# 倒计时锁屏
import time
from ctypes import *
def closewindows(closetime):
  while closetime>0:
    print(closetime)
    time.sleep(1)
    closetime-=1
  user32 = windll.LoadLibrary('user32.dll')
  user32.LockWorkStation()
if __name__ == "__main__":
  closewindows(3)

C:\Users\HAS>python
 Python 3.6.4 (v3.6.4:d48eceb, Dec 19 2017, 06:54:40) [MSC v.1900 64 bit (AMD64)]
 on win32
 Type "help", "copyright", "credits" or "license" for more information.
 >>> from ctypes import *
 >>> user32 = windll.LoadLibrary('user32.dll')
 >>> user32.LockWorkStation()