Scalar and array broadcasting in NumPy - Mini Project: Build & Apply

Scalar and Array Broadcasting with NumPy

📖 Scenario: Imagine you run a small bakery. You have a list of prices for different types of bread. You want to calculate the total cost if a customer buys multiple quantities of each bread type. Instead of writing a loop, you can use NumPy broadcasting to multiply the prices by the quantities easily.

🎯 Goal: Learn how to use scalar and array broadcasting in NumPy to multiply arrays and scalars efficiently.

📋 What You'll Learn

Create a NumPy array with exact bread prices

Create a scalar quantity to multiply with prices

Use broadcasting to multiply the scalar with the array

Print the resulting array showing total costs

💡 Why This Matters

🌍 Real World

Broadcasting helps quickly calculate costs, measurements, or any repeated operation without writing loops, saving time and reducing errors.

💼 Career

Data scientists and analysts use broadcasting to efficiently manipulate and analyze large datasets with fewer lines of code.

1

Create a NumPy array of bread prices

Import NumPy as np and create a NumPy array called prices with these exact values: 2.5, 3.0, 4.0, 5.5.

NumPy

# Import numpy and create the prices array
# Your code here

Need a hint?

Use np.array([...]) to create the array.

2

Create a scalar quantity for number of breads

Create a scalar variable called quantity and set it to the integer 3.

NumPy

import numpy as np
prices = np.array([2.5, 3.0, 4.0, 5.5])
# Create the quantity scalar
# Your code here

Need a hint?

Just assign the number 3 to quantity.

3

Multiply prices by quantity using broadcasting

Create a new variable called total_costs that multiplies the prices array by the scalar quantity using broadcasting.

NumPy

import numpy as np
prices = np.array([2.5, 3.0, 4.0, 5.5])
quantity = 3
# Multiply prices by quantity using broadcasting
# Your code here

Need a hint?

Use the * operator to multiply the array by the scalar.

4

Print the total costs array

Print the variable total_costs to display the total cost for each bread type.

NumPy

import numpy as np
prices = np.array([2.5, 3.0, 4.0, 5.5])
quantity = 3
total_costs = prices * quantity
# Print the total_costs array
# Your code here

Need a hint?

Use print(total_costs) to show the result.