Scheduling tasks in Windows with PyWin32

I am posting this small entry because it took me quite a time to compute all informations to programmatically add tasks in Windows using pywin32, so this post should be an helpfull example.

The process to schedule a task is as follows:
- create an instance of the COM TaskScheduler interface - adding a task within the task scheduler - adding a trigger within the task

Here's how it can look in Python, to create daily tasks:
import pythoncom, win32api

import time

from win32com.taskscheduler import taskscheduler

def create_daily_task(name, cmd, hour=None, minute=None):

    """creates a daily task"""

    cmd = cmd.split()

    ts = pythoncom.CoCreateInstance(taskscheduler.CLSID_CTaskScheduler,None,

                                    pythoncom.CLSCTX_INPROC_SERVER,

                                    taskscheduler.IID_ITaskScheduler)

    if '%s.job' % name not in ts.Enum():

        task = ts.NewWorkItem(name)

        task.SetApplicationName(cmd[0])

        task.SetParameters(' '.join(cmd[1:]))

        task.SetPriority(taskscheduler.REALTIME_PRIORITY_CLASS)

        task.SetFlags(taskscheduler.TASK_FLAG_RUN_ONLY_IF_LOGGED_ON)

        task.SetAccountInformation('', None)

        ts.AddWorkItem(name, task)

        run_time = time.localtime(time.time() + 300)

        tr_ind, tr = task.CreateTrigger()

        tt = tr.GetTrigger()

        tt.Flags = 0

        tt.BeginYear = int(time.strftime('%Y', run_time))

        tt.BeginMonth = int(time.strftime('%m', run_time))

        tt.BeginDay = int(time.strftime('%d', run_time))

        if minute is None:

            tt.StartMinute = int(time.strftime('%M', run_time))

        else:

            tt.StartMinute = minute

        if hour is None:

            tt.StartHour = int(time.strftime('%H', run_time))

        else:

            tt.StartHour = hour

        tt.TriggerType = int(taskscheduler.TASK_TIME_TRIGGER_DAILY)

        tr.SetTrigger(tt)

        pf = task.QueryInterface(pythoncom.IID_IPersistFile)

        pf.Save(None,1)

        task.Run()

    else:

        raise KeyError("%s already exists" % name)

    task = ts.Activate(name)

    exit_code, startup_error_code = task.GetExitCode()

    return win32api.FormatMessage(startup_error_code)

You can see an example of usage here, in the iw.win32 package we have started to build, to gather all win32 specific Python things.

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