Django 其他dict必须是映射（类似字典）对象

我有以下上下文处理器：

def btc_price(request):
    price = get_price()
    return {'btc_price', price}

如果有关系，下面是我的get_price函数：

def get_price():
    now = datetime.datetime.now()
    if PriceCache.objects.all().exists():
        last_fetch = PriceCache.objects.latest('time_fetched')
        time_last_fetched = last_fetch.time_fetched
        day = datetime.timedelta(days=1)

        if now - time_last_fetched > day:
            api_url = urllib2.Request("https://www.bitstamp.net/api/ticker/")
            opener = urllib2.build_opener()
            f = opener.open(api_url)
            fetched_json = json.loads(f.read())
            cost_of_btc = fetched_json['last']

            PriceCache.objects.create(price=cost_of_btc, time_fetched=now)
            last_fetch.delete()
            return cost_of_btc
        else:
            return last_fetch.price
    else:
        api_url = urllib2.Request("https://www.bitstamp.net/api/ticker/")
        opener = urllib2.build_opener()
        f = opener.open(api_url)
        fetched_json = json.loads(f.read())
        cost_of_btc = fetched_json['last']

        PriceCache.objects.create(price=cost_of_btc, time_fetched=now)
    return cost_of_btc

我在TEMPLATE_context_PROCESSORS中声明了上下文处理器，如下所示：

TEMPLATE_CONTEXT_PROCESSORS = (
"django.contrib.auth.context_processors.auth",
"django.core.context_processors.debug",
"django.core.context_processors.i18n",
"django.core.context_processors.media",
"django.core.context_processors.request",
"Computer_store.processors.btc_price",
)

在我的

render\u to\u response

函数中正确定义了请求上下文

return render_to_response('home.html', {}, context_instance = RequestContext(request))

然而，当我试图在主页上运行此代码时，我得到一个奇怪的错误。

TypeError位于/
其他dict必须是映射（类似字典）对象。

可以进行完整的回溯。

看起来

return {'btc_price', price}

应成为：

return {'btc_price': price}

---

哇！我真傻。谢谢。有人能详细解释一下这个错误消息的意思吗？