fenic.api.functions.core

Core functions for Fenic DataFrames.

Functions:

• col –

  Creates a Column expression referencing a column in the DataFrame.

• lit –

  Creates a Column expression representing a literal value.

col

col(col_name: str) -> Column

Creates a Column expression referencing a column in the DataFrame.

Parameters:

• col_name (str) –

  Name of the column to reference

Returns:

• Column –

  A Column expression for the specified column

Raises:

• TypeError –

  If colName is not a string

Source code in src/fenic/api/functions/core.py

@validate_call(config=ConfigDict(strict=True))
def col(col_name: str) -> Column:
    """Creates a Column expression referencing a column in the DataFrame.

    Args:
        col_name: Name of the column to reference

    Returns:
        A Column expression for the specified column

    Raises:
        TypeError: If colName is not a string
    """
    return Column._from_column_name(col_name)

lit

lit(value: Any) -> Column

Creates a Column expression representing a literal value.

Parameters:

• value (Any) –

  The literal value to create a column for

Returns:

• Column –

  A Column expression representing the literal value

Raises:

• ValueError –

  If the type of the value cannot be inferred

Source code in src/fenic/api/functions/core.py

def lit(value: Any) -> Column:
    """Creates a Column expression representing a literal value.

    Args:
        value: The literal value to create a column for

    Returns:
        A Column expression representing the literal value

    Raises:
        ValueError: If the type of the value cannot be inferred
    """
    try:
        inferred_type = infer_dtype_from_pyobj(value)
    except TypeInferenceError as e:
        raise ValidationError(f"`lit` failed to infer type for value `{value}`") from e
    literal_expr = LiteralExpr(value, inferred_type)
    return Column._from_logical_expr(literal_expr)