django自定义分页器

"""
自定义分页组件的使用方法：

views.py
    # 模拟数据
    HOST_LIST = models.Host.objects.all()
    pager_obj = Pagination(request.GET.get('page',1),len(HOST_LIST),request.path_info,request.GET)
    host_list = HOST_LIST[pager_obj.start:pager_obj.end]
    html = pager_obj.page_html()
    return render(request,'hosts.html',{'host_list':host_list,"page_html":html})

templates
    {{ page_html|safe }}

"""

class Pagination(object):
    """
    自定义分页
    """
    def __init__(self,current_page,total_count,base_url,params,per_page_count=10,max_pager_count=11):
        """
        初始化分页组件
        :param current_page: 当前页
        :param total_count: 共多少条数据
        :param base_url: 基本路径（不带参数）
        :param params: 分页前的其他查询条件参数
        :param per_page_count: 每条多少条
        :param max_pager_count: 导航条内显示多少个页码
        """
        try:
            current_page = int(current_page)
        except Exception as e:
            current_page = 1
        if current_page <=0:
            current_page = 1
        self.current_page = current_page
        # 数据总条数
        self.total_count = total_count

        # 每页显示10条数据
        self.per_page_count = per_page_count

        # 页面上应该显示的最大页码
        max_page_num, div = divmod(total_count, per_page_count)
        if div:
            max_page_num += 1
        self.max_page_num = max_page_num

        # 页面上默认显示11个页面（当前页在中间）
        self.max_pager_count = max_pager_count
        self.half_max_pager_count = int((max_pager_count - 1) / 2)

        # URL前缀
        self.base_url = base_url

        # request.GET
        import copy
        params = copy.deepcopy(params)
        params._mutable = True
        # 包含当前列表页面所有的搜索条件
        # {source:[2,], status:[2], gender:[2],consultant:[1],page:[1]}
        # self.params[page] = 8
        # self.params.urlencode()
        # source=2&status=2&gender=2&consultant=1&page=8
        # href="/hosts/?source=2&status=2&gender=2&consultant=1&page=8"
        # href="%s?%s" %(self.base_url,self.params.urlencode())
        self.params = params

    @property
    def start(self):
        return (self.current_page - 1) * self.per_page_count

    @property
    def end(self):
        return self.current_page * self.per_page_count

    def page_html(self):
        # 如果总页数 <= 11
        if self.max_page_num <= self.max_pager_count:
            pager_start = 1
            pager_end = self.max_page_num
        # 如果总页数 > 11
        else:
            # 如果当前页 <= 5
            if self.current_page <= self.half_max_pager_count:
                pager_start = 1
                pager_end = self.max_pager_count
            else:
                # 当前页 + 5 > 总页码
                if (self.current_page + self.half_max_pager_count) > self.max_page_num:
                    pager_end = self.max_page_num
                    pager_start = self.max_page_num - self.max_pager_count + 1
                else:
                    pager_start = self.current_page - self.half_max_pager_count
                    pager_end = self.current_page + self.half_max_pager_count

        page_html_list = []
        page_html_list.append('
')
        page_html_list.append('
')
        # {source:[2,], status:[2], gender:[2],consultant:[1],page:[1]}

        # 首页
        self.params['page'] = 1
        first_page = '
首页
' % (self.base_url,self.params.urlencode(),)
        page_html_list.append(first_page)

        # 上一页
        if self.current_page == 1:
            self.params['page'] = 1
            prev_page = '
«
'
        else:
            self.params['page'] = self.current_page - 1
            prev_page = '
«
' % (self.base_url, self.params.urlencode(),)
        page_html_list.append(prev_page)


        for i in range(pager_start, pager_end + 1):
            self.params['page'] = i
            if i == self.current_page:
                temp = '
%s
' % (self.base_url,self.params.urlencode(), i,)
            else:
                temp = '
%s
' % (self.base_url,self.params.urlencode(), i,)
            page_html_list.append(temp)

        # 下一页
        if self.current_page == self.max_page_num:
            self.params['page'] = self.max_page_num
            prev_page = '
»
'
        else:
            self.params['page'] = self.current_page + 1
            prev_page = '
»
' % (
            self.base_url, self.params.urlencode(),)
        page_html_list.append(prev_page)

        # 尾页
        self.params['page'] = self.max_page_num
        last_page = '
尾页
' % (self.base_url, self.params.urlencode(),)
        page_html_list.append(last_page)

        page_html_list.append('
')
        page_html_list.append('
')
        return ''.join(page_html_list)