Question

假设我有这段代码：

# Get 30 threads
threads = Thread.objects.all()[:30]
threads_id = [o.pk for o in threads]
# Extra info about threads that the user have visited
visited_threads = VisitedThread.objects.filter(pk__in=threads_id, user=request.user)

# I want to loop the visited_threads and add info to thread in threads with new info
for visited_thread in visited_threads:
    # Here I want to add things to thread (visited_thread.thread), something like:
    # thread.has_unread_post = thread.post_count > visited_thread.post_count

如何将信息添加到线程列表中的线程，就像代码示例中的某些内容一样？我不想更新数据库，只是在为用户显示数据之前操纵数据。

Answer 1

您展示的示例代码很好，至少在一般情况下如此。一旦开始迭代查询集，Django将创建内存模型实例，并且可以像任何其他Python对象一样将属性添加到内存版本中。

为了能够根据第二个qs编辑第一个qs中的线程：

threads = Thread.objects.all()[:30]
threads_by_pk = dict((t.pk, t) for t in threads)
# Extra info about threads that the user have visited
visited_threads = VisitedThread.objects.filter(pk__in=threads_by_pk.keys(), user=request.user)

# I want to loop the visited_threads and add info to thread in threads with new info
for visited_thread in visited_threads:
    thread = threads_by_pk[visited_thread.pk]
    thread.has_unread_post = thread.post_count > visited_thread.post_count

在object_list中循环/更改某些对象的最佳方法

1 个答案: