Conditional operator in Python?

[Terry Reedy]

<thp at cs.ucr.edu> wrote in message news:9n1hr7$7op$1 at glue.ucr.edu...
> Marcin 'Qrczak' Kowalczyk <qrczak at knm.org.pl> wrote:
> : Sat, 31 Mar 2001 21:22:54 -0800, Erik Max Francis
<max at alcyone.com> pisze:
>
> :> The Python FAQ, for instance, suggests x ? a : b can be reliably
> :> substituted with
> :>
> :>     (x and [a] or [b])[0]

If you *know* that a will always evaluate as <true>, then 'x and a or
b' works fine.  All the rigamarole of tuples or lambdas is only needed
to protect against the possibility of a evaulating as false.  When it
is not possible, said protection is not necessary.

> Agreed.  Something more aesthetic is definitely needed.  I hate
writing:
>
>   factorial = lambda x : (x<=1 and [1] or [x*factorial(x-1)])[0]

Since 1 != 0, quite dependably, you do not need to. try "x<=1 and 1 or
x*factorial(x-1)"

Terry J. Reedy