5

当我尝试反转时，我收到一个错误“_reverse_with_prefix() 参数后 * 必须是一个序列，而不是 int”。我之前在视图中对参数进行了硬编码，但正在尝试使其动态化。有什么建议吗？

看法：

def add_review(request, product_id):
    p = get_object_or_404(Product, pk=product_id)
    if request.method == 'POST':
        form = ReviewForm(request.POST)
        if form.is_valid():
            form.save()
            #HARDCODED: return HttpResponseRedirect('/products/1/reviews/')
            return HttpResponseRedirect(reverse('view_reviews', args=(p.id)))
    else:
        form = ReviewForm()
    variables = RequestContext(request, {'form': form})
    return render_to_response('reserve/templates/create_review.html', variables)        


def view_reviews(request, product_id):
    product = get_object_or_404(Product, pk=product_id)
    reviews = Review.objects.filter(product_id=product_id)
    return render_to_response('reserve/templates/view_reviews.html', {'product':product, 'reviews':reviews},
    context_instance=RequestContext(request))


urlpatterns = patterns('reserve.views',
    url(r'^clubs/$', 'index'),
    url(r'^products/(?P<product_id>\d+)/reviews/$', 'view_reviews'),
    url(r'^products/(?P<product_id>\d+)/add_review/$', 'add_review'),
    url(r'^admin/', include(admin.site.urls)),
)
4

3 回答 3

21

检查args=(p.id)里面reverse()，一定是args=(p.id,)。第一种形式被视为整数而不是序列。

参考文档和教程：

一个特殊的问题是包含 0 或 1 项的元组的构造：语法有一些额外的怪癖来适应这些。空元组由一对空括号构成；一个包含一个项目的元组是通过一个带有逗号的值来构造的（将单个值括在括号中是不够的）。

此外，使用'reserve.views.view_reviews'而不是仅'view_reviews'，因此：

reverse('reserve.views.view_reviews', args=(p.id,))

检查反向文档

于 2012-06-25T05:18:18.577 回答
2

由于您的模式将匹配项分配给变量，因此它被视为关键字参数，因此您应该将调用调整为 reverse。

return HttpResponseRedirect(reverse('view_reviews', kwargs={'product_id':p.id})

于 2012-06-25T05:39:59.507 回答
0

那是因为 args 需要元组，但是当你使用 args=(p.id) 时，实际上，python 会认为是整数 p.id，你可以查看源代码 django 1.6 如下： 

def reverse(viewname, urlconf=None, args=None, kwargs=None, prefix=None, current_app=None):
if urlconf is None:
    urlconf = get_urlconf()
resolver = get_resolver(urlconf)
args = args or []
kwargs = kwargs or {}
if prefix is None:
    prefix = get_script_prefix()
if not isinstance(viewname, six.string_types):
    view = viewname
else:
    parts = viewname.split(':')
    parts.reverse()
    view = parts[0]
    path = parts[1:]
    resolved_path = []
    ns_pattern = ''
    while path:
        ns = path.pop()

        # Lookup the name to see if it could be an app identifier
        try:
            app_list = resolver.app_dict[ns]
            # Yes! Path part matches an app in the current Resolver
            if current_app and current_app in app_list:
                # If we are reversing for a particular app,
                # use that namespace
                ns = current_app
            elif ns not in app_list:
                # The name isn't shared by one of the instances
                # (i.e., the default) so just pick the first instance
                # as the default.
                ns = app_list[0]
        except KeyError:
            pass

        try:
            extra, resolver = resolver.namespace_dict[ns]
            resolved_path.append(ns)
            ns_pattern = ns_pattern + extra
        except KeyError as key:
            if resolved_path:
                raise NoReverseMatch(
                    "%s is not a registered namespace inside '%s'" %
                    (key, ':'.join(resolved_path)))
            else:
                raise NoReverseMatch("%s is not a registered namespace" %
                                     key)
    if ns_pattern:
        resolver = get_ns_resolver(ns_pattern, resolver)

return iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs))

看看这个 iri_to_uri(resolver._reverse_with_prefix(view, prefix, *args, **kwargs))，它使用 *args，所以你应该确保 args 是一个序列，

根据文档，一个项目的元组应该添加逗号来创建，你的代码应该是这样的： 

return HttpResponseRedirect(reverse('view_reviews', args=(p.id,)))
于 2013-12-14T12:02:18.750 回答