39.Python：yield的表达式形式

# x = yield 返回值
# def dog(name):
#     print('dog %s' % name)
#     while True:
#         x = yield   # x得到的不是yield的返回值，而是yield接收到的值
#         print('dog %s eat %s' % (name, x))
#
#
# g = dog('alex')
# g.send(None)        # 等同于next(g)
#
# g.send('food')      # g.send()给yield赋值
# g.send('1')
# g.send('2')
# g.close()           # 关闭后传值会报错

# ---------------------------------------------------------------
def dog(name):
    food_list = []
    print('dog %s' % name)
    while True:
        x = yield food_list
        print('dog %s eat %s' % (name, x))
        food_list.append(x)


g = dog('alex')
res = g.send(None)        # 等同于next(g)

res = g.send('food')      # g.send()给yield赋值
res = g.send('1')
res = g.send('2')
g.close()           # 关闭后传值会报错
print(res)