number.py 文件源码

def __init__(self,
            to_nearest  = 1,
            rounding    = ROUND_HALF_UP,
            result_type = DecimalType,
    ):
        # type: (Union[int, Text, DecimalType], Text, type) -> None
        """
        :param to_nearest:
            The value that the filter should round to.

            E.g., ``Round(1)`` rounds to the nearest whole number.

            If you want to round to a float value, it is recommended
            that you provide it as a string or Decimal, to avoid
            floating point problems.

        :param rounding:
            Controls how to round values.

        :param result_type:
            The type of result to return.
        """
        super(Round, self).__init__()

        self.to_nearest = DecimalType(to_nearest)

        # Rounding to negative values isn't supported.
        # I'm not even sure if that concept is valid.
        Min(DecimalType('0')).apply(self.to_nearest)

        self.result_type    = result_type
        self.rounding       = rounding