[python-win32] How to invoke Python program from Windows service?

[Tim Golden]

> Yeah, that was exactly my problem; I had no way to diagnose what was
> going on, and needed a springboard to tell me what I needed to know
> in order to figure out what was happening (or not).  I could verify
> that the script *worked*, since I could run it from a DOS prompt
> without errors.  But when I ran it using CreateProcess (and
> ProcessStartInfo), I didn't see it execute (since it would have
> created a file in its directory).
> 
> However, your answer that I can write it directly with pywin32
> intrigues me, especially since I'd rather develop in Python anyway.
> I'll go see what's involved in doing that.  Thanks for the pointer! 

For reference, this is the kind of pattern I use when writing
Windows Services in Python:

<my_module.py>
class Engine(object):

  def __init__(self):
    self._stop_event = threading.Event()

  def start(self):
    # do stuff until self._stop_event is set

  def stop(self):
    # set self._stop_event

if __name__ == '__main__':
  Engine().start()

</my_module.py>

<my_service.py>

import win32event
import win32service
import win32serviceutil

import my_module

class Service (win32serviceutil.ServiceFramework):

  _svc_name_ = "MyService"
  _svc_display_name_ = "A Service of Mine"

  def __init__ (self, args):
    win32serviceutil.ServiceFramework.__init__ (self, args)
    self.stop_event = win32event.CreateEvent (None, 0, 0, None)
    self.engine = my_module.Engine ()

  def SvcDoRun (self):
    self.engine.start (True)
    win32event.WaitForSingleObject (self.stop_event, win32event.INFINITE)

  def SvcStop (self):
    self.ReportServiceStatus (win32service.SERVICE_STOP_PENDING)
    self.engine.stop ()
    win32event.SetEvent (self.stop_event)

if __name__ == '__main__':
  win32serviceutil.HandleCommandLine (Service)


</code>

To install the service you run the my_service.py module with
the parameter "install". (The reverse is done by passing "remove").

HTH

TJG