第三十四天- 线程队列、线程池(map/submit/shutd…

 1 # 先进先出：
 2 q = queue.Queue(3)  # 也可以不加数字表示不限
 3 q.put('约吗')
 4 q.put('你个糟老头')
 5 q.put('约个鬼！')
 6 # q.put_nowait() # 没有数据会报错 可以try解决
 7 print(q.get())
 8 print(q.get())
 9 print(q.get())
10 q.get_nowait()

 1 import queue
 2 
 3 # 后进先出：
 4 q = queue.LifoQueue(4)
 5 q.put('first')
 6 q.put('second')
 7 q.put('third')
 8 q.put_nowait(1)
 9 print(q.get())
10 print(q.get())
11 print(q.get())
12 print(q.get_nowait())

 1 # 设置优先
 2 q = queue.PriorityQueue(6)
 3 
 4 # put进入元组,元组第一个元素是优先级(通常是数字,也可以是非数字之间的比较),数字越小优先级越高
 5 q.put((3,'a'))
 6 q.put((2,'b'))
 7 q.put((-3,'c'))
 8 
 9 # 优先级相同的两个数据,比较第二个元素ASCII码大小，若第二元素为字符串且第一个字符相同则比较第二个
10 q.put((20,'ww'))
11 q.put((20,'ws'))
12 # q.put(20,{'ws',22}) # 不能是字典
13 # q.put((20,('w',1))) # 后面的值必须是相同数据类型才能比较，可以是元祖，ascii码顺序排序
14 
15 print(q.get())
16 print(q.get())
17 print(q.get())
18 print(q.get())
19 print(q.get())
20 # print(q.get())

 1 import time
 2 from concurrent.futures import ProcessPoolExecutor,ThreadPoolExecutor
 3 
 4 
 5 def func(n):
 6     time.sleep(0.5)
 7     return n*n
 8 
 9 
10 if __name__ == '__main__':
11     t_pool = ThreadPoolExecutor(max_workers=4)
12     # t_pool = ProcessPoolExecutor(max_workers=4)  # 用concurrent.futures可直接转换成进程
13     t_list = []
14     for i in range(10):
15         res = t_pool.submit(func,i)  # submit异步提交任务
16         # print(res.result()) # 等待res的执行结果,拿到了就运行，拿不到就阻塞，放这会变成串行
17         t_list.append(res)
18 
19     t_pool.shutdown()  # 相当于进程池的pool.close() pool.join()
20 
21     print('主线程结束')
22 
23     for res1 in t_list:
24         print(res1.result())

 1 import time
 2 from concurrent.futures import ThreadPoolExecutor
 3 
 4 
 5 def func(n):
 6     time.sleep(1)
 7     return n*n
 8 
 9 
10 if __name__ == '__main__':
11 
12     t_pool = ThreadPoolExecutor(6)
13     res = t_pool.map(func,range(10))  # map 取代for循环submit的操作
14     t_pool.shutdown()
15 
16     print('主线程执行结束')
17     for i in res:
18         print(i)
19 
20 # map包含了for循环和submit操作

 1 import time
 2 from concurrent.futures import ThreadPoolExecutor
 3 
 4 
 5 def func1(n):
 6     time.sleep(1)
 7     return n*n
 8 
 9 
10 def callback(s):
11     # print(s)
12     ss = s.result()+1
13     print(ss)
14 
15 
16 if __name__ == '__main__':
17     t_pool = ThreadPoolExecutor(4)
18     for i in range(10):
19         t_pool.submit(func1,i).add_done_callback(callback)
20 
21     # 注意map函数没有callback，不能如下使用
22     # res = t_pool.map(func1,range(10))
23     # for i in res:
24     #     i.add_done_callback(callback)