how to simulate keydown and keyup events using win32api .

[ppk.phanikumar at gmail.com]

win32api.keybd_event(code,0,0,0)
time.sleep(2)
win32api.keybd_event(code,0,win32con.KEYEVENTF_KEYUP,0)



the above code is simulating single click on button but not press Key Hold
but i want to hold the until key up event is called
eg: for key 'a' down it have to simulate key continous set  until keyUp is called but not like "a" 
please specify any python API to simulate continues keyDown until it receives keyUp event