[Python-Dev] PEP 409 and the stdlib (original) (raw)

Serhiy Storchaka storchaka at gmail.com
Tue May 21 11:56:14 CEST 2013

21.05.13 12:28, Hrvoje Niksic написав(ла):

On 05/21/2013 10:36 AM, Serhiy Storchaka wrote:

The above exception was converted to the following exception: ...

That makes it clear that the conversion was explicit and (hopefully) intentional, and that the latter exception supersedes the former. How do you distinguish intentional and unintentional exceptions? By the use of the "raise" keyword. Given the code: try: x = d['key'] except KeyError: raise BusinessError(...) ....the explicit raising is a giveaway that the new exception was quite intentional.

try: x = d['key'] except KeyError: x = fallback('key')

def fallback(key): if key not in a: raise BusinessError(...) return 1 / a[key] # possible TypeError, ZeroDivisionError, etc

More information about the Python-Dev mailing list