[ python ] interactive with altair

# test interactive chart in github blog

---

import polars as pl
import altair as alt

# make DatraFrame

---

df = pl.DataFrame( { 
    'a' : [ 1, 3 ,4 ], 
    'b' : [ 1, 3, 4 ],
    'c' : [ 3, 8, 4 ]
} )

# Visualiztion with altair

---

sel = alt.selection_point( fields = [ 'key' ] )

base = alt.Chart( df ).transform_fold(
    df.columns
).encode(
    alt.X( 'key:N' )
)

bar = base.mark_bar().encode(
    alt.Y( 'sum(value):Q' )
)

circle = base.mark_circle().encode(
    alt.Size( 'sum(value):Q' ).legend( None )
)

alt.vconcat(
    circle.add_params( sel ), bar.transform_filter( sel )
).configure_axis( 
    title = None, labelAngle = 0, grid = False
).configure_view( stroke = None )