comprehension

c.coffee

coffee> i*i for i in [1..9] when i % 2 == 0
[ 4, 16, 36, 64 ]

# https://github.com/jashkenas/coffee-script/issues/2030
# http://brehaut.net/blog/2011/coffeescript_comprehensions
coffee> [i,j] for j in [1..3] for i in [1..3]
[ [ [ 1, 1 ],
    [ 1, 2 ],
    [ 1, 3 ] ],
  [ [ 2, 1 ],
    [ 2, 2 ],
    [ 2, 3 ] ],
  [ [ 3, 1 ],
    [ 3, 2 ],
    [ 3, 3 ] ] ]

c.py

>>> [i*i for i in range(1,10) if i % 2 == 0]
[4, 16, 36, 64]

>>> [(i, j) for i in range(1, 4) for j in range(1, 4)]
[(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)]

c.scala

scala> for{ i <- 1 until 10; if i % 2 == 0 } yield i*i
res1: scala.collection.immutable.IndexedSeq[Int] = Vector(4, 16, 36, 64)

scala> for{ i <- 1 until 4; j <- 1 until 4 } yield (i,j)
res2: scala.collection.immutable.IndexedSeq[(Int, Int)] = Vector((1,1), (1,2), (1,3), (2,1), (2,2), (2,3), (3,1), (3,2), (3,3))

Python では以下のように書けます.

>>> [(i, j) for i in range(1, 4) for j in range(1, 4)]
[(1, 1), (1, 2), (1, 3), (2, 1), (2, 2), (2, 3), (3, 1), (3, 2), (3, 3)]

Awesome! Updated. Thanks!!!