python - wxPython childframes interaction -

i've created simple program consists 1 mainframe(frame) , 2 childframes (childframe1 , childframe2). mainframe has 2 buttons 1 check if childframe1 created , create same if not , other check if childframe2 created , create same if not. tricky part (at least tricky me), childframe1 has button needs check if childframe2 created mainframe , if not create it. in code button creates childframe2 alongside created childframe2 mainframe. how can make work? have 2 buttons on 2 frames 1 event.

code

import wx  class frame(wx.frame):     def __init__(self):         wx.frame.__init__(self, none, wx.id_any,'parent')         panel = wx.panel(self, -1)          sizer = wx.boxsizer(wx.vertical)         button = wx.button(panel, -1, 'open child1')         button2 = wx.button(panel, -1, 'open child2')          sizer.add(button, 0, wx.center|wx.all, 5)         sizer.add(button2, 0, wx.center|wx.all, 5)          panel.setsizer(sizer)          self.bind(wx.evt_button, self.onbutton,  button)         self.bind(wx.evt_button, self.onbutton2,  button2)      def onbutton(self, e):         try:             self.childf.show()         except:             self.childf = childframe1()             self.childf.show()          self.childf.setfocus()      def onbutton2(self, e):         try:             self.childf2.show()         except:             self.childf2 = childframe2()             self.childf2.show()          self.childf2.setfocus()  class childframe1(wx.frame):     def __init__(self):         wx.frame.__init__(self, wx.getapp().topwindow, wx.id_any, 'child1')         panel = wx.panel(self, -1)          sizer = wx.boxsizer(wx.vertical)         button = wx.button(panel, -1, 'open child2')         sizer.add(button, 0, wx.center|wx.all, 5)          panel.setsizer(sizer)          self.bind(wx.evt_button, self.onbutton, button)      def onbutton(self,e):         try:             self.childf.show()         except:             self.childf = childframe2()             self.childf.show()          self.childf.setfocus()  class childframe2(wx.frame):     def __init__(self):         wx.frame.__init__(self, wx.getapp().topwindow, wx.id_any, 'child2')  if __name__ == '__main__':     app = wx.app()     frame = frame().show()     app.mainloop() 

you bind childframe1's button handler parent frames method opening/showing childframe2.

import wx   class frame(wx.frame):     def __init__(self):         wx.frame.__init__(self, none, wx.id_any, 'parent')         panel = wx.panel(self, -1)          sizer = wx.boxsizer(wx.vertical)         button = wx.button(panel, -1, 'open child1')         button2 = wx.button(panel, -1, 'open child2')          sizer.add(button, 0, wx.center | wx.all, 5)         sizer.add(button2, 0, wx.center | wx.all, 5)          panel.setsizer(sizer)          self.bind(wx.evt_button, self.onbutton, button)         self.bind(wx.evt_button, self.onbutton2, button2)      def onbutton(self, e):         try:             self.childf.show()         except:             self.childf = childframe1()             self.childf.show()          self.childf.setfocus()      def onbutton2(self, e):         try:             self.childf2.show()         except:             self.childf2 = childframe2()             self.childf2.show()          self.childf2.setfocus()   class childframe1(wx.frame):     def __init__(self):         wx.frame.__init__(self, wx.getapp().topwindow, wx.id_any, 'child1')         panel = wx.panel(self, -1)          sizer = wx.boxsizer(wx.vertical)         button = wx.button(panel, -1, 'open child2')         sizer.add(button, 0, wx.center | wx.all, 5)          panel.setsizer(sizer)          self.bind(wx.evt_button, self.getparent().onbutton2, button)   class childframe2(wx.frame):     def __init__(self):         wx.frame.__init__(self, wx.getapp().topwindow, wx.id_any, 'child2')  if __name__ == '__main__':     app = wx.app()     frame = frame().show()     app.mainloop()