[threeducks]

You don't have to wrap the lists in np.array if you use NumPy functions (or if one of the arguments already is a NumPy array, which usually is the case):

    from numpy import *

    A = [[1, 2], [3, 4]]
    x = [[5], [6]]
    y = dot(A, x)

[nis251413]

That's nice, but only works, as I understand it, if you use numpy-only functions, which means that you should not use those who denote also base-pythonic, eg +,* etc operations, because then they are interpreted differently. Eg `A + x` gives

    [[1, 2], [3, 4], [5], [6]] 

instead of

    array([[ 6,  7],[ 9, 10]])

You have to keep track of the context there to know what you can do and what not I guess, which is not ideal.