[Python-Dev] I'd like list.pop to accept an optional second

[Skip Montanaro]

    Fred> Skip Montanaro writes:
    >> Why not go all the way to Perl with
    >> 
    >> top = list.pop() unless IndexError


    Fred> Trying to kill me, Skip?  ;-)

Nope, just a flesh wound.  I'll wait for the resulting infection to really
do you in. ;-)

    Fred> Actually, the semantics are different.  If we interpret that using
    Fred> the Perl semantics for "unless", don't we have the same thing as:

Yes, but the flavor is the same.  Reading Perl code that uses the unless
keyword always seemed counterintuitive to me.  Something like

    x = y unless foo;

always reads to me like, "Assign y to x.  No, wait a minute.  I forgot
something.  Only do that if foo isn't true."  What was so bad about

    if (!foo) { x = y; }

That was my initial reaction to the use of the trailing except.

We argue a lot in the Python community about whether or not a proposed
language feature increases the expressive power of the language or not
(which is a good idea in my opinion).  The Perl community has apparently
never been afflicted with that disease.

smiles all 'round...

Skip