How to I factorize a list of tuples?

Question

definition
factorize: Map each unique object into a unique integer. Typically, the range of integers mapped to is from zero to the n - 1 where n is

Answer 1

I don't know about timings, but a simple approach would be using numpy.unique along the respective axes.

tups = [(1, 2), ('a', 'b'), (3, 4), ('c', 5), (6, 'd'), ('a', 'b'), (3, 4)]
res = np.unique(tups, return_inverse=1, axis=0)
print res

which yields

(array([['1', '2'],
       ['3', '4'],
       ['6', 'd'],
       ['a', 'b'],
       ['c', '5']],
      dtype='|S11'), array([0, 3, 1, 4, 2, 3, 1], dtype=int64))

The array is automatically sorted, but that should not be a problem.