如何让应用程序一次只运行一个实例？

import os
import sys
import threading

mutex = threading.Lock()

def main():
    with mutex:
        print("Running the application...")
        # Your application code here

if __name__ == "__main__":
    if os.path.exists("app.lock"):
        print("Another instance is already running.")
        sys.exit(1)
    with open("app.lock", "w") as f:
        f.write(str(os.getpid()))
    main()
    os.remove("app.lock")

import os
import sys
import fcntl

lock_file = "app.lock"

def main():
    with open(lock_file, "w") as f:
        try:
            fcntl.flock(f, fcntl.LOCK_EX | fcntl.LOCK_NB)
            print("Running the application...")
            # Your application code here
        except IOError:
            print("Another instance is already running.")
            sys.exit(1)

if __name__ == "__main__":
    main()