title: folium.GeoJson (style function) not working as i want
body: <pre><code>import folium ,pandas ,json
  
  df=pandas.read_csv('Volcanoes_2.txt')
  
  def colors(elev):
      minimum=int(min(df['ELEV']))
      step=int(max((df['ELEV'])-min(df['ELEV']))/3)
      if elev in range (minimum,minimum+step):
          col= "green"
      elif elev in range(minimum+step,minimum+step*2):
          col= "orange"
      else:
          col= "red"
      return col
  
  
  map_1=folium.Map(location=[df['LAT'].mean(), df['LON'].mean()] ,
  zoom_start=6,tiles='mapbox bright')
  
  for name, lon, lat, elev in zip(df['NAME'], df['LON'], df['LAT'],
  df['ELEV'] ):
      folium.Marker([lat, lon], popup= name,
       icon = folium.Icon(color =colors(elev))).add_to(map_1)
  
  folium.GeoJson(open('world_geojson.json'),
             name='geojson',
             style_function= lambda x :{'fillcolor':'green' if \
    x['properties']['POP2005']&lt;10000000 \
         else 'orange' if 10000000 &lt;x['properties']['POP2005']&gt;20000000 else 'red'},
         ).add_to(map_1)
  
  folium.LayerControl().add_to(map_1)
  
  map_1.save("map.html")
  </code></pre>
  
  <p>this is the map file <a href="https://github.com/xxspider4/new_repo/blob/master/map.html" rel="noreferrer">https://github.com/xxspider4/new_repo/blob/master/map.html</a></p>
  
  <p>this is the json file <a href="https://github.com/xxspider4/new_repo/blob/master/world_geojson.json" rel="noreferrer">https://github.com/xxspider4/new_repo/blob/master/world_geojson.json</a> </p>