Sorting list dict by index and get top n elements

Question

What I have is a list of dict:

x = [{25: 16}, {40: 32}, {11: 50}]

What i am trying is to sort it by value and get the top n elements:

where n = 2

what i did:

sorted_lst = x.sort(key=lambda d: d.values)
print(sorted_lst)
filtered = sorted_lst[:n]

but this did not work.

the output that I am trying to get is:

[{11: 50}, {40: 32}]

https://stackoverflow.com/questions/613183/how-do-i-sort-a-dictionary-by-value — Ava_Katushka, Sep 20 '20 at 09:59
`sorted(x, key = lambda i: next(i.values().__iter__()), reverse = True)[:2]` — deeenes, Sep 20 '20 at 10:00
Does this answer your question? [How do I sort a dictionary by value?](https://stackoverflow.com/questions/613183/how-do-i-sort-a-dictionary-by-value) — baduker, Sep 20 '20 at 10:04
The linked question is not about a list of dictionaries. This questions has a different solution — Michael Szczesny, Sep 20 '20 at 10:09

score 2 · Accepted Answer · answered Sep 20 '20 at 10:16

2

Without iterator in lambda

x = [{25: 16}, {40: 32}, {11: 50}]
sorted(x, key = lambda i: list(i.values()), reverse = True)[:2]
>>> [{11: 50}, {40: 32}]

answered Sep 20 '20 at 10:16

Michael Szczesny

4,911
5
15
32

Is it better without iter? like sorted(x, key = lambda x: next(iter(x.values())), reverse=True)[:2] – Christian Sloper Sep 20 '20 at 10:19
1

For me it is more readable and i don't have to know what `next(iter(...))`does. But I like your solution, too. Perhaps post as answer and let the voting system decide? – Michael Szczesny Sep 20 '20 at 10:21

score 2 · Answer 2 · answered Sep 20 '20 at 10:24

2

Here is a slightly different solution to @mikksu's variant, using iter and next. Iter turns the view of values into an iterator and next gets the first value.

sorted(x, key = lambda x: next(iter(x.values())), reverse=True)[:2]

answered Sep 20 '20 at 10:24

Christian Sloper

7,440
3
15
28

RoadRunner · Answer 3 · 2020-09-20T10:45:08.600

1

You could use collections.Counter.most_common to get the top n elements:

>>> from collections import Counter
>>> lst = [{25: 16}, {40: 32}, {11: 50}]
>>> [{k: v} for k, v in Counter(dict(tuple(*d.items()) for d in lst)).most_common(2)]
[{11: 50}, {40: 32}]

edited Sep 20 '20 at 10:45

answered Sep 20 '20 at 10:36

RoadRunner

25,803
6
42
75

Sorting list dict by index and get top n elements

3 Answers3