Question

我正在使用urllib2与发回多个Set-Cookie标头的网站进行交互。但是响应头字典只包含一个 - 似乎重复键相互重叠。

有没有办法用urllib2访问重复的标题？

Answer 1

根据urllib2 docs，结果网址对象的.headers属性为httplib.HTTPMessage（似乎未记录，至少在Python文档中）。

然而，

help(httplib.HTTPMessage)
...

If multiple header fields with the same name occur, they are combined
according to the rules in RFC 2616 sec 4.2:

Appending each subsequent field-value to the first, each separated
by a comma. The order in which header fields with the same field-name
are received is significant to the interpretation of the combined
field value.

因此，如果您访问u.headers ['Set-Cookie']，您应该获得一个Set-Cookie标头，其值以逗号分隔。

事实上，情况确实如此。

import httplib
from StringIO import StringIO

msg = \
"""Set-Cookie: Foo
Set-Cookie: Bar
Set-Cookie: Baz

This is the message"""

msg = StringIO(msg)

msg = httplib.HTTPMessage(msg)

assert msg['Set-Cookie'] == 'Foo, Bar, Baz'

Answer 2

set-cookie虽然不同。来自RFC 6265：

原始服务器不应该将多个Set-Cookie头字段折叠成单个标题字段。折叠HTTP标头的常用机制字段（即[RFC2616]中定义的）可能会改变语义 Set-Cookie标头字段，因为使用了％x2C（＆＃34;，＆＃34;）字符通过Set-Cookie以与这种折叠相冲突的方式。

理论上，这看起来像个错误。

urllib2多个Set-Cookie标头作为响应

2 个答案: