"""

Closing a generator raises ``GeneratorExit`` at the pending ``yield``

>>> coro_avg = averager()

>>> next(coro_avg)

0.0

>>> coro_avg.send(10)

10.0

>>> coro_avg.send(20)

15.0

>>> coro_avg.send(30)

20.0

>>> coro_avg.close()

-> total: 60.0 average: 20.0 terms: 3

Other exceptions propagate to the caller:

>>> coro_avg = averager()

>>> next(coro_avg)

0.0

>>> coro_avg.send(10)

10.0

>>> coro_avg.send('spam')

Traceback (most recent call last):

...

TypeError: unsupported operand type(s) for +=: 'float' and 'str'

"""

# BEGIN CORO_AVERAGER

def averager():

total = average = 0.0

count = 0

try:

while True:

term = yield average

total += term

count += 1

average = total/count

except GeneratorExit:

msg = '-> total: {} average: {} terms: {}'

print(msg.format(total, average, count))

# END CORO_AVERAGER