append not working as expected

[buran]

You aren't appending, you are redefining things.

what you want it is

megalist.append(list_of_three)

This will tack it onto the end.

They insert the list always in position 0. Technically not appending, you are right, but that is not the cause of the problem. Even if they append, the problem will persist.

@teachinggeek: Lists are mutable object. Basically you insert the same object over and over again. Changes that you make affect also elements already inserted in the final list. That said, it's better to look at itertools.combinations()

>>> import itertools
>>> numbers=[1, 3, 5, 7, 9, 11, 13, 15]
>>> list(itertools.combinations(numbers, 3))
[(1, 3, 5), (1, 3, 7), (1, 3, 9), (1, 3, 11), (1, 3, 13), (1, 3, 15), (1, 5, 7), (1, 5, 9), (1, 5, 11), (1, 5, 13), (1, 5, 15), (1, 7, 9), (1, 7, 11), (1, 7, 13), (1, 7, 15), (1, 9, 11), (1, 9, 13), (1, 9, 15), (1, 11, 13), (1, 11, 15), (1, 13, 15), (3, 5, 7), (3, 5, 9), (3, 5, 11), (3, 5, 13), (3, 5, 15), (3, 7, 9), (3, 7, 11), (3, 7, 13), (3, 7, 15), (3, 9, 11), (3, 9, 13), (3, 9, 15), (3, 11, 13), (3, 11, 15), (3, 13, 15), (5, 7, 9), (5, 7, 11), (5, 7, 13), (5, 7, 15), (5, 9, 11), (5, 9, 13), (5, 9, 15), (5, 11, 13), (5, 11, 15), (5, 13, 15), (7, 9, 11), (7, 9, 13), (7, 9, 15), (7, 11, 13), (7, 11, 15), (7, 13, 15), (9, 11, 13), (9, 11, 15), (9, 13, 15), (11, 13, 15)]