Select certain rows (condition met), but only some columns in Python/Numpy

Question

I have an numpy array with 4 columns and want to select columns 1, 3 and 4, where the value of the second column meets a certain condition (i.e. a fixed value). I tried to f

Answer 1

If you do not want to use boolean positions but the indexes, you can write it this way:

A[:, [0, 2, 3]][A[:, 1] == i]

Going back to your example:

>>> A = np.array([[1,2,3,4],[6,1,3,4],[3,2,5,6]])
>>> print A
[[1 2 3 4]
 [6 1 3 4]
 [3 2 5 6]]
>>> i = 2
>>> print A[:, [0, 2, 3]][A[:, 1] == i]
[[1 3 4]
 [3 5 6]]

Seriously,