trafarets.py 文件源码

def check_and_return(self, data):
        data = super(DecimalTrafaret, self).check_and_return(data)

        if self.allow_nan:
            if data.is_nan():
                return decimal.Decimal('NaN')  # avoid sNaN, -sNaN and -NaN
        else:
            if data.is_nan() or data.is_infinite():
                self._failure('Special numeric values are not permitted.',
                              value=data)

        if self.places is not None and data.is_finite():
            try:
                data = data.quantize(self.places, rounding=self.rounding)
            except decimal.InvalidOperation:
                self._failure('Decimal can not be properly quantized.',
                              value=data)

        return data