“TypeError: 'NoneType' 对象不支持项目分配” 我该如何解决这个问题？

Question

I am currently trying to make a calculator in python, and I have created a simple GUI for it first. However, while making the buttons work, I keep getting a type error when attempting to output a number. How do I fix this problem? I have started with trying to output 0 to test run before making for all the other commands needed.

import tkinter as t

window = None
display_label = None
expression = ''


def setup_GUI():


    global window
    global dsiplay_label

    window = t.Tk()
    window.title("calculator")


    display_label = t.Label(window, textvariable='', anchor='e', relief=t.GROOVE, width=15, font='Arial 20')
    display_label.grid(row=0, column=0, columnspan=4, padx=10, pady=10)


    #numbers

    btn1 = t.Button(window, text='1', width=5, height=2, font='Arial 15',command = press0)
    btn2 = t.Button(window, text='2', width=5, height=2, font='Arial 15')
    btn3 = t.Button(window, text='3', width=5, height=2, font='Arial 15')
    btn4 = t.Button(window, text='4', width=5, height=2, font='Arial 15')
    btn5 = t.Button(window, text='5', width=5, height=2, font='Arial 15')
    btn6 = t.Button(window, text='6', width=5, height=2, font='Arial 15')
    btn7 = t.Button(window, text='7', width=5, height=2, font='Arial 15')
    btn8 = t.Button(window, text='8', width=5, height=2, font='Arial 15')
    btn9 = t.Button(window, text='9', width=5, height=2, font='Arial 15')
    btn0 = t.Button(window, text='0', width=5, height=2, font='Arial 15')

    #operators

    clear = t.Button(window, text = "C", width=5, height=2, font='Arial 15')
    percent = t.Button(window, text = "％", width=5, height=2, font='Arial 15')
    squared = t.Button(window, text = "X²", width=5, height=2, font='Arial 15')
    ineq = t.Button(window, text = "＜", width=5, height=2, font='Arial 15')
    period = t.Button(window, text = "ㆍ", width=5, height=2, font='Arial 15')
    mul = t.Button(window, text = "×", width=5, height=2, font='Arial 15')
    div = t.Button(window, text = "÷", width=5, height=2, font='Arial 15')
    add = t.Button(window, text = "+", width=5, height=2, font='Arial 15')
    sub = t.Button(window, text = "-", width=5, height=2, font='Arial 15')
    result = t.Button(window, text = "=", width=5, height=2, font='Arial 15')


    #positions

    btn1.grid(row=2, column=0)
    btn2.grid(row=2, column=1)
    btn3.grid(row=2, column=2)
    btn4.grid(row=3, column=0)
    btn5.grid(row=3, column=1)
    btn6.grid(row=3, column=2)
    btn7.grid(row=4, column=0)
    btn8.grid(row=4, column=1)
    btn9.grid(row=4, column=2)
    btn0.grid(row=5, column=1)
    clear.grid(row=1, column=0)
    result.grid(row=5, column=2)
    add.grid(row=2, column=3)
    sub.grid(row=3, column=3)
    mul.grid(row=4, column=3)
    div.grid(row=5, column=3)
    period.grid(row=5, column=0)
    ineq.grid(row=1, column=1)
    percent.grid(row=1,column=2)
    squared.grid(row=1,column=3)




def press0():
    global expression
    expression = expression + '0'
    display_label['text']= expression


setup_GUI()
window.mainloop()

Answer 1

当您在 GUI 函数中定义了全局变量display_label 时，您拼错了它。

Answer 2

您将display_label拼错为global dsiplay_label 。