> > def invert(p): > > inverse = [None] * len(p) > > for (i, j) in enumerate(p): > > inverse[j] = i > > return inverse > > Elegant. This seems like the best solution, although it isn't as much > fun to write as a "one-liner". Thanks >>> invert([1, 2, 3, 1]) [None, 3, 1, 2] #blah