我是django和python的新手，我正在关注django教程并且我一直收到以下错误
UnboundLocalError at /blog/search/
local variable 'total_results' referenced before assignment
继承我的代码
def post_search(request):
form = SearchForm()
if 'query' in request.GET:
form = SearchForm(request.GET)
if form.is_valid():
cd = form.cleaned_data
results = SearchQuerySet().models(Post)\
.filter(content=cd['query']).load_all()
# count total results
total_results = results.count()
template = 'blog/post/search.html'
context = {
'form': form,
'cd': cd,
'results': results,
'total_results': total_results
}
return render(request, template, context)
我也尝试过这样的原因，因为教程是如何实现的
return render(request, template, {
'form': form,
'cd': cd,
'results': results,
'total_results': total_results
})
但这也没有用
我理解错误消息的内容，但这是本教程的内容。使这项工作的正确语法是什么。欢迎所有指导
编辑：这是模板代码
{% extends "blog/base.html" %}
{% block title %}Search{% endblock %}
{% block content %}
{% if "query" in request.GET %}
<h1>Posts containing "{{ cd.query }}"</h1>
<h3>Found {{ total_results }} result{{ total_results|pluralize}}</h3>
{% for result in results %}
{% with post=result.object %}
<h4><a href="{{ post.get_absolute_url }}">{{ post.title }}</a></h4>
{{ post.body|truncatewords:5 }}
{% endwith %}
{% empty %}
<p>There are no results for your query.</p>
{% endfor %}
<p><a href="{% url 'blog:post_search' %}">Search again</a></p>
{% else %}
<h1>Search for posts</h1>
<form action="." method="get">
{{ form.as_p }}
<input type="submit" value="Search">
</form>
{% endif %}
{% endblock %}
答案 0 :(得分：3)
如果没有传递query GET参数，或者表单无法通过验证 - 在这种情况下，total_results和results将不会被定义。您需要为该情况提供默认值，例如：
def post_search(request):
results = []
total_results = 0
form = SearchForm()
if 'query' in request.GET:
form = SearchForm(request.GET)
if form.is_valid():
cd = form.cleaned_data
results = SearchQuerySet().models(Post)\
.filter(content=cd['query']).load_all()
# count total results
total_results = results.count()
template = 'blog/post/search.html'
context = {
'form': form,
'cd': cd,
'results': results,
'total_results': total_results
}
return render(request, template, context)
或者，抛出特定的＆＃34;验证＆＃34;如果没有query参数或表单无效，则出错。
答案 1 :(得分：3)
2
1 3
0 4
Python指出如果＆＃39; if＆＃39;会发生什么？条件失败，你仍然在使用变量＆total;'结果＆＃39;在上下文中。因此，根据需要将其初始化为0或无。类似于＆＃39;结果＆＃39;变量也是如此。
EDIT1：由于我并不完全知道你想要达到的目标，我最好的猜测就是使用这段代码。
EDIT2：模板代码更改
def post_search(request):
results = [] # or None
total_results = 0 # or None
form = SearchForm(request.GET or None)
if 'query' in request.GET:
if form.is_valid():
cd = form.cleaned_data
results = SearchQuerySet().models(Post)\
.filter(content=cd['query']).load_all()
# count total results
total_results = results.count()
template = 'blog/post/search.html'
context = {
'form': form,
'cd': cd,
'results': results,
'total_results': total_results
}
return render(request, template, context)
else:
return render(request, 'blog/post/search.html', {'form': form,})
else:
return render(request, 'blog/post/search.html', {'form': form,})
答案 2 :(得分：1)
我已经阅读了同一本书，并注意到该特定视图存在同样的问题。这是我在视图中的解决方案。我按原样离开了模板（在书中）：
def post_search(request):
if 'query' in request.GET:
form = SearchForm(request.GET)
if form.is_valid():
cd = form.cleaned_data
results = SearchQuerySet().models(Post).filter(content=cd['query']).load_all()
total_results = results.count()
context = {'form':form, 'cd':cd, 'results':results, 'total_results':total_results}
return render (request, 'blog/post/search.html', context)
else:
form = SearchForm()
context = {'form':form}
return render (request, 'blog/post/search.html', context)
答案 3 :(得分：1)
有完全相同的问题...下面的代码可以使用
def post_search(request):
results = []
total_results = 0
cd = None
form = SearchForm()
if 'query' in request.GET:
form = SearchForm(request.GET)
if form.is_valid():
cd = form.cleaned_data
results = SearchQuerySet().models(Post).filter(content=cd['query']).load_all()
total_results = results.count()
return render(request, 'search/search.html', {'form':form,
'cd':cd,
'results':results,
'total_results':total_results,
})
但出于兴趣，您是否也发现post_detail视图产生了类似的错误？用这个版本的代码解决了那个问题
def post_detail(request, year, month, day, post):
post = get_object_or_404(Post, slug=post,
status='published',
publish__year=year,
publish__month=month,
publish__day=day)
#list of active comments for this post
comments = post.comments.filter(active=True)
if request.method == 'POST':
# A comment was posted
comment_form = CommentForm(data=request.POST)
if comment_form.is_valid():
#create comment object but don't save to DB
new_comment = comment_form.save(commit=False)
# assitgn comment to post
new_comment.post = post
# save the comment to the DB
new_comment.save()
else:
comment_form =CommentForm()
post_tags_ids = post.tags.values_list('id', flat=True)
similar_posts = Post.published.filter(tags__in=post_tags_ids).exclude(id=post.id)
similar_posts = similar_posts.annotate(same_tags=Count('tags')).order_by('-same_tags','-publish')[:4]
args = {}
args['post'] = post
args['comment_form']= comment_form
args['comments'] = comments
args['similar_posts'] = similar_posts
return render(request, 'detail.html', args )