如何添加静态标签来巧妙地表达“choropleth_mapbox”？

Question

使用当前代码，我得到了悬停工具提示，但是这些在 PNG 导出时不可见。我需要在每个多边形上都有静态标签。

import plotly.express as px

df = px.data.election()
geojson = px.data.election_geojson()

fig = px.choropleth_mapbox(df, geojson=geojson, color="Bergeron",
                           locations="district", featureidkey="properties.district",
                           center={"lat": 45.5517, "lon": -73.7073},
                           mapbox_style="carto-positron", zoom=9)
fig.update_layout(margin={"r":0,"t":0,"l":0,"b":0})
fig.show()

我发现的解决方案不起作用，它们仅适用于 choropleth 但不适用于我想使用的 choropleth_mapbox。他们的名单：

https://community.plotly.com/t/labels-inside-counties-for-a-map/13953

https://community.plotly.com/t/annotations-on-plotly-choropleth/36219

https://community.plotly.com/t/how-can-i-change-the-hover-labels-into-static-labels/4690/2

Answer 1

显而易见的答案是添加一个 Scattermapbox 图层，其中包含您想要的文本。这被这个bug. I did not find an clear replacement for carto-positron as a replacement on https://www.mapbox.com复杂化了，所以地图样式改变了
在https://account.mapbox.com to get a token, create a base map on https://studio.mapbox.com上创建一个帐户以创建底图
也尝试使用 plotly annotations。但是我找不到一种方法来获取地图的边界框，以便能够将 lat/lot 坐标转换为域坐标 (0-1)

mapboxtoken="****"
mapboxstyle="mapbox://styles/***"

使用 geopandas 来简单访问 centroid 的几何图形

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

df = px.data.election()
geojson = px.data.election_geojson()
gdf = (
    gpd.GeoDataFrame.from_features(geojson)
    .merge(df, on="district")
    .assign(lat=lambda d: d.geometry.centroid.y, lon=lambda d: d.geometry.centroid.x)
    .set_index("district", drop=False)
)

# for convenience of rebuilding and adding traces...
def basemap():
    fig = px.choropleth_mapbox(
        df,
        geojson=geojson,
        color="Bergeron",
        locations="district",
        featureidkey="properties.district",
        center={"lat": 45.5517, "lon": -73.7073},
        mapbox_style=mapboxstyle,
#         mapbox_style="carto-positron",
        zoom=9,
    )
    fig.update_layout(margin={"r": 0, "t": 0, "l": 0, "b": 0},
                      mapbox={"accesstoken":mapboxtoken}
                     )
    return fig

齐心协力

texttrace = go.Scattermapbox(
        lat=gdf.geometry.centroid.y,
        lon=gdf.geometry.centroid.x,
        text=gdf["Bergeron"].astype(str),
        textfont={"color":"white","size":20, "family":"Courier New"},
        mode="text",
        name="Bergeron"
    )

basemap().add_trace(texttrace)

如何添加静态标签来巧妙地表达“choropleth_mapbox”？

How to add static labels to plotly express `choropleth_mapbox`?

python

charts

plotly

choropleth

plotly-python

齐心协力

输出