使用urllib2的Python表单POST（也是有关保存/使用Cookie的问题）

Question

我正在尝试编写一个函数来发布表单数据并将返回的cookie信息保存在文件中，以便下次访问该页面时，该cookie信息被发送到服务器（即正常的浏览器行为）。

我使用curlib在C ++中相对容易地编写了此代码，但是花了整整一天的时间尝试使用urllib2在Python中编写此代码-仍然没有成功。

这是我到目前为止所拥有的：

import urllib, urllib2
import logging

# the path and filename to save your cookies in
COOKIEFILE = 'cookies.lwp'

cj = None
ClientCookie = None
cookielib = None


logger = logging.getLogger(__name__)

# Let's see if cookielib is available
try:
    import cookielib
except ImportError:
    logger.debug('importing cookielib failed. Trying ClientCookie')
    try:
        import ClientCookie
    except ImportError:
        logger.debug('ClientCookie isn\'t available either')
        urlopen = urllib2.urlopen
        Request = urllib2.Request
    else:
        logger.debug('imported ClientCookie succesfully')
        urlopen = ClientCookie.urlopen
        Request = ClientCookie.Request
        cj = ClientCookie.LWPCookieJar()

else:
    logger.debug('Successfully imported cookielib')
    urlopen = urllib2.urlopen
    Request = urllib2.Request

    # This is a subclass of FileCookieJar
    # that has useful load and save methods
    cj = cookielib.LWPCookieJar()


login_params = {'name': 'anon', 'password': 'pass' }

def login(theurl, login_params):
  init_cookies();

  data = urllib.urlencode(login_params)
  txheaders =  {'User-agent' : 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)'}

  try:
    # create a request object
    req = Request(theurl, data, txheaders)

    # and open it to return a handle on the url
    handle = urlopen(req)

  except IOError, e:
    log.debug('Failed to open "%s".' % theurl)
    if hasattr(e, 'code'):
      log.debug('Failed with error code - %s.' % e.code)
    elif hasattr(e, 'reason'):
      log.debug("The error object has the following 'reason' attribute :"+e.reason)
      sys.exit()

  else:

    if cj is None:
      log.debug('We don\'t have a cookie library available - sorry.')
    else:
      print 'These are the cookies we have received so far :'
      for index, cookie in enumerate(cj):
        print index, '  :  ', cookie

      # save the cookies again  
      cj.save(COOKIEFILE)

      #return the data
      return handle.read()



# FIXME: I need to fix this so that it takes into account any cookie data we may have stored
  def get_page(*args, **query):
    if len(args) != 1:
        raise ValueError(
            "post_page() takes exactly 1 argument (%d given)" % len(args)
        )
    url = args[0]
    query = urllib.urlencode(list(query.iteritems()))
    if not url.endswith('/') and query:
        url += '/'
    if query:
        url += "?" + query
    resource = urllib.urlopen(url)
    logger.debug('GET url "%s" => "%s", code %d' % (url,
                                                    resource.url,
                                                    resource.code))
    return resource.read()

当我尝试登录时，我传递了正确的用户名和密码。但是登录失败，并且没有保存cookie数据。

我的两个问题是：

• 谁能看到login（）函数出了什么问题，我该如何解决？
• 我如何修改get_page（）函数以利用我保存的任何cookie信息？

Answer 1

您发布的代码有很多问题。通常，您需要构建一个可以处理重定向，https等的自定义打开器，否则会遇到麻烦。至于cookie本身，您需要在上调用load和save方法cookiejar，并使用子类之一，例如MozillaCookieJar或LWPCookieJar。

这是我写的用于登录Facebook的课程，当时我在玩愚蠢的网络游戏。我刚刚对其进行了修改，以使用基于文件的cookiejar，而不是内存中的cookiejar。

import cookielib
import os
import urllib
import urllib2

# set these to whatever your fb account is
fb_username = "[e-mail]"
fb_password = "secretpassword"

cookie_filename = "facebook.cookies"

class WebGamePlayer(object):

    def __init__(self, login, password):
        """ Start up... """
        self.login = login
        self.password = password

        self.cj = cookielib.MozillaCookieJar(cookie_filename)
        if os.access(cookie_filename, os.F_OK):
            self.cj.load()
        self.opener = urllib2.build_opener(
            urllib2.HTTPRedirectHandler(),
            urllib2.HTTPHandler(debuglevel=0),
            urllib2.HTTPSHandler(debuglevel=0),
            urllib2.HTTPCookieProcessor(self.cj)
        )
        self.opener.addheaders = [
            ('User-agent', ('Mozilla/4.0 (compatible; MSIE 6.0; '
                           'Windows NT 5.2; .NET CLR 1.1.4322)'))
        ]

        # need this twice - once to set cookies, once to log in...
        self.loginToFacebook()
        self.loginToFacebook()

        self.cj.save()

    def loginToFacebook(self):
        """
        Handle login. This should populate our cookie jar.
        """
        login_data = urllib.urlencode({
            'email' : self.login,
            'pass' : self.password,
        })
        response = self.opener.open("https://login.facebook.com/login.php", login_data)
        return ''.join(response.readlines())

test = WebGamePlayer(fb_username, fb_password)

设置用户名和密码后，您应该会看到一个文件facebook.cookies，其中包含您的Cookie。实际上，您可能需要对其进行修改，以检查是否有活动的cookie并使用它，如果访问被拒绝，请再次登录。