Update CR0601_wxcalculator.py

Fix crazy error when mixing wx.EXPAND with center

Author: driscollis

chapter6_calculator/CR0601_wxcalculator.py

@@ -29,9 +29,9 @@ def create_ui(self):
             btn_sizer = wx.BoxSizer()
             for label in label_list:
                 button = wx.Button(self, label=label)
-                btn_sizer.Add(button, 1, wx.ALIGN_CENTER|wx.EXPAND, 0)
+                btn_sizer.Add(button, 1, wx.EXPAND, 0)
                 button.Bind(wx.EVT_BUTTON, self.update_equation)
-            main_sizer.Add(btn_sizer, 1, wx.ALIGN_CENTER|wx.EXPAND)
+            main_sizer.Add(btn_sizer, 1, wx.EXPAND)
 
         equals_btn = wx.Button(self, label='=')
         equals_btn.Bind(wx.EVT_BUTTON, self.on_total)
@@ -100,4 +100,4 @@ def __init__(self):
 if __name__ == '__main__':
     app = wx.App(False)
     frame = CalcFrame()
-    app.MainLoop()
+    app.MainLoop()