Semi Circle Donut Chart with Altair

Question

I'm new to Altair. Could you help me to figure out how to plot something like this in Python?

Answer 1

This seems to work for me.

import pandas as pd
import altair as alt

source = pd.DataFrame({"category": [1, 2, 3, 4, 5, 6], "value": [4, 6, 10, 3, 7, 8]})

pie = alt.Chart(source).mark_arc(innerRadius=75).encode(
    theta=alt.Theta(field="value", type="quantitative", stack=True, scale=alt.Scale(type="linear",rangeMax=1.5708, rangeMin=-1.5708 )),
    color=alt.Color(field="category", type="nominal"),
)

pie + pie.mark_text(radius=170, fontSize=16).encode(text='category')