On 3/19/2010 10:53 AM, gerardob wrote: > I would like to know a simple way to generate a list containing all the > lists having two 1's at each element. > > Example, n = 4 > L2 = [[1,1,0,0],[1,0,1,0],[1,0,0,1],[0,1,1,0],[0,1,0,1],[0,0,1,1]] >
I like list(set(itertools.permutations([1,1]+[0]*(n-2)))) (Modify if you don't like the tuples.) But you can use a NumPy array if you wish: cols = list(itertools.combinations(range(n),2)) r = len(cols) rows = np.arange(r)[:,None] a = np.zeros((r,n),dtype=np.int_) a[rows,cols] = 1 a.tolist() hth, Alan Isaac _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
