如何避免在 for-in 循环中使用 return 语句？

Question

我下面的观点是只经历一个迭代周期，然后打破循环。我知道这可能是因为这一行中的 return 语句：return JsonResponse([post.serialize() for post in posts], safe=False) 但我怎样才能避免这种情况？

我尝试将 return 语句更改为 print 语句，但随后出现 ValueError： The view network.views.followingPosts didn't return an HttpResponse object. It returned None instead.

就在 except 语句之前，我尝试在那里放置一个 continue 但这没有效果。

我不太确定如何解决这个问题。有什么想法吗？

def followingPosts(request, user_username):
    try:
        user_profile = get_object_or_404(User, username=user_username)
        following_users = user_profile.get_following()
        for person in following_users:
            posts = Post.objects.filter(creator=person)
    except Profile.DoesNotExist:
        return JsonResponse({"error": "No user found."}, status=404)

    if request.method == "GET":
        return JsonResponse([post.serialize() for post in posts], safe=False)
    
    else:
        return JsonResponse({
            "error": "GET request required."
        }, status=400)

Answer 1

作为@quamrana，我认为循环实现得很好，除了你只为最后一个循环存储帖子运行。这是更正：

def followingPosts(request, user_username):
    try:
        user_profile = get_object_or_404(User, username=user_username)
        following_users = user_profile.get_following()
        posts = list()
        for person in following_users:
            posts += Post.objects.filter(creator=person)
    except Profile.DoesNotExist:
        return JsonResponse({"error": "No user found."}, status=404)

    if request.method == "GET":
        return JsonResponse([post.serialize() for post in posts], safe=False)
    
    else:
        return JsonResponse({
            "error": "GET request required."
        }, status=400)

此外，在try-clause中保持一行是一个好习惯。因此，

def followingPosts(request, user_username):
    try:
        user_profile = get_object_or_404(User, username=user_username)
    except Profile.DoesNotExist:
        return JsonResponse({"error": "No user found."}, status=404)

    if request.method == "GET":
        following_users = user_profile.get_following()
        posts = list()
        for person in following_users:
            posts += Post.objects.filter(creator=person)
        return JsonResponse([post.serialize() for post in posts], safe=False)
    
    else:
        return JsonResponse({
            "error": "GET request required."
        }, status=400)

如何避免在 for-in 循环中使用 return 语句？

How to avoid using a return statement in a for-in loop?

python

django

json

django-views

for-in-loop