import urllib
1.用urlib.urlretrieve
f = urllib.urlretrieve('http://www.baidu.com/img/bdlogo.gif','/tmp/logo.gif') ##将文件保存到/tmp/logo.gif，f为返回的元组，f[0]为文件的path,f[1]为实例
2.用urllib.urlopen 大文件迭代写
sourcefile = urllib.urlopen('http://202.108.33.148/soft/OM_6.2.0_ManNode_A00.tar.gz')
tarfile = open('/tmp/OM1.tar.gz','wb')
while True:
pin = sourcefile.read(1024*5)
if len(pin) == 0:
break
tarfile.write(pin)
sourcefile.close()
tarfile.close()