Checklist

• I have searched the existing issues for similar issues.
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• I have provided sufficient information below to help reproduce this issue.

Summary

If indices of a pandas dataframe has pd.Categorical type, st.dataframe seems not showing such indices properly. This behavior occurs for streamlit >= 1.32.0.

Reproducible Code Example

import streamlit as st
import pandas as pd

data = [["a", 1], ["b", 2]]
df = pd.DataFrame(data, columns=["x", "y"])
df["x"] = pd.Categorical(df["x"], categories=["a", "b"])
st.dataframe(df.set_index("x"))

Steps To Reproduce

Run streamlit run <filename>.py

Expected Behavior

Column a should display "a" and "b" like the image below.

Current Behavior

Column a shows empty values as follows.

If you double-click the cell, the value is displayed.

Is this a regression?

• Yes, this used to work in a previous version.

Debug info

• Streamlit version: 1.39.0
• Python version: 3.10.10
• Operating System: Mac OS 15.0
• Browser: Google Chrome

Additional Information

Downgrading to streamlit==1.31.1 removes this bug.