Question

Is there any easy way to exchange the position of 2 elements – or better yet, n elements – in an array?

I came up with some code, but it looks quite ugly and the performance should be a bit bad:

chromo = [[1,2], [3,4], [5,6]]

gene1Pos = random.randrange(0, len(chromo)-1, 1)
gene2Pos = random.randrange(0, len(chromo)-1, 1)
tmpGene1 = chromo[gene1Pos]
tmpGene2 = chromo[gene2Pos]
chromo[gene1Pos] = tmpGene2
chromo[gene2Pos] = tmpGene1

This should work, but well, it’s not nice. The better way would be a routine like random.shuffle but that instead of mixing everything would mix just a number n of elements. Do you have any idea?

Answer 1

try

>>> chromo[gene1Pos], chromo[gene2Pos] = chromo[gene2Pos], chromo[gene1Pos]

So you just need to make sure you have the right genXPos