pola-rs/polars · error · TypeError

DataTypeExpr.collect_dtype did not expect {context!r}

Error message

DataTypeExpr.collect_dtype did not expect {context!r}

What it means

Error "DataTypeExpr.collect_dtype did not expect {context!r}" thrown in pola-rs/polars.

Source

Thrown at py-polars/src/polars/datatype_expr/datatype_expr.py:302

        ...     }
        ... )
        >>> pl.dtype_of("a").collect_dtype(lf)
        Int64
        >>> pl.dtype_of("a").collect_dtype({"a": pl.String})
        String
        """
        schema: pl.Schema
        if isinstance(context, pl.Schema):
            schema = context
        elif isinstance(context, Mapping):
            schema = pl.Schema(context)
        elif isinstance(context, pl.DataFrame):
            schema = context.schema
        elif isinstance(context, pl.LazyFrame):
            schema = context.collect_schema()
        else:
            msg = f"DataTypeExpr.collect_dtype did not expect {context!r}"
            raise TypeError(msg)

        return self._pydatatype_expr.collect_dtype(schema)

View on GitHub (pinned to df599052da)

When it happens

Trigger: Thrown at py-polars/src/polars/datatype_expr/datatype_expr.py:302 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/4b3f886cd51b3a9e. Report an issue: GitHub.