Is any simpler way to plot GeoPandas data in Altair chart? - geopandas

Question

The basic way to display GeoDataFrame in Altair:
import altair as alt
import geopandas as gpd
alt.renderers.enable('notebook')
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
data = alt.InlineData(values = world[world.continent=='Africa'].__geo_interface__, #geopandas to geojson
# root object type is "FeatureCollection" but we need its features
format = alt.DataFormat(property='features',type='json'))
alt.Chart(data).mark_geoshape(
).encode(
color='properties.pop_est:Q', # GeoDataFrame fields are accessible through a "properties" object
tooltip=['properties.name:N','properties.pop_est:Q']
).properties(
width=500,
height=300
)
But it will crush if I add column with Nan or DateTime values.

Answer 1

At first you can use world = alt.utils.sanitize_dataframe(world) to convert columns with JSON incompatible types.
Or you can use gpdvega module to simplify code.
import altair as alt
import geopandas as gpd
import gpdvega
alt.renderers.enable('notebook')
world = gpd.read_file(gpd.datasets.get_path('naturalearth_lowres'))
alt.Chart(world[world.continent=='Africa']).mark_geoshape(
).encode(
color='pop_est',
tooltip=['name','pop_est']
).properties(
width=500,
height=300
)
Just pip install gpdvega and import gpdvega. altair will work with GeoDataFrame as usual DataFrame. See details in documentation