本文介绍python调用api的几种方式
1.urllib2

def run(self):
		username, password = getword()
		try:
			print "-"*12
			print "User:",username,"Password:",password
			req = urllib2.Request(sys.argv[1])
			passman = urllib2.HTTPPasswordMgrWithDefaultRealm()
			passman.add_password(None, sys.argv[1], username, password)
			authhandler = urllib2.HTTPBasicAuthHandler(passman)
			opener = urllib2.build_opener(authhandler)
			fd = opener.open(req)
			print "\t\n\nUsername:",username,"Password:",password,"----- Login successful!!!\n\n"			
			print "Retrieved", fd.geturl()
			info = fd.info()
			for key, value in info.items():
    				print "%s = %s" % (key, value)
			sys.exit(2)
		 except (urllib2.HTTPError, httplib.BadStatusLine,socket.error), msg: 
			print "An error occurred:", msg
			pass

2 urllib

def dorequest(url, data = "", method = 'GET'):
    try: 
        if method == 'GET':
            response = urllib.request.urlopen(url, timeout=10).read()
        else:
            # use PUT/DELETE/POST, data should be encoded in ascii/bytes 
            request = urllib.request.Request(url, data = data.encode('ascii'), method = method)
            response = urllib.request.urlopen(request, timeout=10).read()
    # etcd may return json result with response http error code
    # http error code will raise exception in urlopen
    # catch the HTTPError and get the json result
    except urllib.error.HTTPError as e:
        # e.fp must be read() in this except block.
        # the e will be deleted and e.fp will be closed after this block
        response = e.fp.read()
    # response is encoded in bytes. 
    # recoded in utf-8 and loaded in json
    result = json.loads(str(response, encoding='utf-8'))
    return result


# client to use etcd
# not all APIs are implemented below. just implement what we want

3.pycurl

def put (url, data, headers={}):
    """Make a PUT request to the url, using data in the message body,
    with the additional headers, if any"""

    reply = -1 # default, non-http response

    curl = pycurl.Curl()
    curl.setopt(pycurl.URL, url)
    if len(headers) > 0:
        curl.setopt(pycurl.HTTPHEADER, [k+': '+v for k,v in headers.items()])
    curl.setopt(pycurl.PUT, 1)
    curl.setopt(pycurl.INFILESIZE, len(data))
    databuffer = StringIO(data)
    curl.setopt(pycurl.READFUNCTION, databuffer.read)
    try:
        curl.perform()
        reply = curl.getinfo(pycurl.HTTP_CODE)
    except Exception:
        pass
    curl.close()

    return reply

4.requests

import requests
>>> r = requests.get('https://api.github.com/user', auth=('user', 'pass'))
>>> r.status_code
200
>>> r.headers['content-type']
'application/json; charset=utf8'
>>> r.encoding
'utf-8'
>>> r.text
u'{"type":"User"...'
>>> r.json()
{u'private_gists': 419, u'total_private_repos': 77, ...}