Grouped Bar Chart with xOffset

Like Grouped Bar Chart, this example shows a grouped bar chart. Whereas Grouped Bar Chart used the column encoding channel, this example uses the xOffset encoding channel. This is adapted from a corresponding Vega-Lite Example: Grouped Bar Chart.

import altair as alt
import pandas as pd

source = pd.DataFrame({"Category":list("AAABBBCCC"),
                     "Group":list("xyzxyzxyz"),
                     "Value":[0.1, 0.6, 0.9, 0.7, 0.2, 1.1, 0.6, 0.1, 0.2]})

alt.Chart(source).mark_bar().encode(
    x="Category:N",
    y="Value:Q",
    xOffset="Group:N",
    color="Group:N"
)