Create Matplotlib Plot Legends

Introduction

Matplotlib is a Python library that enables users to create various types of graphs and plots. This tutorial will guide you through the process of creating a legend in a Matplotlib plot.

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Skills Graph

%%%%{init: {'theme':'neutral'}}%%%% flowchart RL python(("`Python`")) -.-> python/BasicConceptsGroup(["`Basic Concepts`"]) 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`"]) python/BasicConceptsGroup -.-> python/comments("`Comments`") 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/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 python/comments -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} matplotlib/importing_matplotlib -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} matplotlib/figures_axes -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} matplotlib/line_plots -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} matplotlib/legend_config -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} python/lists -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} python/tuples -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} python/importing_modules -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} python/data_visualization -.-> lab-48941{{"`Create Matplotlib Plot Legends`"}} end

Import necessary libraries

Before we start, we need to import the necessary libraries. In this case, we will be using the Matplotlib library.

import matplotlib.pyplot as plt

Create a figure and subplot

We need to create a figure and subplot to plot our data. We will be creating a plot with two subplots.

fig = plt.figure()

ax = fig.add_subplot(211)
ax.plot([1, 2, 3], label="test1")
ax.plot([3, 2, 1], label="test2")

ax = fig.add_subplot(223)
ax.plot([1, 2, 3], label="test1")
ax.plot([3, 2, 1], label="test2")

Add a legend to the plot

We will now add a legend to the plot. There are two ways to add a legend in Matplotlib. We will use both methods in this example.

## Method 1: Place a legend above the subplot
ax.legend(bbox_to_anchor=(0., 1.02, 1., .102), loc='lower left',
           ncols=2, mode="expand", borderaxespad=0.)

## Method 2: Place a legend to the right of the subplot
ax.legend(bbox_to_anchor=(1.05, 1), loc='upper left', borderaxespad=0.)

Display the plot

Finally, we will display the plot.

plt.show()

Summary

In this tutorial, we learned how to add a legend to a Matplotlib plot. We used two different methods to add a legend. The first method placed the legend above the subplot, while the second method placed the legend to the right of the subplot.