title: Plotly: Adding custom Text to px.Treemap visual
body: <p>I am using plotly express to make a treemap. I would like to annotate my data sectors with a label as well as the % of the parent and the value that is used in the color scale.</p>
  <p>How can I add an annotation to display the actual value that is used in the <code>color</code> argument of the treemap? In the below example code I would like to annotate &quot;salary&quot; for each sector. I would like to add some additional text to describe the numbers in each sector as well. For example &quot;Percent of Total:&quot; Appended to the percent value for more text description would be ideal to help annotate the treemap a bit more. Any ways to add custom text would be beneficial.</p>
  <pre><code>import pandas as pd
  import numpy as np
  import matplotlib.pyplot as plt
  import plotly.express as px
  
  d = {'count': [1,1,1,2,2,3,3,3,4], 
       'name': ['bob','bob','bob','shelby','shelby','jordan','jordan','jordan','jeff'],
       'type': ['type1','type2','type4','type1','type6','type5','type8','type2',None],
       'salary':[1000,2000,3000,10000,15000,30000,100000,50000,25000]}
  df = pd.DataFrame(data=d)
  
  # group data and aggregate
  df_plot = df.groupby(['name','type'])[['salary','count']].sum().reset_index()
  
  avg_salary = df_plot['salary'].sum()/df_plot['count'].sum()
  
  # plot treemap
  fig = px.treemap(df_plot,
                   values='count',
                   color='salary',
                   color_continuous_scale='balance',
                   color_continuous_midpoint=avg_salary,
                   path=['type','name'])
  fig.data[0].textinfo = 'label+value+percent parent'
  fig.show()
  </code></pre>