為什么爬下來(lái)的圖片是原網(wǎng)頁(yè)中按照最熱排序的，而手動(dòng)打開(kāi)原網(wǎng)頁(yè)卻是自動(dòng)按最新排序的

#??Python?3.6.1
#?????????????????????????----By??Wang
import?re
import?urllib.request

req=urllib.request.urlopen('http://idcbgp.cn/course/list')
buf=req.read()
buf=buf.decode('utf-8')
listurl=re.findall(r'src=.+?\.jpg',buf)

i=0
for?url?in?listurl:
??????url=re.search(r'http:.+?\.jpg',url)
??????f=open(str(i)+'.jpg','wb')
??????req=urllib.request.urlopen(url.group())
??????buf=req.read()
??????f.write(buf)
??????f.close()
??????i+=1