getting error AttributeError: '_tkinter.tkapp' object has no attribute 'getitems'
I see two mistakes:
First: you define method get_items (with _ in name) but you use command=self.getitems (without _ in name)
self.b = Button(command=self.get_items)Second: you have arguments in wrong order is
__init__(kwargs, self, master=None, *args)so it assigns class instance to variabla kwargs instead of self and it assigns root to self and later it has problem to find self.get_items because it means root.get_items
kwargs should be at the end, and self at the beginning
__init__(self, master=None, *args, **kwargs)