Color specific region based on user selection

Question

In the documetation, there is an attibute selected while calling go.choropleth to build a map. I want to ask if anyone knows what is it for?

Because currently I have a map of regions of France. I want that when a user clicks on a specific region, this region should be shaded with light blue color.

Answer 1

I was looking for clickmode='event+select' like that:

fig = px.choropleth(df1, geojson=jdataNo, color="winner",
                    locations="district", featureidkey="properties.NAME_1",
                    projection="gnomonic", color_discrete_sequence=['red','green','blue']
                   )
fig.update_geos(fitbounds="locations", visible=False)
fig.update_layout(margin={"r":0,"t":0,"l":0,"b":0},clickmode='event+select')
fig.show()

In Dash, I can use clickData to read which region is clicked, as suggested by @r-beginners.