def sum_matrix (matrix):
    #
    # | 1 2 3 |
    # | 1 2 3 |
    # | 1 2 3 |  ->  |4 8 12|
    # | 1 2 3 |
    # _________
    #   4 8 12
    vektor = [[0] for i in range(0,len(matrix[0]))]
    for j  in range(0, len(matrix[0])):        #rows 0-3 4
        buffer = 0
        for i in range(0, len(matrix)):  #columns 3
            if matrix[i][j] !=None:
                buffer = buffer + matrix[i][j]
                #vektor[j][0] = buffer
            elif matrix[i][j] ==None:
                vektor[j][0] = None
        vektor[j][0] = buffer
    return vektor

print (sum_matrix ([[0,0,0],[0,0,1],[0,1,0],[0,0,0]]))
print (sum_matrix ([[0,0,0],[0,None,1],[0,1,None],[0,0,0]]))