km

def doit(a):    b = []    while len(a) > 0:        x = a.pop(0)        if not x in b or not x in a:            b.append(x)    return b[G:/] $ python -i foo.py>>> doit([1,2,3,3,2,1,1,2,3,2,2,3])[1, 2, 3, 1, 2, 3]>>> doit([0,1,0,3,0,0,0,0,0])[0, 1, 3, 0]>>>