python - 根据公共(public)元素重建python数组

Question

我正在尝试创建一个字典列表，将给定数据集中的公共(public)值分组。数据格式如下

data = [{"CustName":"customer1", "PartNum":"part1"},
{"CustName":"customer2", "PartNum":"part2"}, 
{"CustName":"customer1", "PartNum":"part3"}, 
{"CustName":"customer2", "PartNum":"part4"}]

我想要的是

cleanedData = [
{"CustName":"customer1", "parts":[{"PartNum":"part1"}, {"PartNum":"part3"}]},
{"CustName":"customer2", "parts":[{"PartNum":"part2"}, {"PartNum":"part4"}]}]

我试图开始工作的方式需要几个循环，看起来很丑，而且感觉不是很 pythonic。我也觉得这不会很好地扩展。目前，输入数据很小 - 不到 100 个元素，但可能有数千个元素，因此循环中的多个循环似乎效率低下。

data = [{"CustName":"customer1", "PartNum":"part1"},
{"CustName":"customer2", "PartNum":"part2"}, 
{"CustName":"customer1", "PartNum":"part3"}, 
{"CustName":"customer2", "PartNum":"part4"}]

customers = []
cleanedData = []
for d in data:
    if d["CustName"] not in customers:
        customers.append(d["CustName"])

for c in customers:
    parts = []
    for d in data:
        if d["CustCode"] == c:
            parts.append(d)
    cust = {"CustName":c}
    cust.update({"parts":parts})
    cleanedData.append(cust)

有人可以提供帮助并提供更简单的方法吗？是否有有助于此类数据操作的内置函数？

Answer 1

您可以使用 collections.defaultdict .

d = defaultdict(list)
for item in data:
    d[item['CustName']].append({'PartNum': item['PartNum']})
print(d)

如果你想在列表中，可以选择遵循列表理解:

print([{'CustName': key, 'parts': value} for key, value in d.items()])