擅长:python、mysql、java
<p>问题是try块没有执行,execept块在<code>cart_id = cart_id</code>出现的地方开始执行,这就是为什么会出现错误。在</p>
<p>您可以在现有代码中执行类似的操作</p>
<pre><code>def cart_view(request):
cart_id = request.session['cart_id'] # before try block
try:
cart = Cart.objects.get(id=cart_id)
request.session['total'] = cart.items.count()
except:
cart = Cart()
cart.save()
cart_id = cart_id
request.session['cart_id'] = cart_id
cart = Cart.objects.get(id=cart_id)
categories = Category.objects.all()
return render(request, 'cart.html', locals())
</code></pre>