DAY18-Django之分页和中间件
Posted guoyunlong666
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分页
Django的分页器（paginator）
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) #把所有数据按10条一页分 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range（1,8） 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) #如果get请求的page为空，则使用默认值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})
index.html:
<!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>
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())
自己写的low版：
from django.shortcuts import render,HttpResponse,redirect from app01.models import Book from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger # Create your views here. def index(request): #插入数据 # obj_list=[] # for i in range(1,101): # obj=Book(title=\'book%s\'%i,price=i*i) # obj_list.append(obj) # Book.objects.bulk_create(obj_list) # return HttpResponse("ok") book_list=Book.objects.all() paginator=Paginator(book_list,5) currentPage=request.GET.get("page",1) if not currentPage.isdigit() or currentPage=="0": currentPage=1 currentPage=int(currentPage) if currentPage > paginator.num_pages: currentPage=paginator.num_pages book_list=paginator.page(currentPage) start=currentPage-3 if start<2: start=2 end=start+7 if end>paginator.num_pages: end=paginator.num_pages if end-7>2: start=end-7 page_range=range(start,end) return render(request,"index.html",locals())
<!DOCTYPE html> <html lang="zh-CN"> <head> <meta charset="UTF-8"> <title>Title</title> <!-- 最新版本的 Bootstrap 核心 CSS 文件 --> <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> {% for book in book_list %} <div>{{ book.title }}----->{{ book.price }}</div> {% endfor %} <nav aria-label="Page navigation"> <ul class="pagination"> {% if currentPage == 1 %} <li class="disabled"> {% else %} <li> {% endif %} <a href="?page={{ currentPage|add:-1 }}" aria-label="Previous"> <span aria-hidden="true">«</span> </a> </li> {% if currentPage == 1 %} <li class="active"> {% else %} <li> {% endif %} <a href="?page=1">1</a></li> {% if start == 2 %} <li><span class="hidden">...</span></li> {% else %} <li><span>...</span></li> {% endif %} {% for num in page_range %} {% if num == currentPage %} <li class="active"> {% else %} <li> {% endif %} <a href="?page={{ num }}">{{ num }}</a></li> {% endfor %} {% if end == paginator.num_pages %} <li><span class="hidden">...</span></li> {% else %} <li><span>...</span></li> {% endif %} {% if currentPage == paginator.num_pages %} <li class="active"> {% else %} <li> {% endif %} <a href="?page={{ paginator.num_pages }}">{{ paginator.num_pages }}</a></li> {% if currentPage == paginator.num_pages %} <li class="disabled"> {% else %} <li> {% endif %} <a href="?page={{ currentPage|add:1 }}" aria-label="Next"> <span aria-hidden="true">»</span> </a> </li> </ul> </nav> </div> </body> </html>
自定义分页器
""" 分页组件使用示例： obj = Pagination(request.GET.get(\'page\',1),len(USER_LIST),request.path_info) page_user_list = USER_LIST[obj.start:obj.end] page_html = obj.page_html() return render(request,\'index.html\',{\'users\':page_user_list,\'page_html\':page_html}) """ class Pagination(object): def __init__(self,current_page,all_count,base_url,per_page_num=2,pager_count=11): """ 封装分页相关数据 :param current_page: 当前页 :param all_count: 数据库中的数据总条数 :param per_page_num: 每页显示的数据条数 :param base_url: 分页中显示的URL前缀 :param pager_count: 最多显示的页码个数 """ try: current_page = int(current_page) except Exception as e: current_page = 1 if current_page <1: current_page = 1 self.current_page = current_page self.all_count = all_count self.per_page_num = per_page_num self.base_url = base_url # 总页码 all_pager, tmp = divmod(all_count, per_page_num) if tmp: all_pager += 1 self.all_pager = all_pager self.pager_count = pager_count self.pager_count_half = int((pager_count - 1) / 2) @property def start(self): return (self.current_page - 1) * self.per_page_num @property def end(self): return self.current_page * self.per_page_num def page_html(self): # 如果总页码 < 11个： if self.all_pager <= self.pager_count: pager_start = 1 pager_end = self.all_pager + 1 # 总页码 > 11 else: # 当前页如果<=页面上最多显示11/2个页码 if self.current_page <= self.pager_count_half: pager_start = 1 pager_end = self.pager_count + 1 # 当前页大于5 else: # 页码翻到最后 if (self.current_page + self.pager_count_half) > self.all_pager: pager_end = self.all_pager + 1 pager_start = self.all_pager - self.pager_count + 1 else: pager_start = self.current_page - self.pager_count_half pager_end = self.current_page + self.pager_count_half + 1 page_html_list = [] first_page = \'<li><a href="%s?page=%s">首页</a></li>\' % (self.base_url,1,) page_html_list.append(first_page) if self.current_page <= 1: prev_page = \'<li class="disabled"><a href="#">上一页</a></li>\' else: prev_page = \'<li><a href="%s?page=%s">上一页</a></li>\' % (self.base_url,self.current_page - 1,) page_html_list.append(prev_page) for i in range(pager_start, pager_end): if i == self.current_page: temp = \'<li class="active"><a href="%s?page=%s">%s</a></li>\' % (self.base_url,i, i,) else: temp = \'<li><a href="%s?page=%s">%s</a></li>\' % (self.base_url,i, i,) page_html_list.append(temp) if self.current_page >= self.all_pager: next_page = \'<li class="disabled"><a href="#">下一页</a></li>\' else: next_page = \'<li><a href="%s?page=%s">下一页</a></li>\' % (self.base_url,self.current_page + 1,) page_html_list.append(next_page) last_page = \'<li><a href="%s?page=%s">尾页</a></li>\' % (self.base_url,self.all_pager,) page_html_list.append(last_page) return \'\'.join(page_html_list)
