked when we create an object from a class. Let’s say we have a Dog class:

class Dog:
    def __init__(self, name, age, breed):
        self.name = name
        self.age = age
        self.breed = breed

Here, our __init__ function takes in 3 attributes name, age and breed. This means that when we create a Dog object, we must pass in these 3 arguments.

rocky = Dog("rocky", 4, "german shepherd")
fifi = Dog("fifi", 5, "german shepherd")
baaron = Dog("baaron", 6, "german shepherd")

Here, each Dog object is created with 3 attributes — name, age and breed.

The __str__ Method

The __str__ method returns a string representation of the object, and is called when we convert an object into a string. If we didn’t have a __str__ method, we might get something like this if we print the object directly