#第一种：用urllib2模块下载
import urllib2
link = ' '
headers = { }
request = urllib2.Request(link, headers=headers)
image = urllib2.urlopen(request).read()
filename = link[-5:]
# 注意这里要用wb模式
with open (filename, "wb") as f:
  f.write(image)

#第二种：requests模块下载同理

import os
from urllib.request import urlretrieve
.......
urlretrieve(link, "路径"+"文件名")