Python中怎么自定义对话框

def rbutton_down(event):    iid = list_view.identify_row(event.y)    if iid:        if iid not in list_view.selection():            list_view.selection_set(iid)            list_view.focus(iid)        path, selections = selected_files()        if path:            menu = Menu(list_view, tearoff=False)            menu.add_command(label='Open', command=open_current)            if len(list(selections))==1:                menu.add_command(label='Rename', command=rename_current)            menu.add_command(label='Delete', command=delete_current)            menu.post(event.x_root, event.y_root)

def rename_current():    path, selections = selected_files()    if path:        for fn in selections:            # 构建顶层窗口作为对话框            rename_dlg = Toplevel(takefocus=True)            # 指定窗口标题            rename_dlg.title('Rename')            # 禁止窗口尺寸调整            rename_dlg.resizable(width=False, height=False)            # 构建Frame对象以容纳Label和Entry对象            # 使用Frame可以分别调整Label/Entry区域和下面的按钮区域            fn_frame = Frame(rename_dlg)            fn_frame.grid(row=0,column=0)            Label(fn_frame, text='File Name:').grid(row=0, column=0)            fn_var = StringVar()            fn_var.set(fn)            fn_entry = Entry(fn_frame, textvariable=fn_var)            fn_entry.grid(row=0, column=1)            # 构建Frame对象以容纳OK和Cancel按钮            btn_frame = Frame(rename_dlg)            btn_frame.grid(row=1, column=0, sticky='e')            # 通过labmda表达式传递构建按钮控件时的对话框控件，路径和文件名信息            # 修改后的文件名要在按下【OK】按钮是通过fn_var.get获取。            ok_btn = Button(btn_frame, text='OK',                            command=(lambda w=rename_dlg,p=path,s=fn: rename_ok(w,p,s,fn_var.get())))            ok_btn.grid(row=0, column=0)            # 取消按钮直接销毁窗口对象            cancel_btn=Button(btn_frame, text='Cancel', command=rename_dlg.destroy)            cancel_btn.grid(row=0, column=1)            # 限定rename_dlg接收鼠标和键盘事件，这是实现模态对话框的关键。            rename_dlg.grab_set()            # 使对话框相对于root窗口居中            center_window(rename_dlg, root)            # 启动对话框主循环            rename_dlg.mainloop()            # 销毁对话框窗口            rename_dlg.destroy()            # 更新文件列表            select_node(None)

def center_window(wnd, ref):    wnd.update()    width = wnd.winfo_width()    height = wnd.winfo_height()    if ref:        ref_width = ref.winfo_width()        ref_height = ref.winfo_height()        x = ref.winfo_x()        y = ref.winfo_y()        size = '%dx%d+%d+%d' % (width, height, x + (ref_width - width) / 2, y+(ref_height - height) / 2)    else:        s_width = wnd.winfo_screenwidth()        s_height = wnd.winfo_screenheight()        size = '%dx%d+%d+%d' % (width, height, (s_width - width) / 2, (s_height - height) / 2)    wnd.geometry(size)