Annotation with arrows in Matplotlib - Mini Project: Build & Apply

Annotation with arrows

📖 Scenario: You are creating a simple line chart to show sales over 5 months. You want to highlight the highest sales point with an arrow and a label.

🎯 Goal: Build a line plot of sales data and add an annotation with an arrow pointing to the highest sales point.

📋 What You'll Learn

Create a list called months with values: 'Jan', 'Feb', 'Mar', 'Apr', 'May'

Create a list called sales with values: 200, 450, 300, 500, 400

Create a variable called max_sales that stores the highest sales value

Create a variable called max_month that stores the month corresponding to the highest sales

Plot the sales data as a line chart with months on the x-axis and sales on the y-axis

Add an annotation with an arrow pointing to the highest sales point with the text 'Highest Sales'

💡 Why This Matters

🌍 Real World

Annotations with arrows help highlight important points in charts, making reports clearer and easier to understand.

💼 Career

Data analysts and scientists often use annotations to explain trends or outliers in data visualizations for stakeholders.

1

Create sales data lists

Create a list called months with these exact values: 'Jan', 'Feb', 'Mar', 'Apr', 'May'. Create a list called sales with these exact values: 200, 450, 300, 500, 400.

Matplotlib

# Create the lists months and sales with the exact values
# Your code here

Need a hint?

Use square brackets to create lists and separate values with commas.

2

Find highest sales and corresponding month

Create a variable called max_sales that stores the highest value in the sales list. Create a variable called max_month that stores the month from months that matches the highest sales.

Matplotlib

months = ['Jan', 'Feb', 'Mar', 'Apr', 'May']
sales = [200, 450, 300, 500, 400]
# Create max_sales and max_month variables
# Your code here

Need a hint?

Use the max() function to find the highest sales. Use list.index() to find the position of that value.

3

Plot sales data line chart

Import matplotlib.pyplot as plt. Plot the sales data as a line chart with months on the x-axis and sales on the y-axis. Use plt.plot(months, sales).

Matplotlib

months = ['Jan', 'Feb', 'Mar', 'Apr', 'May']
sales = [200, 450, 300, 500, 400]
max_sales = max(sales)
max_month = months[sales.index(max_sales)]
# Import matplotlib.pyplot as plt and plot the sales line chart
# Your code here

Need a hint?

Use import matplotlib.pyplot as plt to import plotting functions.

4

Add annotation with arrow and show plot

Add an annotation with plt.annotate() that shows the text 'Highest Sales' pointing to the highest sales point. Use xy=(max_month, max_sales) and xytext=('Apr', 550) for the arrow start. Use arrowprops=dict(arrowstyle='->'). Finally, use plt.show() to display the plot.

Matplotlib

import matplotlib.pyplot as plt

months = ['Jan', 'Feb', 'Mar', 'Apr', 'May']
sales = [200, 450, 300, 500, 400]
max_sales = max(sales)
max_month = months[sales.index(max_sales)]

plt.plot(months, sales)
# Add annotation with arrow pointing to highest sales
# Show the plot
# Your code here

Need a hint?

Use plt.annotate() with xy for the arrow tip and xytext for the label position. Use arrowprops to draw the arrow.