如何从python中的嵌套数组中计算嵌套的json对象

Question

如何获得所有运动中的对象总数？

目前，尽管下面所有尝试挖掘节点的尝试都失败了，但我在下面的代码片段中并未获得成功。

import json

RESULTS = 'sample.json'
with open(RESULTS) as f:
    data = json.load(f)
    results = data
print(len(results[0]['result']['movements'])) #Expected: 3

sample.json

[
  {
    "result": {
      "TempId": "369477387",
      "movements": [
        {
          "date": "2018-05-03",
          "credit": 100.0,
          "shorttext": "My<br/>Expense "
        },
        {
          "date": "2018-05-03",
          "debit": 200.0,
          "shorttext": "My<br/>F\u00dcR"
        }
      ]
    }
  },
  {
    "result": {
      "TempId": "369477395",
      "movements": []
    }
  },
  {
    "result": {
      "TempId": "369477402",
      "movements": [
        {
          "date": "2018-05-07",
          "credit": 100.0,
          "shorttext": "My<br/>Expense "
        }
      ]
    }
  }
]

Answer 1

使用列表推导，您可以从样本列表中找出每个元素的movements次数。

然后只需将sum方法应用于count列表即可找出总和。

count = sum([len(item['result']['movements']) for item in sample])

输出量

>> count
3