Use cases for each method type in Python - Cheat Sheet & Quick Revision

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 can access and modify the object's attributes using 'self'.

beginner

When should you use a class method?

Use a class method when you need to access or modify the class itself, not an individual object. It receives the class as the first argument, usually named 'cls'.

beginner

What is a static method and when is it useful?

A static method is a function inside a class that does not access the instance or class. Use it for utility functions related to the class but that don't need class or instance data.

intermediate

Why use instance methods instead of class or static methods?

Instance methods are used when behavior depends on the specific data of an object. They can read or change the object's attributes.

intermediate

Give an example use case for a class method.

Class methods are useful for alternative constructors, like creating an object from different data formats or counting how many objects have been created.

Which method type can modify the class state but not instance state?

A Class method

B Instance method

C Static method

D None of the above

Class methods receive the class as the first argument and can modify class-level data.

Which method type does NOT receive 'self' or 'cls' as the first argument?

A Instance method

B Static method

C All receive one of them

D Class method

Static methods do not receive 'self' or 'cls' because they don't depend on instance or class data.

When should you use an instance method?

A For utility functions unrelated to class or instance

B To create alternative constructors

C To access or modify instance attributes

D To modify class variables

Instance methods operate on individual objects and their data.

What is a common use case for class methods?

A Utility functions

B Modifying instance attributes

C Performing calculations unrelated to class

D Alternative constructors

Class methods are often used to create objects in different ways than the default constructor.

Which method type is best for a function that does not need access to class or instance data?

A Static method

B Class method

C Instance method

D Property method

Static methods are used for functions related to the class but independent of class or instance data.

Explain the differences and use cases for instance, class, and static methods in Python.

Think about what each method type can access and when you might want to use it.

Describe a scenario where a class method is more appropriate than an instance method.

Consider when you want to work with the class as a whole, not just one object.