def scan():
    # Again, split() is too high-level for this style, but using
    # it for doing this fast and short. Left as exercise.
    stack.extend(stack.pop()[0].split())
Filter from list of routers the ones that are not scheduled.
dataset/ETHPy150Open crista/exercises-in-programming-style/02-go-forth/tf-02.py/scan--crossover with--dataset/ETHPy150Open openstack/neutron/neutron/scheduler/l3_agent_scheduler.py/L3Scheduler._filter_unscheduled_routers