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#0009
Find Revenue By Category
EasyPandas15 min10 XP
Problem
Given a DataFrame with category, price, and quantity columns, return total revenue per category sorted from highest to lowest.
Why This Matters
This is one of the most common data analysis moves: choose the grain, group rows, and aggregate a metric.
Function Signature
def revenue_by_category(df):
Examples
Example 1
Inputcategory: ["book", "pen", "book"], price: [100, 10, 150], quantity: [2, 5, 1]
Outputbook revenue = 350, pen revenue = 50
Book revenue is 100*2 + 150*1. Pen revenue is 10*5.
Constraints
- Do not modify the original DataFrame in place.
- Return columns category and revenue.
- Sort by revenue descending.
CodePython
Visible browser tests run here when available.
Testcases1 visible / 4 hidden categories
Two categories
Inputbook/pen rows with price and quantity
Expectedbook first, then pen
Book has the larger total revenue.
Hidden Test Categories
Single categoryCategories already sorted incorrectlyZero quantity rowsDecimal prices