gistfile1.py

def _checkSizer(self):                                                      
    """Makes sure the sizer is created before setting props that need it."""
    if self.Sizer is None:                                                  
        self.Sizer = self.SizerClass(Parent=self)                           
    self.Sizer.Orientation = self.Orientation                           
    self.Sizer.Caption = self.Caption