[bionoid]

I have seen it a lot of code over the years, sometimes referred to as "shorthand ternary" or the "and-or-trick". In Python and/or do not return a boolean, but one of its input arguments. So I am going to say it is official syntax, but I don't know to what extent it's encouraged

[wruza]

Not only in python, but in most scripting languages. It’s hard to find one that doesn’t. But it’s neither official, nor ternary syntax anywhere.

  true and false or true
  true ?   false :  true

These are not equivalent. If the second argument is evaluated as false, the “ternary” breaks.

Lua suggests to use this as ternary, but it has only two false values (nil, false), which reduces the number of problematic cases a little.