Altair – how to show a dataframe column as label with its respective color
I am trying to show on an Area Chart the column name(s) I selected from a Dataframe as label, along with its respective color using Altair.
The problem is that every time I do it, the chart disappear and I can’t customize the colors based on a list of hex Codes.
Is there any way to achieve this?
import altair as alt import pandas as pd import os df = { 'Month': ['Apr', 'May'], 'Status': ['Working', 'Complete'], 'Revenue': [1000, 2000], 'Profit': [500, 600] } df = pd.DataFrame(df) hexList = [ '#002664', '#72BF44', '#EED308', '#5E6A71', '#7C9DBE', '#F47920', '#1C536E', '#2D580C', ] xSelected = 'Status' ySelected = ['Revenue'] chartsList = [] chart = alt.Chart(df).mark_area().encode( x=xSelected, y=ySelected[0], #color=alt.Color(f'{xSelected}:N'), ### **==> this gives me the labels I neeed, but no chart is plotted** color=alt.value(f'{hexList[0]}'), ### **==> this gives me the chart with the color I want, but without the labels I need** tooltip=ySelected ) mainDir = os.path.dirname(__file__) filePath = os.path.join(mainDir, 'altairChart.html') chart.save(filePath) 
The reason the chart disappears with a color encoding is because your color groups each contain only a single point, and the area under a point has zero width and thus appears empty. Perhaps a bar chart would be a better fit?
chart = alt.Chart(df).mark_bar().encode( x=xSelected, y=ySelected[0], color=alt.Color(f'{xSelected}:N'), tooltip=ySelected ) 
