title: Choropleth with folium
body: <p>I'm trying to create a choropleth map using folium. I'm using the following site as a guide, although I want to create a world map.</p>
  
  <p><a href="https://python-graph-gallery.com/292-choropleth-map-with-folium/" rel="nofollow noreferrer">https://python-graph-gallery.com/292-choropleth-map-with-folium/</a></p>
  
  <p>I got the JSON file from here: </p>
  
  <p><a href="https://github.com/python-visualization/folium/blob/master/examples/data/world-countries.json" rel="nofollow noreferrer">https://github.com/python-visualization/folium/blob/master/examples/data/world-countries.json</a></p>
  
  <p>My 'test4' data is this:</p>
  
  <pre><code>    Country_0                   Count_0
  0   United States of America    18425
  1   United Kingdom              3070
  2   France                      2705
  3   Canada                      1498
  4   Japan                       1493
  5   Italy                       1471
  6   Germany                     1418
  7   Russia                      800
  8   India                       783
  9   Spain                       601
  10  Australia                   506
  11  Hong Kong                   468
  12  South Korea                 457
  13  Sweden                      396
  14  Finland                     324
  15  China                       300
  16  Belgium                     299
  17  Denmark                     297
  18  Brazil                      262
  19  Poland                      245
  20  Mexico                      236
  21  Netherlands                 226
  22  Argentina                   211
  23  Czech Republic              163
  24  Austria                     151
  25  Ireland                     135
  26  Turkey                      134
  27  Greece                      131
  28  Norway                      124
  29  Hungary                     119
  30  Switzerland                 99
  </code></pre>
  
  <p>My code is here:</p>
  
  <pre><code>import folium
  country_count = pd.read_csv('test4.csv')
  
  country_geo = os.path.join('world-countries.json')
  
  m = folium.Map(location=[0, 0], zoom_start=2)
  m.choropleth(
   geo_data=country_geo,
   name='choropleth',
   data=country_count,
   columns=['Country_0', 'Count_0'],
   key_on='feature.id',
   fill_color='YlGn',
   fill_opacity=0.7,
   line_opacity=0.2,
   legend_name='Test'
  )
  folium.LayerControl().add_to(m)
  </code></pre>
  
  <p>I get the following error:</p>
  
  <pre><code>JSONDecodeError: Expecting value: line 7 column 1 (char 6)
  </code></pre>