I suggest you should build your list using a list comprehension: >>>a = [[0]*3 for i in range(3)] >>>a [[0, 0, 0], [0, 0, 0], [0, 0, 0]] >>>a[0][1] = 1 [[0, 1, 0], [0, 0, 0], [0, 0, 0]] -- Steve R. Hastings "Vita est" steve at hastings.org http://www.blarg.net/~steveha