Day 35/100: Practice Problem – Data Structure Challenge

#python #programming #learning #100daysofcode

Welcome to Day 35 of your Python journey!
After diving deep into lists, dictionaries, sets, comprehensions, and modules like itertools and collections, it’s time to put your knowledge to the test.

Let’s solve a fun and practical data structure challenge! 💡

🎯 Challenge Overview

You’re given a list of orders placed on an online store. Each order contains:

Customer name
Product name
Quantity
Price per unit

Your task is to:

Calculate the total amount spent by each customer.
Find the top 3 products based on total quantity sold.
Show the most valuable single order (by total value).

📦 Sample Data

orders = [
    {'customer': 'Alice', 'product': 'Pen', 'quantity': 3, 'price': 5},
    {'customer': 'Bob', 'product': 'Notebook', 'quantity': 2, 'price': 15},
    {'customer': 'Alice', 'product': 'Notebook', 'quantity': 1, 'price': 15},
    {'customer': 'Dave', 'product': 'Pen', 'quantity': 10, 'price': 5},
    {'customer': 'Carol', 'product': 'Pen', 'quantity': 1, 'price': 5},
    {'customer': 'Bob', 'product': 'Pen', 'quantity': 2, 'price': 5},
    {'customer': 'Alice', 'product': 'Pencil', 'quantity': 5, 'price': 2},
]

🛠️ Step-by-Step Solution

✅ 1. Total Amount Spent by Each Customer

from collections import defaultdict

customer_totals = defaultdict(float)

for order in orders:
    name = order['customer']
    total = order['quantity'] * order['price']
    customer_totals[name] += total

print("💰 Total spent by each customer:")
for customer, total in customer_totals.items():
    print(f"{customer}: ₹{total}")

✅ 2. Top 3 Products by Quantity Sold

from collections import Counter

product_counter = Counter()

for order in orders:
    product_counter[order['product']] += order['quantity']

print("\n📦 Top 3 products sold:")
for product, qty in product_counter.most_common(3):
    print(f"{product}: {qty} units")

✅ 3. Most Valuable Single Order

max_order = max(orders, key=lambda o: o['quantity'] * o['price'])

print("\n💎 Most valuable order:")
print(max_order)

🔎 Output Example

💰 Total spent by each customer:
Alice: ₹40.0
Bob: ₹45.0
Dave: ₹50.0
Carol: ₹5.0

📦 Top 3 products sold:
Pen: 16 units
Pencil: 5 units
Notebook: 3 units

💎 Most valuable order:
{'customer': 'Dave', 'product': 'Pen', 'quantity': 10, 'price': 5}

🧠 Concepts Reviewed

defaultdict for grouped totals
Counter for frequency counting
max() with custom key
Looping and dictionary access
Clean, readable logic

🧪 Try This Extension

Sort the customers by total spending.
Show total revenue per product.
Return top customers who spent more than ₹40.

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