可能有更好的方法，但这可行.添加一个按钮，并在按下该按钮时从文本输入中获取输入，并将其传递给裁剪功能.

There is probably a nicer way to do it, but this works. Add a button, and when that button is pressed get the input from the text entries and pass them to the crop function.

def crop(self):
    self.root = Tk()
    self.root.wm_title("Insert Coords")

    self.x0 = Entry(self.root)
    self.x0.grid()

    self.x1 = Entry(self.root)
    self.x1.grid()

    self.y0 = Entry(self.root)
    self.y0.grid()

    self.y1 = Entry(self.root)
    self.y1.grid()

    Button(self.root, text="Crop", command=self.close_crop).grid()

def close_crop(self):        
    self.crop1(self.x0.get(), self.x1.get(), self.y0.get(), self.y1.get())
    self.root.destroy()                

def crop1(self, x0, x1, y0, y1):
    print x0, x1, y0, y1