# [Tutor] n.isalnum() is failing

Terry terry.kemmerer at gmail.com
Sat Jul 7 00:49:39 CEST 2007

```Hi Janos,

Quote: Your logic is backward, and mine is the forward, isn't it?  ;)

The Story of My Life!

--Terry

On Thu, 2007-07-05 at 07:30 +0200, János Juhász wrote:

>
> Hi Terry
>
> > "According to the Gregorian calendar, which is the civil calendar in
> use
> > today, years evenly divisible by 4 are leap years, with the
> exception of
> > centurial years that are not evenly divisible by 400."
>
> > def isLeapYear(y):
> >   if y % 4 == 0: return True
> As it always return True, if y%4 == 0, there is problem with the
> exceptions
> >   if (y % 4 == 0) and not (y %100 == 0): return True
> >   else: return False
>
>
> I feel that, the cleanest way to translate the definition into Boolean
> logic
> is to do it backward instead of thinking on the exceptions.
>
> def leap_year(year):
>     if year%400 == 0: return True    # We said these years are always
> leap year
>     if year%100 == 0: return False   # the exception handled already
>     if year%4   == 0: return True    # no problem with the exceptions
>     return False                     # this it the default
>
>
> ps
> hungarians name format: family name, christian name
> hungarian date format: year/month/day
> Your logic is backward, and mine is the forward, isn't it?  ;)
>
>
> Janos
>
> _______________________________________________
> Tutor maillist  -  Tutor at python.org
> http://mail.python.org/mailman/listinfo/tutor
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