Sort list of dicts by specific list of values

Question

I'm trying to code a faster way to solve the following problem but I don't know how to do it:

I have the following list of dicts and list of identifiers:

list_of_dicts = [{'id': 1, 'name': 'A'}, {'id': 2, 'name': 'B'}, {'id': 3, 'name': 'C'}, {'id': 4, 'name': 'D'}]
list_of_ids = [1, 3, 2, 4, 1, 3, 4]

I'd like to have the following output:

[{'id': 1, 'name': 'A'}, {'id': 3, 'name': 'C'}, {'id': 2, 'name': 'B'}, {'id': 4, 'name': 'D'}, {'id': 1, 'name': 'A'}, {'id': 3, 'name': 'C'}, {'id': 4, 'name': 'D'}]

The way I'm doing it is:

list_of_dict_ids = [d['id'] for d in list_of_dicts]
ordered_list_by_ids = [list_of_dicts[list_of_dict_ids.index(i)] for i in list_of_ids]

Is there any faster way to do it?

Answer 1

You can do like this:

dic = {d["id"]: d for d in list_of_dicts}
dic
>>>{1: {'id': 1}, 2: {'id': 2}, 3: {'id': 3}, 4: {'id': 4}}
lst =[dic[i] for i in list_of_ids]
lst
>>>[{'id': 1}, {'id': 3}, {'id': 2}, {'id': 4}, {'id': 1}, {'id': 3}, {'id': 4}]