线程返回值

1. 在方法变量中传入全局变量，在方法中对全局变量进行赋值

2. （不堵塞）重新创建一个线程类，将方法写在run的方法中，然后run返回出结果在线程变量中，外部通过方法get到变量的值

   import time
   from threading import Thread
    
   def foo(number):
       time.sleep(20)
       return number
    
   class MyThread(Thread):
    
       def __init__(self, number):
           Thread.__init__(self)
           self.number = number
    
       def run(self):
           self.result = foo(self.number)
    
       def get_result(self):
           return self.result
    
    
   thd1 = MyThread(3)
   thd2 = MyThread(5)
   thd1.start()
   thd2.start()
   thd1.join()
   thd2.join()
    
   print(thd1.get_result())
   print(thd2.get_result())

   适合于 获取每一个线程的运算结果

3. （阻塞）使用ThreadPoolExecutor的submit

   def thread_function(age):
       return age+1
    
   def run_thread_pool_sub(target, args, max_work_count=3):
       with ThreadPoolExecutor(max_workers=max_work_count) as t:
           res = [t.submit(target, i) for i in args]
           return res
       
   if __name__ == '__main__':
       ages = [1, 3, 4]
       res = run_thread_pool_sub(thread_function, ages)
       for future in as_completed(res):
           data = future.result()
           print dat

   通过future.result()获得结果 submit的返回是无序

4. （阻塞）使用ThreadPoolExecutor的map

   def thread_function(age):
       for i in age:
           yield i+1
    
   def run_thread_pool(target, args, max_work_count=6):
       with ThreadPoolExecutor(max_workers=max_work_count) as t:
           res = t.map(target, args)
           return res
    
   if __name__ == '__main__':
       ages = [1, 3, 4]
       # 2222
       res = run_thread_pool(target=thread_function, args=(ages,))
       for j in res:
           for i in j:
               print i

   map的输出是有序

   参考：https://blog.csdn.net/qq_43178297/article/details/102805223