class Main:
def __init__(self, rt):
    self.rt = rt
    self.navbar = navbar.NavBar(rt)
    self.rt.mainloop()

class NavBar(tkinter.Frame):
def __init__(self, master):
    tkinter.Frame.__init__(self, master)
    self.master = master
    self.bg='red'
    self.text = tkinter.Text(self, height=1, width=30)
    self.text.insert(tkinter.END, "File")
    self.text.pack()
    self.grid(row=0, column=0)

if __name__ == "__main__":
    root = tkinter.Tk()
    root.title('Automation')
    main = Main(root)