"Collapsing" a list into a list of changes

[Raymond Hettinger]

[Alan McIntyre]
> I have a list of items that has contiguous repetitions of values, but
> the number and location of the repetitions is not important, so I just
> need to strip them out.  For example, if my original list is
> [0,0,1,1,1,2,2,3,3,3,2,2,2,4,4,4,5], I want to end up with [0,1,2,3,2,4,5].

>>> import itertools
>>> [k for k, v in itertools.groupby(lst)]
[0, 1, 2, 3, 2, 4, 5]


Raymond Hettinger