Selecting rows from a NumPy ndarray

Question

I want to select only certain rows from a NumPy array based on the value in the second column. For example, this test array has integers from 1 to 10 in the second column.

Answer 1

numpy.in1d is what you are looking for:

print test[numpy.in1d(test[:,1], wanted)]

It should easily be the fastest solution if wanted is large; plus, it is the most readable one, id say.