Python 多线程。MyLock.acquire（），锁应该放在哪里？

问候

在以下代码中，应在尝试之前或之后获取锁？哪个是有效的？代码运行良好，但是，我希望确保我的代码完全锁定了线程

def DoThis(name, repeat):
    global x, MyLock
    MyLock.acquire()
    try:
        print ("Thread ",name, "Has Acquired the LOCK")
        while repeat > 0:
            x = x * 2
            print (" X = ", x)
            repeat -= 1
    except:
        raise #raise exception
    finally:
        MyLock.release()
        print("Thread ", name, "Has Released the LOCK")

def DoAfter(name, repeat):
    global x, MyLock
    MyLock.acquire()
    try:
        print ("Thread ",name, "Has Acquired the LOCK")
        while repeat > 0:
            x = x + 1
            print (" X = ", x)
            repeat -= 1
    except:
        raise #raise exception
    finally:
        MyLock.release()
        print("Thread ", name, "Has Released the LOCK")

def main():
    print("Hello World")
    global x, MyLock
    x = 2
    MyLock = threading.Lock()
    # My_Thread = threading.Thread(target = MyFunc)
    # We can modify the previous line by adding a thread name
    My_Thread_1 = threading.Thread(target = DoThis, args = ('My Thread 1',20))
    My_Thread_1.start()
    My_Thread_2 = threading.Thread(target = DoAfter, args = ('My Thread 2', 20))
    My_Thread_2.start()
    print ("Final X = ", x )

---

我希望您知道

锁的用途。在您的情况下，如果您想要处理锁异常，例如
无法获得锁
，那么您可以在try块中使用lock并处理它

我之所以建议这样做，是因为在重要的工作中，例如
db事务
最好在try块中使用锁，因为您可以通过还原db事务来处理锁异常。所以最好在
try
块中处理锁