Calculator python code M3

import tkinter as tk def press(n): global expression global label1Text expression = expression+n label1Text.set(expression) m=tk.Tk() m.title('Calculator Somchai') expression=' ' label1Text=tk.StringVar() label1Text.set(expression) label1 = tk.Label(m,borderwidth=2,relief='ridge',textvariable=label1Text,width=20) label1.grid(row=0,columnspan=2) button1 = tk.Button(m,text='1',width=6,command=lambda:press('1')) button1.grid(row=2,column=0) button2 = tk.Button(m,text='2',width=6,command=lambda:press('2')) button2.grid(row=2,column=1) button3 = tk.Button(m,text='3',width=6,command=lambda:press('3')) button3.grid(row=1,column=0) button4 = tk.Button(m,text='4',width=6,command=lambda:press('4')) button4.grid(row=1,column=1) button = tk.Button (m,text='Stop',width=16,command=lambda:m.destroy()) button.grid(row=3,columnspan=2) m.mainloop()