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Creating and customizing plot legends in Pandas is a simple process. You can use the .legend() function to create a legend, customize the legend’s location, font size, and other attributes, and even specify the exact labels and colors to use. Additionally, you can use the .set_title() function to add a title to the legend. Finally, you can use the .set_visible() function to toggle the visibility of the legend. With these tools, you can easily create and customize a plot legend with Pandas.
You can use the following basic syntax to add a legend to a plot in pandas:
plt.legend(['A', 'B', 'C', 'D'], loc='center left', title='Legend Title')
The following example shows how to use this syntax in practice.
Example: Create and Customize Plot Legend in Pandas
Suppose we have the following pandas DataFrame:
import pandas as pd #create DataFrame df = pd.DataFrame({'A':7, 'B':12, 'C':15, 'D':17}, index=['Values'])
We can use the following syntax to create a bar chart to visualize the values in the DataFrame and add a legend with custom labels:
import matplotlib.pyplot as plt
#create bar chart
df.plot(kind='bar')
#add legend to bar chart
plt.legend(['A Label', 'B Label', 'C Label', 'D Label'])
We can also use the loc argument and the title argument to modify the location and the title of the legend:
import matplotlib.pyplot as plt
#create bar chart
df.plot(kind='bar')
#add custom legend to bar chart
plt.legend(['A Label', 'B Label', 'C Label', 'D Label'],
loc='upper left', title='Labels')
Lastly, we can use the size argument to modify the font size in the legend:
import matplotlib.pyplot as plt
#create bar chart
df.plot(kind='bar')
#add custom legend to bar chart
plt.legend(['A Label', 'B Label', 'C Label', 'D Label'], prop={'size': 20})
Notice that the font size in the legend is much larger now.