For Python 2.7 - cythonized version only works for 3.5

def create_design_matrix_2(Z, data, Y_len, lag_no):
    """
    For Python 2.7 - cythonized version only works for 3.5
    """
    row_count = 1

    for lag in range(1, lag_no+1):
        for reg in range(Y_len):
            Z[row_count, :] = data[reg][(lag_no-lag):-lag]
            row_count += 1

    return Z