Proposed PEP for a Conditional Expression

[Terry Reedy]

<James_Althoff at i2.com> wrote in message
news:mailman.1000491857.7594.python-list at python.org...
> Why not just start with something simple like a builtin "cond"
function
> approximating the following:
> >>> def cond(expr, iftrue, iffalse=lambda:None):
> ...   if expr: return iftrue()
> ...   return iffalse()

Because, as explained before, both iftrue and iffalse expressions are
always both evaluated, which defeats one of the purposes of
conditional expressions, which is to not evaluate expressions that
will raise an exception.

Terry J. Reedy