如何在 plotly express 中将离散变量映射到连续色标

Question

我希望为分类变量定义一个顺序，并为每条线的颜色使用连续色标。以下是我当前产生错误的代码。谁能帮我实现这个，或者这是不可能的？

import pandas as pd
import plotly.express as px

df = pd.DataFrame({'dt':['2021-01-01', '2021-02-01', '2021-03-01', '2021-01-01', '2021-02-01', '2021-03-01', '2021-01-01', '2021-02-01', '2021-03-01'],
                   'group':['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c', 'c'],
                   'val':[3, 5, 3, 2, 1, 5, 6, 7,  3]})

df['group'] = pd.Categorical(df['group'], ordered=True, categories=['a', 'b', 'c'])

px.line(df,
        x='dt',
        y='val',
        color='group',
        color_continuous_scale=px.colors.sequential.Blues)

当前错误消息：TypeError：line() 得到了意外的关键字参数 'color_continuous_scale'

Answer 1

如果你读the documentation，没有color_continuous_scale，但是有color_discrete_sequence。

import pandas as pd
import plotly.express as px

df = pd.DataFrame({'dt':['2021-01-01', '2021-02-01', '2021-03-01', '2021-01-01', '2021-02-01', '2021-03-01', '2021-01-01', '2021-02-01', '2021-03-01'],
                   'group':['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c', 'c'],
                   'val':[3, 5, 3, 2, 1, 5, 6, 7,  3]})

df['group'] = pd.Categorical(df['group'], ordered=True, categories=['a', 'b', 'c'])

px.line(df,
        x='dt',
        y='val',
        color='group',
        color_discrete_sequence=px.colors.sequential.Blues)

如何在 plotly express 中将离散变量映射到连续色标

How to map a discrete variable to a continuous color scale in plotly express

python

plotly