django之session与分页
前面我们介绍了cookies，主要应用在用户登录上，保存用户登录状态，不过cookies直接放在了浏览器上，安全性较低，所以我们便引出了session功能与cookies相同，不同的是它放在了客户端，相比较cookies来说安全性更高。还有分页，这是一个比较常用的功能。
本篇导航：
1、基本语法：
1、设置Sessions值 request.session['session_name'] ="admin" 2、获取Sessions值 session_name = request.session["session_name"] session_name = request.session.get("session_name") 3、删除Sessions值 del request.session["session_name"] request.session.flush() 4、检测是否操作session值 if "session_name" is request.session :
2、解析图
3、实例
1）views
def login(requset): if requset.method=="POST": username=requset.POST.get("user") password=requset.POST.get("pwd") ret=models.UserInfo.objects.filter(username=username,password=password) if ret: requset.session["IS_LOGON"]=True requset.session["USER"]=username return redirect("/home/") else: return redirect("/login/") return render(requset,"login.html") def home(request): ret=request.session.get("IS_LOGON",None) if ret : username=request.session.get("USER") return render(request, "home.html",locals()) else: return redirect("/login/")
2）template
<form action="/login/" method="post"> {% csrf_token %} <p>姓名 <input type="text" name="user"></p> <p>密码 <input type="password" name="pwd"></p> <input type="submit"> </form>
1、view
from django.shortcuts import render,HttpResponse # Create your views here. from app01.models import * from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger def index(request): ''' 批量导入数据: Booklist=[] for i in range(100): Booklist.append(Book(title="book"+str(i),price=30+i*i)) Book.objects.bulk_create(Booklist) ''' ''' 分页器的使用: book_list=Book.objects.all() paginator = Paginator(book_list, 10) print("count:",paginator.count) #数据总数 print("num_pages",paginator.num_pages) #总页数 print("page_range",paginator.page_range) #页码的列表 page1=paginator.page(1) #第1页的page对象 for i in page1: #遍历第1页的所有数据对象 print(i) print(page1.object_list) #第1页的所有数据 page2=paginator.page(2) print(page2.has_next()) #是否有下一页 print(page2.next_page_number()) #下一页的页码 print(page2.has_previous()) #是否有上一页 print(page2.previous_page_number()) #上一页的页码 # 抛错 #page=paginator.page(12) # error:EmptyPage #page=paginator.page("z") # error:PageNotAnInteger ''' book_list=Book.objects.all() paginator = Paginator(book_list, 10) page = request.GET.get('page',1) currentPage=int(page) try: print(page) book_list = paginator.page(page) except PageNotAnInteger: book_list = paginator.page(1) except EmptyPage: book_list = paginator.page(paginator.num_pages) return render(request,"index.html",{"book_list":book_list,"paginator":paginator,"currentPage":currentPage})
2、templates
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> <link rel="stylesheet" href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous"> </head> <body> <div class="container"> <h4>分页器</h4> <ul> {% for book in book_list %} <li>{{ book.title }} -----{{ book.price }}</li> {% endfor %} </ul> <ul class="pagination" id="pager"> {% if book_list.has_previous %} <li class="previous"><a href="/index/?page={{ book_list.previous_page_number }}">上一页</a></li> {% else %} <li class="previous disabled"><a href="#">上一页</a></li> {% endif %} {% for num in paginator.page_range %} {% if num == currentPage %} <li class="item active"><a href="/index/?page={{ num }}">{{ num }}</a></li> {% else %} <li class="item"><a href="/index/?page={{ num }}">{{ num }}</a></li> {% endif %} {% endfor %} {% if book_list.has_next %} <li class="next"><a href="/index/?page={{ book_list.next_page_number }}">下一页</a></li> {% else %} <li class="next disabled"><a href="#">下一页</a></li> {% endif %} </ul> </div> </body> </html>
3、扩展
def index(request): book_list=Book.objects.all() paginator = Paginator(book_list, 15) page = request.GET.get('page',1) currentPage=int(page) # 如果页数十分多时，换另外一种显示方式 if paginator.num_pages>30: if currentPage-5<1: pageRange=range(1,11) elif currentPage+5>paginator.num_pages: pageRange=range(currentPage-5,paginator.num_pages+1) else: pageRange=range(currentPage-5,currentPage+5) else: pageRange=paginator.page_range try: print(page) book_list = paginator.page(page) except PageNotAnInteger: book_list = paginator.page(1) except EmptyPage: book_list = paginator.page(paginator.num_pages) return render(request,"index.html",locals())
