pola-rs/polars · error · ValueError

`orient` must be one of {{'col', 'row', None}}, got {orient!

Error message

`orient` must be one of {{'col', 'row', None}}, got {orient!r}

What it means

ValueError raised in the numpy-array construction path for DataFrames: the orient argument fell through the recognized branches ('col', 'row', None interpretation) and hit the terminal else. It is a sentinel guard reporting the unrecognized orient value so callers fix the orientation hint.

Source

Thrown at py-polars/src/polars/_utils/construction/dataframe.py:638

    elif orient == "col":
        column_names, schema_overrides = _unpack_schema(
            schema, schema_overrides=schema_overrides, n_expected=len(data)
        )
        data_series: list[PySeries] = [
            pl.Series(
                column_names[i],
                element,
                dtype=schema_overrides.get(column_names[i]),
                strict=strict,
                nan_to_null=nan_to_null,
            )._s
            for i, element in enumerate(data)
        ]
        return PyDataFrame(data_series)

    else:
        msg = f"`orient` must be one of {{'col', 'row', None}}, got {orient!r}"
        raise ValueError(msg)


def _sequence_of_series_to_pydf(
    first_element: Series,  # noqa: ARG001
    data: Sequence[Any],
    schema: SchemaDefinition | None,
    *,
    schema_overrides: SchemaDict | None,
    strict: bool,
    **kwargs: Any,  # noqa: ARG001
) -> PyDataFrame:
    series_names = [s.name for s in data]
    column_names, schema_overrides = _unpack_schema(
        schema or series_names,
        schema_overrides=schema_overrides,
        n_expected=len(data),
    )
    data_series: list[PySeries] = []

View on GitHub (pinned to 68506541d2)

Solutions

1. Use orient='col', orient='row', or leave it as None.

Example fix

pl.DataFrame(data, orient='row')

When it happens

Trigger: Invalid orient argument to the DataFrame constructor.

Common situations: See trigger scenarios.

AI-assisted analysis of pola-rs/polars@68506541d2 (2026-08-19). Data as JSON: /api/errors/b552d2a4ef59ffca. Report an issue: GitHub.