从Python文档：
import urllib.requestreq = urllib.request.Request( url, data=None, headers={ 'User-Agent': 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/35.0.1916.47 Safari/537.36' })f = urllib.request.urlopen(req)print(f.read().depre('utf-8'))
