Mini Shell

from tkinter import *
import sys
import gc


class FixedMenu(Menu):
    # A fix for the .delete() method in Menu.
    # To delete commands defined in the menu items deleted.
    # Also changed the comment: INDEX2 is actually INCLUDED.
    def delete(self, index1, index2=None):
        """Delete menu items between INDEX1 and INDEX2 (included)."""
        print(self._tclCommands)
        if index2 is None:
            index2 = index1
        # First find out what entries have defined commands.
        cmds = []
        for i in range(self.index(index1), self.index(index2)+1):
            c = str(self.entrycget(i, 'command'))
            if c in self._tclCommands:
                # I don't want to delete the command already, since it
                # seems mystical to do that while the entry is not yet deleted.
                cmds.append(c)
        # Delete the menu entries.
        self.tk.call(self._w, 'delete', index1, index2)
        # Now that the menu entries have been deleted, we can delete their commands.
        for c in cmds:
            self.deletecommand(c)


def test1(M):
    # Test with a single command
    gc.collect()
    root = Tk()
    button = Menubutton(root, text='Window')
    menu = M(button)
    button['menu'] = menu

    def command():
        print('command button pressed')
    rc = sys.getrefcount(command)
    menu.add_command(command=command)  # or add_radiobutton etc
    idx = menu.index(END)
    menu.delete(idx)
    gc.collect()
    rc1 = sys.getrefcount(command)
    print('leak test with class', M, end=' ')
    if rc1 != rc:
        print('failed: command is now hold by', rc1, 'references')
    else:
        print('succeeded: command is now hold by', rc1, 'references')

    root.destroy()


def test2(M):
    # Test with 3 commands, especially to see that deleting a range works.

    gc.collect()
    root = Tk()
    button = Menubutton(root, text='Window')
    menu = M(button)
    button['menu'] = menu

    def command0():
        print('command 0 button pressed')
        'deleting 0 and 1'
        menu.delete(idx0, idx1)

    def command1():
        print('command 1 button pressed')

    def command2():
        print('command 2 button pressed')
        print('deleting at END')
        menu.delete(END)
        root.quit()
    rc = [sys.getrefcount(x) for x in (command0, command1, command0)]
    button.pack()
    # or add_radiobutton etc
    menu.add_command(command=command0, label='press first')
    idx0 = menu.index(END)
    menu.add_radiobutton(command=command1, label='command1')
    # to see that delete works even when no command supplied
    menu.add_command(label='no Command')
    idx1 = menu.index(END)
    menu.add_command(command=command2, label='press last')
    idx2 = menu.index(END)
    root.mainloop()

    gc.collect()
    rc1 = [sys.getrefcount(x) for x in (command0, command1, command0)]
    print('leak test with class', M, end=' ')
    if rc1 != rc:
        print('failed: command is now hold by',
              rc1, 'references, should be', rc)
    else:
        print('succeeded: command is now hold by', rc1, 'references')

    root.destroy()


for M in (Menu, FixedMenu,):
    test1(M)
    test2(M)