CODEWITHSUNDEEP
pythonpandasplotlychoropleth
Sean Carter
Sean Carter

Reputation: 121

Plotly.express choropleth only shows one color

I am trying to create a choropleth using plotly.express. The figure is able to load, but it only shows one color. I can mouse over each feature and it displays the relevant information, but not in variable color. This implies that it is reading the geojson but not displaying properly. u/geds133 had the same issue, but I am unable to contact them or comment due to low reputation.

Here is my "predictions" df:

import pandas as pd
predictions = pd.read_csv("Predictions_DF_2002.csv")

predictions.head()


huc12           Predicted PRBT   Std
170102120304    30.677075        23.348831
170102120603    31.362211        23.784001
90400010201     5.697461         7.688427
100301040401    3.493039         5.36472
170101011208    4.421055         11.924093

I am attempting to match the DataFrame with a property within the geojson file:

#Read in geojson
import geopandas as gpd
import json


hucs = gpd.read_file(~/"HUC.geojson")

#Populate hucs['properties'] (i.e. convert to plotly-readible geojson-type)
hucs = json.loads(hucs.to_json())

#Print Properties for sanity check
print(hucs['features'][0]['properties'])

#...<a bunch of stuff we don't care about> 
{'huc12':170102120304}
#...

Thus, I can use the featureidkey parameter to specify where to match the values of locations as written in the docs. Here is the code I use to create the choropleth:

fig = px.choropleth(predictions,
                    geojson=hucs, color='Predicted PRBT',
                    locations='huc12', featureidkey='properties.huc12',
                    color_continuous_scale="Viridis", labels={'Predicted PRBT':'Predicted % RBT'})
fig.update_geos(fitbounds="locations",visible=False)
fig.show()

And here is what the output shows. Note that mouse-over shows relevant information: Choropleth Output

My geojson and csv are available for download here.

Upvotes: 2

Views: 1001

Answers (1)

Sean Carter
Sean Carter

Reputation: 121

The geojson must be unwound before plotting:

#Read in geojson
import geopandas as gpd
import json


hucs = gpd.read_file(~/"HUC.geojson")

#Populate hucs['properties'] (i.e. convert to plotly-readible geojson-type)
hucs = json.loads(hucs.to_json())


from geojson_rewind import rewind
hucs_rewound = rewind(hucs,rfc7946=False)


fig = px.choropleth(predictions,
                    geojson=hucs_rewound, color='Predicted PRBT',
                    locations='huc12', featureidkey='properties.huc12',
                    color_continuous_scale="Viridis", labels={'Predicted PRBT':'Predicted % RBT'})
fig.update_geos(fitbounds="locations",visible=False)
fig.show()

See https://github.com/plotly/plotly.py/issues/2354#issuecomment-638742767 and https://github.com/plotly/plotly.py/issues/2619 Solved

Upvotes: 3

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