7 Magic Methods That Will Turn You Into a Python Wizard

Anyone familiar with Data Science will confirm that Python is the most popular and preferred programming language in data science? This is also supported by many researches, like this one.

Due to its vast features, expanding from web scraping to model building, mastering it might take time. As you gain experience, you might want to operate high-level operations, like defining classes and internal manipulation. This is where Python magic methods come into play.

In this article, you will explore some of these Python magic methods, starting with the len method and extending to the getitem method.? You can detect magic methods, by looking at the double underscores at the beginning and end. “__”.

Magic Methods in Python

Before we go into the Python magic methods further, it's worth mentioning how many magic methods exist in Python.? These methods, which might called Python "dunder" methods due to their double underscores, are special in that they allow us to define how our custom objects should behave in different situations, which we will cover later in this article.

To check how many magic methods are available in Python for a particular type, you can use the dir() function, which lists all attributes of an object, including its magic methods. Let’s see.

Here is the output, that contains Python magic methods.

Great, now you know all the Python magic methods, let’s discover 7 of them, by starting with init method.

Python Magic Method #1: The init method

The init method gets run when you create a new instance of a class.

Here we will define a class named FruitSalad. Think of a class as a blueprint for making objects, like a recipe. Objects are instances made using that blueprint.

Inside the class, there's a function called init. This function sets up each new object when it's created. It needs some initial info like size and fruits to set up the object.

When you do my_salad = FruitSalad('large', ['apple', 'banana', 'cherry']), you're making a new object using the FruitSalad blueprint. The init function jumps in and sets the size to 'large' and fruits to ['apple', 'banana', 'cherry'].

Finally, print(my_salad.size) and print(my_salad.fruits) show what size and fruits got saved as when we made my_salad.

So, the init function is like the starting point that sets up each new FruitSalad object with its own size and fruits.

Let’s see the code.

Here is the output.

Python Magic Method #2: The len method

The len method is used to find out the length or count of something. In Python, when you call len() on an object, Python looks for a len method inside that object's class to get the answer.

When you have a FruitSalad object and you want to know how many fruits are in it, the len method comes to the rescue. Just like init sets up the object, len gives us the count of fruits in the salad.

When you use len(my_salad), Python automatically runs the len method inside the FruitSalad class. This Python magic method returns the count of items in self.fruits, which is the list of fruits you provided when creating the salad.

In this case, the print statement shows '3', which tells you that there are three fruits in my_salad.

So, the len method helps you quickly find out how many fruits are in your FruitSalad.

Let’s see the code.

Let’s see the output.

Python Magic Method #3: The iter method

The iter method is all about going through the items in an object one by one. When you want to look at each fruit in your FruitSalad, you can use a for loop. But for that to work, Python needs to know how to move from one fruit to the next. That's where iter comes in.

When you use for fruit in my_salad, Python starts the iter method. It sets self.n to zero as a starting point. Then the next method takes over. It looks at self.fruits and gives you the next fruit on the list. Once it reaches the end, it stops and says there's no more.

The output will show each fruit, one by one: 'apple', 'banana', 'cherry'.

So, iter lets you loop through the fruits in your FruitSalad easily.

Let’s see the code.

Here is the output.

Python Magic Method #4: The add method

The add method is like a magic trick that lets you combine two fruit salads into one. When you have two separate FruitSalads and you want to make a bigger one, you use the + symbol. It's as if you're adding them up, but instead, you're mixing the fruits from both.

So when you do mixed_salad = salad1 + salad2, Python calls the add method. It checks if you're adding another FruitSalad. If yes, it takes the fruits from both salads and puts them in a new FruitSalad. Finally, it shows you the new list of fruits: ['apple', 'banana', 'cherry', 'orange'].

That's how add lets you mix two FruitSalads into one.

Simple, right? Let’s see the code.

Here is the output.

Python Magic Method #5: The str Method

The str method is like your salad's name tag. It tells Python what to show when you want to print a FruitSalad object. This way, instead of seeing something confusing, you get a neat sentence describing your fruit salad.

When you run the code below, Python checks for a str method in your class. It finds one and uses it to print "A large fruit salad with apple, banana, cherry."

So, the str method helps us see our FruitSalad in a friendly, readable way. It's like asking your salad, "Who are you?" and the salad answers back.

Let’s see the code:

Here is the output.

Python Magic Method #6: The repr Method

The repr method is a way for your fruit salad to describe itself so clearly that Python could recreate it just by reading this description. It's useful for developers to understand the object better, it is often used for debugging or development purposes.

In the following code, When you do print(repr(salad)), Python uses the repr method to print out "FruitSalad(size='large', fruits=['apple', 'banana', 'cherry'])". This is like the salad saying, "Hey, this is exactly how you can make another salad just like me!"

So, the repr method is for giving a detailed, clear description that could be used to make a new, identical fruit salad.

Here is the code.

Here is the output.

Python Magic Method #7: The getitem Method

The getitem method lets you access the fruits in your salad as if the salad were a list. This method makes your object behave like a Python list when you try to get items from it using square brackets.

So, when you do print(salad[0]), Python looks for the first fruit in your salad, which is 'apple'. Similarly, print(salad[1]) will give you 'banana'. It's like asking, "What's the fruit at this position in my salad?"

So, the getitem method allows you to pick fruits out of your salad by their position.

Let’s see the code.

Here is the output.

Conclusion

In this article, we've shed light on the magical world of Python's magic methods, from the fundamental init method to the more specialized getitem method. These tools not only elevate your Python game but also unlock endless customization possibilities.

It might be for data manipulation or creating seamless, user-friendly interfaces. You've seen how magic methods make your classes behave like Python's built-in types, saving you time and making your code more intuitive.

If you're looking to truly become a Python wizard, understanding magic methods is an invaluable step. To dive even deeper, visit our platform, and try to solve interview questions, like these Top 30 Python interview questions and answers, to gain experience, and prepare for interviews at the same time!

See you there!

FAQ’s

What are magic methods in Python?

Magic methods in Python are special methods with double underscores (__) at the beginning and end of their names. They let you define how your custom objects behave in various situations, like addition or length checks.

What is the magic call method in Python?

The call magic method in Python allows an object to be called like a function. This makes your object's instances callable, enhancing their behavior.

What is an example of a magic method?

An example of a magic method is init, which initializes new instances of a class. When you create an object, Python automatically calls the init method to set it up.