Obtaining Altair binned table from plot

Question

I would like to access a table with the bin counts and intervals from the histogram resulting from the code snippet below. Is there any way to do this?

import altair as alt
from vega_datasets import data

movies = data.movies.url

alt.Chart(movies).mark_bar().encode(
    alt.X("IMDB_Rating:Q", bin=True),
    y='count()',
)

Answer 1

You can try using the altair_transform package for this, example from the readme:

import altair as alt
import pandas as pd
import numpy as np
from altair_transform import transform_chart


np.random.seed(12345)

df = pd.DataFrame({
    'x': np.random.randn(20000)
})
chart = alt.Chart(df).mark_bar().encode(
    alt.X('x', bin=True),
    y='count()'
)

new_chart = transform_chart(chart)
new_chart.data

x_binned x_binned2  count
-4.0    -3.0    29
-3.0    -2.0    444
-2.0    -1.0    2703
-1.0    0.0     6815
0.0     1.0     6858
1.0     2.0     2706
2.0     3.0     423
3.0     4.0     22