How to Wrap Text in Plotly's Sunburst Diagram   

To improve readability in Plotly's Sunburst Diagram, we need a way to wrap text inside the chart. This is needed when work with long text labels which get cut off sometimes. We can fix the issue by using simple method:

def customwrap(s,width=30):
    return "<br>".join(textwrap.wrap(s,width=width))

Ways to Wrap Text in a Sunburst Diagram

Since Plotly does not support direct text wrapping, we can use the following techniques:

1. Insert Line Breaks (<br>) in Labels
2. Use texttemplate to Format Labels

Data

We are going to use the following data:

import pandas as pd

df = pd.DataFrame({
    "labels": ["Sales Department", "Sales Department", "Marketing Team", "Software Engineering", 
               "Software Engineering", "Sales Department"],
    "parents": ["Company1", "Company1", "Company2", "Company2", "Company1", "Company1"],
    "people": ["Augustus Caesar Augustus", "Tiberius Caesar Augustus", "Caligula Gaius Caesar Augustus Germanicus", 
               "Claudius Tiberius Claudius Caesar Augustus Germanicus", "Nero Claudius Caesar", "Galba Servius Galba Caesar"]
})

df

data:

Example: Wrapping Text in a Sunburst Chart

First we are going to change the labels for the outmost values to wrap in a given lenght by:

import textwrap
def customwrap(s,width=20):
    try:
        return "<br>".join(textwrap.wrap(s,width=width))
    except:
        return None

df['people adj'] = df['people'].map(customwrap)

then we are going to plot the Sunburst diagram:

import plotly.express as px
fig2 = px.sunburst(df, path=['parents', 'people adj'], color= 'labels')
fig2.update_layout(title_text="Wrap up text ", font_size=15,
                  width=500, height=500)
fig2.show()

You can compare the results below:

Resources

This post is inspired by:

• https://stackoverflow.com/questions/62151608/how-to-wrap-text-in-plotly-pys-sunburst-diagram

Conclusion

Although Plotly does not support automatic text wrapping, using wrap with line breaks (<br>) significantly improves label readability in Sunburst Charts.