There is no unique solution to that problem since sometime you want consumption, and sometimes not, for one or more of the parameters. __builtins__.zip chose t

There is no unique solution to that problem since sometime you want consumption, and sometimes not, for one or more of the parameters. __builtins__.zip chose to consume iterators in the order they are passed as a parameter, and therefor end up with an assymetric consumption. That's why itertools.tee exists, so that we can chose case by case.