[Python-Dev] (try-except) conditional expression similar to (if-else) conditional (PEP 308) (original) (raw)

Alexander Kozlovsky alexander.kozlovsky at gmail.com
Sat Aug 15 00:41:30 CEST 2009

Jeff McAninch wrote:

I very often want something like a try-except conditional expression similar to the if-else conditional.

I think it may be done currently with the help of next function:

def guard(func, *args):
    try:
        return func()
    except Exception, e:
        for exc_type, exc_func in args:
            if isinstance(e, exc_type):
                return exc_func()
            raise

Example usage:

a, b, c = 10, 20, 0

result = a + b/c  # raise ZeroDivisionError

result = a + guard(lambda: b/c, (TypeError, lambda: 10),
                                (ZeroDivisionError, lambda: b/2))

May be not very concise, but it works...

-- Best regards, Alexander mailto:alexander.kozlovsky at gmail.com

More information about the Python-Dev mailing list