import tkinter as tk

class MyApp(tk.Tk):

    def __init__(self, *args, **kwargs):
        tk.Tk.__init__(self, *args, **kwargs)

        def hello():
            print("hello2")

        submit_button = tk.Button(self, text="Submit", command=lambda:
                  MyApp.test1())
        submit_button.pack()

    def test1():
        print("hello")
        MyApp.hello()

if __name__ == "__main__":
app = MyApp()
app.mainloop()