How to encode categorical values in Python

Question

Given a vocabulary ["NY", "LA", "GA"], how can one encode it in such a way that it becomes:

"NY" = 100
"LA" = 010
"GA" = 001

So if I do a lookup on "NY GA", I get 101

Answer 1

you can use numpy.in1d:

>>> xs = np.array(["NY", "LA", "GA"])
>>> ''.join('1' if f else '0' for f in np.in1d(xs, 'NY GA'.split(' ')))
'101'

or:

>>> ''.join(np.where(np.in1d(xs, 'NY GA'.split(' ')), '1', '0'))
'101'