How to eliminate the rows from an array which have common elements at different index position in py-CodePudding

I have a 2D array of form

[[ 1  6]
 [ 2  7]
 [ 5  6]
 [ 6  1]
 [ 6  5]
 [ 7  2]]

I want the output of the form

[[ 1  6]
 [ 2  7]
 [ 5  6]]

How I can get this output?

CodePudding user response：

Here's a solution using plain Python, but I'm sure there's a more idiomatic way with NumPy.

import numpy as np

a = np.array([
    [1, 6],
    [2, 7],
    [5, 6],
    [6, 1],
    [6, 5],
    [7, 2]])

seen = set()
out = []
for row in a:
    elements = frozenset(row)
    if elements not in seen:
        seen.add(elements)
        out.append(row)
print(np.array(out))

Output:

[[1 6]
 [2 7]
 [5 6]]