On Sun, Oct 3, 2021 at 11:40 PM Steven D'Aprano firstname.lastname@example.org wrote:
On Sun, Oct 03, 2021 at 11:34:55AM -0700, Guido van Rossum wrote:
I also think that the bar should be pretty high before we reopen the *syntax* -- the PEP was approved without anyone (neither the SC, nor Nathaniel, nor anyone else) providing any feedback on the use of 'except *'. So I think it's a bit late to be bikeshedding the syntax. This thread was meant to solicit feedback on how to *format* it: does the space go before or after the '*'.
`except* E`, otherwise it looks like unpacking E.
I think it's worth noting that the following is already legal:
Python 3.9.7 (tags/v3.9.7:1016ef3, Aug 30 2021, 20:19:38) [MSC v.1929 64 bit (AMD64)] on win32 Type "help", "copyright", "credits" or "license" for more information.
exceptions = (ValueError, TypeError) try:
... raise TypeError ... except exceptions: ... print("caught") ... caught
Indeed, when I first learned that you could do this (a few years ago IIRC), my first thought was to unpack the "exceptions" tuple with a star. It wasn't until I tried that and got a SyntaxError that I tried it the way shown here and it worked.
Allowing `except *E` for this new feature would take that helpful-to-a-beginner SyntaxError and turn it into a subtle and unhelpful bug.
Therefore my vote is for requiring `except* E` and keeping `except *E` as a SyntaxError.