Altair 添加选择器以更改配色方案

Question

I have a simple plot withe the color scheme dark2

import altair as alt
from vega_datasets import data

source = data.cars.url

alt.Chart(source).mark_circle(size=60).encode(
    x='Horsepower:Q',
    y='Miles_per_Gallon:Q',
    color='Origin:N',
).configure_range(
    category={'scheme': 'dark2'}
)

I'd like to add a dropdown selector that allows the user to switch between dark2 and accent. I've tried a variety of different approaches but nothing seems to be correct. Any help is greatly appreciated.

Answer 1

Was able to figure out the solution by using the approach below

import altair as alt
from vega_datasets import data

cars = data.cars()
input_dropdown = alt.binding_select(options=['accent','dark2'], name='Color Scheme')
param = alt.Parameter(name="schemeselect", value = "accent", bind = input_dropdown)

alt.Chart(cars,params = [param]).mark_circle(size=60).encode(
    x='Horsepower:Q',
    y='Miles_per_Gallon:Q',
    color=alt.Color('Origin', scale=alt.Scale(scheme={"expr": "schemeselect"})),
)