Why export quality matters in Matplotlib - See It in Action

Why export quality matters

📖 Scenario: You have created a simple bar chart to show sales data for three products. Now, you want to save this chart as an image file. The quality of the saved image matters because it affects how clear and professional the chart looks when shared or printed.

🎯 Goal: Learn how to create a basic bar chart using matplotlib and save it as an image file with good quality settings.

📋 What You'll Learn

Create a bar chart with given sales data

Set a variable for image resolution (DPI)

Save the chart as a PNG file using the DPI setting

Print a confirmation message with the file name

💡 Why This Matters

🌍 Real World

Exporting charts with good quality is important when sharing reports, presentations, or publishing data visuals online or in print.

💼 Career

Data analysts and scientists often need to create clear and professional visuals that maintain quality across different platforms and devices.

1

Create sales data for products

Create a dictionary called sales with these exact entries: 'Product A': 150, 'Product B': 200, 'Product C': 120.

Matplotlib

# Create the sales dictionary with product names and sales numbers
# Your code here

Need a hint?

Use curly braces {} to create a dictionary with keys as product names and values as sales numbers.

2

Set image resolution for export

Create a variable called image_dpi and set it to 300 to define the image resolution for saving the chart.

Matplotlib

sales = {'Product A': 150, 'Product B': 200, 'Product C': 120}
# Set the image resolution (DPI) for saving the chart
# Your code here

Need a hint?

DPI stands for dots per inch and controls the sharpness of the saved image.

3

Create and save the bar chart with quality setting

Use matplotlib.pyplot to create a bar chart from the sales dictionary. Then save the figure as 'sales_chart.png' using the image_dpi variable for the dpi parameter.

Matplotlib

import matplotlib.pyplot as plt

sales = {'Product A': 150, 'Product B': 200, 'Product C': 120}
image_dpi = 300

# Create bar chart and save it with the specified DPI
# Your code here

Need a hint?

Use plt.bar() to create the bar chart and plt.savefig() with the dpi argument to save the image with good quality.

4

Print confirmation of saved file

Write a print statement to display the message: "Chart saved as sales_chart.png with DPI 300".

Matplotlib

import matplotlib.pyplot as plt

sales = {'Product A': 150, 'Product B': 200, 'Product C': 120}
image_dpi = 300

plt.bar(sales.keys(), sales.values())
plt.title('Sales by Product')
plt.xlabel('Product')
plt.ylabel('Sales')
plt.savefig('sales_chart.png', dpi=image_dpi)

# Print confirmation message
# Your code here

Need a hint?

Use print() to show the exact message confirming the file save and DPI.