代码：

import threading
import time


num = 0 
mutex = threading.Lock()

def test1(cnt):
        global num
    
        for i in range(cnt):
                mutex.acquire()
                print("test1, before add num = %d--" % num)
                num += 1
                print("test1, after add num = %d--" % num)
                print("------------------\r\n")
                mutex.release()
                time.sleep(0.001)


def test2(cnt):
        global num
    
        for i in range(cnt):
                mutex.acquire()
                print("test2, before add num = %d--" % num)
                num += 1
                print("test2, after add num = %d--" % num)
                print("------------------\r\n")
                mutex.release()
                time.sleep(0.001)


if __name__ == "__main__":
    
        print("--创建线程之前, num = %d--" % num)

        t1 = threading.Thread(target=test1, args=(100000,))
        t1.start()

        t2 = threading.Thread(target=test2, args=(100000,))
        t2.start()
    
        while len(threading.enumerate()) != 1:
                time.sleep(1)
    
        print("最终结果为：num=%d" % num)

执行结果：

root@ubuntu:/tmp# python3 main.py
test1, before add num = 138694--
test1, after add num = 138695--
------------------

test2, before add num = 138695--
test2, after add num = 138696--
------------------

test1, before add num = 138696--
test1, after add num = 138697--
------------------

test2, before add num = 138697--
test2, after add num = 138698--
------------------

test1, before add num = 138698--
test1, after add num = 138699--
------------------

test2, before add num = 138699--
test2, after add num = 138700--
------------------

test1, before add num = 138700--
test1, after add num = 138701--
------------------

test2, before add num = 138701--
test2, after add num = 138702--
------------------

test1, before add num = 138702--
test1, after add num = 138703--
------------------

test2, before add num = 138703--
test2, after add num = 138704--
------------------

test1, before add num = 138704--
test1, after add num = 138705--
------------------
root@ubuntu:/tmp#