python3 线程 threading

最基础的线程的使用

import threading, time

value = 0
lock = threading.Lock()

def change(n):
    global value
    value += n 
    value -= n


def thread_fun(n):
    for i in range(1000):
        lock.acquire()
        try:
            change(n)
        finally:
            lock.release()
        

t1 = threading.Thread(target=thread_fun, args=(2,))
t2 = threading.Thread(target=thread_fun, args=(3,))

t1.start()
t2.start()
t1.join()
t2.join()

print(value)

output: 0
import th