class MyObj:

    def __init__(self, arg):
        self.arg = arg

def callback(self, event):
    print(self.arg)
obj = MyObj('I am Obj')
root = Tk()
btn = Button(root, text='Click')
btn.bind('<Button-1>', obj.callback)
btn.pack()
root.mainloop()
How to pass an argument to event handler in tkinter?