Purpose of magic methods in Python - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a magic method that returns a string representation of an object.

Python

class Book:
    def __init__(self, title):
        self.title = title
    def [1](self):
        return f"Book: {self.title}"

Drag options to blanks, or click blank then click option'

A__call__

B__str__

C__repr__

D__init__

Attempts:

3 left

💡 Hint

Common Mistakes

Using __init__ instead of __str__

Confusing __repr__ with __str__

Forgetting to return a string

The __str__ method is a magic method that returns a readable string representation of an object.

2fill in blank

medium

Complete the code to define a magic method that allows adding two objects of the class.

Python

class Number:
    def __init__(self, value):
        self.value = value
    def [1](self, other):
        return Number(self.value + other.value)

Drag options to blanks, or click blank then click option'

A__mul__

B__sub__

C__add__

D__eq__

Attempts:

3 left

💡 Hint

Common Mistakes

Using __sub__ instead of __add__

Not returning a new object

Forgetting the second parameter

The __add__ magic method lets you define how the + operator works for your objects.

3fill in blank

hard

Fix the error in the magic method that compares two objects for equality.

Python

class Person:
    def __init__(self, name):
        self.name = name
    def [1](self, other):
        return self.name == other.name

Drag options to blanks, or click blank then click option'

A__eq__

B__lt__

C__str__

D__init__

Attempts:

3 left

💡 Hint

Common Mistakes

Using __lt__ which is for less than comparison

Using __str__ which returns string representation

Not defining the method at all

The __eq__ method defines how two objects are compared using ==.

4fill in blank

hard

Fill both blanks to create a magic method that returns the length of a custom container.

Python

class CustomList:
    def __init__(self, items):
        self.items = items
    def [1](self):
        return [2]

Drag options to blanks, or click blank then click option'

A__len__

Blen(self.items)

Cself.items

Dself.length

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the list itself instead of its length

Using wrong method name

Not returning anything

The __len__ method returns the number of items in the container. Using len(self.items) gets the length of the internal list.

5fill in blank

hard

Fill all three blanks to create a magic method that allows indexing into a custom container.

Python

class CustomList:
    def __init__(self, items):
        self.items = items
    def [1](self, [2]):
        return [3]

Drag options to blanks, or click blank then click option'

A__getitem__

Bindex

Cself.items[index]

Dself.items

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method name

Forgetting the index parameter

Returning the whole list instead of one item

The __getitem__ method allows using square brackets to access elements. It takes an index and returns the item at that position.