debugged center, added visualization file

create_multi_polygon.py

 import json
 import geopandas as gpd
 from shapely.geometry import Polygon, MultiPolygon, Point
-import fiona
 
 
-def find_center(mlp):
+def find_center(mlp, how='json'):
     if isinstance(mlp, MultiPolygon):
         area = 0
         for p in mlp.geoms:
             if p.area > area:
-                center = json.dumps([p.centroid.x, p.centroid.y])
+                area = p.area
+                center = [p.centroid.x, p.centroid.y]
     elif isinstance(mlp, Polygon):
-        center = json.dumps([mlp.centroid.x, mlp.centroid.y])
+        center = [mlp.centroid.x, mlp.centroid.y]
     else:
         raise TypeError('object not polygon nor multipolygon')
+    if how == 'json':
+        center = json.dumps(center)
+    elif how == 'point':
+        center = Point(center)
     return center
 
 
-df = gpd.read_file('Iran-Districts-Test.json')
-df = df.loc[df['geometry'].notna()]
-gdf = gpd.GeoDataFrame(columns=['geometry', 'clmd_id', 'center'])
-for climate in df['clmd_id'].unique():
-    a = {'geometry': MultiPolygon(), 'clmd_id': climate}
-    df.loc[df['clmd_id'] == climate, 'geometry'].apply(lambda x: a.update({'geometry': a['geometry'].union(x)}))
-    gdf = gdf.append(a, ignore_index=True)
+if __name__ == '__main__':
+    df = gpd.read_file('Iran-Districts-Test.json')
+    df = df.loc[df['geometry'].notna()]
+    gdf = gpd.GeoDataFrame(columns=['geometry', 'clmd_id', 'center'])
+    for climate in df['clmd_id'].unique():
+        a = {'geometry': MultiPolygon(), 'clmd_id': climate}
+        df.loc[df['clmd_id'] == climate, 'geometry'].apply(lambda x: a.update({'geometry': a['geometry'].union(x)}))
+        gdf = gdf.append(a, ignore_index=True)
 
-gdf['center'] = gdf['geometry'].apply(find_center)
-gdf.to_file('output.json', driver='GeoJSON')
+    gdf['center'] = gdf['geometry'].apply(find_center)
+    gdf.to_file('output.json', driver='GeoJSON')

visualization.py

+import plotly.express as px
+import plotly.graph_objs as go
+import geopandas as gpd
+from create_multi_polygon import find_center
+
+dist = gpd.read_file('output.json')
+dist['center'] = dist['geometry'].apply(lambda x: find_center(x, 'point'))
+dist['lat'] = dist['center'].y
+dist['lon'] = dist['center'].x
+dist.append(gpd.GeoDataFrame())
+counties = {'type': 'FeatureCollection', 'features': list(dist[['clmd_id', 'geometry']].iterfeatures())}
+
+fig = go.Figure(go.Choroplethmapbox(geojson=counties, locations=dist.reset_index()['index'].values,
+                                    hovertext=dist['clmd_id'].values,
+                                    z=dist['clmd_id'].values, colorscale="Cividis_r", zmin=0))
+fig.add_trace(
+    px.scatter_mapbox(dist, lat='lat', lon='lon', hover_name='clmd_id', color_discrete_sequence=["blue"]).data[0])
+fig.update_layout(mapbox_style="carto-positron", margin={"r": 0, "t": 0, "l": 0, "b": 0},
+                  mapbox_zoom=5, mapbox_center={"lat": 35.7, "lon": 51.4})
+
+fig.show()