如何在 plotly 甘特图中为元素指定颜色？

Question

我在此处学习 python 教程：https://plotly.com/python/gantt/

import pandas as pd
import plotly.express as px
df = pd.DataFrame([
    dict(Task="Job A", Start='2009-01-01', Finish='2009-02-25'),
    dict(Task="Job A", Start='2009-02-26', Finish='2009-03-28'),
    dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15'),
    dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30')
])

print(df)

    Task       Start      Finish
0  Job A  2009-01-01  2009-02-25
1  Job A  2009-02-26  2009-03-28
2  Job B  2009-03-05  2009-04-15
3  Job C  2009-02-20  2009-05-30

上面教程中的代码给我图表：

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task")
fig.update_yaxes(autorange="reversed") # otherwise tasks are listed from the bottom up
fig.show()

请注意 Job A.

有两个事件

我想为每个起点和终点交替使用颜色。例如第一事件红色，第二事件蓝色，第三事件红色，第四事件蓝色等

我已经尝试了 color_discrete_sequence 和 color_discrete_map 参数，但颜色没有交替。

我尝试过的：

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task",color_discrete_sequence=["red", "blue"])
fig.update_yaxes(autorange="reversed") 
fig.show()

和

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task",color_discrete_map={"Start": "red","Finish":'blue'})
fig.update_yaxes(autorange="reversed") 
fig.show()

关于如何交替颜色有什么想法吗？

我希望工作 A 看起来像的示例：

Answer 1

只需添加一个描述所需颜色的列。

import pandas as pd
import plotly.express as px
df = pd.DataFrame([
    dict(Task="Job A", Start='2009-01-01', Finish='2009-02-25', Color='blue'),
    dict(Task="Job A", Start='2009-02-26', Finish='2009-03-28', Color='red'),
    dict(Task="Job B", Start='2009-03-05', Finish='2009-04-15', Color='blue'),
    dict(Task="Job C", Start='2009-02-20', Finish='2009-05-30', Color='blue')
])

fig = px.timeline(df, x_start="Start", x_end="Finish", y="Task", color="Color")
fig.update_yaxes(autorange="reversed") # otherwise tasks are listed from the bottom up
fig.show()

如何在 plotly 甘特图中为元素指定颜色？

How to specify color for elements in plotly Gannt chart?

python

plotly

plotly-python