Python3.9通过xpath获取中关村网站平板电脑所有字段

首先，需要使用Python的第三方库requests和lxml来获取和解析中关村网站的页面。具体代码如下：

import requests
from lxml import etree

url = "http://detail.zol.com.cn/tablepc/"
headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36"
}
response = requests.get(url, headers=headers)
response.encoding = "utf-8"
html = etree.HTML(response.text)

接下来，使用xpath来获取平板电脑的所有字段。可以先使用浏览器的开发者工具来查看网页源代码和元素的路径。例如，中关村网站平板电脑的名称、价格和链接分别对应以下xpath表达式：

name_xpath = '//*[@id="J_PicMode"]/li/div/a/h3/text()'
price_xpath = '//*[@id="J_PicMode"]/li/div/div[2]/span[1]/b/text()'
link_xpath = '//*[@id="J_PicMode"]/li/div/a/@href'

使用xpath的`xpath()`方法即可获取对应的元素。具体代码如下：

names = html.xpath(name_xpath)
prices = html.xpath(price_xpath)
links = html.xpath(link_xpath)

最后，可以将这些字段放到一个列表中，以便后续处理。完整代码如下：

import requests
from lxml import etree

url = "http://detail.zol.com.cn/tablepc/"
headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36"
}
response = requests.get(url, headers=headers)
response.encoding = "utf-8"
html = etree.HTML(response.text)

name_xpath = '//*[@id="J_PicMode"]/li/div/a/h3/text()'
price_xpath = '//*[@id="J_PicMode"]/li/div/div[2]/span[1]/b/text()'
link_xpath = '//*[@id="J_PicMode"]/li/div/a/@href'

names = html.xpath(name_xpath)
prices = html.xpath(price_xpath)
links = html.xpath(link_xpath)

data = []
for i in range(len(names)):
    item = {}
    item["name"] = names[i]
    item["price"] = prices[i]
    item["link"] = links[i]
    data.append(item)

print(data)