当值已知时从 json 文件中提取密钥(groovy 或 python)

Pull key from json file when values is known (groovy or python)

如果我只知道值,有没有办法从 JSON 中提取密钥? (在 groovy 或 python 中) 一个例子: 我知道“_number”值,我需要一把钥匙。 比方说,已知 _number 是 2 作为输出,我应该得到 dsf34f43f34f34f

{
  "id": "8e37ecadf4908f79d58080e6ddbc",
  "project": "some_project",
  "branch": "master",
  "current_revision": "3rtgfgdfg2fdsf",
  "revisions": {
    "43g5g534534rf34f43f": {
      "_number": 3,
      "created": "2019-04-16 09:03:07.459000000",
      "uploader": {
        "_account_id": 4
      },
      "description": "Rebase"
    },
    "dsf34f43f34f34f": {
      "_number": 2,
      "created": "2019-04-02 10:54:14.682000000",
      "uploader": {
        "_account_id": 2
      },
      "description": "Rebase"
    }
  }
}

Python 3:(假设数据保存在data.json):

import json

with open('data.json') as f:
    json_data = json.load(f)

for rev, revdata in json_data['revisions'].items():
    if revdata['_number'] == 2:
        print(rev)

打印所有 _number 等于 2 的转速。

使用 dict-comprehension:

print({k for k,v in d['revisions'].items() if v.get('_number') == 2})

输出:

{'dsf34f43f34f34f'}

与Groovy:

def json = new groovy.json.JsonSlurper().parse("x.json" as File)
println(json.revisions.findResult{ it.value._number==2 ? it.key : null })
// => dsf34f43f34f34f