如何用Plotly scatter_mapbox仅将目的地坐标与原点坐标连线

我正在使用scatter_mapbox创建带连线的地图，目前已实现所有坐标间相互连线，但需求是仅将数据集中key列为Destination的坐标与key列为Origin的唯一坐标相连。

测试数据 #

import pandas as pd

lat_dest = [21.028321, 10.426675, 10.776390,-35.297591,21.028321]
lon_dest = [105.854022,-75.544342,106.701139,149.101268,105.854022]
locations = ['Hanoi, Vietnam','Cartagena, Colombia','Ho Chi Minh City, Vietnam','Canberra, Australia','Hanoi, Vietnam']
dest_key = ['Destination','Destination','Destination','Destination','Origin']

test_df = pd.DataFrame({
  'lat': lat_dest,
  'lon': lon_dest,
  'name': locations,
  'key':dest_key
})

现有地图代码 #

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

fig = px.scatter_mapbox(
    test_df, 
    lat="lat", lon="lon", 
    color="key",
    zoom=2,
    center = {"lat": orig_lat, "lon": orig_lon}
)

fig.update_layout(
    mapbox_style="carto-positron",
    margin={"r":0,"t":0,"l":0,"b":0},
    showlegend=False
)

fig.add_trace(go.Scattermapbox(
    mode = "lines",
    lon = new_df['lon_dest'],
    lat = new_df['lat_dest']
))

解决方案 #

要实现仅连接起点与所有终点，需先提取唯一的起点坐标，再为每个终点生成「起点-终点」的坐标对序列来绘制连线，具体实现代码如下：

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

# 测试数据
lat_dest = [21.028321, 10.426675, 10.776390,-35.297591,21.028321]
lon_dest = [105.854022,-75.544342,106.701139,149.101268,105.854022]
locations = ['Hanoi, Vietnam','Cartagena, Colombia','Ho Chi Minh City, Vietnam','Canberra, Australia','Hanoi, Vietnam']
dest_key = ['Destination','Destination','Destination','Destination','Origin']

test_df = pd.DataFrame({
  'lat': lat_dest,
  'lon': lon_dest,
  'name': locations,
  'key':dest_key
})

# 提取唯一的起点坐标
origin_row = test_df[test_df['key'] == 'Origin'].iloc[0]
orig_lat, orig_lon = origin_row['lat'], origin_row['lon']

# 创建基础散点地图
fig = px.scatter_mapbox(
    test_df, 
    lat="lat", lon="lon", 
    color="key",
    zoom=2,
    center = {"lat": orig_lat, "lon": orig_lon}
)

fig.update_layout(
    mapbox_style="carto-positron",
    margin={"r":0,"t":0,"l":0,"b":0},
    showlegend=False
)

# 为每个终点添加到起点的连线
destinations = test_df[test_df['key'] == 'Destination']
for _, row in destinations.iterrows():
    fig.add_trace(go.Scattermapbox(
        mode = "lines",
        lon = [orig_lon, row['lon']],
        lat = [orig_lat, row['lat']],
        line = dict(width=2, color='blue')
    ))

fig.show()

代码说明 #

• 通过test_df[test_df['key'] == 'Origin'].iloc[0]精准获取唯一的起点经纬度
• 筛选所有Destination行，循环生成每条从起点到终点的连线轨迹
• 可通过line参数自定义连线的宽度、颜色等样式，适配不同可视化需求

内容的提问来源于stack exchange，提问作者user2813606