Why axis formatting matters in Matplotlib - See It in Action

Why axis formatting matters

📖 Scenario: You are analyzing sales data for a small store. You want to create a simple line chart to show sales over days. Proper axis formatting will help make the chart clear and easy to understand.

🎯 Goal: Build a line chart using matplotlib that shows sales over days with clear axis labels and formatted ticks.

📋 What You'll Learn

Create a list called days with values 1 to 7 representing days of the week

Create a list called sales with exact values: 150, 200, 170, 220, 180, 210, 190

Create a matplotlib line plot using days and sales

Set the x-axis label to 'Day of Week'

Set the y-axis label to 'Sales ($)'

Format the y-axis ticks to show dollar sign and no decimals

Display the plot

💡 Why This Matters

🌍 Real World

Axis formatting helps make charts easy to read and understand in reports and presentations.

💼 Career

Data scientists and analysts use axis formatting to communicate data insights clearly to others.

1

Create the sales data lists

Create a list called days with values 1, 2, 3, 4, 5, 6, 7 and a list called sales with values 150, 200, 170, 220, 180, 210, 190.

Matplotlib

# Create the days and sales lists
# Your code here

Need a hint?

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

2

Import matplotlib and create the plot

Import matplotlib.pyplot as plt. Use plt.plot(days, sales) to create a line plot.

Matplotlib

days = [1, 2, 3, 4, 5, 6, 7]
sales = [150, 200, 170, 220, 180, 210, 190]
# Import matplotlib.pyplot as plt
# Create a line plot with days and sales
# Your code here

Need a hint?

Use import matplotlib.pyplot as plt and then plt.plot() with the two lists.

3

Add axis labels and format y-axis ticks

Use plt.xlabel('Day of Week') and plt.ylabel('Sales ($)') to label the axes. Then import matplotlib.ticker and use plt.gca().yaxis.set_major_formatter(matplotlib.ticker.StrMethodFormatter('${x:,.0f}')) to format y-axis ticks with dollar sign and no decimals.

Matplotlib

import matplotlib.pyplot as plt
days = [1, 2, 3, 4, 5, 6, 7]
sales = [150, 200, 170, 220, 180, 210, 190]
plt.plot(days, sales)
# Add x-axis label 'Day of Week'
# Add y-axis label 'Sales ($)'
# Format y-axis ticks to show dollar sign and no decimals
# Your code here

Need a hint?

Use plt.xlabel() and plt.ylabel() for labels. Use matplotlib.ticker.StrMethodFormatter to format y-axis ticks.

4

Display the plot

Use plt.show() to display the plot with the formatted axes.

Matplotlib

import matplotlib.pyplot as plt
import matplotlib.ticker

days = [1, 2, 3, 4, 5, 6, 7]
sales = [150, 200, 170, 220, 180, 210, 190]
plt.plot(days, sales)
plt.xlabel('Day of Week')
plt.ylabel('Sales ($)')
plt.gca().yaxis.set_major_formatter(matplotlib.ticker.StrMethodFormatter('${x:,.0f}'))
# Display the plot
# Your code here

Need a hint?

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