httplib 未获取所有重定向代码

Question

我正在尝试获取似乎多次重定向的页面的最终网址。在浏览器中尝试此示例 URL，并将其与我的代码片段底部的最终 URL 进行比较：

链接多次重定向

这是我正在运行的测试代码，请注意，获得代码 200 的最终 URL 与浏览器中的 URL 不同。我有什么选择？

Python 2.7.1+ (r271:86832, Apr 11 2011, 18:13:53)
[GCC 4.5.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import httplib
>>> from urlparse import urlparse
>>> url = 'http://www.usmc.mil/units/hqmc/'
>>> host = urlparse(url)[1]
>>> req = ''.join(urlparse(url)[2:5])
>>> conn = httplib.HTTPConnection(host)
>>> conn.request('HEAD', req)
>>> resp = conn.getresponse()
>>> print resp.status
    301
>>> print resp.msg.dict['location']
    http://www.marines.mil/units/hqmc/

>>> url = 'http://www.marines.mil/units/hqmc/'
>>> host = urlparse(url)[1]
>>> req = ''.join(urlparse(url)[2:5])
>>> conn = httplib.HTTPConnection(host)
>>> conn.request('HEAD', req)
>>> resp = conn.getresponse()
>>> print resp.status
    302
>>> print resp.msg.dict['location']
    http://www.marines.mil/units/hqmc/default.aspx

>>> url = 'http://www.marines.mil/units/hqmc/default.aspx'
>>> host = urlparse(url)[1]
>>> req = ''.join(urlparse(url)[2:5])
>>> conn = httplib.HTTPConnection(host)
>>> conn.request('HEAD', req)
>>> resp = conn.getresponse()
>>> print resp.status
    200
>>> print resp.msg.dict['location']
    Traceback (most recent call last):
    File "<stdin>", line 1, in <module>
    KeyError: 'location'
>>> print url
    http://www.marines.mil/units/hqmc/default.aspx //THIS URL DOES NOT RETURN A 200 IN ANY BROWSER I HAVE TRIED 

Answer 1

您可以使用 HttpLib2 获取 URL 的实际位置：

import httplib2

def getContentLocation(link):
    h = httplib2.Http(".cache_httplib")
    h.follow_all_redirects = True
    resp = h.request(link, "GET")[0]
    contentLocation = resp['content-location']
    return contentLocation

if __name__ == '__main__':
    link = 'http://podcast.at/podcast_url344476.html'
    print getContentLocation(link)

执行如下所示：

$ python2.7 getContentLocation.py
http://keyinvest.podcaster.de/8uhr30.rss

请注意这一点示例还使用了缓存（urllib 和 httplib 都不支持缓存）。因此，这将显着更快地重复运行。这对于爬行/抓取可能很有趣。如果您不需要缓存，请将 h = httplib2.Http(".cache_httplib") 替换为 h = httplib2.Http()。

Answer 2

您可以尝试将 User-Agent 标头设置为浏览器的 User-Agent。

附：
urllib2 自动重定向

编辑：

In [2]: import urllib2
In [3]: resp = urllib2.urlopen('http://www.usmc.mil/units/hqmc/')
In [4]: resp.geturl()
Out[4]: 'http://www.marines.mil/units/hqmc/default.aspx