According to RFC 2109

"For backward compatibility, the separator in the
Cookie header
is semi-colon (;) everywhere.  A server should also
accept comma (,)
as the separator between cookie-values for future
compatibility."

The Cookie standard module does not support this as it
should.

>>> import Cookie
>>> c=Cookie.SimpleCookie()
>>> c.load('foo=2, bar=3')
>>> print c['foo'].value
2,

Logged In: YES 
user_id=11375

The updated cookie RFC, RFC 2965, also has this language.

Logged In: YES 
user_id=261020

Unfortunately one can't take the cookie specs at face value.

Netscape cookies behaviour (the de-facto standard, ie. IE &
Firefox behaviour -- cookie_spec.html is barely worth the
web page it's written on, being flat-out wrong in several
major ways, and very under-specified) has, I'm told, always
simply been simply "split on semicolons".  Certainly that's
what IE and Mozilla do now:

(this is just the text of a CGI for viewing: I didn't make
it executable on reportlab.org)

http://www.reportlab.org/~jjlee/cookie_demo.py

IIRC RFC 2965 is only implemented by Opera, and is certainly
now quite dead as an internet standard.  (though I think it
is useful as a guide for writing cookie-handling code, you
can't follow blindly - not even close :-( )

Logged In: YES 
user_id=261020

Forgot to add or demo in that CGI script: even

Set-Cookie: abc=def, ghi=jkl

is just one Netscape cookie, name 'abc', value 'def, ghi=jkl'.

Logged In: YES 
user_id=261020

I notice I didn't say explicitly: I think this should be
closed, for the reasons given in my last two comments.

Will close if nobody objects.