爬虫（Xpath）——爬tieba.baidu.com (bug)

import urllib.request
import re
from lxml import etree


class Spider:
    def __init__(self):
        self.headers = {
            "User-Agent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.181 Safari/537.36",
        }

    def loadPage(self, link):
        """
        下载页面
        """
        print("正在下载数据。。。。。。")

        request = urllib.request.Request(link, headers=self.headers)
        html = urllib.request.urlopen(request).read()
        # html = html.decode("utf-8")

        with open("meinvba.txt", "w") as f:
            f.write(str(html))

        # 获取每页的HTML源码字符串
        # html = html.decode("gbk")


        # 解析html文档为HTML DOM类型
        content = etree.HTML(html)
        print(content)
        # 返回所有匹配成功的列表集合
        link_list = content.xpath(‘//div[@class="t_con cleafix"]/div/div/div/a/@href‘)
        print(link_list)
        for i in link_list:
            print("__4__")
            fulllink = "http://tieba.baidu.com" + i
            self.loadImage(fulllink)
        print("___3___")

    # 取出每个帖子的图片链接
    def loadImage(self, link):
        request = urllib.request.Request(link, headers=self.headers)
        html = urllib.request.urlopen(request).read()
        content = etree.HTML(html)
        link_list = content.xpath(‘//img[@class="BDE_Image"]/@src‘)
        print("____1____")
        for link in link_list:
            self.writeImage(link)

    def writeImage(self, link):
        request = urllib.request.Request(link, headers=self.headers)
        image = urllib.request.urlopen(request).read()
        filename = link[-5:]
        print("___2____")
        with open(filename, "wb") as f:
            f.write(image)
        print("*"*30)

    def startWork(self, kw, beginpage, endpage):
        """
        控制爬虫运行

        """
        url = "http://tieba.baidu.com/f?"
        key = urllib.parse.urlencode({"kw": kw})
        print("key:" + key)
        fullurl = url + key
        for page in range(int(beginpage), int(endpage) + 1):
            pn = (page - 1)*50
            fullurl = fullurl + "&pn=" + str(pn)

            self.loadPage(fullurl)
            # print("fullurl:" + fullurl)



if __name__ == "__main__":
    tiebaSpider = Spider()
    kw = input("请输入要爬取的贴吧名：")
    beginpage = input("请输入起始页：")
    endpage = input("请输入结束页：")

    tiebaSpider.startWork(kw, beginpage, endpage)