Matplotlib Legend Creation Tutorial

Introduction

Matplotlib is a plotting library for the Python programming language and its numerical mathematics extension NumPy. In this tutorial, we will learn how to create a simple legend with Matplotlib.

VM Tips

After the VM startup is done, click the top left corner to switch to the Notebook tab to access Jupyter Notebook for practice.

Sometimes, you may need to wait a few seconds for Jupyter Notebook to finish loading. The validation of operations cannot be automated because of limitations in Jupyter Notebook.

If you face issues during learning, feel free to ask Labby. Provide feedback after the session, and we will promptly resolve the problem for you.

Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL matplotlib(("`Matplotlib`")) -.-> matplotlib/BasicConceptsGroup(["`Basic Concepts`"]) matplotlib(("`Matplotlib`")) -.-> matplotlib/PlottingDataGroup(["`Plotting Data`"]) matplotlib(("`Matplotlib`")) -.-> matplotlib/PlotCustomizationGroup(["`Plot Customization`"]) python(("`Python`")) -.-> python/DataStructuresGroup(["`Data Structures`"]) python(("`Python`")) -.-> python/ModulesandPackagesGroup(["`Modules and Packages`"]) python(("`Python`")) -.-> python/DataScienceandMachineLearningGroup(["`Data Science and Machine Learning`"]) matplotlib/BasicConceptsGroup -.-> matplotlib/importing_matplotlib("`Importing Matplotlib`") matplotlib/BasicConceptsGroup -.-> matplotlib/figures_axes("`Understanding Figures and Axes`") matplotlib/PlottingDataGroup -.-> matplotlib/line_plots("`Line Plots`") matplotlib/PlotCustomizationGroup -.-> matplotlib/line_styles_colors("`Customizing Line Styles and Colors`") matplotlib/PlotCustomizationGroup -.-> matplotlib/legend_config("`Legend Configuration`") python/DataStructuresGroup -.-> python/lists("`Lists`") python/DataStructuresGroup -.-> python/tuples("`Tuples`") python/ModulesandPackagesGroup -.-> python/importing_modules("`Importing Modules`") python/DataScienceandMachineLearningGroup -.-> python/data_visualization("`Data Visualization`") subgraph Lab Skills matplotlib/importing_matplotlib -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} matplotlib/figures_axes -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} matplotlib/line_plots -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} matplotlib/line_styles_colors -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} matplotlib/legend_config -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} python/lists -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} python/tuples -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} python/importing_modules -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} python/data_visualization -.-> lab-48942{{"`Matplotlib Legend Creation Tutorial`"}} end

Import Matplotlib

To use Matplotlib, we need to import it first.

import matplotlib.pyplot as plt

Create a Figure and Axes

We need to create a figure and axes to plot our data.

fig, ax = plt.subplots()

Plot the Data

We can plot our data using the plot() function.

line1, = ax.plot([1, 2, 3], label="Line 1", linestyle='--')
line2, = ax.plot([3, 2, 1], label="Line 2", linewidth=4)

Create the First Legend

We can create a legend for the first line using the legend() function.

first_legend = ax.legend(handles=[line1], loc='upper right')

Add the First Legend

We need to add the first legend to the plot using the add_artist() function.

ax.add_artist(first_legend)

Create the Second Legend

We can create another legend for the second line using the legend() function.

ax.legend(handles=[line2], loc='lower right')

Show the Plot

We can show the plot using the show() function.

plt.show()

Summary

In this tutorial, we learned how to create a simple legend with Matplotlib. We imported Matplotlib, created a figure and axes, plotted the data, and created and added two legends to the plot. Finally, we showed the plot using the show() function.