Python_生成器

1.生成器

　　只有在调用时才生成相应的数据，只记录当前位置，只有一个__next__()方法.

def fib(max):
    n,a,b = 0,0,1
    while n < max:
        #print(b)
        yield b
        a,b = b,a + b
        n = n + 1
    return 'done'

f = fib(6)
while True:
    try:
        x = next(f)
        print('f:',x)
    except StopIteration as e:
        print('Generator return value:',e.value)
        break

　　利用生成器达到单线程并行计算的目的

# -*- coding:utf-8 -*-
# Author:Soap
import time

def consumer(name):
    print('%s 准备吃包子啦！'%name)
    while True:
        baozi = yield
        print('包子[%s]来了，被[%s]吃了！'%(baozi,name))


def producer(name):
    c = consumer('A')
    c2 = consumer('B')
    c.__next__()
    c2.__next__()
    print('老子准备开始做包子啦！')
    for i in range(10):
        time.sleep(1)
        print('%s 做了两个包子'%name)
        c.send(i)
        c2.send(i)

producer('soap')