Multiple histograms overlay in Matplotlib - Mini Project: Build & Apply

Multiple histograms overlay

📖 Scenario: You are analyzing the sales data of two different stores. You want to compare the distribution of daily sales amounts for both stores visually.

🎯 Goal: Create two lists of daily sales amounts for Store A and Store B. Then, overlay their histograms on the same plot to compare their sales distributions.

📋 What You'll Learn

Create two lists named store_a_sales and store_b_sales with given sales data.

Create a variable bins to set the number of bins for the histograms.

Use matplotlib.pyplot.hist to plot both histograms on the same figure with transparency.

Add a legend to distinguish Store A and Store B histograms.

Display the plot using plt.show().

💡 Why This Matters

🌍 Real World

Overlaying histograms helps compare distributions of data from different groups, like sales from different stores or test scores from different classes.

💼 Career

Data scientists often compare multiple datasets visually to find patterns or differences, making histogram overlays a useful skill.

1

Create sales data lists

Create two lists called store_a_sales and store_b_sales with these exact values: store_a_sales = [20, 35, 30, 35, 27, 25, 32] and store_b_sales = [25, 32, 34, 20, 25, 40, 38].

Matplotlib

# Create the sales data lists for Store A and Store B
# Your code here

Need a hint?

Use square brackets to create lists with the exact numbers given.

2

Set number of bins for histograms

Create a variable called bins and set it to 5 to define the number of bins for the histograms.

Matplotlib

store_a_sales = [20, 35, 30, 35, 27, 25, 32]
store_b_sales = [25, 32, 34, 20, 25, 40, 38]
# Create a variable bins and set it to 5
# Your code here

Need a hint?

Just assign the number 5 to a variable named bins.

3

Plot the histograms overlay

Import matplotlib.pyplot as plt. Use plt.hist to plot store_a_sales and store_b_sales on the same figure with bins bins, set alpha=0.5 for transparency, and add labels 'Store A' and 'Store B' respectively. Then add a legend with plt.legend().

Matplotlib

store_a_sales = [20, 35, 30, 35, 27, 25, 32]
store_b_sales = [25, 32, 34, 20, 25, 40, 38]
bins = 5
# Import matplotlib.pyplot as plt
# Plot histograms for store_a_sales and store_b_sales with alpha=0.5 and labels
# Add legend
# Your code here

Need a hint?

Use plt.hist() twice with the correct parameters and then call plt.legend().

4

Show the plot

Add a line to display the plot using plt.show().

Matplotlib

import matplotlib.pyplot as plt

store_a_sales = [20, 35, 30, 35, 27, 25, 32]
store_b_sales = [25, 32, 34, 20, 25, 40, 38]
bins = 5

plt.hist(store_a_sales, bins=bins, alpha=0.5, label='Store A')
plt.hist(store_b_sales, bins=bins, alpha=0.5, label='Store B')
plt.legend()
# Display the plot
# Your code here

Need a hint?

Use plt.show() to display the histogram plot window.