python http.client 下载网页

import sys, http.client
showlines = 6
try:
servername, filename = sys.argv[1:] # cmdline args?
except:
servername, filename = 'learning-python.com', '/index.html'

print(servername, filename)
server = http.client.HTTPConnection(servername) # connect to http site/server
server.putrequest('GET', filename) # send request and headers
server.putheader('Accept', 'text/html') # POST requests work here too
server.endheaders() # as do CGI script filenames

reply = server.getresponse() # read reply headers + data
if reply.status != 200: # 200 means success
print('Error sending request', reply.status, reply.reason)
else:
data = reply.readlines() # file obj for data received
reply.close() # show lines with eoln at end
for line in data[:showlines]: # to save, write data to file
print(line) # line already has \n, but bytes