CODEWITHSUNDEEP
pythonplotlygeojsonchoropleth
E43123
E43123

Reputation: 3

Choropleth Map Error (using plotly in python) Using ONS GeoJSON data

I have recently been looking into creating choropleth maps on plotly using Python. I was able to do this using a GeoJSON file I found on the internet (https://emilyshackleton1.carto.com/tables/uk_regions_map/public)

However I then went on the ONS GeoPortal and downloaded some GeoJSON files, I then tried to create a choropleth map in the exact same manner, and it wouldn't work

Code:

import plotly.express as px
import pandas as pd
from urllib.request import urlopen
import json
with urlopen('https://opendata.arcgis.com/datasets/92ebeaf3caa8458ea467ec164baeefa4_0.geojson') as response:
    ons2 = json.load(response)

area={}
for feature in ons2["features"]:
    feature['id'] = feature["properties"]["objectid"]
    area[feature["properties"]["ctry19nm"]] = feature["id"]

df3 = pd.DataFrame((['Wales',6.7],
                    ['Scotland',4.6],
                   ['England',4.7],
                   ['Northern Ireland',4.1],
                   ),columns='fips B'.split())

df3["id"]=df3["fips"].apply(lambda x: area[x])

fig = px.choropleth(df3, locations="id", geojson=ons2["features"][1], color="B", scope = "europe", hover_name="fips")
fig.update_geos(fitbounds="locations", visible=False)
fig.show()

For some reason it is coloring the whole space and only Northern Ireland is showing.

The weird thing is if I hover over this map it still comes up with Scotland, England and Wales where they should be

This has been driving me crazy, would appreciate any help :)

Upvotes: 0

Views: 782

Answers (1)

Pascalco
Pascalco

Reputation: 2826

I tested your code with other GeoJSON files and it worked. Also your GeoJSON file does not have any errors, so there is likely a bug in the plotly library.

As an alternative, I can recommend to use the px.choropleth_mapbox() function which is quite similar to px.choropleth().

import plotly.express as px
import pandas as pd
from urllib.request import urlopen
import json
with urlopen('https://opendata.arcgis.com/datasets/92ebeaf3caa8458ea467ec164baeefa4_0.geojson') as response:
    ons2 = json.load(response)

area={}
for feature in ons2["features"]:
    feature['id'] = feature["properties"]["objectid"]
    area[feature["properties"]["ctry19nm"]] = feature["id"]

df3 = pd.DataFrame((['Wales',6.7],
                    ['Scotland',4.6],
                   ['England',4.7],
                   ['Northern Ireland',4.1],
                   ),columns='fips B'.split())

df3["id"]=df3["fips"].apply(lambda x: area[x])
fig = px.choropleth_mapbox(df3, locations="id", featureidkey="properties.objectid", geojson=ons2, color="B", hover_name="fips", mapbox_style="white-bg", zoom=4, center = {"lat": 55, "lon": 0})

fig.show()

Upvotes: 1

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