reflex-dev/reflex · error · ValueError

Cannot pass in both a pandas dataframe and columns to the…

Error message

Cannot pass in both a pandas dataframe and columns to the data_editor component.

What it means

When data_editor receives a pandas DataFrame, it auto-generates columns from the dataframe; passing explicit columns as well is ambiguous and rejected.

Solutions

Drop the columns prop and let Reflex derive columns from the DataFrame
Or pre-process the DataFrame: df = df[desired_cols].rename(...) and pass only data
Or convert data to a plain list and pass columns explicitly

Example fix

# before
rx.data_editor(data=df, columns=["a", "b"])
# after
rx.data_editor(data=df[["a", "b"]])

Defensive patterns

Strategy: validation

Validate before calling

import pandas as pd
if isinstance(data, pd.DataFrame) and columns:
    data = data[[c if isinstance(c, str) else c['name'] for c in columns]]
    columns = None
rx.data_editor(data=data, columns=columns)

Type guard

def is_dataframe_like(data: Any) -> bool:
    import pandas as pd
    return isinstance(data, pd.DataFrame) or (hasattr(data, '_var_type') and issubclass(getattr(data._var_type, '__mro_entries__', (type,)).__class__, type) and False)

Prevention

Choose one source of truth: DataFrame or explicit columns
Pre-select/rename DataFrame columns in pandas instead of passing columns prop

When it happens

Trigger: rx.data_editor(data=df, columns=[Column(name="x"), ...]) where df is a pandas DataFrame (or a Var typed as a DataFrame).

Common situations: Trying to rename/reorder columns by passing columns alongside a DataFrame instead of transforming the DataFrame itself.

Related errors

AI-assisted analysis of reflex-dev/reflex@45b8ed5ab7 (2026-08-28). Data as JSON: /api/errors/a8a868e03c5f6290. Report an issue: GitHub.

Appendix: source

Thrown at packages/reflex-components-dataeditor/src/reflex_components_dataeditor/dataeditor.py:531

        columns = props.get("columns", [])
        data = props.get("data", [])
        rows = props.get("rows")

        # If rows is not provided, determine from data.
        if rows is None:
            if isinstance(data, Var) and not isinstance(data, ArrayVar):
                msg = "DataEditor data must be an ArrayVar if rows is not provided."
                raise ValueError(msg)

            props["rows"] = data.length() if isinstance(data, ArrayVar) else len(data)

        if not isinstance(columns, Var) and len(columns):
            if types.is_dataframe(type(data)) or (
                isinstance(data, Var) and types.is_dataframe(data._var_type)
            ):
                msg = "Cannot pass in both a pandas dataframe and columns to the data_editor component."
                raise ValueError(msg)
            props["columns"] = [
                format.format_data_editor_column(col) for col in columns
            ]

        if "theme" in props:
            theme = props.get("theme")
            if isinstance(theme, Mapping):
                props["theme"] = DataEditorTheme(**theme)

        # Allow by default to select a region of cells in the grid.
        props.setdefault("get_cells_for_selection", True)

        # Disable on_paste by default if not provided.
        props.setdefault("on_paste", False)

        if props.pop("get_cell_content", None) is not None:
            logger.warning(
                "get_cell_content is not user configurable, the provided value will be discarded"

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