http://stackoverflow.com/questions/10267132/grid-and-sizers-

import wx
import wx.grid

class SceRen:
    pass


class ScRenWindow(wx.Frame):

    dirname = ""
    version = 0.1

    def __init__(self, parent, title):
        self.sc_ren = SceRen("g:\\doesntexist\\", False, False)

        wx.Frame.__init__(self, parent, title=title)
        panel = wx.Panel(self)

        vSizer = wx.BoxSizer(wx.VERTICAL)
        grid = wx.GridBagSizer(hgap=5, vgap=5)

        label = wx.StaticText(panel, label="Select Folder")
        grid.Add(label, pos=(0,0))

        textField = wx.TextCtrl(panel, size=(300, 23))
        self.fieldOne = textField
        grid.Add(textField, pos=(1,0))

        btn = wx.Button(panel, wx.ID_FIND, "Find")
        self.Bind(wx.EVT_BUTTON, self.findFolder, btn)
        grid.Add(btn, pos=(2,0))

        grid.Add((1, 20), pos=(3,0))

        label2 = wx.StaticText(panel, label="Files")
        grid.Add(label2, pos=(4,0))

        # FileGrid
        fileF = wx.grid.Grid(panel)
        #fileF.SetMinSize(minSize=(400,200))
        fileF.CreateGrid(1,3)
        fileF.SetColLabelSize(0)
        fileF.SetRowLabelSize(0)

        fileF.SetCellValue(0, 0, "Old")
        fileF.SetCellValue(0, 1, "New")
        fileF.SetCellValue(0, 2, "Update?")

        fileF.SetReadOnly(0,0)
        fileF.SetReadOnly(0,1)
        fileF.SetReadOnly(0,2)

        fileF.Bind(wx.grid.EVT_GRID_CELL_LEFT_CLICK, self.selectClick)
        #wx.EVT_LEFT_DOWN(fileF, self.selectClick)
        #wx.EVT_KEY_DOWN(fileF, self.selectClick)

        self.fileField = fileF
        grid.Add(fileF, pos=(5,0))
        # FileGrid end


        runBtn = wx.Button(panel, wx.ID_APPLY, "Apply")
        self.Bind(wx.EVT_BUTTON, self.applyScRen, runBtn)
        grid.Add(runBtn, pos=(6,0))

        errlbl = wx.StaticText(panel, label="No Error")
        grid.Add(errlbl, pos=(6,1))

        grid.Add((1, 40), pos=(7,0))

        # MENUBAR not used yet
        filemenu = wx.Menu()
        menuOpen = filemenu.Append(wx.ID_OPEN, "&Open"," Open a file")
        self.Bind(wx.EVT_MENU, self.findFolder, menuOpen)
        menuBar = wx.MenuBar()
        menuBar.Append(filemenu,"&File")
        self.SetMenuBar(menuBar)

        #panel.CreateStatusBar()
        vSizer.Add(grid, 0, wx.ALL, 5)
        panel.SetSizerAndFit(grid)
        self.CreateStatusBar()
        self.SetInitialSize()
        self.Show(True)

    def findFolder(self, e):
        dlg = wx.DirDialog(self, "Select Folder", ".", wx.DEFAULT_DIALOG_STYLE)
        if dlg.ShowModal() == wx.ID_OK:
            self.dirname = dlg.GetPath()
        dlg.Destroy()
        self.fieldOne.SetLabel(self.dirname)
        self.populateGrid()
        return True;

    def populateGrid(self):
        pass

    def applyScRen(self, e):
        pass

    def selectClick(self, e):
        if (e.GetRow() > 0 and e.GetCol() == 2):
            current = self.fileField.GetCellValue(e.GetRow(),e.GetCol()) == "y"
            current = "n" if current else "y"
            self.fileField.SetCellValue(e.GetRow(),e.GetCol(),current)

app = wx.App(False)
frame = ScRenWindow(None, "Scren")
app.MainLoop()