[Python-Dev] conditional expressions?

[Daniel Mahler]

Has an if(cond,exp1,exp2) syntax been considered?
It would have the advantage that existing
syntax sensitive editors would handle without change.
I think conditional exprs badly needed,
but the if/then/else syntax seems too verbose for use inside
expressions.

regards
Daniel Mahler

Tim Peters writes:
 > [Paul Svensson]
 > > ...
 > > I know there's been a long time request for this feature,
 > > supposedly from people coming to Python from C,
 > > but what's the real reason for adding it now,
 > > without even a PEP ?
 > 
 > The reason for *considering* it right now is a rapidly closing window of
 > opportunity -- 2.2b1 goes out later this week.  A fellow on c.l.py has been
 > plugging away at a PEP, Eric Raymond submitted a working patch for C's ?: in
 > January of 2000, Jim Fulton loved the idea then (but not particularly the ?:
 > spelling), David Ascher reported that lack of a conditional was a FAQ in his
 > classes then, etc etc.  Most replies hated the ?: syntax, and Guido
 > eventually remembered (although I think he forgot it this time around) that
 > Algol-60 used the obvious if/then/else.  His reply on Mon, 31 Jan 2000
 > 09:36:52 -0500:
 > 
 >     The solution can be the same as what Algol used:  'if' outside
 >     parentheses is a statement, and inside parentheses is an expression.
 >     It's a bit of a grammar rearrangement, but totally unambiguous.
 > 
 >     However, the added keyword means it won't be in 1.6.  The lively
 >     discussion means that Eric's patch will have a hard time getting
 >     in too...
 > 
 > The only difference between then and now is s/1.6/2.2/.
 > 
 > > Does it really add enough to the language to justify the bloat ?
 > 
 > I expect most people would say it does; by definition I'll adjust my beliefs
 > to whatever Guido decides <wink>.
 > 
 > 
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