Ruby, Clojure, Python の空リストのブール値の違いメモ

(MacOSX10.8, Ruby1.9.3, Clojure1.4, Python2.7)

Ruby

true

irb(main):010:0> [] ? "t" : "n"
"t"

Clojure

true

user> (if () "t" "n" )
"t"

Python

False

>>> "t" if [] else "n"
'n'