Question

我最近参加了会话和cookies。我在理论上很好地理解会话和cookie，但我在理解会话代码时有一个问题。它是关于用户获取last_visit。代码是来自tangowithdjango.com

def index(request):
    context = RequestContext(request)

    category_list = Category.objects.all()
    context_dict = {'categories': category_list}

    for category in category_list:
        category.url = encode_url(category.name)

    page_list = Page.objects.order_by('-views')[:5]
    context_dict['pages'] = page_list

    #### NEW CODE ####
    if request.session.get('last_visit'):
        # The session has a value for the last visit
        last_visit_time = request.session.get('last_visit')
        visits = request.session.get('visits', 0)

        if (datetime.now() - datetime.strptime(last_visit_time[:-7], "%Y-%m-%d %H:%M:%S")).days > 0:
            request.session['visits'] = visits + 1
            request.session['last_visit'] = str(datetime.now())
    else:
        # The get returns None, and the session does not have a value for the last visit.
        request.session['last_visit'] = str(datetime.now())
        request.session['visits'] = 1
    #### END NEW CODE ####

    # Render and return the rendered response back to the user.
    return render_to_response('rango/index.html', context_dict, context)

当我试图理解request.session.get（'last_visit'）的作用时，我总是得到None。我不明白的是关键'last_visit'。它是会话中的默认对象吗？如果它在会话对象中是默认值，那么为什么每次在我的终端中都显示“无”。

请有人让我理解get（）中传递的对象。

Answer 1

将RequestContext内容移至底部

def index(request):


    #### NEW CODE ####
    if request.session.get('last_visit'):
        # The session has a value for the last visit
        last_visit_time = request.session.get('last_visit')
        visits = request.session.get('visits', 0)

        if (datetime.now() - datetime.strptime(last_visit_time[:-7], "%Y-%m-%d %H:%M:%S")).days > 0:
            request.session['visits'] = visits + 1
            request.session['last_visit'] = str(datetime.now())
    else:
        # The get returns None, and the session does not have a value for the last visit.
        request.session['last_visit'] = str(datetime.now())
        request.session['visits'] = 1
    #### END NEW CODE ####

    context = RequestContext(request)

    category_list = Category.objects.all()
    context_dict = {'categories': category_list}

    for category in category_list:
        category.url = encode_url(category.name)

    page_list = Page.objects.order_by('-views')[:5]
    context_dict['pages'] = page_list

    # Render and return the rendered response back to the user.
    return render_to_response('rango/index.html', context_dict, context)

request.session.get（'last_visit'）始终产生无

1 个答案: