from typing import NamedTuple
import requests
from lxml import html


class Main(NamedTuple):
    """ 信息格式 """
    name: str
    price: float
    link: str

    def __str__(self):
        return '价格:{self.price};名称:{self.name};链接:{self.link}'.format(self=self)


class Spider(object):
    """ 爬虫程序体 """
    def __init__(self, goods):
        self.goods = goods
        self.goodslist = []

    def jd(self):
        url = 'https://search.jd.com/Search?keyword={0}'.format(self.goods)
        # 获取HTML文档
        resp = requests.get(url, headers={
            'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36'
        })
        resp.encoding = 'utf-8'
        html_data = resp.text

        # 提取xpath对象
        selector = html.fromstring(html_data)

        # 获取数据列表
        ul_list = selector.xpath('//div[@id="J_goodsList"]/ul/li')

        # 解析对应内容
        n = 0
        for li in ul_list:
            n += 1
            # print('这是第%d条数据' % n)
            try:
                # 获取商品名称
                goods = li.xpath('div/div[@class="p-name p-name-type-2"]/a/em/text()')
                # print(goods)
                goods2 = li.xpath('div/div[@class="p-name p-name-type-2"]/a/em/font[@class="skcolor_ljg"]/text()')
                goods = goods[0] + goods2[0] + goods[1]  # 组合商品名称
                # 获取商品价格
                price = li.xpath('div/div[@class="p-price"]/strong/i/text()')
                # 获取购买链接
                link = li.xpath('div/div[@class="p-name p-name-type-2"]/a/@href')
                link = 'http:' + link[0]  # 链接前加'http:'成为完成的链接
                # print(goods)
                # print(price[0])
                # print(link)
                g_list = Main(
                    name=goods,
                    link=link,
                    price=price[0]
                )
                # print(g_list)
                self.goodslist.append(g_list)
                print(self.goodslist)
            except Exception as e:
                print('There has an Error:', e)

    def info_sorted(self):
        self.jd()

        a_list = sorted(self.goodslist, key=lambda item: float(item.price), reverse=True)
        for goods in a_list:
            # print(a_list)
            pass


if __name__ == '__main__':
    # user_input = str(input('请输入您要查询的内容：'))
    a = Spider('2060')
    a.info_sorted()

输出结果

提问：

老师，代码中我的g_list打印出来的数据是正常的，但是往goodslist添加会重复添加第一条数据，请问是哪里出了问题？