python yield from

def g1(iterable):
    yield iterable

def g2(iterable):
    yield from iterable

for value in g1(range(10)):
    print(value)

for value in g2(range(10)):
    print(value)

　输出

range(0, 10)
0
1
2
3
4
5
6
7
8
9

from itertools import chain

my_list = [1, 2, 3]
my_dict = {
    'jeff1': 'http://baidu.com',
    'jeff2': 'http://google.com',
}

# 与chain等效
def my_chain(*args, **kwargs):
    for my_iterable in args:
        # 与yield from my_iterable等效
        # for value in my_iterable:
        #     yield value
        yield from my_iterable

for value in my_chain(my_list, my_dict, range(5, 10)):
    print(value)

输出

1
2
3
jeff1
jeff2
5
6
7
8