Function cast

python/pathway/internals/common.py:242–272

Changes the type of the column to target_type and converts the data of this column Example: >>> import pathway as pw >>> t1 = pw.debug.table_from_markdown(''' ... val ... 1 10 ... 2 9 ... 3 8 ... 4 7''') >>> t1.schema <pathway.Schema types={'val

(target_type: Any, col: expr.ColumnExpression | Value)

def cast(target_type: Any, col: expr.ColumnExpression | Value) -> expr.CastExpression:
    """Changes the type of the column to target_type and converts the data of this column

    Example:

    >>> import pathway as pw
    >>> t1 = pw.debug.table_from_markdown('''
    ...   val
    ... 1   10
    ... 2    9
    ... 3    8
    ... 4    7''')
    >>> t1.schema
    <pathway.Schema types={'val': <class 'int'>}, id_type=<class 'pathway.engine.Pointer'>>
    >>> pw.debug.compute_and_print(t1, include_id=False)
    val
    7
    8
    9
    10
    >>> t2 = t1.select(val = pw.cast(float, t1.val))
    >>> t2.schema
    <pathway.Schema types={'val': <class 'float'>}, id_type=<class 'pathway.engine.Pointer'>>
    >>> pw.debug.compute_and_print(t2, include_id=False)
    val
    7.0
    8.0
    9.0
    10.0
    """
    return expr.CastExpression(target_type, col)


@check_arg_types