I am learning Python and I just read in a book that Python 3 lets you do this cool list operation:
first, *middle, last = [1, 2, 3, 4, 5]
first: 1
middle: [2, 3, 4]
last: 5
This is great if I want to iterate through the middle of the list, and do separate things with the first and last items.
What's the easiest (read: most sugary) way to do this in Python 2.x, PHP, and JavaScript?
python 2.x
first, middle, last = a[0], a[1:-1], a[-1]
a = [1,2,3,4,5]). Otherwise, if you want to do this on a literal in practice, you would have to spell out the literal three times.
first, middle, last = 1, [2, 3, 4], 5..A solution in PHP could be the following, using array_shift and array_pop:
$first = array_shift($arr);
$last = array_pop($arr);
$middle = $arr;
On Python2, you can just use slice notation, also it's easier to read I think.
>>> t = (1, 2, 3, 4, 5)
>>> a, b, c = t[0], t[1:-1], t[-1]
>>> a, b, c
(1, (2, 3, 4), 5)
In PHP:
list($first, $middle, $last) = array($array[0], array_splice($array, 1, -1), $array[1]);
It destroys the original array though, leaving only the first and last elements.
first, middle, last = a[0], a[1:-1], a[-1]
$first = array_shift($arr);
$last = array_pop($arr);
$middle = $arr;
var a = Array.apply(0,myAry), first = a.shift(), last = a.pop(), middle = a;
For the JavaScript sample, I created a copy of the array so as not to destroy the original.
