Proposed PEP for a Conditional Expression

[Greg Ewing]

Ken Seehof wrote:
> 
> Also, I would propose that ... else None should be implicit.
>    >>> print 'eeek' if pi == 3
>    None
> 
> But ... people could easily be confused and misinterpret the syntax as:
>    <statement> if <cond> [ else <statement> ]

That's a good argument for making the else mandatory.
It's less easy to misinterpret

   print 'eeek' if pi == 3 else None

It would be even clearer if parentheses were required:

   print ('eeek' if pi == 3 else None)

So I suggest that parentheses always be required around
if..else expressions. That would clear up any potential
confusion in list comprehensions, and anywhere else that
it might occur.

-- 
Greg Ewing, Computer Science Dept, University of Canterbury,	  
Christchurch, New Zealand
To get my email address, please visit my web page:	  
http://www.cosc.canterbury.ac.nz/~greg