plotly 条形图 python 如何设置每个类别的颜色

Question

So I have done the bar chart with a pandas dataframe. But how can set color for each bar category.

This is my code.

import plotly.express as px
import plotly.graph_objects as go
import pandas as pd

data = {'Index': ['NAGAJAN', 'JORAJAN','KATHALGURI','HEBEDA','MAKUM','BAREKURI','BAGHJAN','Duliajan Area','LANGKASHI','HAPJAN'],'Category': [0,5,0,0,2,0, 2,0,0, 2]} 
df = pd.DataFrame(data)
labels =df['Index']
value = df['Category']
fig = px.bar(x=labels,y=value, height=400, width=800,title = "Asset Area Vs No of OBS")
fig.update_xaxes(tickangle = 90,)
fig.update_layout(plot_bgcolor="white")
fig.update_traces(width=0.4)
fig.show()

my output:

Answer 1

You're looking for explicit color mapping in plotly with plotly.express.bar and for that you can pass color_discrete_map as a keywork argument ( dict ) that will hold the color of each value individually.

fig = px.bar(
              x=labels,
              y=value,
              height=400,
              width=800,
              title = "Asset Area Vs No of OBS",
              color=labels,
              color_discrete_map={
                        'BAGHJAN': 'green',
                        'JORAJAN': 'blue'}   #<-- add here the others colors
            )

NB: An arbitrary color will be assinged to every non mapped value