Stuck on an issue?

Lightrun Answers was designed to reduce the constant googling that comes with debugging 3rd party libraries. It collects links to all the places you might be looking at while hunting down a tough bug.

And, if you’re still stuck at the end, we’re happy to hop on a call to see how we can help out.

Pandas categories support not implemented

See original GitHub issue

Summary

Streamlit seems to be unable to render Pandas series or dataframes which contain categorical elements, throwing a NotImplementedError: Dtype category not understood. error.

Steps to reproduce

Create a streamlit file with contents of

import streamlit as st
import pandas as pd

s = pd.Series(["a","b","c","a"], dtype="category")
st.write(s)

Run the file with streamlit and view the served result in the browser

Expected behavior:

s is rendered as a table or datatable.

Actual behavior:

An error along the lines of

NotImplementedError: Dtype category not understood.
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/__init__.py", line 352, in write dataframe(arg) # noqa: F821
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/__init__.py", line 126, in wrapped_method return method(dg, *args, **kwargs)
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/DeltaGenerator.py", line 79, in wrapped_method return method(self, *args, **kwargs)
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/DeltaGenerator.py", line 789, in dataframe set_data_frame, "dataframe", elementWidth=width, elementHeight=height
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/DeltaGenerator.py", line 317, in _enqueue_new_element_delta rv = marshall_element(msg.delta.new_element)
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/DeltaGenerator.py", line 786, in set_data_frame data_frame_proto.marshall_data_frame(data, delta.data_frame)
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/elements/data_frame_proto.py", line 50, in marshall_data_frame _marshall_table(df_data, proto_df.data)
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/elements/data_frame_proto.py", line 288, in _marshall_table _marshall_any_array(pandas_array, proto_table.cols.add())
File "/home/caspar/src/streamlit-test/.venv/lib/python3.7/site-packages/streamlit/elements/data_frame_proto.py", line 329, in _marshall_any_array raise NotImplementedError("Dtype %s not understood." % pandas_array.dtype)