How to fill null values with other color in choropleth_mapbox?

📊 Plotly Python
,
2

complete Solution:

from shapely.geometry import Polygon
import geopandas as gpd
import numpy as np
import json
import plotly.express as px

def generateColorScale(colors, naColor):
    colorArray=[]
    colorArray.append([0,naColor])
    for grenze, color in zip(np.linspace(0.01,1,len(colors)), colors):
        colorArray.append([grenze, color])
    return colorArray

geometry = gpd.GeoSeries([Polygon([(0, 0), (1, 0), (1, 1), (0, 1)]), Polygon([(1, 1), (2, 1), (2, 2), (1, 2)]), Polygon([(1, 0), (2, 0), (2, 1), (1, 1)]), Polygon([(0, 1), (1, 1), (1, 2), (0, 2)])])
geoDf = gpd.GeoDataFrame(data={"Name":["a","b","c","d"], "geometry": geometry}, geometry="geometry")
dataDf = pd.DataFrame(data={"Data":[1.0,1.5,2,np.nan]}).fillna(-1)


fig = px.choropleth_mapbox(dataDf,
                           geojson=geoDf.geometry,
                           locations=dataDf.index,
                           color="Data",
                           title="Data",
                           mapbox_style="white-bg",
                           center = {"lat": 1, "lon": 1},
                           zoom=6,
                           color_continuous_scale=generateColorScale(colors=["white","red"], naColor="gray"),
                           range_color=(np.unique(dataDf["Data"])[1]*0.99, np.max(dataDf["Data"])),
                           hover_name="Data",
                          )


fig.update_layout(margin={"r": 0, "t": 0, "l": 0, "b": 0})
fig.show()

grafik
grafik794×345 3.35 KB

I got inspired by this redirecting to this post.

  • you need to change the minimum of range_color, else your lowest value is in the naColor as well
  • fill the missing values with a value lower then all values in the Data

hope that does help some other plotly users

1 Like