import wx

class MainFrame(wx.Frame):
    def __init__(self, parent):
        super(MainFrame, self).__init__(parent)
        self.InitUI()
        self.InitLayout()

    def InitUI(self):
        self.button1 = wx.Button(self, label='vmi')
        self.Bind(wx.EVT_BUTTON, self.onClickGomb1, self.button1)
        self.entry = wx.TextCtrl(self)

    def InitLayout(self):
        self.sizer1 = wx.BoxSizer(wx.VERTICAL)
        self.sizer1.Add(self.button1)
        self.sizer1.Add(self.entry)
        self.SetSizer(self.sizer1)

    def onClickGomb1(self, event):
        numStr = self.entry.GetValue()
        product = int(numStr) * 2
        self.entry.SetValue(str(product))

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

app = App()
app.MainLoop()