fields.py 文件源码

def from_native(self, value):
        """
        Validates that the input is a decimal number. Returns a Decimal
        instance. Returns None for empty values. Ensures that there are no more
        than max_digits in the number, and no more than decimal_places digits
        after the decimal point.
        """
        if value in validators.EMPTY_VALUES:
            return None
        value = smart_text(value).strip()
        try:
            value = Decimal(value)
        except DecimalException:
            raise ValidationError(self.error_messages['invalid'])
        return value