urllib.request.urlretrieve用法

'''
　　urllib.request.urltrieve(url,filename=None,reporthook=None,data=None)
　　url:远程服务器地址（即需要获取数据的地址）
　　filename:将远程获取的数据存放入的文件名
'''
import urllib.request
def callback(blocknum, blocksize, totalsize):
    '''
    :param blocknum: 已下载数据块
    :param blocksize: 数据块大小
    :param totalsize: 远程文件大小
    :return:
    '''
    percent = 100.0*blocknum*blocksize/totalsize
    if(percent>100):
        percent = 100
    print('%.2f%%' % percent)

url = 'http://www.sina.com.cn'
local = 'f:\sina.html'
a,b = urllib.request.urlretrieve(url, local, callback) #从远程下载数据
print(a)
print(b)

#输出结果
0.00%
1.39%

...

88.90%
94.46%
95.84%
97.23%
98.62%
100.00%
#输出a
f:sina.html
#输出b
Server: nginx
Date: Fri, 08 Jun 2018 02:50:40 GMT
Content-Type: text/html
Content-Length: 589755
Connection: close
Last-Modified: Fri, 08 Jun 2018 02:50:01 GMT
Vary: Accept-Encoding
X-Powered-By: shci_v1.03
Expires: Fri, 08 Jun 2018 02:51:22 GMT
Cache-Control: max-age=60
Age: 18
Via: http/1.1 cnc.guangzhou.ha2ts4.59 (ApacheTrafficServer/6.2.1 [cHs f ])
X-Cache: HIT.59
X-Via-CDN: f=edge,s=cnc.guangzhou.ha2ts4.60.nb.sinaedge.com,c=42.49.109.219;f=Edge,s=cnc.guangzhou.ha2ts4.59,c=112.90.6.60
X-Via-Edge: 1528426240834db6d312aee065a707941b2ee