python vetor linha para vetor coluna

Vetor para linha, para vetor coluna

>>> a[None].T
array([[1],
       [2],
       [3]])
>>> np.newaxis is None
True

>>> a.reshape(a.shape+(1,))
array([[1],
       [2],
       [3]])

>>> a[:,None]
array([[1],
       [2],
       [3]])