为什么python爬百度贴吧没有照片呢

import urllib
import urllib.request
from lxml import etree

class Spider(object):
def init(self):
self.tiebaName="java"
self.beginPage=1
self.endPage=3
self.url="http://tieba.baidu.com/f?%22
self.ua_header = {"User-Agent" : "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1 Trident/5.0;"}
self.fileName=1

# 构造url
def tiebaSpider(self):
    for page in range(self.beginPage,self.endPage+1):
        pn=(page-1)*50
        wo={'pn':pn,'kw':self.tiebaName}
        word=urllib.parse.urlencode(wo)
        myurl=self.url+word
        self.loadPage(myurl)

#爬取页面内容
def loadPage(self,url):
    req=urllib.request.Request(url,headers=self.ua_header)
    data=urllib.request.urlopen(req).read()

    html=etree.HTML(data)
    links=html.xpath('//div[@class="threadlist_lz clearfix"]/div/a/@href')

    for link in links:
        link="http://tieba.baidu.com"+link
        self.loadImages(link)
        

#爬取帖子详情页，获得图片的链接
def loadImages(self,link):
    req=urllib.request.Request(link,headers=self.ua_header)
    data=urllib.request.urlopen(req).read()
    html=etree.HTML(data)
    links=html.xpath('//img[@class="BDE_Image"]/@src')
    for imageslink in links:
        self.writeImages(imageslink)


#通过图片所在链接，爬取图片并保存图片到本地：
def writeImages(self,imagesLink):
    print("正在存储图片：",self.fileName,"....")

    image=urllib.request.urlopen(imagesLink).read()

    #保存图片到本地
    file=open(r"C:\Users\Myself\Desktop\image\\"+str(self.fileName)+".jpg","wb")
    file.write(image)

    file.close()

    self.fileName+=1

if name == 'main':

mySpider=Spider()

mySpider.tiebaSpider()

links=html.xpath('//div[@class="threadlist_lz clearfix"]/div/a/@href')

这句有问题，xpath定位错误 尝试去掉clearfix
或者直接 links=html.xpath('//a/@href')