Altair map chart is not rendered

Summary

I am trying to render an altair chart through st.altair_chart. This chart happens to be a map representation of Africa. I constructed this chart through the altair library and wanted to render it in streamlit.

Steps to reproduce

import geopandas as gpd
import altair as alt
import streamlit as st

world = gpd.read_file(gpd.datasets.get_path("naturalearth_lowres"))
africa = world[world.continent == "Africa"]

chart = alt.Chart(africa).mark_geoshape().encode(color="pop_est:Q")
st.altair_chart(chart)

Expected behavior:

Should render the image referenced:

Actual behavior:

Not implemented error: Dtype geometry not understood

Is this a regression?

This is not a regression

Debug info

• Streamlit version: 0.53
• Python version: 3.8.1
• Altair version: 4.0.1
• Geopandas version: 0.6.1
• Using Conda
• OS version: Ubuntu 19.10
• Browser version: Firefox 72.0.1

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[tconkling]

I can repro this - it’s an issue with our dataframe marshaling code.

@kantuni is currently overhauling our dataframe serialization code in #1021. Hopefully Arrow just knows how to handle this out of the box? Let’s circle back when that PR lands.

[fgenoese]

@kantuni Here is a demo of the problem: https://share.streamlit.io/fgenoese/st_bugreports/main/geopandas_map.py