Question

我是Python的新手，并试图弄清楚如何使用dicts。

给出一个json数组：

{
    "accounts": [
        {
            "alias": "mc_beeline_rub",
            "fsAlias": "qb_mc_beeline",
            "title": "MC",
            "type": {
                "id": "MC",
                "title": "Счет мобильного кошелька"
            },
            "hasBalance": false,
            "balance": null,
            "currency": 643
        },
        {
            "alias": "qw_wallet_rub",
            "fsAlias": "qb_wallet",
            "title": "WALLET",
            "type": {
                "id": "WALLET",
                "title": "Visa QIWI Wallet"
            },
            "hasBalance": true,
            "balance": {
                "amount": 8.74,
                "currency": 643
            },
            "currency": 643
        },
        {
            "alias": "qw_wallet_usd",
            "fsAlias": "qb_wallet",
            "title": "WALLET",
            "type": {
                "id": "WALLET",
                "title": "Visa QIWI Wallet"
            },
            "hasBalance": true,
            "balance": {
                "amount": 0,
                "currency": 840
            },
            "currency": 840
        },
        {
            "alias": "qw_wallet_eur",
            "fsAlias": "qb_wallet",
            "title": "WALLET",
            "type": {
                "id": "WALLET",
                "title": "Visa QIWI Wallet"
            },
            "hasBalance": true,
            "balance": {
                "amount": 0.01,
                "currency": 978
            },
            "currency": 978
        }
    ]
}

我需要从“别名”：“qw_wallet_rub”的部分中提取值['balance'] ['amount'] 我对其余的数据不感兴趣，只需知道“数量”值是什么

我不知道如何选择一个特定的子字典来使用。搜索没有为我的案例提供任何有价值的结果。

希望你们能帮我解决这个问题。感谢

Answer 1

像这样它应该有效：

# -*- coding: utf-8 -*-
import json

a = """your json string/file"""

b = json.loads(a)

for e in b["accounts"]:
  if e["alias"] == "qw_wallet_rub":
    print e["balance"]["amount"]

Answer 2

不能保证只有其中一个，但你可以简单地使用列表理解：

>>> data = json.loads(your_json_string)
>>> print([d["balance"]["amount"] for d in data["accounts"] 
           if d["alias"] == "qw_wallet_rub"])
[8.74]

在Python中选择dict中的数据

2 个答案: