HowCanI: inlined exceptions

[Robert Citek]

Hello Pete,

Is this something of what you have in mind?

def catch(expression, errcode=None):
    try:
       return eval(expression)
    except:
        return errcode

if __name__ == '__main__':
    name = catch("fields[1]", 'Anonymous')
    age = catch("now-birth", 100)
    pet = catch("findpet(name, age)") or 'No Pet'
    print name
    print age
    print pet

- Robert

-----

At 02:09 PM 5/26/00 -0700, Pete Shinners wrote:
>after working with python a bit, one thing i find myself
>needing to do really often is test an expression before
>i can use it one simple assignments/etc
>
>what i'd really,really like to do is define something
>that works like this
>
>def catch(expression, errcode=None):
>    try:
>        return expression:
>    except:
>        return errcode
>
>if __name__ == '__main__':
>    name = catch(fields[1], 'Anonymous')
>    age = catch(now-birth, 100)
>    pet = catch(findpet(name, age)) or 'No Pet'
>
>i would really like to do this for myself, because i
>would use it extensively! i understand the problem 
>here is that my "expression" is being evaluated 
>before the function is getting called, so the
>exception is raised outside of my function.
>
>i'm just hoping there's some way to do this be
>defining a lot of 'magic' classes and default
>handling. i could make it work by passing the
>expression in quotes (so it is a string), but
>i'd prefer something a little cleaner
>
>this is a case where C-style macros are handy!
>but i know some python guru can come through
>for me in this case.    (???)
>
>-- 
>_____Pete Shinners______
>   pete at visionart.com