>>> def fun():
... print 'start...'
... m = yield 5
... print m
... print 'middle...'
... d = yield 12
... print d
... print 'end...'
... 
>>> m = fun() //創(chuàng)建一個對象
>>> m.next() //會使函數(shù)執(zhí)行到下一個yield前
start...
5
>>> m.send('message') //利用send()傳遞值
message //send()傳遞進來的 
middle...
12
>>> m.next()
None //可見next()返回值為空
end...
Traceback (most recent call last):
 File "", line 1, in 
StopIteration

for i, task in enumerate(taskseq):
 ...
 try:
 put(task)
 except IOError:
 debug('could not put task on queue')
 break

import multiprocessing as mp
import itertools
import time


def g():
 for el in xrange(50):
 print el
 yield el

import os

def f(x):
 time.sleep(1)
 print str(os.getpid()) +" "+ str(x)
 return x * x

if __name__ == '__main__':
 pool = mp.Pool(processes=4) # start 4 worker processes
 go = g()
 result = []
 N = 11
 while True:
 g2 = pool.imap(f, itertools.islice(go, N))
 if g2:
 for i in g2:
 result.append(i)
 time.sleep(1)
 else:
 break
 print(result)