怎么给wxpython里的窗口添加滚动条

Question

我的程序里面有设置了两个一样的grid表，但是没有滚动条只能看到一个，我在网上看到用Boxsizer来设置的，但是试了之后却让gird的窗口变得特别小，一个表都看不清了。下面是代码

#-*- encoding:UTF-8 -*-
import wx
import wx.grid
class TestTable(wx.grid.PyGridTableBase):#定义网格表
    def __init__(self):
        wx.grid.PyGridTableBase.__init__(self)
        self.data = { (1,1) : 'Here',
        (2,2) : 'is',
        (3,3) : 'some',
        (4,4) : 'data',
        }
        self.odd=wx.grid.GridCellAttr()
        self.odd.SetBackgroundColour('sky blue')
        self.odd.SetFont(wx.Font(10, wx.SWISS, wx.NORMAL, wx.BOLD))
        self.even=wx.grid.GridCellAttr()
        self.even.SetBackgroundColour('sea green')
        self.even.SetFont(wx.Font(10, wx.SWISS, wx.NORMAL, wx.BOLD))
    # these five are the required methods
    def GetNumberRows(self):
        return 50
    def GetNumberCols(self):
        return 50
    def IsEmptyCell(self, row, col):
        return self.data.get((row, col)) is not None
    def GetValue(self, row, col):#为网格提供数据
        value = self.data.get((row, col))
        if value is not None:
            return value
        else:
            return ''
    def SetValue(self, row, col, value):#给表赋值
        self.data[(row,col)] = value
    # # the table can also provide the attribute for each cell
    def GetAttr(self, row, col, kind):
        attr = [self.even, self.odd][row % 2]
        attr.IncRef()
        return attr
class TestFrame(wx.Frame):
    def __init__(self):
        wx.Frame.__init__(self, None, title='Grid Table',
        size=(640,480))
        grid = wx.grid.Grid(self)
        #这里是一个grid表
        table = TestTable()
        grid.SetTable(table, True)
        # 这里是第二个个grid表
        le = TestTable()
        grid.SetTable(le, True)
app = wx.PySimpleApp()
frame = TestFrame()
frame.Show()