Python中的分页管理

#utils文件夹下的page.py文件

class PagerHelper:
    #total_count总的页数，current_page当前页数，base_url页面用来分页显示的URL如http://127.0.0.1:8000/classes.html/?p=71
    #base_url为/calsses.html per_page每一页有多少条数据
    def __init__(self,total_count,current_page,base_url,per_page=10):
        self.total_count = total_count
        self.current_page = current_page
        self.base_url = base_url
        self.per_page = per_page

    @property
    def db_start(self):
        return (self.current_page -1) * self.per_page

    @property
    def db_end(self):
        return self.current_page * self.per_page
    #返回总的页数
    def total_page(self):
        v, a = divmod(self.total_count, self.per_page)
        if a != 0:
            v += 1
        return v
    #返回页码的HTML，默认是11页显示，小于11页时1-总页数，
    #当前页小于6页时总显示1-11页，当前页加5(最后一页大于总页数时)显示（总页数-11，总页数）
    def pager_str(self):

        v = self.total_page()

        pager_list = []
        if self.current_page == 1:
            pager_list.append(‘<a href="javascript:void(0);">上一页</a>‘)
        else:
            pager_list.append(‘<a href="%s?p=%s">上一页</a>‘ % (self.base_url, self.current_page - 1,))

        # 6，1:12
        # 7，2:13
        if v <= 11:
            pager_range_start = 1
            pager_range_end = v
        else:
            if self.current_page < 6:
                pager_range_start = 1
                pager_range_end = 11 + 1
            else:
                pager_range_start = self.current_page - 5
                pager_range_end = self.current_page + 5 + 1
                if pager_range_end > v:
                    pager_range_start = v - 10
                    pager_range_end = v + 1

        for i in range(pager_range_start, pager_range_end):
            if i == self.current_page:
                pager_list.append(‘<a class="active" href="%s?p=%s">%s</a>‘ % (self.base_url, i, i,))
            else:
                pager_list.append(‘<a href="%s?p=%s">%s</a>‘ % (self.base_url, i, i,))

        if self.current_page == v:
            pager_list.append(‘<a href="javascript:void(0);">下一页</a>‘)
        else:
            pager_list.append(‘<a href="%s?p=%s">下一页</a>‘ % (self.base_url, self.current_page + 1,))

        pager = "".join(pager_list)
        return pager

#获取数据
total_count = 总的页数
current_page = 当前页数
 ‘/classes.html‘ --> 当前分页的url
5 每一页显示数据，默认是10

######
from utils.page import PagerHelper
        obj = PagerHelper(total_count, current_page, ‘/classes.html‘,5)
        pager = obj.pager_str()

        cls_list = models.Classes.objects.all()[obj.db_start:obj.db_end]

       # current_user = request.session.get(‘username‘)
        return render(request,
                      ‘classes.html‘,
                      {‘username‘: current_user, ‘cls_list‘: cls_list, ‘str_pager‘: pager})