How to manually add a legend color and legend font size on a plotly figure in Python?

Last Updated : 22 Nov, 2021

In this article, we will learn how to manually add a legend color and legend font size on a plotly figure in Python. A legend is an area describing the elements of the graph. In the plotly legend is used to Place a legend on the axes.

Here we will discuss different methods for manually adding legend color and legend font size in plotly express, using two different examples for each to make it more clear.

Example 1: In this Bar chart, We are adding the legend color and legend font size using fig.update_layout() method, legend_font_color=”red” – this parameter allows you to set the fontcolor whereas legend_font_size= 19 – this parameter allows you to set the fontsize.

Python3

# importing packages 
import plotly.express as px 
  
# using medals_wide dataset 
wide_df = px.data.medals_wide() 
  
# plotting the bar chart 
fig = px.bar(wide_df, x="nation", y=[ 
             "gold", "silver", "bronze"], 
             title="Geeksforgeeks") 
  
# set legend color 
fig.update_layout(legend_font_color="red") 
  
# set font size 
fig.update_layout(legend_font_size=19) 
  
# showing figure. 
fig.show() 

Output:

Example 2: In this Scatter chart, We are adding the legend color and legend font size using fig.update_layout() method, legend_font_color=”gold” – this parameter allows you to set the fontcolor whereas legend_font_size= 10 – this parameter allows you to set the fontsize.

Python3

# importing packages 
import plotly.express as px 
  
# using the gapminder dataset 
df = px.data.tips() 
fig = px.scatter(df, x="total_bill", y="tip", color="sex", 
                 symbol="smoker", facet_col="time", 
                 labels={"sex": "Gender", "smoker": "Smokes"}) 
  
# set legend color 
fig.update_layout(legend_font_color="gold") 
  
# set font size 
fig.update_layout(legend_font_size=10) 
  
fig.show() 