Question

您好我有一个搜索结果页面，使用此视图从数据库返回查询：

def search(request):
show_results = False
# check if POST
if 'q' in request.POST:
    query = request.POST['q'].strip()
# check if GET (paginated)
if 'q' in request.GET:
    query = request.GET['q'].strip()
# check if query length is more than 2 characters and proceed
if query and len(query) > 2:
    # if there is a query string show results (as opposed to arriving without any POST/GET      
    show_results = True
    keywords = query.split()
    q = Q()
    for keyword in keywords:
        q = q & (Q(title__icontains=keyword) | (Q(keywords__icontains=keyword)))
        query_set = Article.objects.filter(q)
    # create a new paginator instance with items-per-page
    paginator = Paginator(query_set, 10)

    # get the page number from a get param if param is blank then set page to 1 
    page = int(request.GET.get('page', '1')) 

    # grab the current page from the paginator...  
    items = paginator.page(page)

    # update search counter with term
    try:
        term = Search.objects.get(term=query)
    except Search.DoesNotExist:
        # if not already in db, then add query
        term = Search(term=query)

    term.counter += 1
    term.last_search = datetime.now()
    term.save()

elif len(query) <= 2:
    short_string = True
else:
    pass
#render the template and pass the contacts page into the template  
return render_to_response('search_results.html',
                            locals(), context_instance=RequestContext(request))

和模板：

{% load i18n %}
<form action="/i18n/setlang/" name=postlink   method="post">
    <ul class="lang">
         <li class="lang" style="color:gray">
                {% for lang in LANGUAGES %}

                    {% if lang.0 != LANGUAGE_CODE %}
                        <input type="hidden" name="language" value="{{ lang.0 }}">
                        <a href=# onclick="submitPostLink()">{{ lang.1 }}</a>
                    {% else %}
                        {{ lang.1 }}
                    {% endif %}
                {% endfor %}
        </li></ul>
</form>

除一种情况外，语言切换在所有页面上都能正常工作。当我在搜索结果页面上提交没有返回结果的语言更改数据时（即空查询集），我收到以下错误：

UnboundLocalError at /search/
local variable 'query' referenced before assignment

我想我需要略微调整视图，但我不知道在哪里。任何建议都非常赞赏。

回溯：

traceback: `Environment:


Request Method: GET
Request URL: http://localhost:8000/search/

Django Version: 1.3
Python Version: 2.7.1
Installed Applications:
['django.contrib.auth',
'django.contrib.contenttypes',
'django.contrib.sessions',
'django.contrib.sites',
'django.contrib.messages',
'django.contrib.staticfiles',
'journal',
'django.contrib.admin']
Installed Middleware:
('django.middleware.common.CommonMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.locale.LocaleMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.csrf.CsrfResponseMiddleware')

 Traceback:
  File "/usr/local/lib/python2.7/dist-packages/django/core/handlers/base.py" in get_response
 111.                         response = callback(request, *callback_args,       **callback_kwargs)
File "/home/sam/public_html/django- projects/galapagos_research/../galapagos_research/journal/views.py" in search
 40.    if query and len(query) > 2:

Exception Type: UnboundLocalError at /search/
Exception Value: local variable 'query' referenced before assignment

Answer 1

如果query不在POST或GET中，则您尚未定义q。由于这是唯一出现此错误的地方，因此您不得传入q。空QuerySet不会导致此错误。

可以肯定的是，触发错误的行（请追溯 - 请）会有所帮助。

def search(request):
    show_results = False

    query = None # set default value for query

    # check if POST
    if 'q' in request.POST:
        query = request.POST['q'].strip()

    # check if GET (paginated)
    if 'q' in request.GET:
        query = request.GET['q'].strip()

    ###########################
    # was `query` defined here if 'q' isn't in POST or GET? 
    ###########################


    # check if query length is more than 2 characters and proceed
    if query and len(query) > 2: # error probably on this line?

Answer 2

一开始，查询永远不会设置为默认值。

if 'q' in request.POST:
    query = request.POST['q'].strip()
# check if GET (paginated)
if 'q' in request.GET:
    query = request.GET['q'].strip()

然后在你的elif中，你尝试确定查询的len（），如果'q'不在GET或POST中，那么它在任何地方都没有定义。

elif len(query) <= 2:
    short_string = True

Django - 使用查询数据进行语言切换

2 个答案: