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Hi, in this case I’m going to show you how to create simple services for the win32 platform using the powerfull Python programming language and the py2exe utility.<\/p>\n[adinserter block=”2″]
\nHi, in this case I’m going to show you how to create simple services for the win32 platform using the powerfull Python programming language and the py2exe utility.<\/p>\n
Writing Python applications under windows is quite simple, maybe you didn’t use windows to develop your application (as I do most times), the code, what you want to do with your application is up to you, and I’m not goint to touch the programming techniques for developing windows applications, Just, create a simple -and useles- win32 service that will help you to uderstand how to create your very own windows service.<\/p>\n
First, every single program that you create with python and compile with py2exe and does run well, may be a win32 service, it may be a program that fetches the RSS xml feed<\/a> for islascruz.org<\/a>, maybe is a more complex program to generate some files and then send them to another server, maybe is a simple program to remind you to sand up an walk 10 minutes.<\/p>\n Said that we don’t really need to create a program thinking on it as a service, we will create a simple program and test it using the python interpreter, who needs to compile?, well, we need it, but just when we are sure that our program performs well.<\/p>\n Now that we have this program running in our windows environment, we can start thinking in converting into a service. First, I don’t know you, but I haven’t make Windows to load a python script and run it as a service. This is because Win32 use it’s own method to start\/stop the services. Then, we will need to create a wrapper for our program, this wrapper will interface with the windows service mananger. Doing it is quite simple, lets see it.<\/p>\n [adinserter block=”2″]<\/p>\n As you can see in this piece of code, we have a class called ServiceLauncher, actually it doesn’t really matter if you name it as you want, but, we need some variables that starts with “svc<\/em>” and the important is _svc_name, this variable should have the name of our service, the very same name of the executable that we are going to compile. The init<\/strong> method initialize our service.<\/p>\n Then, we have two methods. one SvcStop, this method will be called when we want to stop the service in the service mananger. As our program is not running here, is safe to communicate with it by some method, I use a variable stored in “sys” which is “pooled” on the main program to know when it’s time to stop the program.<\/p>\n THe method SvcDoRun is quite explicit, it starts the program. Now, you guess that when you start your service must be doing something, even sleeping, because, if it stops, then an error message will be saved in the Windows logs.<\/p>\n#!\/usr\/bin\/env python\nimport time\nimport thread\nimport os\nimport sys\n\nclass service_test:\n def __init__(self):\n thread.start_new(self.do_something, tuple())\n while True:\n if getattr(sys,'stopservice', False):\n sys.exit()\n time.sleep(0.3)\n\n def do_something(self):\n '''\n Do something\n '''\n while True:\n fname ='C:\\\\\\\\test.txt'\n f = open(fname , 'a')\n f.write(time.time())\n f.close()\n time.sleep(1)\n\n\nif __name__ == \"__main__\":\n tst = service_test()\n\n<\/pre>\n
\nimport win32serviceutil\nimport win32service\nimport win32event\nimport os\nimport sys\nimport time\n\nsys.stopservice = \"false\"\n\ndef main():\n '''\n Modulo principal para windows\n '''\n sys.path.insert(0,os.getcwd())\n import service_module\n a = service_module.service_test()\n\nclass ServiceLauncher(win32serviceutil.ServiceFramework):\n _svc_name_ = 'ServiceTest'\n _scv_display_name_ ='Servicio de pruebas'\n def __init__(self, args):\n win32serviceutil.ServiceFramework.__init__(self, args)\n self.hWaitStop = win32event.CreateEvent(None, 0, 0, None)\n\n def SvcStop(self):\n self.ReportServiceStatus(win32service.SERVICE_STOP_PENDING)\n sys.stopservice = \"true\"\n win32event.SetEvent(self.hWaitStop)\n\n def SvcDoRun(self):\n main()\n<\/pre>\n