自定义分页（葫芦版）
data = [] for i in range(1, 302): tmp = {"id": i, "name": "alex-{}".format(i)} data.append(tmp) print(data) def user_list(request): # user_list = data[0:10] # user_list = data[10:20] try: current_page = int(request.GET.get("page")) except Exception as e: current_page = 1 per_page = 10 # 数据总条数 total_count = len(data) # 总页码 total_page, more = divmod(total_count, per_page) if more: total_page += 1 # 页面最多显示多少个页码 max_show = 11 half_show = int((max_show-1)/2) if current_page <= half_show: show_start = 1 show_end = max_show else: if current_page + half_show >= total_page: show_start = total_page - max_show show_end = total_page else: show_start = current_page - half_show show_end = current_page + half_show # 数据库中获取数据 data_start = (current_page - 1) * per_page data_end = current_page * per_page user_list = data[data_start:data_end] # 生成页面上显示的页码 page_html_list = [] # 加首页 first_li = \'<li><a href="/user_list/?page=1">首页</a></li>\' page_html_list.append(first_li) # 加上一页 if current_page == 1: prev_li = \'<li><a href="#">上一页</a></li>\' else: prev_li = \'<li><a href="/user_list/?page={}">上一页</a></li>\'.format(current_page - 1) page_html_list.append(prev_li) for i in range(show_start, show_end+1): if i == current_page: li_tag = \'<li class="active"><a href="/user_list/?page={0}">{0}</a></li>\'.format(i) else: li_tag = \'<li><a href="/user_list/?page={0}">{0}</a></li>\'.format(i) page_html_list.append(li_tag) # 加下一页 if current_page == total_page: next_li = \'<li><a href="#">下一页</a></li>\' else: next_li = \'<li><a href="/user_list/?page={}">下一页</a></li>\'.format(current_page+1) page_html_list.append(next_li) # 加尾页 page_end_li = \'<li><a href="/user_list/?page={}">尾页</a></li>\'.format(total_page) page_html_list.append(page_end_li) page_html = "".join(page_html_list) return render(request, "user_list.html", {"user_list": user_list, "page_html": page_html})
class Pagination(object): def __init__(self, current_page, total_count, base_url, per_page=10, max_show=11): """ :param current_page: 当前页 :param total_count: 数据库中数据总数 :param per_page: 每页显示多少条数据 :param max_show: 最多显示多少页 """ try: current_page = int(current_page) except Exception as e: current_page = 1 self.current_page = current_page self.total_count = total_count self.base_url = base_url self.per_page = per_page self.max_show = max_show # 总页码 total_page, more = divmod(total_count, per_page) if more: total_page += 1 half_show = int((max_show - 1) / 2) self.half_show = half_show self.total_page = total_page @property def start(self): return (self.current_page - 1) * self.per_page @property def end(self): return self.current_page * self.per_page def page_html(self): if self.current_page <= self.half_show: show_start = 1 show_end = self.max_show else: if self.current_page + self.half_show >= self.total_page: show_start = self.total_page - self.max_show show_end = self.total_page else: show_start = self.current_page - self.half_show show_end = self.current_page + self.half_show # 生成页面上显示的页码 page_html_list = [] # 加首页 first_li = \'<li><a href="{}?page=1">首页</a></li>\'.format(self.base_url) page_html_list.append(first_li) # 加上一页 if self.current_page == 1: prev_li = \'<li><a href="#">上一页</a></li>\' else: prev_li = \'<li><a href="{0}?page={1}">上一页</a></li>\'.format(self.base_url, self.current_page - 1) page_html_list.append(prev_li) for i in range(show_start, show_end + 1): if i == self.current_page: li_tag = \'<li class="active"><a href="{0}?page={1}">{1}</a></li>\'.format(self.base_url, i) else: li_tag = \'<li><a href="{0}?page={1}">{1}</a></li>\'.format(self.base_url, i) page_html_list.append(li_tag) # 加下一页 if self.current_page == self.total_page: next_li = \'<li><a href="#">下一页</a></li>\' else: next_li = \'<li><a href="{0}?page={1}">下一页</a></li>\'.format(self.base_url, self.current_page + 1) page_html_list.append(next_li) # 加尾页 page_end_li = \'<li><a href="{0}?page={1}">尾页</a></li>\'.format(self.base_url, self.total_page) page_html_list.append(page_end_li) return "".join(page_html_list)
def user_list(request): pager = Pagination(request.GET.get("page"), len(data), request.path_info) user_list = data[pager.start:pager.end] page_html = pager.page_html() return render(request, "user_list.html", {"user_list": user_list, "page_html": page_html})
Django内置分页
from django.shortcuts import render from django.core.paginator import Paginator, EmptyPage, PageNotAnInteger L = [] for i in range(999): L.append(i) def index(request): current_page = request.GET.get(\'p\') paginator = Paginator(L, 10) #javaWeb核心技术第十二篇之分页和条件