如何遍历json文件？

Question

我有一个下面的 json 文件，我想获得 hostId，只有当它name包含一些特定的值时。我想使用shell脚本来实现这一点。

{
  "items" : [ {
    "name" : "first-block-e70a2fe8fd0531ad1f87de49f03537a6",
    "type" : "STORE",
    "hostRef" : {
      "hostId" : "166219e3-be5c-46d0-b4c7-33543a29ce32"
    },
    "roleState" : "STARTED",
    "healthSummary" : "GOOD",

    },
  {
   "name" : "second-block-c21a1ae8dd2831cd1b87de49f98274e8",
    "type" : "STORE",
    "hostRef" : {
      "hostId" : "176429e3-be5c-46d0-b4c7-33543a29ad63"
    },
    "roleState" : "STARTED",
    "healthSummary" : "GOOD",
  }

  {
   "name" : "first-block-a85d2fe6fd0482ad1f54de49f45174a0",
    "type" : "STORE",
    "hostRef" : {
      "hostId" : "176429e3-ae1d-46d0-b4c7-66123a24fa82"
    },
    "roleState" : "STARTED",
    "healthSummary" : "GOOD",
  }

}

例如：如果名称包含带有“first-block”的内容，那么我应该将 hosdId 设为

166219e3-be5c-46d0-b4c7-33543a29ce32
176429e3-ae1d-46d0-b4c7-66123a24fa82

如何遍历 json 文件？我应该使用什么正则表达式来过滤包含某些特定值的元素name并获取hostid?

Answer 1

使用 python 的一个非常简单的示例：

#!/usr/bin/env python

import sys
import json

def print_first(data):
    for item in data["items"]:
        if item["name"].startswith("first"):
            print item["hostRef"]["hostId"]

def main(argv):
    for json_file in argv:
        with open(json_file) as data_file:
            data = json.load(data_file)
            print_first(data)

if __name__ == "__main__":
    main(sys.argv[1:])

即您的示例数据重新格式化为：

{
    "items" : [
        {
            "name" : "first-block-e70a2fe8fd0531ad1f87de49f03537a6",
            "type" : "STORE",
            "hostRef" : {
                "hostId" : "166219e3-be5c-46d0-b4c7-33543a29ce32"
            },
            "roleState" : "STARTED",
            "healthSummary" : "GOOD"

        },
        {
            "name" : "second-block-c21a1ae8dd2831cd1b87de49f98274e8",
            "type" : "STORE",
            "hostRef" : {
                "hostId" : "176429e3-be5c-46d0-b4c7-33543a29ad63"
            },
            "roleState" : "STARTED",
            "healthSummary" : "GOOD"
        },
        {
            "name" : "first-block-a85d2fe6fd0482ad1f54de49f45174a0",
            "type" : "STORE",
            "hostRef" : {
                "hostId" : "176429e3-ae1d-46d0-b4c7-66123a24fa82"
            },
            "roleState" : "STARTED",
            "healthSummary" : "GOOD"
        }
    ]
}