numpy 1D array --> column/row matrix:
>>> a=np.array([1,2,4])
>>> a[:, None] # col
array([[1],
[2],
[4]])
>>> a[None, :] # row, or faster `a[None]`
array([[1, 2, 4]])
And as @joe-kington said, you can replace None
with np.newaxis
for readability.