utilities.py 文件源码

def get_queryset_size(klass,  *args, **kwargs):
    queryset = _get_queryset(klass)
    try:
        obj_list = list(queryset.filter(*args, **kwargs))
    except AttributeError:
        klass__name = klass.__name__ if isinstance(klass, type) else klass.__class__.__name__
        raise ValueError(
            "First argument get_queryset_size() must be a Model, Manager, or "
            "QuerySet, not '%s'." % klass__name
        )
    if not obj_list:
        return 0
    return len(obj_list)