import copy

class Pagination:

    def __init__(self, current_page_num, all_count, request, per_page_num=10, page_count=11):

        """

        封装分页相关数据

        :param current_page_num: 当前页码数

        :param all_count: 数据库中总数据条数

        :param per_page_num: 每页显示的数据量

        :param page_count: 最大显示页数

        """

        try:

            current_page = int(current_page_num)

        except Exception as e:

            current_page = 1

        # 页码数小于1时显示第一页

        if current_page < 1:

            current_page = 1

        # 取总页码数

        self.all_page_count, temp = divmod(all_count, per_page_num)

        if temp:

            self.all_page_count += 1

        # 页码数大于最大页码数时显示最后一页

        if current_page > self.all_page_count:

            current_page = self.all_page_count

        self.current_page = current_page

        self.per_page_num = per_page_num

        self.half_page_count = int((page_count - 1) / 2)

        # 总页码数小于最大页码数

        if self.all_page_count < page_count:

            self.start_page = 1

            self.end_page = self.all_page_count + 1

        else:

            if self.current_page < self.half_page_count:

                # 当页码条数据靠近最左边时

                self.start_page = 1

                self.end_page = page_count + 1

            elif self.all_page_count - self.current_page < self.half_page_count:

                # 当页码条数据靠近最右边时

                self.start_page = self.all_page_count - page_count + 1

                self.end_page = self.all_page_count + 1

            else:

                # 页码条正常显示在中间位置

                self.start_page = self.current_page - self.half_page_count

                self.end_page = self.current_page + self.half_page_count + 1

        # 获取get参数: <QueryDict:{key: value}>

        params = request.GET

        # 不进行deepcopy将无法改变其里面的值

        self.new_params = copy.deepcopy(params)

    @property

    def start(self):

        return (int(self.current_page - 1)) * self.per_page_num

    @property

    def end(self):

        return int(self.current_page) * self.per_page_num

    def show_html(self):

        html_list = []

        if self.current_page == 1:

            first_page = '<li class="disabled"><a>{0}</a></li>'.format('首页')

        else:

            # 将page传入new-params中

            self.new_params['page'] = 1

            # 对new_params进行urlencode格式化: 'key=value&key2=value2&page=1'

            first_page = '<li><a href="?{0}">{1}</a></li>'.format(self.new_params.urlencode(), '首页')

        # 将"首页"html代码加入html_list中

        html_list.append(first_page)

        if self.current_page == 1:

            prev_page = '<li class="disabled"><a>{0}</a></li>'.format('&laquo;')

        else:

            self.new_params['page'] = self.current_page - 1

            prev_page = '<li><a href="?{0}">{1}</a></li>'.format(self.new_params.urlencode(), '&laquo;')

        # 将"上一页"html代码加入html_list中

        html_list.append(prev_page)

        for i in range(self.start_page, self.end_page):

            if self.current_page == i:

                page_bar = '<li class="active"><a>{0}</a></li>'.format(i)

            else:

                self.new_params['page'] = i

                page_bar = '<li><a href="?{0}">{1}</a></li>'.format(self.new_params.urlencode(), i)

            # 将"每一页"html代码加入html_list中

            html_list.append(page_bar)

        if self.current_page == self.all_page_count:

            next_page = '<li class="disabled"><a>{0}</a></li>'.format('&raquo;')

        else:

            self.new_params['page'] = self.current_page + 1

            next_page = '<li><a href="?{0}">{1}</a></li>'.format(self.new_params.urlencode(), '&raquo;')

        # 将"下一页"html代码加入html_list中

        html_list.append(next_page)

        if self.current_page == self.all_page_count:

            last_page = '<li class="disabled"><a>{0}</a></li>'.format('尾页')

        else:

            self.new_params['page'] = self.all_page_count

            last_page = '<li><a href="?{0}">{1}</a></li>'.format(self.new_params.urlencode(), '尾页')

        # 将"尾页"html代码加入到html_list中

        html_list.append(last_page)

        return ''.join(html_list)

class CustomerView(View):

    def get(self, request):

        customer_list = Customer.objects.all()

        page = request.GET.get('page')

        # 实例化pagination对象

        pagination = Pagination(page, customer_list.count(), request, per_page_num=1)

        # 对数据列表进行分页

        customer_list = customer_list[pagination.start:pagination.end]

        context = {

            'customer_list': customer_list,

            'page_html': pagination.show_html()

        }

        return render(request, 'customer_list.html', context)

    def post(self, request):

        pass

<nav aria-label="Page navigation" class="pull-right">

    <ul class="pagination">

        {{ page_html|safe }}

     </ul>

</nav>