On Fri, Feb 21, 2014 at 8:41 PM, Greg Ewing <greg.ewing@canterbury.ac.nz> wrote:

Ethan Furman wrote:

On 02/21/2014 03:29 PM, Greg Ewing wrote:

value = lst[2] except "No value" if IndexError

It does read nicely, and is fine for the single, non-nested, case (which is probably the vast majority), but how would it handle nested exceptions?

Hmmm, probably not very well, unless we define

a except b if E1 except c if E2

to mean

a except (b except c if E2) if E1

If E1 == E2, that could perhaps be abbreviated to

a except b except c if E

Or we could just decide that the nested case is going
to be so rare it's not worth worrying about.

+1 on not caring. Keep the expression for simple, obvious cases of a single exception type and fall back to the statement for fancier use (just like listcomps). The focus should be ease of expressiveness for a common pattern, not trying to convert tons of try/except statements into an expression just because we can.