gistfile1.py

def isSame(a, b):
    return a==b

last = None
def f(sum, b):
    global last
    first = b[0]
    if isSame(last, first):
        sum[-1].extend(b[1:])
    else:
        sum.append(b)
    last = first

    return sum

print reduce(f, [["1", 1, 2], ["1", 3, 4], ["2", 5, 6], ["2", 7, 8], ["3", 1], ["4", 1]], [])