polars.lit#

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

Return an expression representing a literal value.

Parameters:
value

Value that should be used as a literal.

dtype

Optionally define a dtype.

allow_object

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

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]]))

Expected datatypes

  • ‘’pl.lit([])’’ -> empty Series Float32

  • ‘’pl.lit([1, 2, 3])’’ -> Series Int64

  • ‘’pl.lit([[]])’’-> empty Series List<Null>

  • ‘’pl.lit([[1, 2, 3]])’’ -> Series List<i64>

  • ‘’pl.lit(None)’’ -> Series Null