For review: PEP 308 - If-then-else expression

[Roy Smith]

Erik Max Francis <max at alcyone.com> wrote:

> 	if cond:
> 	    statement1
> 	else:
> 	    statement2
> 
> and collapsing it into an expression:
> 
> 	(if cond: expression1 else: expression2)
> 
> That really doesn't strike me as so bad.  Particularly if most of the
> objections center around overloading the meaning of if, or the
> awkwardness of reading the proposed x if p else y structure not reading
> left-to-right, maybe this makes sense after all?

It seems to me we're getting very close to "let's take some arbitrary 
code and turn it into an expression", which is essentially what a lambda 
is.  I'm not particularly fond of lambdas, but given that we have them, 
I don't really see the point of having two versions of them.

I guess deep down, my real objection to all this is that it blurs the 
line between statements and expressions.  In some languages (lisp, for 
example) there is no such distinction, and everything returns a value.  
But in Python, there is a distinction.  So is "if" a statement or an 
expression?  With this PEP, the answer becomes, "it depends", which I 
think is a bad answer.