How can I avoid TypeError: MouseSwitch() missing 8 required positional arguments: 'msg', 'x', 'y', 'data', 'time', 'hwnd', and 'window_name'

Question

Trying to hook into mouse events but in my early tests the program stops responding after about 30 seconds[EDIT: See bottom of post] and gives this error

TypeError: MouseSwitch() missing 8 required positional arguments: 'msg', 'x', 'y', 'data', 'time', 'hwnd', and 'window_name'

Here's the code. It's supposed to just print all the event info, which it does until it crashes.

import pythoncom
import pyHook

def OnMouseEvent(event):
    print ('MessageName:',event.MessageName)
    print ('Message:',event.Message)
    print ('Time:',event.Time)
    print ('Window:',event.Window)
    print ('WindowName:',event.WindowName)
    print ('Position:',event.Position)
    print ('Wheel:',event.Wheel)
    print ('Injected:',event.Injected)
    print ('---')
    return True

hm = pyHook.HookManager()
hm.MouseAll = OnMouseEvent
hm.HookMouse()
pythoncom.PumpMessages()

Any help would be appreciated.

UPDATE! Having done some further testing, the crash only seems to happen when mousing over certain windows (such as the skype contact list). I also get the same error message (but with no crash) if I mouse over the header of a google chrome window.

Answer 1

I had this with KeyboardSwitch instead of MouseSwitch and traced it to a UnicodeDecodeError when pyHook tries to interpret the window name as ascii. It fails on Skype which has unicode characters in its window name. I've posted how I fixed it here. But I had to rebuild pyHook.