cleaner way to write this try/except statement?

[Simon Forman]

Boris Borcic wrote:
> John Salerno wrote:
> > The code to look at is the try statement in the NumbersValidator class,
> > just a few lines down. Is this a clean way to write it? i.e. is it okay
> > to have all those return statements? Is this a good use of try? Etc.
> >
> > Thanks.
> >
> > ----------------------------
> >
> > import wx
> >
> >
> > class NumbersValidator(wx.PyValidator):
> >
> >     def __init__(self):
> >         wx.PyValidator.__init__(self)
> >
> >     def Clone(self):
> >         return NumbersValidator()
> >
> >     def Validate(self, parent):
> >         text_ctrl = self.GetWindow()
> >         text = text_ctrl.GetValue()
> >
> >         try:
> >             if not text or int(text) <= 0:
> >                 wx.MessageBox('Enter a valid time.', 'Invalid time
> >                               entered', wx.OK | wx.ICON_ERROR)
> >                 return False
> >             else:
> >                 return True
> >         except ValueError, error:
> >             wx.MessageBox('Enter a valid time.', 'Invalid time entered',
> >                           wx.OK | wx.ICON_ERROR)
> >             return False
>
> well, assuming you are unsatisfied with the above, you could try to assert the
> validation condition and catch together all failures, eg :
>
> def Validate(self, parent):
>          text_ctrl = self.GetWindow()
>          text = text_ctrl.GetValue()
>          try :
>              assert int(text)>0
>              return True
>          except (ValueError,AssertionError) :
>              wx.MessageBox('Enter a valid time.', 'Invalid time entered',
>                            wx.OK | wx.ICON_ERROR)
>              return False
>
> hth, BB

Assertion statements "go away" when you run python with the '-O' or
'-OO' options.  They're only meant for debugging and shouldn't be used
as part of your actual program logic.

You run the risk of introducing hard-to-find bugs if you use them like
this and somebody, somewhere, sometime runs your code in "optimized"
mode.

Peace,
~Simon