fields.py 文件源码

def from_native(self, value):
        if value in validators.EMPTY_VALUES:
            return None

        if isinstance(value, datetime.datetime):
            return value
        if isinstance(value, datetime.date):
            value = datetime.datetime(value.year, value.month, value.day)
            if settings.USE_TZ:
                # For backwards compatibility, interpret naive datetimes in
                # local time. This won't work during DST change, but we can't
                # do much about it, so we let the exceptions percolate up the
                # call stack.
                warnings.warn("DateTimeField received a naive datetime (%s)"
                              " while time zone support is active." % value,
                              RuntimeWarning)
                default_timezone = timezone.get_default_timezone()
                value = timezone.make_aware(value, default_timezone)
            return value

        for fmt in self.input_formats:
            if fmt.lower() == ISO_8601:
                try:
                    parsed = parse_datetime(value)
                except (ValueError, TypeError):
                    pass
                else:
                    if parsed is not None:
                        return parsed
            else:
                try:
                    parsed = datetime.datetime.strptime(value, fmt)
                except (ValueError, TypeError):
                    pass
                else:
                    return parsed

        msg = self.error_messages['invalid'] % readable_datetime_formats(self.input_formats)

        raise ValidationError(msg)