utils.py 文件源码

def datetime_or_none(dt):
    """Validate a datetime or None value."""
    if dt is None:
        return None
    elif isinstance(dt, datetime.datetime):
        if dt.utcoffset() is None:
            # NOTE(danms): Legacy objects from sqlalchemy are stored in UTC,
            # but are returned without a timezone attached.
            # As a transitional aid, assume a tz-naive object is in UTC.
            return dt.replace(tzinfo=iso8601.UTC)
        else:
            return dt
    raise ValueError(_("A datetime.datetime is required here"))