python 中线程、进程、协程

1.线程和线程池

 t1 =  threading.Thread(target = task, args=("a"))t2 =  threading.Thread(target = task, args=("b"))with concurrent.futures.ThreadPoolExecutor(max_workers=3) as executor:executor.map(task, ["A,B,C,D"])
threads = [threading.Thread(target = increment()) for _ in range(4)]for t in threads:t.start()for t in threads:t.join()
count = 0
lock = threading.Lock()
def increment():global countfor i in range(100):with lock:count +=1

2.进程和进程池

def send(conn):conn.send("helloworld")
def receive(conn):print(conn.recv())val =  multiprocessing.Value("i",1) // 共享变量queue = multiprocessing.Queue()process = multiprocessing.Process(target = worker,args= (queue,))process2 = multiprocessing.Process(target = worker, args=(queue,))process.start()process2.start()process.join()process2.join()with concurrent.futures.ProcessPoolExecutor(5) as executor:executor.map(worker,["a","b","c","d"])processes = [multiprocessing.Process(target = printVal, args =(val,))for _ in range(4)]for process in processes:process.start()for process in processes:process.join()

asyncio  

async def cpu_bound_task(n):total = 0for i in range(10**8):total += i*nprint(f"total is {total}")await asyncio.sleep(10)return total
def event_loop(n):asyncio.run(cpu_bound_task(n))
async def main():loop = asyncio.get_event_loop()with ProcessPoolExecutor() as pool:result = await loop.run_in_executor(pool,cpu_bound_task, 10)print(f"result is {result}")
for i in range(4):p = multiprocessing.Process(target= event_loop, args=(10,))pList.append(p)p.start()for p in pList:p.join()
asyncio.run(main())
print("主线程执行结束")

五、总结

如何选择？