import wx

class ValamiDialog(wx.Dialog):
    def __init__(self, parent, title):
        super(ValamiDialog, self).__init__(parent, title=title, size=(300, 400))
        panel = wx.Panel(self)
        self.btn = wx.Button(panel, wx.ID_OK, label='ok')

class MainFrame(wx.Frame):
    def __init__(self, parent, title):
        super(MainFrame, self).__init__(parent, title=title)

        dialog = ValamiDialog(self, 'valami')
        dialog.Show()

class SimpleApp(wx.App):
    def OnInit(self):
        frame = MainFrame(None, 'Párbeszéd')
        frame.Show()
        return True

if __name__ == "__main__":
    app = SimpleApp()
    app.MainLoop()