2015-02-17 10:07:07 -02:00

88 lines
1.5 KiB
Python

"""
>>> adder = adder_coro()
>>> next(adder)
0
>>> adder.send(10)
10
>>> adder.send(20)
30
>>> adder.send(30)
60
>>> try:
... next(adder)
... except StopIteration as exc:
... result = exc.value
...
>>> result
Result(sum=60, terms=3, average=20.0)
Closing a coroutine:
>>> adder = adder_coro()
>>> next(adder)
0
>>> adder.send(1)
1
>>> adder.send(10)
11
>>> adder.close()
>>> try:
... next(adder)
... except StopIteration as exc:
... exc.value is None
...
True
"""
import sys
import collections
Result = collections.namedtuple('Result', 'sum terms average')
def adder_coro(initial=0):
total = initial
count = 0
while True:
try:
term = yield total
except GeneratorExit:
break
if term is None:
break
total += term
count += 1
return Result(total, count, total/count)
def prompt():
while True:
try:
term = float(input('+ '))
except ValueError:
break
yield term
def main(get_terms):
adder = adder_coro()
next(adder)
for term in get_terms:
adder.send(term)
try:
next(adder)
except StopIteration as exc:
result = exc.value
print(result)
if __name__ == '__main__':
if len(sys.argv) > 1:
get_terms = (float(n) for n in sys.argv[1:])
else:
get_terms = prompt()
main(get_terms)