在python2中销毁Label

Question

我试图在 python2 中破坏 Label 并且我不断收到错误。 添加我正在使用的代码：

def log_in():
    for i in range(3,0,-1):
        if entry3 == entry1:
            break
        else:   
            self_label5.place(x=100, y=105)
            self_label5.destroy()
    if i == 1:
        self_label6 = Label(root1, text = "you have been denied access").place(x=100, y=105)
        self_label6.destroy() 
    else: 
        self_label7 = Label(root1, text = "username has been accepted").place(x=100, y=105)
        self_label7.destroy()
    for i in range(3,0,-1):
        if entry4 == entry2:
            break
        else:   
            self_label5 = Label(root1, text = "incorrect!").place(x=100, y=105)
            self_label5.destroy()
    if i == 1:
        self_label7 = Label(root1, text = "you have been denied access").place(x=100, y=105)
        self_label7.destroy()
    else: 
        self_label8 = Label(root1, text = "password has been accepted").place(x=100, y=105)
        self_label8.destroy() 
        self_label9 = Label(root1, text = "login succesful").place(x=100, y=105)
        self_label9.destroy()

我运行代码并得到错误：

Exception in Tkinter callback
Traceback (most recent call last):
  File "/usr/lib/python2.7/lib-tk/Tkinter.py", line 1550, in __call__
    return self.func(*args)
  File "new2.py", line 28, in log_in
    self_label5.destroy()
AttributeError: 'NoneType' object has no attribute 'destroy'

有人可以帮帮我吗？ 谢谢！