How to add text to folium choropleth maps - folium

Question

I am using sample data from geopandas for this example. But basically what I want to do is have a choropleth map with text displayed on it by default.
Currently, I have used tooltip='BoroCode' to display the text I need however, I don't want the text displayed only when you hover over the area. I'd like it to be displayed all the time.
import folium
import branca.colormap as cmp
import geopandas
path_to_data = geopandas.datasets.get_path("nybb")
gdf = geopandas.read_file(path_to_data)
# create map
m= folium.Map(location=[40.730610, -73.935242])
# add boroughs
gdf.explore(
m=m,
column="BoroName",
scheme="naturalbreaks",
legend=True,
k=10,
cmap='winter',
legend_kwds=dict(),
name="boroughs" ,
tooltip='BoroCode'
)
folium.LayerControl().add_to(m)
m

Answer 1

I don't have enough experience with geopandas, but in this case, gdf.explore() doesn't seem to have the ability to add annotations, so you can add a marker with html format text set with an icon on the folium side. If the map coordinate system in geopandas is The map coordinate system of geopandas is not in a format that can be used by folium, so it is converted. Then, the center point of the borough is obtained. A warning will be displayed if this center point is not correct. I think the solution to avoid this warning is to use the actual center point.
import folium
from folium.features import DivIcon
import branca.colormap as cmp
import geopandas
path_to_data = geopandas.datasets.get_path("nybb")
gdf = geopandas.read_file(path_to_data)
gdf = gdf.to_crs(epsg=4326)
gdf['centroid'] = gdf.centroid
gdf['lat'] = gdf['centroid'].map(lambda p: p.y)
gdf['lon'] = gdf['centroid'].map(lambda p: p.x)
m = folium.Map(location=[40.730610, -73.935242])
for i, row in gdf.iterrows():
folium.map.Marker(
[row['lat'],row['lon']],
icon=DivIcon(
icon_size=(100,24),
icon_anchor=(0,0),
html=f'<div style="font-size:16px; color:white;">{row["BoroName"]}</div>',
)
).add_to(m)
#add boroughs
gdf.explore(
m=m,
column="BoroName",
scheme="naturalbreaks",
legend=True,
k=10,
cmap='winter',
legend_kwds=dict(),
name="boroughs",
tooltip='BoroName'
)
folium.LayerControl().add_to(m)
m