Choropleth map is not coloring the regions

Question

So I have previously done a choropleth map and it was working. This time I used the same approach but its not showing anymore

map and unis_colleges have the same shape, as well as index The map and the csv file:text

#put a choropleth on top of the map 
m = folium.Map(location=[48.0196, 66.9237], tiles='cartodbpositron', zoom_start=6)
# Add a choropleth map to the base map

folium.Choropleth(geo_data=map.__geo_interface__, name = 'choropleth',
           data=student_total, columns = ['unis_colleges'],
           key_on="feature.id", 
           fill_color='YlGnBu', 
           legend_name='Number of students per region 2023').add_to(m)

# Display the map
m 

Answer 1

That's most likely a CRS issue. I can reproduce the behaviour you describe with this .shp file (that is projected in EPSG:3857) along with the .csv file you provided. So, assuming what you call map (better to name it gdf) is a GeoDataFrame, you can do :

m = folium.Map(location=[48.0196, 66.9237], tiles="cartodbpositron", zoom_start=6)

folium.Choropleth(
    geo_data=gdf.to_crs("EPSG:4326").__geo_interface__, # here we use `.to_crs`
    name="choropleth",
    data=student_total,
    columns=["regions", "unis_colleges"], # folium requires 2 columns
    key_on="feature.properties.ADM1_EN",  # replace ADM1_EN if needed
    fill_color="YlGnBu",
    legend_name="Number of students per region 2023",
).add_to(m)

Output (m) :