Miscellany

import wx
def load(event):
    file = open(filename.GetValue())
    contents.SetValue(file.read())
    file.close()

def save(event):
    file = open(filename.GetValue(),'w')
    file.write(contents.GetValue())
    file.close()

app = wx.App()
win = wx.Frame(None, title="Simple Editor",size=(410,365))

bkg = wx.Panel(win)

loadButton = wx.Button(bkg, label='Open')
loadButton.Bind(wx.EVT_BUTTON, load)

saveButton = wx.Button(bkg, label='Save')
saveButton.Bind(wx.EVT_BUTTON,save)

color = wx.ColourDialog(bkg)

filename = wx.TextCtrl(bkg)
contents = wx.TextCtrl(bkg, style=wx.TE_MULTILINE | wx.HSCROLL)

hbox = wx.BoxSizer()
hbox.Add(filename, proportion=1,flag=wx.EXPAND)
hbox.Add(loadButton,proportion=0,flag=wx.LEFT,border=5)
hbox.Add(saveButton,proportion=0,flag=wx.LEFT,border=5)
hbox.Add(color,proportion=0,flag=wx.LEFT,border=5)

vbox = wx.BoxSizer(wx.VERTICAL)
vbox.Add(hbox,proportion=0, flag=wx.EXPAND|wx.ALL,border=5)
vbox.Add(contents, proportion=1,flag=wx.EXPAND|wx.LEFT|wx.BOTTOM|wx.RIGHT,border=5)

bkg.SetSizer(vbox)
win.Show()

app.MainLoop()