python yield from (一)
作者:互联网
1. yield from 会抛出iterator中所有的值;而yield只是抛出传进来的值,如果是值,就抛出值,如果是iterator对象,抛出iterator对象
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
2. yield from会在调用方与子生成器之间建立一个双向通道
final_result = {} def sales_sum(pro_name): # 子生成器 total = 0 nums = [] while True: x = yield print(pro_name+"销量: ", x) if not x: break total += x nums.append(x) return total, nums def middle(key): # 委托生成器 while True: final_result[key] = yield from sales_sum(key) print(key+"销量统计完成!!.") def main(): # 调用方 data_sets = { "bobby牌面膜": [1200, 1500, 3000], "bobby牌手机": [28,55,98,108 ], "bobby牌大衣": [280,560,778,70], } for key, data_set in data_sets.items(): print("start key:", key) m = middle(key) m.send(None) # 预激middle协程 for value in data_set: m.send(value) # 给协程传递每一组的值 m.send(None) print("final_result:", final_result) if __name__ == '__main__': main()
输出:
start key: bobby牌面膜 bobby牌面膜销量: 1200 bobby牌面膜销量: 1500 bobby牌面膜销量: 3000 bobby牌面膜销量: None bobby牌面膜销量统计完成!!. start key: bobby牌手机 bobby牌手机销量: 28 bobby牌手机销量: 55 bobby牌手机销量: 98 bobby牌手机销量: 108 bobby牌手机销量: None bobby牌手机销量统计完成!!. start key: bobby牌大衣 bobby牌大衣销量: 280 bobby牌大衣销量: 560 bobby牌大衣销量: 778 bobby牌大衣销量: 70 bobby牌大衣销量: None bobby牌大衣销量统计完成!!. final_result: {'bobby牌面膜': (5700, [1200, 1500, 3000]), 'bobby牌手机': (289, [28, 55, 98, 108]), 'bobby牌大衣': (1688, [280, 560, 778, 70])}
标签:bobby,python,销量,yield,大衣,key,面膜 来源: https://www.cnblogs.com/callyblog/p/11185618.html