Trellis Histogram

This example shows how to make a basic trellis histogram. https://vega.github.io/vega-lite/examples/trellis_bar_histogram.html

import altair as alt
from vega_datasets import data

source = data.cars()

alt.Chart(source).mark_bar().encode(
    alt.X("Horsepower:Q", bin=True),
    y='count()',
    row='Origin'
)