translated_python_code.py

unit = [1,0,-1]

Mi = np.empty((27,6), dtype='float')
M_orig = np.flip(np.array(list(itertools.product(unit, repeat=3))), axis=1).astype('float')
M = M_orig.copy()

for row_idx, row_vector in enumerate(M_orig):
    row_sum = np.sum(abs(row_vector))
    if row_sum == 2:
        M[row_idx] = row_vector * (1 / np.sqrt(2))
    elif row_sum == 3:
        M[row_idx] = row_vector * (1 / np.sqrt(3))
    Mi[row_idx] = [M[row_idx,0]**2,             # x^2
                   2*M[row_idx,0]*M[row_idx,1], # 2xy
                   2*M[row_idx,0]*M[row_idx,2], # 2xz
                   M[row_idx,1]**2,             # y^2
                   2*M[row_idx,1]*M[row_idx,2], # 2yz
                   M[row_idx,2]**2]             # z^2
                   
Mi = np.delete(Mi, 13, axis=0)
M_orig = np.delete(M_orig, 13, axis=0)

T = np.linalg.inv(Mi.T @ Mi) @ Mi.T