Rating and review system in LLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a Review class with a rating attribute.

LLD

class Review:
    def __init__(self, rating):
        self.[1] = rating

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

Arating

Bscore

Cvalue

Drate

Attempts:

3 left

💡 Hint

Common Mistakes

Using unrelated attribute names like 'score' or 'value' which may confuse readers.

The attribute to store the rating should be named rating for clarity and consistency.

2fill in blank

medium

Complete the code to add a method that calculates the average rating from a list of reviews.

LLD

def average_rating(reviews):
    total = 0
    for review in reviews:
        total += review.[1]
    return total / len(reviews) if reviews else 0

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

Ascore

Brating

Cvalue

Drate

Attempts:

3 left

💡 Hint

Common Mistakes

Using an incorrect attribute name causing attribute errors.

The method accesses the rating attribute of each review to sum ratings correctly.

3fill in blank

hard

Fix the error in the code that adds a new review to the system's review list.

LLD

class ReviewSystem:
    def __init__(self):
        self.reviews = []

    def add_review(self, review):
        self.reviews.[1](review)

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

Ainsert

Badd

Cappend

Dextend

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'add' which is not a list method in Python.

Using 'extend' which expects an iterable, causing errors.

The append method adds a single item to the list, which is correct here.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps user IDs to their average rating.

LLD

user_avg_ratings = {user_id: sum(r.rating for r in reviews) [1] len(reviews) for user_id, reviews [2] user_reviews.items()}

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

A//

B/

Cin

Dof

Attempts:

3 left

💡 Hint

Common Mistakes

Using integer division '//' which truncates decimals.

Using 'of' instead of 'in' causing syntax errors.

The division operator / calculates the average, and in is used to iterate over dictionary items.

5fill in blank

hard

Fill all three blanks to filter reviews with rating above 3 and create a dictionary of user to their filtered reviews count.

LLD

filtered_counts = {user: len([r for r in reviews if r.[1] [2] [3]]) for user, reviews in user_reviews.items()}

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

Arating

B>

C3

Dscore

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'score' instead of 'rating' causing attribute errors.

Using '<' instead of '>' causing wrong filtering.

The code filters reviews where the rating is greater than 3 using the > operator.