(obj)
return type(obj) is str and obj == SENTINEL
Predicate to determine whether an item from the queue is the
    signal to stop
Predicate to determine whether an item from the queue is the
    signal to stop
Predicate to determine whether an item from the queue is the signal to stop
def is_sentinel(obj):
    """Predicate to determine whether an item from the queue is the
    signal to stop"""
    return type(obj) is str and obj == SENTINEL
def is_sentinel ( obj ) : return type ( obj ) is str and obj == SENTINEL