通过调用GetSystemPowerStatus Windows Api来判断AC Power是开启还是关闭状态。是一个python调用windows api的例子。

import os
import win32con
import sys
import time
from ctypes import *

class PowerClass(Structure):
    _fields_ = [('ACLineStatus', c_byte),
            ('BatteryFlag', c_byte),
            ('BatteryLifePercent', c_byte),
            ('Reserved1',c_byte),
            ('BatteryLifeTime',c_ulong),
            ('BatteryFullLifeTime',c_ulong)]

powerclass = PowerClass()

while True:
    result = windll.kernel32.GetSystemPowerStatus( byref(powerclass) )

    try:
        state = int(powerclass.ACLineStatus)
    except:
        state = 0 

    if state == 1:
        print 'Power is on...'
    else:
        print 'Power is off...\a'  #\a = bell sounds beep on computer

    print 'Sleeping for 5 seconds...'
    time.sleep(5)