1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3
4 final_result = {}
5
6
7 # 子生成器
8 def sales_sum(pro_name):
9 total = 0
10 nums = []
11 while True:
12 x = yield
13 print(pro_name+'销量: ', x)
14 if not x:
15 break
16 total += x
17 nums.append(x)
18 return total, nums
19
20
21 # 委托生成器
22 def middle(key):
23 while True:
24 final_result[key] = yield from sales_sum(key)
25 print(key+'销量统计完成！！.')
26
27
28 # 调用方
29 def main():
30 data_sets = {
31 '小米9': [1200, 1500, 3000],
32 '小米8': [28, 55, 98, 108],
33 '小米5': [200, 560, 778, 70],
34 }
35 for key, data_set in data_sets.items():
36 print('start key:', key)
37 m = middle(key)
38 # 预激middle协程
39 m.send(None)
40 for value in data_set:
41 # 给协程传递每一组的值
42 m.send(value)
43 # 结束
44 m.send(None)
45 print('final_result:', final_result)
46
47
48 if __name__ == '__main__':
49 main()
start key: 小米9
小米9销量: 1200
小米9销量: 1500
小米9销量: 3000
小米9销量: None
小米9销量统计完成！！.
start key: 小米8
小米8销量: 28
小米8销量: 55
小米8销量: 98
小米8销量: 108
小米8销量: None
小米8销量统计完成！！.
start key: 小米5
小米5销量: 200
小米5销量: 560
小米5销量: 778
小米5销量: 70
小米5销量: None
小米5销量统计完成！！.
final_result: {'小米9': (5700, [1200, 1500, 3000]), '小米8': (289, [28, 55, 98, 108]), '小米5': (1608, [200, 560, 778, 70])}
yield from最主要的用法
1 # main调用方、g1（委托生成器）、gen 子生成器 2 # yield from会在调用方与子生成器之间建立一个双向通道 3 def g1(gen): 4 yield from gen 5 6 7 def main(): 8 g = g1() 9 g.send(None)
yield from 处理了StopIteration的异常
yield from 其他用法
1 #!/usr/bin/env python
2 # -*- coding:utf-8 -*-
3 # python3.3新加了yield from语法
4
5
6 from itertools import chain
7
8
9 my_list = [1, 2, 3]
10 my_dict = {
11 'zy1': 'http://projectsedu.com',
12 'zy2': 'http://www.imooc.com'
13 }
14
15
16 # yield from iterable（可迭代对象）
17 def my_chain(*args, **kwargs):
18 for my_iterable in args:
19 yield from my_iterable
20 # for value in my_iterable:
21 # yield value
22
23
24 for value in my_chain(my_list, my_dict, range(5, 10)):
25 print(value)
1 2 3 zy1 zy2 5 6 7 8 9