xception in Tkinter callback
    Traceback (most recent call last):
    File "/usr/lib/python3.7/tkinter/__init__.py", line 1705, in __call__
    return self.func(*args)
    File "/usr/lib/python3.7/tkinter/__init__.py", line 749, in callit
    func(*args)
    TypeError: shukkin() missing 1 required positional argument: 'event'