Introduction to Matplotlib

What is Matplotlib?

Matplotlib is Python's most popular charting library. It creates:

Line charts
Bar charts
Scatter plots
Histograms
And many more!

Install Matplotlib

terminal

pip install matplotlib

Your First Chart

code.py

import matplotlib.pyplot as plt

# Data
x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

# Create chart
plt.plot(x, y)

# Show it
plt.show()

This creates a simple line chart!

Add Title and Labels

code.py

import matplotlib.pyplot as plt

x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

plt.plot(x, y)
plt.title('My First Chart')
plt.xlabel('X Axis')
plt.ylabel('Y Axis')
plt.show()

Save Chart to File

code.py

plt.plot(x, y)
plt.title('My Chart')
plt.savefig('my_chart.png')

Saves as PNG image file.

Basic Chart Types

code.py

import matplotlib.pyplot as plt

# Line chart
plt.plot([1, 2, 3], [1, 4, 9])

# Bar chart
plt.bar(['A', 'B', 'C'], [10, 20, 15])

# Scatter plot
plt.scatter([1, 2, 3], [1, 4, 9])

The plt Pattern

Most matplotlib code follows this pattern:

code.py

import matplotlib.pyplot as plt

# 1. Create the chart
plt.plot(data)

# 2. Customize it
plt.title('Title')
plt.xlabel('X')
plt.ylabel('Y')

# 3. Show or save it
plt.show()

Key Points

import matplotlib.pyplot as plt is standard
plt.plot() creates line charts
plt.bar() creates bar charts
plt.scatter() creates scatter plots
plt.show() displays the chart
plt.savefig() saves to file

What's Next?

Learn about Figure and Axes - the building blocks of matplotlib charts.