在 Python 中从列表中添加值以根据键生成总值

Question

我目前正在为我用 Python 编写的一段特定代码而苦苦挣扎。

我需要根据同一个键获取单独对象值的总值。

这是我目前得到的 JSON 数据

[{
        "name": "John",
        "data": [{
                "currency": "Euro",
                "amount": 100.00
            },
            {
                "currency": "Dollar",
                "amount": 223
            },
            {
                "currency": "Yen",
                "amount": 800
            }
        ]
    },
    {
        "name": "Jack",
        "data": [{
                "currency": "Dollar",
                "amount": 32
            },
            {
                "currency": "Euro",
                "amount": 80
            }
        ]
    },
    {
        "name": "Elise",
        "data": [{
                "currency": "Dollar",
                "amount": 12
            },
            {
                "currency": "Yen",
                "amount": 66
            }
        ]
    }
]

但是！在这个对象数组中，我还想添加另一个对象，其中包含有关每种货币总值的信息。我一直在为此苦苦挣扎，我尝试过嵌套 for 循环，但感觉这是浪费时间，必须有更快的方法......

谁能帮我得到我正在寻找的输出？

想要的输出 =

[{
        "name": "Total",
        "data": [{
            "Euro": {
                "amount": 180
            },
            "Dollar": {
                "amount": 267
            },
            "Yen": {
                "amount": 866
            }
        }]
    },



    {
        "name": "John",
        "data": [{
                "currency": "Euro",
                "amount": 100.00
            },
            {
                "currency": "Dollar",
                "amount": 223
            },
            {
                "currency": "Yen",
                "amount": 800
            }
        ]
    },
    {
        "name": "Jack",
        "data": [{
                "currency": "Dollar",
                "amount": 32
            },
            {
                "currency": "Euro",
                "amount": 80
            }
        ]
    },
    {
        "name": "Elise",
        "data": [{
                "currency": "Dollar",
                "amount": 12
            },
            {
                "currency": "Yen",
                "amount": 66
            }
        ]
    }
]

Answer 1

假设您的列表名为s，试试这个：

total = dict()
for d in s:
    for ccy in d["data"]:
        if ccy["currency"] in total:
            total[ccy["currency"]]["amount"] += ccy["amount"]
        else:
            total[ccy["currency"]] = {"amount": ccy["amount"]}
>>> total
'Euro': {'amount': 180.0}, 'Dollar': {'amount': 267}, 'Yen': {'amount': 866}}

如果你想在之后将两者合并到一个列表中，你可以这样做：

s = [{"name": "Total", "data": [total]}] + s
>>> s
[{'name': 'Total',
  'data': [{'Euro': {'amount': 180.0},
            'Dollar': {'amount': 267},
            'Yen': {'amount': 866}}]},
 {'name': 'John',
  'data': [{'currency': 'Euro', 'amount': 100.0},
           {'currency': 'Dollar', 'amount': 223},
           {'currency': 'Yen', 'amount': 800}]},
 {'name': 'Jack',
  'data': [{'currency': 'Dollar', 'amount': 32},
           {'currency': 'Euro', 'amount': 80}]},
 {'name': 'Elise',
  'data': [{'currency': 'Dollar', 'amount': 12},
           {'currency': 'Yen', 'amount': 66}]}]