This idiom is however out of flavor, unless you need to support python 2.4.

Nowadays you would do this: truecase if condition else falsecase

Heh; my "age" is starting to show. The first version of Python I learned was Python 2.4 and it was only a few years ago I finally moved to 2.6. Skipping 2.7 and moving to 3.3+ soon.

Personally, I prefer the brevity of the older syntax, but to each his own. However, I understand the "ternary" expression was added because the older syntax was error-prone:

http://mail.python.org/pipermail/python-dev/2005-September/0... http://www.python.org/dev/peps/pep-0308/

ah! I've been trying to write Python lately (I'm more of a Rubyist) and the internet suggested:

truecase if condition else falsecase

which is so inside-out that it hurts.

It didn't occur to me to use the boolean style - I guess I think of that as a perl idiom, and assumed that it would get sneered at in py-land

I've never seen:

  $CONDITION && $TRUE_CASE || $FALSE_CASE

used as a Perl idiom in lieu of:

  $CONDITION ? $TRUE_CASE : $FALSE_CASE

I can't claim to have worked with Perl much prior to Perl 5.6/5.8 though, so it may have been an older idiom (though I doubt it as one of Perl's influences was Awk, which also has a C ternary operator, IIRC).

That said, using truthy/falsey values in Python doesn't seem super common. I surprised a couple of interviewers by doing that while implementing some tree manipulation functions.

It was mostly used before the creation of the ternary operator in Python 2.5.

This is how you do it in Lua, as well, since it doesn't have a ternary operator.