生成器

def func():
    print(‘第一次‘)
    yield 1
    print(‘第二次‘)
    yield 2
    print(‘第三次‘)
    yield 3
    print(‘第四次‘)


g=func()
print(g)
# 生成器就是迭代器
g.__iter__()
g.__next__()

res1=g.__next__()
print(res1)


res2=g.__next__()
print(res2)

res3=g.__next__()
print(res3)

res4=g.__next__()


len(‘aaa‘) # ‘aaa‘.__len__()

next(g)    # g.__next__()
iter(可迭代对象)     # 可迭代对象.__iter__()

def my_range(start,stop,step=1):
    # print(‘start...‘)
    while start < stop:
        yield start
        start+=step
    # print(‘end....‘)


g=my_range(1,5,2) # 1 3
print(next(g))
print(next(g))
print(next(g))

for n in my_range(1,7,2):
    print(n)

def dog(name):
    print(‘道哥%s准备吃东西了...‘ % name)
    while True:
        # x拿到的是yield接收到的值
        x = yield  # x = ‘一根骨头‘
        print(‘道哥%s吃了 %s‘ % (name, x))


g = dog(‘alex‘)

g.send(None)  # 等同于next(g)，先完成初始化

g.send(‘一根骨头‘)
# g.send(‘一根骨头‘,‘肉包子‘)    # 不能传2个值，会报错：TypeError: send() takes exactly one argument (2 given)
g.send([‘一根骨头‘,‘肉包子‘])    # 可以放到列表里传输，列表算是一个值
g.send(‘肉包子‘)
g.send(‘一桶泔水‘)
# g.close()
# g.send(‘1111‘) # 关闭之后无法传值

def dog(name):
    food_list = []
    print(‘大哥%s准备吃东西了...‘ % name)
    while True:
        # x拿到的是yield接收到的值
        # x = yield 111 # x = [‘一根骨头‘,‘肉包子‘]
        x = yield food_list # x = [‘一根骨头‘,‘肉包子‘]
        print(‘大哥%s抽了 %s‘ % (name, x))
        food_list.append(x)


g = dog(‘egon‘)

res = g.send(None)  # 等同于next(g)，先完成初始化
print(res)

res = g.send([‘一个鞭炮‘,‘一根烟‘])
print(res)

res = g.send(‘一个地雷‘)
print(res)
def func():
    print(‘start...‘)
    x = yield 111
    print(‘H哈哈‘)
    print(‘H哈哈‘)
    print(‘H哈哈‘)
    yield 222

g = func()
res = next(g)
print(res)

res = g.send(‘xxxx‘)
print(res)