import wx

app = wx.App()

win = wx.Frame(

    None,

    title="simple editor",

    size=(410, 335))

bkg = wx.Panel(win)

def openFile(evt):

    dlg = wx.FileDialog(

        win,

        "Open",

        "",

        "",

        "All files (*.*)|*.*",

        wx.FD_OPEN | wx.FD_FILE_MUST_EXIST)

    filepath = ''

    if dlg.ShowModal() == wx.ID_OK:

        filepath = dlg.GetPath()

    else:

        return

    filename.SetValue(filepath)

    fopen = open(filepath)

    fcontent = fopen.read()

    contents.SetValue(fcontent)

    fopen.close()

def saveFile(evt):

    fcontent = contents.GetValue()

    fopen = open(filename.GetValue(), 'w')

    fopen.write(fcontent)

    fopen.close()

openBtn = wx.Button(bkg, label='open')

openBtn.Bind(wx.EVT_BUTTON, openFile)

saveBtn = wx.Button(bkg, label='save')

saveBtn.Bind(wx.EVT_BUTTON, saveFile)

filename = wx.TextCtrl(bkg, style=wx.TE_READONLY)

contents = wx.TextCtrl(bkg, style=wx.TE_MULTILINE)

hbox = wx.BoxSizer()

hbox.Add(openBtn, proportion=0, flag=wx.LEFT | wx.ALL, border=5)

hbox.Add(filename, proportion=1, flag=wx.EXPAND | wx.TOP | wx.BOTTOM, border=5)

hbox.Add(saveBtn, proportion=0, flag=wx.LEFT | wx.ALL, border=5)

bbox = wx.BoxSizer(wx.VERTICAL)

bbox.Add(hbox, proportion=0, flag=wx.EXPAND | wx.ALL)

bbox.Add(

    contents,

    proportion=1,

    flag=wx.EXPAND | wx.LEFT | wx.BOTTOM | wx.RIGHT,

    border=5)

bkg.SetSizer(bbox)

win.Show()

app.MainLoop()