Instance methods 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 that class. It can access and modify the object's attributes using the 'self' parameter.

beginner

Why do instance methods use 'self' as their first parameter?

'self' represents the specific object calling the method. It allows the method to access or change the object's own data and other methods.

beginner

How do you call an instance method on an object?

You call it using the dot notation: object.method_name(). Python automatically passes the object as 'self' to the method.

beginner

Example: What will this code print?

class Dog:
    def bark(self):
        print('Woof!')

my_dog = Dog()
my_dog.bark()

It will print: Woof! Because 'bark' is an instance method called on 'my_dog', it prints 'Woof!'.

intermediate

Can instance methods modify the object's attributes? How?

Yes, instance methods can change the object's attributes by using 'self.attribute_name = new_value'. This updates the data stored in that specific object.

What does the 'self' parameter in an instance method represent?

A The instance of the class calling the method

B The class itself

C A global variable

D A static method

'self' always refers to the specific object that calls the instance method.

How do you define an instance method inside a class?

A def method_name(cls):

B def method_name():

C def method_name(self):

D def method_name(static):

Instance methods must have 'self' as the first parameter to access the object.

Which of these calls an instance method correctly?

A Class.method()

B obj.method()

C method(obj)

D method()

You call instance methods on an object using dot notation: obj.method()

Can instance methods access other methods in the same class?

A Yes, using self.other_method()

B No, methods are isolated

C Only if they are static methods

D Only if they are class methods

Instance methods can call other instance methods using self.other_method()

What happens if you forget to include 'self' in an instance method definition?

A The method is ignored

B The method works normally

C The method becomes a static method

D Python raises an error when calling the method

Python expects 'self' as the first parameter; missing it causes errors when calling the method.

Explain what an instance method is and why 'self' is important.

Think about how methods know which object they belong to.

Describe how to call an instance method and what happens behind the scenes.

Remember the dot notation and the role of 'self'.