Get all combinations of elements from two lists?

Question

If I have two lists

l1 = [ \'A\', \'B\' ]

l2 = [ 1, 2 ]

what is the most elegant way to get a pandas data frame which looks like:

Answer 1

You can also use the sklearn library, which uses a NumPy-based approach:

from sklearn.utils.extmath import cartesian

df = pd.DataFrame(cartesian((L1, L2)))

For more verbose but possibly more efficient variants see Numpy: cartesian product of x and y array points into single array of 2D points.