Python-сообщество

import tkinter as tk
class CustomText(tk.Text):
    def __init__(self, parent=None):
        tk.Text.__init__(self, parent, undo=True, wrap='word')
        self.pack(expand=1, fill='both')
        self.cmenu = tk.Menu(self, tearoff=False)
        self.cmenu.add_command(label='Undo',
                            command=self.undo,
                            accelerator='Ctrl+Z')
        self.cmenu.add_command(label='Redo',
                            command=self.redo,
                            accelerator='Ctrl+Y')
        self.bind('<ButtonPress-3>', self.right_but_bind)
    def right_but_bind(self, event):
        #Проверка изменялся ли текст
        #Для Undo
        if self.edit_modified():
            self.cmenu.entryconfig(0, state='normal')
        else:
            self.cmenu.entryconfig(0, state='disabled')
        #Для Redo
        try:
            self.edit_redo()
        except:
            print('Стек redo пуст')
            self.cmenu.entryconfig(1, state='disabled')
        else:
            self.edit_undo()
            self.cmenu.entryconfig(1, state='normal')
        pos_x = self.winfo_rootx() + event.x
        pos_y = self.winfo_rooty() + event.y
        self.cmenu.tk_popup(pos_x, pos_y)
    #Отменить действие
    def undo(self):
        self.edit_undo()
    #Вернуть действие
    def redo(self):
        self.edit_redo()
if __name__ == '__main__':
    root = tk.Tk()
    root.title('Custom Text')
    frm = tk.Frame(root)
    CustomText(frm)
    frm.pack()
    root.mainloop()