Difference between method types in Python - Quick Revision & Key Differences

Recall & Review

beginner

What is an instance method in Python?

An instance method is a function defined inside a class that operates on an instance of the class. It takes <code>self</code> as the first parameter, which refers to the specific object calling the method.

beginner

What is a class method in Python?

A class method is a method that takes the class itself as the first argument, usually named <code>cls</code>. It is marked with the <code>@classmethod</code> decorator and can access or modify class state shared by all instances.

beginner

What is a static method in Python?

A static method is a method inside a class that does not take <code>self</code> or <code>cls</code> as the first parameter. It behaves like a regular function but belongs to the class's namespace. It is marked with the <code>@staticmethod</code> decorator.

intermediate

How do instance, class, and static methods differ in how they are called?

Instance methods are called on objects and receive the object as <code>self</code>. Class methods are called on the class and receive the class as <code>cls</code>. Static methods can be called on the class or instance but do not receive any automatic first argument.

intermediate

Why use a class method instead of an instance method?

Use a class method when you need to access or modify class-level data that is shared across all instances, or when you want to create alternative constructors. Instance methods are for behavior related to individual objects.

Which method type automatically receives the instance as the first argument?

A None of the above

B Class method

C Static method

D Instance method

Instance methods receive the instance (self) automatically when called on an object.

Which decorator is used to define a class method?

A @staticmethod

B @instance

C @classmethod

D @class

The @classmethod decorator marks a method as a class method.

What is true about static methods?

A They receive the class as the first argument

B They do not receive any automatic first argument

C They receive the instance as the first argument

D They can only be called on instances

Static methods behave like regular functions inside the class and do not receive self or cls automatically.

When would you use a class method?

A To access or modify class-level data

B To access or modify instance-specific data

C To create a regular function inside a class

D To override instance methods

Class methods are used to work with class-level data shared by all instances.

Which method type can be called on both the class and its instances?

A Static method

B Class method

C None of the above

D Instance method

Static methods can be called on the class or instances without receiving any automatic argument.

Explain the differences between instance, class, and static methods in Python.

Think about what each method receives as the first parameter and what data it can access.

When should you choose to use a class method over an instance method?

Consider the difference between data that belongs to the whole class versus data that belongs to one object.