Python - 从Google快讯Feed中获取重定向的链接网址

时间:2014-10-14 10:23:32

标签: python rss google-alerts

如果您将Google提醒创建为rss提要(不是自动发送到您的电子邮件地址),则其中包含以下链接:https://www.google.com/url?rct=j&sa=t&url=http://www.statesmanjournal.com/story/opinion/readers/2014/10/13/gmo-labels-encourage-people-make-choices/17171289/&ct=ga&cd=CAIyGjkyZjE1NGUzMGIwZjRkNGQ6Y29tOmVuOlVT&usg=AFQjCNHrCLmbml7baTXaqySagcuKHp-KHA

这个链接显然是一个重定向(只是尝试它,你最终会在这里:http://www.statesmanjournal.com/story/opinion/readers/2014/10/13/gmo-labels-encourage-people-make-choices/17171289/),但我不能用Python得到这个最终的URL(除了删除url的开头,这是非常难看。

到目前为止,我已尝试使用包urllib2,httplib2和requests:

    来自返回值的
  • urllib2.urlopen和geturl()
  • httplib2请求,其中follow_all_redirects = True,返回值为“content-location”
  • 来自返回值的request.get和历史记录

有人已经遇到过这个问题吗? 谢谢!

1 个答案:

答案 0 :(得分:2)

Google 为您提供HTTP重定向;返回200 OK响应,而不是30x重定向:

>>> import requests
>>> url = 'https://www.google.com/url?rct=j&sa=t&url=http://www.statesmanjournal.com/story/opinion/readers/2014/10/13/gmo-labels-encourage-people-make-choices/17171289/&ct=ga&cd=CAIyGjkyZjE1NGUzMGIwZjRkNGQ6Y29tOmVuOlVT&usg=AFQjCNHrCLmbml7baTXaqySagcuKHp-KHA'
>>> response = requests.get(url)
>>> response.url
u'https://www.google.com/url?rct=j&sa=t&url=http://www.statesmanjournal.com/story/opinion/readers/2014/10/13/gmo-labels-encourage-people-make-choices/17171289/&ct=ga&cd=CAIyGjkyZjE1NGUzMGIwZjRkNGQ6Y29tOmVuOlVT&usg=AFQjCNHrCLmbml7baTXaqySagcuKHp-KHA'
>>> response.text
u'<script>window.googleJavaScriptRedirect=1</script><script>var m={navigateTo:function(b,a,d){if(b!=a&&b.google){if(b.google.r){b.google.r=0;b.location.href=d;a.location.replace("about:blank");}}else{a.location.replace(d);}}};m.navigateTo(window.parent,window,"http://www.statesmanjournal.com/story/opinion/readers/2014/10/13/gmo-labels-encourage-people-make-choices/17171289/");\n</script><noscript><META http-equiv="refresh" content="0;URL=\'http://www.statesmanjournal.com/story/opinion/readers/2014/10/13/gmo-labels-encourage-people-make-choices/17171289/\'"></noscript>'

响应是一段HTML和JavaScript,您的浏览器会将其解释为加载新网址。您必须解析该响应以提取目标。

字符串拆分可以实现:

>>> response.text.partition("URL='")[-1].rpartition("'\"")[0]
u'http://www.statesmanjournal.com/story/opinion/readers/2014/10/13/gmo-labels-encourage-people-make-choices/17171289/'

如果我们假设正文中的URL参数只是查询字符串中url参数的直接反映,那么您也可以从那里提取它,而我们不会甚至不得不要求Google执行重定向:

try:
    from urllib.parse import parse_qs, urlsplit
except ImportError:
    # Python 2
    from urlparse import parse_qs, urlsplit

target = parse_qs(urlsplit(url).query)['url'][0]