Delete a dict in a list if a value in dict is duplicate

Question

Okay, so, I have something that looks like this:

[ 
  { "abc": "123",
    "id": 9,
  },
  { "azc": "153",
    "id": 2,
  },
  { "oau": "321",
    "id": 9,
  },
]

As you can see above, it can happen that the ID duplicates in the file I have, however, I'd like that if the ID is duplicated in two of these lists, one of the lists is deleted, and the other is kept.

Is it possible? I've been trying for way too long now.

Yes, of course that's possible. What did you get to when you were trying? — Martijn Pieters, Mar 04 '19 at 19:26
And perhaps you mean *if the ID is duplicated in two of these **dictionaries***? — Martijn Pieters, Mar 04 '19 at 19:26
Well it deleted both duplicate elements, not leaving one in the list. — Folfy Blue, Mar 04 '19 at 19:26
Without seeing your code, we can't really help fix that. There is a canonical post on the subject, I've closed this as a duplicate of that one. — Martijn Pieters, Mar 04 '19 at 19:28
Since you are looking for duplication based on a single key, use the `seen = set()` approach and make `t = d['id']` instead of `t = tuple(d.items())`. — Martijn Pieters, Mar 04 '19 at 19:29

score 0 · Accepted Answer · answered Mar 04 '19 at 19:27

You can use dict comprehension to build a dict with the id key of each sub-dict in the list as the key and the sub-dict as the value, so that duplicating entries would be overridden by the latter values (assuming your list of dicts is stored in variable l):

list({d['id']: d for d in l}.values())

This returns:

[{'oau': '321', 'id': 9}, {'azc': '153', 'id': 2}]

Delete a dict in a list if a value in dict is duplicate

1 Answers1