polars.lit

polars.lit(
    value: Any,
    dtype: PolarsDataType | DataTypeExpr | None = None,
    *,
    allow_object: bool = False,
) → Expr

Return an expression representing a literal value.

Parameters:

value

Value that should be used as a literal.

dtype

The data type of the resulting expression. If set to None (default), the data type is inferred from the value input.

allow_object

If type is unknown use an ‘object’ type. By default, we will raise a ValueException if the type is unknown.

Notes

Expected datatypes:

• pl.lit([]) -> empty List<Null>
• pl.lit([1, 2, 3]) -> List<i64>
• pl.lit(pl.Series([]))-> empty Series Null
• pl.lit(pl.Series([1, 2, 3])) -> Series Int64
• pl.lit(None) -> Null

Examples

Literal scalar values:

>>> pl.lit(1)  
>>> pl.lit(5.5)  
>>> pl.lit(None)  
>>> pl.lit("foo_bar")  
>>> pl.lit(date(2021, 1, 20))  
>>> pl.lit(datetime(2023, 3, 31, 10, 30, 45))  

Literal list/Series data (1D):

>>> pl.lit([1, 2, 3])  
>>> pl.lit(pl.Series("x", [1, 2, 3]))  

Literal list/Series data (2D):

>>> pl.lit([[1, 2], [3, 4]])  
>>> pl.lit(pl.Series("y", [[1, 2], [3, 4]]))