Alternative sum of list of dictionaries

elisabethirgens.py

# O(n) alternative to:
# https://elisabethirgens.github.io/notes/2021/12/step-away/
from collections import defaultdict

mylist = [
    {'thing': 'A', 'count': 4},
    {'thing': 'B', 'count': 2},
    {'thing': 'A', 'count': 6},
]

tmp = defaultdict(int)
for d in mylist:
    tmp[d['thing']] += d['count']

mylist = [{'thing': key, 'count': value} for key, value in tmp.items()]