Altair: How to keep bars in original order

[caseyahlan]

I am creating a bar chart:

incidents = alt.Chart(off_by_bias).mark_bar().encode( x='Bias motivation', y='incidents + offenses', color='Type' )

And when I do this, it's sorting x alphabetically. However, I want the bars to retain their original order from the data. Is this possible?

[jakevdp]

Axes are sorted (either numerically or alphabetically) by default. If you would like them to be ordered differently, you can specify the sort keyword. For example:

import altair as alt
import pandas as pd

data = pd.DataFrame({
  'x': ['B', 'A', 'C'],
  'y': [1, 2, 3]
})

alt.Chart(data).mark_bar().encode(
  x=alt.X('x', sort=['A', 'B', 'C']),
  y='y'
)

[iaindillingham]

I believe you can also pass sort=None to use the original (insertion) order (Vega-Lite docs). Here's an example:

data = alt.InlineData([
    {'letter': 'b', 'index': 2},
    {'letter': 'a', 'index': 1},
    {'letter': 'c', 'index': 3},
])

alt.Chart(data).mark_bar().encode(x=alt.X('letter', type='nominal', sort=None), y='index:Q')