In python 3.8 cookiejar.py is full of code that compares cookie.version to integers, which raises as exception when cookie.version is None. For example, in set_ok_version() and set_ok_path(). Both the Cookie constructor and _cookie_from_cookie_tuple() explicitly assume version can be None and setting version to None worked fine in previous pythonreleases.

Can you please add a sample script to reproduce this that worked fine before Python 3.8?

The issue is obvious with a simple glance at the code. Either the Cookie constructor needs to change version = None to zero or some other integer or the various methods in that module need to handle a None version. I dont personally care about this issue any more since I have worked around it in my code, feel free to fix it or not, as you wish.

You specifically mentioned Python 3.8 and I just wanted to understand the issue to see if it's a regression. I don't see any version related code changes in recent times. Hence this is not necessarily a regression in 3.8 unless there is a reproducible script. The code in set_ok_version for cookie.version to be None is not tested hence I assume there are no tests for the reported scenario that would be good to have. I have also changed the issue title accordingly.

It's trivially True that it is a regression from python 2 since in python 2 comparison to None is fine. Whether it ever worked in any python 3 version before 3.8 I'm not sure about.

Here's a trivial script to reproduce:

from urllib.request import Request
from http.cookiejar import Cookie, CookieJar

jar = CookieJar()
jar.set_cookie(Cookie(
            None, 'test', 'test',
            None, False,
            '.test.com', True, False,
            '/', True,
            False, None, False, None, None, None
        ))
r = Request('http://www.test.com')
jar.add_cookie_header(r)

Hi, it looks like this needs a fix - I'll write a patch to fix up the handling and add some more testing to cover this scenario.