Checklist

• I have searched the existing issues for similar issues.
• I added a very descriptive title to this issue.
• I have provided sufficient information below to help reproduce this issue.

Summary

Setting height value for st.dataframe/st.data-editor intended for flex layout as described on the page of the update (#11930) will lead to error:

If we try to use mentioned in the error "stretch" value, we still get same error:

Reproducible Code Example

Steps To Reproduce

1. Create some dataframe, let's say named as test_df, with generated data, so that it has more than 10 rows
2. Try to render it as st.dataframe or st.data-editor, for example:
   st.dataframe(test_df, height="content", key="testing_flex_layout")

Expected Behavior

st.dataframe element is successfully rendered, and its height is properly adjusted to number of rows our test_df has

Current Behavior

Error message:

streamlit.errors.StreamlitInvalidHeightError: Invalid height value: 'content'. Height must be either an integer (pixels) or 'stretch'.

Is this a regression?

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

Debug info

• Streamlit version: 1.49.0, 1.49.1
• Python version: 3.13.6
• Operating System: Windows 10 Enterprise 22H2
• Browser: Chrome 139.0.7258.155

Additional Information

No response