Removing elements that have consecutive duplicates

Question

I was curios about the question: Eliminate consecutive duplicates of list elements, and how it should be implemented in Python.

What I came up with is this:

Answer 1

Here is a solution without dependence on outside packages:

list = [1,1,1,1,1,1,2,3,4,4,5,1,2] 
L = list + [999]  # append a unique dummy element to properly handle -1 index
[l for i, l in enumerate(L) if l != L[i - 1]][:-1] # drop the dummy element

Then I noted that Ulf Aslak's similar solution is cleaner :)