Obviously, that's a really short expression.

So, the question is, if you have a long expression, should you have to worry too much about either adding parentheses, or making sure that your line break occurs inside a pair of parentheses.

It boils down to preference, but a language feature that supports whatever preference you have might be nice.

  priority = "URGENT"  if hours < 2  else
             "HIGH"    if hours < 24 else
             "MEDIUM"  if hours < 72 else
             "LOW"