python multithreading vb6 event-handling

Python Equivalent of VB6 DoEvents

Is there Python equivalent of VB6 DoEvents statement where the handler will temporarily pass to the OS? I found similar code in http://code.activestate.com/recipes/496767-set-process-priority-in-windows/

def setpriority(pid=None,priority=1):
    """ Set The Priority of a Windows Process.  Priority is a value between 0-5 where
        2 is normal priority.  Default sets the priority of the current
        python process but can take any valid process ID. """

    import win32api,win32process,win32con

    priorityclasses = [win32process.IDLE_PRIORITY_CLASS,
                       win32process.BELOW_NORMAL_PRIORITY_CLASS,
                       win32process.NORMAL_PRIORITY_CLASS,
                       win32process.ABOVE_NORMAL_PRIORITY_CLASS,
                       win32process.HIGH_PRIORITY_CLASS,
                       win32process.REALTIME_PRIORITY_CLASS]
    if pid == None:
        pid = win32api.GetCurrentProcessId()
    handle = win32api.OpenProcess(win32con.PROCESS_ALL_ACCESS, True, pid)
    win32process.SetPriorityClass(handle, priorityclasses[priority])

Is there better and more pythonic way?

Solution

Your code doesn't do what you say it does. It sets priority for a program.

DoEvents is an internal VB thing that allows VB to suspend its code and run other code in your program. Thus it's dangerous because events can become reentrant.

The part about switching to the OS is done at the end of DoEvents and it calls the Windows API to call Sleep(0) which is sleep 0 seconds but surrender the rest of your 20 ms of time to other processes.

See documentation: https://learn.microsoft.com/en-us/windows/desktop/api/synchapi/nf-synchapi-sleep