yield

yield不僅可以返回值，也可以接收值

# yield返回值, 生成器

def gen():
    for x in ["a", "b", "c"]:
        yield x

for i in gen():
    print(i)

# a b c

# yield接收值, 協程
def gen():
    while True:
        x = yield
        print("x = %s"% x)

g = gen()
next(g)  # 執行到yield， 啟用協程 send(None) ”預激(prime)“協程
g.send(10
 
)
g.send(20)
g.send(30)
g.close()
"""
x = 10
x = 20
x = 30
"""

yield from

yield from呼叫生成器

# 呼叫生成器

def gen():
    yield from ["x", "y", "z"]

for i in gen():
    print(i)

# x y z