closures.py

def make_averager():
    count = 0
    total = 0
    def averager(new_value):
        # nonlocal count, total # doesn't work
        # global count, total
        count = count + 1
        total = total + new_value
        print(total/count)
        return total/count
    return averager
averager = make_averager()
averager(1)
averager(2)