生成器

#生成器函数
def func():
    print('abc')
    yield 333
    yield 444

ret = func()
print(next(ret))
print(next(ret))
#一个next对应一个yield

#return:函数中只存在一个return结束函数，并且给函数执行者返回值
#yield:只要函数中有yield那么他就是生成器函数而不是函数
#生成器函数中可以存在多个yield，yield不会结束函数


def gen_func():
    for i in range(1,5000):
        yield f'{i}号包子'
ret = gen_func()
for i in range(200):
    print(next(ret))
for i in range(200):
    print(next(ret))




def func1():
    li = [1,2,3,4,5,6]
    yield from li
    #将li这个列表变成了迭代器返回
ret = func1()
print(next(ret))
print(next(ret))
print(next(ret))
print(next(ret))



def func2():
    li1 = [1,2,3,4,5,6]
    li2 = [7,8,9,10,11]
    yield from li1
    yield from li2
ret = func2()
for i in ret:
    print(i)