如何使用update_traces()的selector按名称修改饼图特定trace的悬停模板？

需要仅修改饼图中名为“Resto”的扇区的悬停模板（hovertemplate），但尝试使用fig.update_traces(hovertemplate=None, selector=dict(name='Resto'))时无法生效，可复现代码如下：

import pandas as pd
import plotly.graph_objects as go
import numpy as np

df_stack = pd.DataFrame({"Country": ['Brasil','China','Estados unidos','Chile','India','Paises bajos','Vietnam','Peru','Corea, republica de','Indonesia','Resto'],
              "Dolars": [11599.42961799,7671.6791054099995,6198.81430321,4578.07,4153.13352132,3352.11349841,2998.44092833,2247.29957849,1968.7549113200002,1890.7284090800001,35635.107780379985],
              "Pct_change":[0.0846110761489467,0.2953716769009316,0.41561413372310074,0.21787800280514857,0.09245460739576772,0.18325289020293622,0.023857445957433443,0.2555960957383905,0.2319776811635097,0.12068329801455069,0.0]
              })


fig = go.Figure(data=[go.Pie(labels=df_stack["Country"], values=df_stack['Dolars'], hole=.5,
                customdata = np.transpose([df_stack["Pct_change"],
                                            ]),
                hovertemplate="<b>%{label}</b> <br>Dolars: $%{value:,.2f}"
    "<br>Percent: %{percent:.1%}"
    "<br>Pct_change: %{customdata[0]:.1%}"
    "<br><extra></extra>",
                )])

fig.update_layout(title_text = f"Change hover of specific trace in pie chart", template = None, font_family = "verdana",
                margin = dict(t=70, l=10, r=10, b=30), separators = ",.",
                showlegend= False,)
fig.update_traces(hovertemplate=None, selector=dict(name = 'Resto')) #It won't work!!!

Pie图和Scatter图的核心结构不一样：Scatter可以把每个数据点做成单独trace，但Pie图的所有扇区都属于同一个trace，所以selector=dict(name='Resto')根本找不到目标——因为“Resto”只是trace里的一个label，不是单独的trace名称。

下面提供两种可行的解决方法：

方法1：用hovertext自定义单个扇区的悬停内容（推荐） #

给每个扇区生成对应的悬停文本，其中单独给“Resto”设置特殊内容，然后在hovertemplate里直接引用这个文本即可：

import pandas as pd
import plotly.graph_objects as go
import numpy as np

df_stack = pd.DataFrame({
    "Country": ['Brasil','China','Estados unidos','Chile','India','Paises bajos','Vietnam','Peru','Corea, republica de','Indonesia','Resto'],
    "Dolars": [11599.42961799,7671.6791054099995,6198.81430321,4578.07,4153.13352132,3352.11349841,2998.44092833,2247.29957849,1968.7549113200002,1890.7284090800001,35635.107780379985],
    "Pct_change":[0.0846110761489467,0.2953716769009316,0.41561413372310074,0.21787800280514857,0.09245460739576772,0.18325289020293622,0.023857445957433443,0.2555960957383905,0.2319776811635097,0.12068329801455069,0.0]
})

# 逐个生成悬停文本，给Resto单独定制
hover_texts = []
total_dolars = df_stack['Dolars'].sum()
for _, row in df_stack.iterrows():
    if row['Country'] == 'Resto':
        # 自定义Resto的悬停内容，比如把Pct_change改成“无变化”
        text = f"<b>{row['Country']}</b><br>Dolars: ${row['Dolars']:,.2f}<br>Percent: {row['Dolars']/total_dolars:.1%}<br>Pct_change: 无变化"
    else:
        text = f"<b>{row['Country']}</b><br>Dolars: ${row['Dolars']:,.2f}<br>Percent: {row['Dolars']/total_dolars:.1%}<br>Pct_change: {row['Pct_change']:.1%}"
    hover_texts.append(text)

fig = go.Figure(data=[go.Pie(
    labels=df_stack["Country"], 
    values=df_stack['Dolars'], 
    hole=.5,
    hovertext=hover_texts,  # 传入自定义的悬停文本列表
    hovertemplate="%{hovertext}<extra></extra>"  # 直接引用hovertext
)])

fig.update_layout(
    title_text = "Change hover of specific trace in pie chart", 
    template = None, 
    font_family = "verdana",
    margin = dict(t=70, l=10, r=10, b=30), 
    separators = ",.",
    showlegend= False
)
fig.show()

方法2：拆分多个Pie trace（不推荐） #

把“Resto”单独做成一个Pie trace，其他扇区做成另一个，这样就能用update_traces单独修改它的hovertemplate。但这种方法会破坏饼图的整体性，交互逻辑也会变，只适合特殊场景：

import pandas as pd
import plotly.graph_objects as go
import numpy as np

df_stack = pd.DataFrame({
    "Country": ['Brasil','China','Estados unidos','Chile','India','Paises bajos','Vietnam','Peru','Corea, republica de','Indonesia','Resto'],
    "Dolars": [11599.42961799,7671.6791054099995,6198.81430321,4578.07,4153.13352132,3352.11349841,2998.44092833,2247.29957849,1968.7549113200002,1890.7284090800001,35635.107780379985],
    "Pct_change":[0.0846110761489467,0.2953716769009316,0.41561413372310074,0.21787800280514857,0.09245460739576772,0.18325289020293622,0.023857445957433443,0.2555960957383905,0.2319776811635097,0.12068329801455069,0.0]
})

# 拆分数据为Resto和其他国家
df_resto = df_stack[df_stack['Country'] == 'Resto']
df_others = df_stack[df_stack['Country'] != 'Resto']

fig = go.Figure()

# 添加其他国家的trace，用默认悬停模板
fig.add_trace(go.Pie(
    labels=df_others["Country"], 
    values=df_others['Dolars'], 
    hole=.5,
    customdata=np.transpose([df_others["Pct_change"]]),
    hovertemplate="<b>%{label}</b> <br>Dolars: $%{value:,.2f}"
    "<br>Percent: %{percent:.1%}"
    "<br>Pct_change: %{customdata[0]:.1%}"
    "<extra></extra>",
    domain={'x': [0, 1], 'y': [0, 1]}  # 确保两个trace在同一区域显示
))

# 添加Resto的trace，设置自定义悬停模板
fig.add_trace(go.Pie(
    labels=df_resto["Country"], 
    values=df_resto['Dolars'], 
    hole=.5,
    hovertemplate="<b>%{label}</b> <br>Dolars: $%{value:,.2f}"
    "<br>Percent: %{percent:.1%}"
    "<br>Pct_change: 无变化"
    "<extra></extra>",
    domain={'x': [0, 1], 'y': [0, 1]}
))

fig.update_layout(
    title_text = "Change hover of specific trace in pie chart", 
    template = None, 
    font_family = "verdana",
    margin = dict(t=70, l=10, r=10, b=30), 
    separators = ",.",
    showlegend= False
)
fig.show()

内容的提问来源于stack exchange，提问作者Keynes is not dead