How can I compare each object with each?

Question

How can I compare each object with each and if ratio ()> 0.7 set possible_duplicate=True for both objects?

My attempt:

 from difflib import SequenceMatcher class Item(models.Model): name = models.CharField(max_length=255) desc = models.TextField() possible_duplicate = models.BooleanField(default=False) items = Item.objects.all() for item in items: obj = Item.objects.get(pk=item.pk) similarity = SequenceMatcher(None, item.desc, obj.desc).ratio() if similarity > 0.7: item.possible_duplicate = True item.save() obj.possible_duplicate = True obj.save() 

Answer 1

You can use itertools.combinations to get comparison combinations:

 >>> import itertools >>> items = [1, 2, 3] >>> itertools.combinations(items, 2) # 2 -> yields tuples with 2 items <itertools.combinations object at 0x7f5e456d5ba8> >>> list(itertools.combinations(items, 2)) [(1, 2), (1, 3), (2, 3)] 

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 import itertools items = Item.objects.all() for item1, item2 in itertools.combinations(items, 2): similarity = SequenceMatcher(None, item1.desc, item2.desc).ratio() if similarity > 0.7: for item in item1, item2: item.possible_duplicate = True item.save() 

Answer 2

In your code, you are comparing an object to itself. To compare all objects with each other, you can use itertools.combinations

 items_list = list(Items.objects.all()) for a,b in itertools.combinations(items_list, 2): similarity = SequenceMatcher(None, a.desc, b.desc).ratio() if similarity > 0.7: a.possible.duplicate = True a.save() b.possible.duplicate = True b.save()