python3之天天生鲜列表页排序order_by()和分页器Paginator

Z时代
2024-01-10
分类：综合

python

 url(r"^list/(?P<category_id>d*)/(?P<page_num>d*)$", views.ListGoods.as_view(), name="list"),

(?P<category_id>d*)/(?P<page_num>d*)  定义了   def get(self,request,category_id,page_num):   传参必须要用的 变量名

class ListGoods(View):
def get(self,request,category_id,page_num):
# 获取sort参数:如果用户不传，就是默认的排序规则
        sort = request.GET.get("sort")
#商品种类
        categorys = GoodsCategory.objects.all()
#得到某一种类  get
try:
            category = GoodsCategory.objects.get(id=category_id)
except GoodsCategory.DoesNotExist: #DoesNot:不 Exist:存在
return  redirect("/list/1/1")
# 查询该类别所有商品SKU信息：按照排序规则来查询
if sort == "price":
# 按照价格由低到高
            skus = GoodsSKU.objects.filter(category=category).order_by("price")
elif sort == "hot":
# 按照销量由高到低
            skus = GoodsSKU.objects.filter(category=category).order_by("-sales")                              #倒序
else:
# 默认 如果不传入.order_by(字段),会发出警告!!  UnorderedObjectListWarning
            skus = GoodsSKU.objects.filter(category=category).order_by("id")
# 无论用户是否传入或者传入其他的排序规则，我在这里都重置成"default"
            sort = "default"
#新品推荐
        new_skus = skus.order_by("-create_time")[:2]
# 创建分页器 对象     一页显示的数量
        paginator = Paginator(skus,2)
        page_num = int(page_num) #转换
try:
#获取  第几页的对象
            page_skus = paginator.page(page_num)
except EmptyPage:
# except Exception:
            page_skus = paginator.page(1)
#获得页数列表 一共几页 可遍历出来1,2,3...
        page_list = paginator.page_range
        context = {
"sort":sort,
"categorys": categorys,
"category": category,
"page_skus":page_skus,
"new_skus":new_skus,
"page_list":page_list,
        }
# 购物车
        cart_num = 0
# 自定义购物车函数
        cart_num = cartnum(request, cart_num)
# 字典更新 /添加 购物车数量
        context.update(cart_num=cart_num)
return render(request, "list.html", context)

html

<div class="sort_bar">
<a href="{% url "goods:list" category.id 1 %}?sort=default" {% if sort == "default" %}class="active"{% endif %}>默认</a>
<a href="{% url "goods:list" category.id 1 %}?sort=price" {% if sort == "price" %}class="active"{% endif %}>价格</a>
<a href="{% url "goods:list" category.id 1 %}?sort=hot" {% if sort == "hot" %}class="active"{% endif %}>人气</a>
</div>

{% if sort == "default" %}class="active"{% endif %}   active 在css里设定了样式

类似于这样：

分页器

# 创建分页器 对象  一页显示2个商品
        paginator = Paginator(skus,2)
        page_num = int(page_num) #转换
try:
#获取  第几页的对象
            page_skus = paginator.page(page_num)
except EmptyPage:
# except Exception:
            page_skus = paginator.page(1)
#获得页数列表 一共几页 可遍历出来1,2,3...
        page_list = paginator.page_range

<div class="pagenation">
<a href="{% url "goods:list" category.id 1 %}?sort={{ sort }}">首页</a>
                {% if page_skus.has_previous %}
<!-- previous page number:之前的页码  -->
<a href="{% url "goods:list" category.id page_skus.previous_page_number %}?sort={{ sort }}">&lt;上一页</a>
                {% endif %}
                {% for page in page_list %}
<a href="{% url "goods:list" category.id page %}?sort={{ sort }}"
                       {% if page == page_skus.number %} class="active" {% endif %}>{{ page }}</a>
                {% endfor %}
                {% if page_skus.has_next %}
<a href="{% url "goods:list" category.id page_skus.next_page_number %}?sort={{ sort }}">下一页></a>
                {% endif %}
</div>