folium Choropleth colors showing grey only

Question

I'm trying to show happiness levels based on the country using folium choropleth, however, it doesn't work and all countries are just grey. This is what I get:

json file: https://github.com/python-visualization/folium/blob/master/examples/data/world-countries.json

csv file: https://drive.google.com/file/d/1aI5tILdPYyx0yjbgPPZcJHEqxbZ4oPBg/view?usp=sharing

and this is my code:

import folium
import pandas as pd


country_geo = 'world-countries.json'

country_data = pd.read_csv('Happiness_Dataset_2016.csv')

bins = list(country_data['Happiness Score'].quantile([0, 0.25, 0.5, 0.75, 1]))

m = folium.Map(location=[0,0], zoom_start=2)


folium.Choropleth(
    geo_data=country_geo,
    name='choropleth',
    data=country_data,
    columns=['Country','Happiness Score'],
    Key_on='feature.properties.name',
    fill_color='BuPu',
    fill_opacity=0.2,
    line_opacity=0.5,

    legend_name='Happiness Rates (%)',
    bins =bins,

    reset=True
).add_to(m)
# folium.LayerControl().add_to(m)
m
m.save('worldmap.html')

Answer 1

Here the error:

Key_on='feature.properties.name',

Modify it as:

key_on='feature.properties.name',

and you get: