Small multiples (facet grid) in Matplotlib - Mini Project: Build & Apply

Create Small Multiples (Facet Grid) with Matplotlib

📖 Scenario: You are a data analyst at a fruit store. You have sales data for different fruits over several months. You want to compare the monthly sales of each fruit side by side to see trends easily.

🎯 Goal: Build a small multiples (facet grid) plot using matplotlib to show monthly sales for each fruit in separate subplots.

📋 What You'll Learn

Create a dictionary with fruit names as keys and lists of monthly sales as values.

Create a list of month names to use as x-axis labels.

Use a configuration variable to store the number of fruits.

Use a loop to create subplots for each fruit.

Plot monthly sales data for each fruit in its own subplot.

Add titles to each subplot with the fruit name.

Display the final figure with all subplots.

💡 Why This Matters

🌍 Real World

Small multiples help compare different groups or categories side by side, making it easier to spot patterns or differences in data over time or conditions.

💼 Career

Data analysts and scientists often use facet grids to visualize segmented data clearly, which helps in reporting and decision-making.

1

Create the sales data dictionary and months list

Create a dictionary called fruit_sales with these exact entries: 'Apple': [30, 35, 40, 45], 'Banana': [20, 25, 30, 35], 'Cherry': [15, 18, 20, 22]. Also create a list called months with these exact values: 'Jan', 'Feb', 'Mar', 'Apr'.

Matplotlib

# Create the fruit_sales dictionary and months list
# Your code here

Need a hint?

Use curly braces {} to create the dictionary and square brackets [] for the lists.

2

Create a variable for the number of fruits

Create a variable called num_fruits and set it to the number of keys in the fruit_sales dictionary.

Matplotlib

fruit_sales = {
    'Apple': [30, 35, 40, 45],
    'Banana': [20, 25, 30, 35],
    'Cherry': [15, 18, 20, 22]
}
months = ['Jan', 'Feb', 'Mar', 'Apr']
# Create num_fruits variable
# Your code here

Need a hint?

Use the len() function to count the keys in the dictionary.

3

Create subplots and plot each fruit's sales

Import matplotlib.pyplot as plt. Use plt.subplots() with num_fruits rows and 1 column to create subplots. Use a for loop with variables index and fruit from enumerate(fruit_sales) to plot each fruit's sales on its subplot. Use ax.plot(months, fruit_sales[fruit]) to plot. Set the subplot title with ax.set_title(fruit). Use plt.tight_layout() to adjust spacing.

Matplotlib

fruit_sales = {
    'Apple': [30, 35, 40, 45],
    'Banana': [20, 25, 30, 35],
    'Cherry': [15, 18, 20, 22]
}
months = ['Jan', 'Feb', 'Mar', 'Apr']
num_fruits = len(fruit_sales)

# Import matplotlib and create subplots
# Use a for loop to plot each fruit's sales
# Your code here

Need a hint?

Remember to handle the case when there is only one subplot (axes is not a list).

4

Display the final figure

Use plt.show() to display the figure with all the subplots.

Matplotlib

import matplotlib.pyplot as plt

fruit_sales = {
    'Apple': [30, 35, 40, 45],
    'Banana': [20, 25, 30, 35],
    'Cherry': [15, 18, 20, 22]
}
months = ['Jan', 'Feb', 'Mar', 'Apr']
num_fruits = len(fruit_sales)

fig, axes = plt.subplots(num_fruits, 1, figsize=(6, 4 * num_fruits))

for index, fruit in enumerate(fruit_sales):
    ax = axes[index] if num_fruits > 1 else axes
    ax.plot(months, fruit_sales[fruit])
    ax.set_title(fruit)

plt.tight_layout()
# Display the plot
# Your code here

Need a hint?

Use plt.show() to display the figure window.