分页

class Pagination(object):
    def __init__(self,totalCount,currentPage,perPageItemNum=10,maxPageNum=7):
        # 数据总个数
        self.total_count = totalCount
        # 当前页
        try:
            v = int(currentPage)
            if v <= 0:
               v = 1
            self.current_page = v
        except Exception as e:
            self.current_page = 1
        # 每页显示的行数
        self.per_page_item_num = perPageItemNum
        # 最多显示页面
        self.max_page_num = maxPageNum

    def start(self):
        return (self.current_page-1) * self.per_page_item_num

    def end(self):
        return self.current_page * self.per_page_item_num
    @property
    def num_pages(self):
        """
        总页数
        :return:
        """
        # 666
        # 10
        a,b = divmod(self.total_count,self.per_page_item_num)
        if b == 0:
            return a
        return a+1

    def pager_num_range(self):
        # self.num_pages()
        # self.num_pages
        # 当前页
        #self.current_page
        # 最多显示的页码数量 11
        #self.per_pager_num
        # 总页数
        # self.num_pages
        if self.num_pages < self.max_page_num:
            return range(1,self.num_pages+1)
        # 总页数特别多 5
        part = int(self.max_page_num/2)
        if self.current_page <= part:
            return range(1,self.max_page_num+1)
        if (self.current_page + part) > self.num_pages:
            return range(self.num_pages-self.max_page_num+1,self.num_pages+1)
        return range(self.current_page-part,self.current_page+part+1)

    def page_str(self):
        page_list = []

        first = "<li><a href='/index2.html?p=1'>首页</a></li>"
        page_list.append(first)

        if self.current_page == 1:
            prev = "<li><a href='#'>上一页</a></li>"
        else:
            prev = "<li><a href='/index2.html?p=%s'>上一页</a></li>" %(self.current_page-1,)
        page_list.append(prev)
        for i in self.pager_num_range():
            if i == self.current_page:
                temp = "<li class='active'><a href='/index2.html?p=%s'>%s</a></li>" %(i,i)
            else:
                temp = "<li><a href='/index2.html?p=%s'>%s</a></li>" % (i, i)
            page_list.append(temp)

        if self.current_page == self.num_pages:
            nex = "<li><a href='#'>下一页</a></li>"
        else:
            nex = "<li><a href='/index2.html?p=%s'>下一页</a></li>" % (self.current_page + 1,)
        page_list.append(nex)

        last = "<li><a href='/index2.html?p=%s'>尾页</a></li>" %(self.num_pages,)
        page_list.append(last)

        return ''.join(page_list)