垂直扩展一个小部件,同时使用Tkinter/ttk锁定另一个小部件

我在一个框架内有一个树状视图,它位于另一个包含按钮的框架顶部。我想顶部框架扩大时,我调整窗口,但保持按钮框架做同样的事情。

Python 2.7.5中的代码:

    class MyWindow(Tk.Toplevel, object):
      def __init__(self, master=None, other_stuff=None):
        super(MyWindow, self).__init__(master)
        self.other_stuff = other_stuff
        self.master = master
        self.resizable(True, True)
        self.grid_columnconfigure(0, weight=1)
        self.grid_rowconfigure(0, weight=1)

        # Top Frame
        top_frame = ttk.Frame(self)
        top_frame.grid(row=0, column=0, sticky=Tk.NSEW)
        top_frame.grid_columnconfigure(0, weight=1)
        top_frame.grid_rowconfigure(0, weight=1)
        top_frame.grid_rowconfigure(1, weight=1)

        # Treeview
        self.tree = ttk.Treeview(top_frame, columns=('Value'))
        self.tree.grid(row=0, column=0, sticky=Tk.NSEW)
        self.tree.column("Value", width=100, anchor=Tk.CENTER)
        self.tree.heading("#0", text="Name")
        self.tree.heading("Value", text="Value")

        # Button Frame
        button_frame = ttk.Frame(self)
        button_frame.grid(row=1, column=0, sticky=Tk.NSEW)
        button_frame.grid_columnconfigure(0, weight=1)
        button_frame.grid_rowconfigure(0, weight=1)

        # Send Button
        send_button = ttk.Button(button_frame, text="Send", 
        command=self.on_send)
        send_button.grid(row=1, column=0, sticky=Tk.SW)
        send_button.grid_columnconfigure(0, weight=1)

        # Close Button
        close_button = ttk.Button(button_frame, text="Close", 
        command=self.on_close)
        close_button.grid(row=1, column=0, sticky=Tk.SE)
        close_button.grid_columnconfigure(0, weight=1)

我在其他地方举了这样的例子:

    window = MyWindow(master=self, other_stuff=self._other_stuff)

尝试锁定可调整大小,但只会使按钮消失。我也试着改变重量,但我目前的配置是所有东西都显示在屏幕上的唯一方式。

无论高度有多高,它都应该是什么样子:

提前谢谢。