How to split a numpy array based on a column?

Question

I have an array of the form :

[[ 1. ,    2.,     3.,     1.,     3.,     3.,     4.   ],
 [ 1.3,    2.3,    3.3,    3.,     3.3,    3.3,    4.3  ],
 [ 1.2,    2.         


        

Answer 1

To make a list of arrays:

y = [x[x[:,3]==k] for k in np.unique(x[:,3])]