Purpose of constructors in Python - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a constructor in Python?

A constructor is a special method in a class that runs automatically when an object is created. It usually sets up the initial state of the object.

beginner

Why do we use constructors in classes?

We use constructors to initialize an object's properties with values right when the object is created, so it is ready to use.

beginner

What is the name of the constructor method in Python?

The constructor method in Python is called __init__ (double underscore init double underscore).

intermediate

How does a constructor help when creating multiple objects?

A constructor lets you create many objects with different starting values easily, without writing extra code to set each property after creating the object.

intermediate

Can a class have more than one constructor in Python?

Python does not support multiple constructors directly, but you can use default values or class methods to simulate different ways to create objects.

What does the constructor method __init__ do in a Python class?

A Initializes the object when it is created

B Deletes the object

C Prints the object

D Runs only when the program ends

The __init__ method runs automatically to set up the object when it is created.

When is the constructor called in Python?

A When the class is defined

B When a method is called

C When the program finishes

D When an object of the class is created

The constructor runs automatically right after an object is created.

Which of these is the correct way to define a constructor in Python?

A def __init__(self):

B def constructor(self):

C def start(self):

D def create(self):

The constructor method must be named __init__ with self as the first parameter.

What happens if you do not define a constructor in your Python class?

A Python will give an error

B The program will crash

C Python uses a default constructor that does nothing

D The class cannot create objects

Python provides a default constructor that does nothing if you don't define one.

How can you give default values to constructor parameters in Python?

A By using a separate method

B By assigning values in the __init__ method parameters

C By calling the constructor twice

D By creating multiple __init__ methods

You can assign default values to parameters in the __init__ method to make them optional.

Explain in your own words what a constructor does in a Python class.

Think about what happens right after you make a new object.

Why is it useful to have a constructor when creating multiple objects from the same class?

Consider how you would set up each object without a constructor.