我有一个看起来像这样的字典列表:
l = [{'name': 'john', 'amount': 50}, {'name': 'al', 'amount': 20}, {'name': 'john', 'amount': 80}]
有什么方法可以合并/合并匹配的名称值字典并求和吗？
请您参考如下方法:
您可以使用 collections.Counter() object将名称映射到数量，并在进行时对它们求和:
from collections import Counter
summed = Counter()
for d in l:
summed[d['name']] += d['amount']
result = [{'name': name, 'amount': amount} for name, amount in summed.most_common()]
然后结果也按金额排序(最高在前):
>>> from collections import Counter
>>> l = [{'name': 'john', 'amount': 50}, {'name': 'al', 'amount': 20}, {'name': 'john', 'amount': 80}]
>>> summed = Counter()
>>> for d in l:
... summed[d['name']] += d['amount']
...
>>> summed
Counter({'john': 130, 'al': 20})
>>> [{'name': name, 'amount': amount} for name, amount in summed.most_common()]
[{'amount': 130, 'name': 'john'}, {'amount': 20, 'name': 'al'}]
