Edit: For the latest CouchDB v2.3.0
In client.py line 284, in the login method, the cookie was set to
if sys.version_info[0] > 2: cookie = headers._headers[0][1] else: cookie = headers.headers[0].split(';')[0]
_headers[0][1] which is not the auth token, but some string as "must-revalidate". the actual token is at _headers[5][1]. So by change that, you will be able to get a correct return from this login method.