tkinter按钮后的神秘额外空间

你想要这种行为吗?

import tkinter as tk

class App(tk.Tk):
    def __init__(self):
        tk.Tk.__init__(self)
        self.initialize()

    def initialize(self):        

        button_crop = tk.Button(self, text=u"Crop", command=self.OnCrop)
        button_crop.grid(row=0, column=0, sticky=(tk.N, tk.S, tk.E, tk.W))

        button_crop = tk.Button(self, text=u"Reset", command=self.OnReset)
        button_crop.grid(row=0, column=1, sticky=(tk.N, tk.S, tk.E, tk.W))

        for i in range(2):
            self.columnconfigure(i, weight=1)

        self.rowconfigure(0, weight=1)

    def OnCrop(self):
        pass

    def OnReset(self):
        pass

app = App()

app.mainloop()