Yes, a second function would give more flexibility.

Due to the "approval" in msg166175 to use the name parse_intermixed_args for the functionality described there, it would probably be best to use that name for that functionality.

So then we are left naming your current function something else. parse_known_intermixed_args certainly is descriptive, and fits the naming conventions of the other methods in the class. Quite long, unfortunately... but then I doubt it will get used much. I am using parse_intermixed_args regularly (via my wrapper class), and it is quite long enough.