sorted unique elements from a list; using 2.3 features

[Peter Abel]

Andrew Dalke <adalke at mindspring.com> wrote in message news:<avbltt$kb4$1 at slb0.atl.mindspring.net>...

Hi Andrew,
Im using Python 2.2.2 and without the 2.3. - features the
following seems to work fine:

>>> input=[5, 3, 1, 2, 5, 4, 3, 4, 1, 1, 5, 4, 5, 1, 4, 3, 2, 2, 4, 1]
>>> output=dict( zip(input ,range(len(input)) ) ).keys()
>>> output
[1, 2, 3, 4, 5]

What Im wondering about is the fact that in several examples
even without the statment:

>>> output.sort()

I always got a sorted output.

Cheers Peter