The dimension of an array can be extended with the method newaxis:
>>> x = np.array([1,3,5,17,23])
>>> x
array([ 1, 3, 5, 17, 23])
>>> y = x[:, np.newaxis]
>>> y
array([[ 1],
[ 3],
[ 5],
[17],
[23]])
>>> y[0,0]
1
>>> y[4,0]
23
>>> x[np.newaxis,:]
array([[ 1, 3, 5, 17, 23]])