GeoJsonTooltip on Choropleth showing a pandas column?

I want to have a tooltip on my Choropleth to show the actual value of a region. Specifically Im making a choropleth of Amsterdam with the count of customers in a certain postal code.

density = (df
    .reset_index()
    .rename(columns={'Id': 'Count'})
    .groupby('Postcode cijfers')
    .count()
)[['Count']].reset_index()

# Postcode cijfers, Count
# array([['1011', 213],
#        ['1012', 146],
#        ['1013', 402],
#        ['1014', 49],
#        ['1015', 354]], dtype=object)

m = folium.Map(location=(52.3740300, 4.8896900),
               min_zoom=11)

choropleth = folium.Choropleth('../Resources/PC4_BUURTEN.json',
                  name='Postal Codes',
                  data=density,
                  key_on='properties.Postcode4',
                  columns=['Postcode cijfers', 'Count'],
                  fill_color='YlGn',
                  fill_opacity=0.7,
                  line_opacity=0.2,
                  legend_name='Customer Count',
).add_to(m)

choropleth.geojson.add_child(
    folium.features.GeoJsonTooltip(['Postcode4'])
)

Problem description

The documentation states:

fields (list or tuple.) – Labels of GeoJson/TopoJson ‘properties’ or GeoPandas GeoDataFrame columns you’d like to display.

However when I try to add Count to the fields (GeoJsonTooltip(['Postcode4', 'Count'])) I get the following error:

AssertionError: The field Count is not available in the data. Choose from: ('Postcode4', 'Opp_m2').

Suggesting that it only looks to the GeoJSON properties list.

Question

How can I refer to the attached dataframe for showing the Count in the tooltip? Is there a possibility for this, or is the documentation wrong / did I misunderstood it?

In the mean time I could iterate over the GeoJSON and manually add the Count field to the properties.

[pbower]

Is this something that can be re-considered? As a user it’s really annoying to have to bounce this data back to the GeoJSON data structure instead of the convenience of using a pandas column.

[jtbaker]

you were suggesting is use the GeoJson class to create the choropleth

Yep! That will give you more granular control over the styling, highlighting etc. using the style_function, highlight_function, etc. kwargs.

Is there an example notebook on that?

Check the examples repository on NBViewer for some examples on how to those and other features of the library. The Plugin-search.ipynb notebook has a good example for your usage, likely.