matrix_multiply

mul.py

A = [[1, 2, 3],
     [1, 2, 3],
     [1, 2, 3],
     [1, 2, 3]]

B = [[1, 2, 3, 4],
     [1, 2, 3, 4],
     [1, 2, 3, 4]]


def multiply(A, B):
    A_rows = len(A)
    A_cols = len(A[0])
    B_rows = len(B)
    B_cols = len(B[0])

    if A_cols != B_rows:
        print "Can\'t multiply"
        return

    C = []
    for x in range(A_rows):
        C.append(list())
        for y in range(B_cols):
            C[x].append(0)

    print C

    for i in range(A_rows):
        for j in range(B_rows):
            for el in range(A_cols):
                C[i][j] += A[i][j] + B[el][j]

    print C


if __name__ == '__main__':
    multiply(A, B)