On Fri, Feb 21, 2014 at 6:46 AM, Nick Coghlan <ncoghlan@gmail.com> wrote:
On 22 February 2014 00:37, Eli Bendersky <eliben@gmail.com> wrote:
> This goes against anything I understand about how exceptions should and
> should not be used.

I think you're thinking of a language that isn't Python - we use
exceptions for control flow all over the place (it's how hasattr() is
*defined*, for example).

No, it is Python I'm thinking about. As I mentioned in the reply to Brett's message, I see a difference between allowing exceptions on expression level and statement level. The latter is less likely to be abused. Once you add exceptions into expressions, all bets are off.

For instance, it is sometime non-trivial to know which exceptions some function may throw. When you write a try...raise statement, you think hard about covering all the bases. In an expression you're unlikely to, which opens up a lot of possibilities for bugs. Again, please stop focusing just on the list[index] case -- the proposal adds a new significant feature to the language that can (and thus will) be used in a variety of scenarios.