column must be a Series or Expr, got {column!r} (type={quali

Error message

column must be a Series or Expr, got {column!r} (type={qualified_type_name(column)})

What it means

Error "column must be a Series or Expr, got {column!r} (type={qualified_type_name(column)})" thrown in pola-rs/polars.

Source

Thrown at py-polars/src/polars/dataframe/frame.py:5388

            if index < 0:
                msg = f"column index {original_index} is out of range (frame has {self.width} columns)"
                raise IndexError(msg)
        elif index > self.width:
            msg = f"column index {original_index} is out of range (frame has {self.width} columns)"
            raise IndexError(msg)

        if isinstance(column, pl.Series):
            self._df.insert_column(index, column._s)
        else:
            if isinstance(column, str):
                column = F.col(column)
            if isinstance(column, pl.Expr):
                cols = self.columns
                cols.insert(index, column)  # type: ignore[arg-type]
                self._df = self.select(cols)._df
            else:
                msg = f"column must be a Series or Expr, got {column!r} (type={qualified_type_name(column)})"
                raise TypeError(msg)
        return self

    def filter(
        self,
        *predicates: (
            IntoExprColumn
            | Iterable[IntoExprColumn]
            | bool
            | list[bool]
            | np.ndarray[Any, Any]
        ),
        **constraints: Any,
    ) -> DataFrame:
        """
        Filter rows, retaining those that match the given predicate expression(s).

        The original order of the remaining rows is preserved.

View on GitHub (pinned to df599052da)

When it happens

Trigger: Thrown at py-polars/src/polars/dataframe/frame.py:5388 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of pola-rs/polars@df599052da (2026-08-16). Data as JSON: /api/errors/d89247c022ad2653. Report an issue: GitHub.