Django 自定义分页类

分页类代码：

class Page(object):
    '''
    自定义分页类
    可以实现Django ORM数据的的分页展示
    输出HTML代码：

    使用说明：
    from utils import mypage
        page_obj = mypage.Page(total_num, current_page, 'publisher_list')
        publisher_list = data[page_obj.data_start:page_obj.data_end]
        page_html = page_obj.page_html()

        为了显示效果，show_page_num最好使用奇数
    '''

    def __init__(self, total_num, current_page, url_prefix, per_page=10, show_page_num=9):
        '''

        :param total_num: 数据总条数
        :param current_page: 当前访问的页码
        :param url_prefix: 分页代码里a标签的前缀
        :param per_page: 每一页显示多少数据
        :param show_page_num: 页面上最多显示多少个页码

        '''
        self.total_num = total_num
        self.url_prefix = url_prefix
        self.per_page = per_page
        self.show_page_num = show_page_num
        # 根据传入的值计算当前页码左右放置多少个页码
        self.half_show_page_num = self.show_page_num // 2
        # 计算当前数据总共需要多少页码
        total_page, more = divmod(self.total_num, self.per_page)
        # 如果有余数就把页码加1
        if more:
            total_page += 1
        self.total_page = total_page
        # 数据有效性校验
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        # 如果当前页码数大于总页码数，默认展示最后一页数据
        if current_page > self.total_page:
            current_page = self.total_page
        # 如果当前页码小于1，默认展示第一页数据
        if current_page < 1:
            current_page = 1
        self.current_page = current_page
        # 计算页面上需要展示的页码范围
        # 页码过小处理
        if self.current_page - self.half_show_page_num <= 1:
            page_start = 1
            page_end = show_page_num
        # 页码过大处理
        elif self.current_page + self.half_show_page_num >= self.total_page:
            page_end = self.total_page
            page_start = self.total_page - self.show_page_num + 1
        # 未超过正常范围
        else:
            page_start = self.current_page - self.half_show_page_num
            page_end = self.current_page + self.half_show_page_num

        # 计算得到的最终页码数
        self.page_start = page_start
        self.page_end = page_end
        # 如果计算得到的页码数比总共需要展示页码数多，则把页码结束指定为总页码数
        if self.page_end > self.total_page:
            self.page_end = self.total_page

    @property
    def data_start(self):
        '''

        :return: 返回当前页面应该从哪里开始切数据
        '''
        return (self.current_page - 1) * self.per_page

    @property
    def data_end(self):
        '''

        :return: 返回当前页面从哪里结束数据
        '''
        return self.current_page * self.per_page

    def page_html(self):
        li_list = []
        # 添加前面的nav和ul标签
        li_list.append("""
        <nav aria-label="Page navigation">
        <ul class="pagination">
        """)
        # 添加首页
        li_list.append('<li><a href="/{}/?page=1">首页</a></li>'.format(self.url_prefix))
        # 添加上一页
        if self.current_page <= 1:  # 没有上一页
            prev_html = '<li class="disabled"><a aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>'
        else:
            prev_html = '<li><a href="/{}/?page={}" aria-label="Previous"><span aria-hidden="true">&laquo;</span></a></li>'.format(
                self.url_prefix,
                self.current_page - 1)
        li_list.append(prev_html)
        # 循环添加内部所有的页码
        for i in range(self.page_start, self.page_end + 1):
            if i == self.current_page:
                tmp = '<li class="active"><a href="/{0}/?page={1}">{1}</a></li>'.format(self.url_prefix, i)
            else:
                tmp = '<li><a href="/{0}/?page={1}">{1}</a></li>'.format(self.url_prefix, i)
            li_list.append(tmp)
        # 添加下一页
        if self.current_page >= self.total_page:  # 表示没有下一页
            next_html = '<li class="disabled"><a aria-label="Previous"><span aria-hidden="true">&raquo;</span></a></li>'
        else:
            next_html = '<li><a href="/{}/?page={}" aria-label="Previous"><span aria-hidden="true">&raquo;</span></a></li>'.format(
                self.url_prefix, self.current_page + 1)
        li_list.append(next_html)
        # 添加尾页
        li_list.append('<li><a href="/{}/?page={}">尾页</a></li>'.format(self.url_prefix, self.total_page))
        # 添加结尾nav和ul标签
        li_list.append("""
        </ul>
        </nav>
        """)
        # 将生成的标签拼接成一个大字符串
        page_html = ''.join(li_list)
        return page_html

导入文件后调用代码：

# 获取分页所需数据
total_num = data.count() # 获取数据总计条数
current_page = request.GET.get('page') # 获取当前页页码
url_prefix = request.path_info.strip('/') # 获取a标签所需参数

# 调用分页类
# 调用类传入参数生成实例
page_obj = mypage.Page(total_num, current_page, url_prefix, per_page=1)
# 按照分页所需数据对总数据进行分割获取当前页面所需展示的数据
data = data[page_obj.data_start:page_obj.data_end]
# 获取HTML代码
page_html = page_obj.page_html()