Python生成器建议收藏

def fun(li):
    for i in li:
        #print (i)
        yield i

li = [1,2,3,4,5]
for i in fun(li):
    print (i)

#方法1
def fun1():
    l = []
    for i in range(1,6):
        l.append(i * i)
    return l

print (fun1())

#方法2
def fun2():
    return (i*i for i in range(1,6))

ll = list(fun2())
print (ll)

#方法3
def fun3():
    for i in range(1,6):
        yield i*i
for i in fun3():
    print (i)

输出：
>>>> [1,4,9,16,25]
>>>> [1,4,9,16,25]
>>>> 1
>>>> 4
>>>> 9
>>>> 16
>>>> 25

#coding = utf-8

'''
    yield实现协程任务调度
'''
from collections import deque

class TaskScheduler:
    def __init__(self):
        self.taskqueue = deque()

    def new_task(self, task):
        self.taskqueue.append(task)

    def run(self):
        while self.taskqueue:
            task = self.taskqueue.popleft()
            try:
  
                next(task)
                self.taskqueue.append(task)
            except Exception:
                print ("run exception")

def task1(n):
    while n > 0:
        print ("say hello: %d" %(n))
        yield n
        n -=1
    print ("task1 say goodble")

def task2(n):
    x= 0
    while x < n:
        print ("say hi:%d" %(x))
        yield x
        x += 1

    print ("task2 say goodbye")

taskschequler = TaskScheduler()
taskschequler.new_task(task1(4))
taskschequler.new_task(task2(4))
taskschequler.run()