jq 可以处理嵌套的 JSON 数据吗？答案

【问题标题】：Can jq handle nested JSON data?jq 可以处理嵌套的 JSON 数据吗？
【发布时间】：2016-05-04 07:05:14
【问题描述】：

也许这对于“jq”来说太过分了，我需要跳入 python json 模块，但是让我们为大师们提出一个挑战！！

我有一些看起来有点像这样（简化）的 JSON 数据（来自 i3 窗口管理器）。我想深入挖掘任意数量的 .nodes/.floating_nodes 级别并拉出“window”设置为非空的 .nodes 或 .floating_nodes。：

{
  "floating_nodes": [],
  "nodes": [
    {
      "floating_nodes": [],
      "nodes": [
        {
          "floating_nodes": [],
          "nodes": [
            {
              "floating_nodes": [],
              "nodes": [],
              "window": null,
              "name": "__i3_scratch",
            }
          ],
          "window": null,
          "name": "foobar",
        }
      ],
      "window": null,
      "name": "__i3",
    },
    {
      "floating_nodes": [],
      "nodes": [
        {
          "floating_nodes": [],
          "nodes": [],
          "window": null,
          "name": "topdock",
        },
        {
          "floating_nodes": [],
          "nodes": [
            {
              "floating_nodes": [],
              "nodes": [
                {
                  "floating_nodes": [],
                  "nodes": [],
                  "window": 8388613,
                  "name": "16:11 bhepple:.../~ — Konsole",
                  "rect": {
                    "height": 1061,
                    "width": 1920,
                    "y": 0,
                    "x": 0
                  },
              ],
              "window": null,
              "name": "1",
            }
          ],
          "window": null,
          "name": "content",
        },
        {
          "floating_nodes": [],
          "nodes": [
            {
              "floating_nodes": [],
              "nodes": [],
              "window": 14680070,
              "name": "i3bar for output VNC-0",
            }
          ],
          "window": null,
          "name": "bottomdock",
        }
      ],
      "window": null,
      "name": "VNC-0",
    }
  ],
  "window": null,
  "name": "root",
}

我的简化示例有点破坏了我的 JSON 示例，所以这里是完整版本：

{"id":10883136,"type":"root","orientation":"horizontal","scratchpad_state":"none","percent":null,"urgent":false,"focused":false,"layout":"splith","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":1920,"height":1080},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"root","window":null,"nodes":[{"id":10883568,"type":"output","orientation":"none","scratchpad_state":"none","percent":0.5,"urgent":false,"focused":false,"layout":"output","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":1920,"height":1080},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"__i3","window":null,"nodes":[{"id":10884128,"type":"con","orientation":"horizontal","scratchpad_state":"none","percent":null,"urgent":false,"focused":false,"layout":"splith","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":0,"height":0},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"content","window":null,"nodes":[{"id":10884720,"type":"workspace","orientation":"none","scratchpad_state":"none","percent":null,"urgent":false,"focused":false,"layout":"splith","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":0,"height":0},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"__i3_scratch","num":-1,"window":null,"nodes":[],"floating_nodes":[],"focus":[],"fullscreen_mode":1,"sticky":false,"floating":"auto_off","swallows":[]}],"floating_nodes":[],"focus":[10884720],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[]}],"floating_nodes":[],"focus":[10884128],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[]},{"id":10886256,"type":"output","orientation":"none","scratchpad_state":"none","percent":0.5,"urgent":false,"focused":false,"layout":"output","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":1920,"height":1080},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"VNC-0","window":null,"nodes":[{"id":10886944,"type":"dockarea","orientation":"none","scratchpad_state":"none","percent":null,"urgent":false,"focused":false,"layout":"dockarea","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":1920,"height":0},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"topdock","window":null,"nodes":[],"floating_nodes":[],"focus":[],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[{"dock":2,"insert_where":2}]},{"id":10887648,"type":"con","orientation":"horizontal","scratchpad_state":"none","percent":null,"urgent":false,"focused":false,"layout":"splith","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":1920,"height":1061},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"content","window":null,"nodes":[{"id":10889056,"type":"workspace","orientation":"horizontal","scratchpad_state":"none","percent":null,"urgent":false,"focused":false,"layout":"splith","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":0,"width":1920,"height":1061},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"1","num":1,"window":null,"nodes":[{"id":10895664,"type":"con","orientation":"none","scratchpad_state":"none","percent":1.0,"urgent":false,"focused":true,"layout":"splith","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":1,"rect":{"x":0,"y":0,"width":1920,"height":1061},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":1,"y":1,"width":1918,"height":1059},"geometry":{"x":0,"y":0,"width":958,"height":1059},"name":"16:11 bhepple:.../~ — Konsole","window":8388613,"window_properties":{"class":"konsole","instance":"konsole","title":"16:11 bhepple:.../~ — Konsole","transient_for":null},"nodes":[],"floating_nodes":[],"focus":[],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[]}],"floating_nodes":[],"focus":[10895664],"fullscreen_mode":1,"sticky":false,"floating":"auto_off","swallows":[]}],"floating_nodes":[],"focus":[10889056],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[]},{"id":10888352,"type":"dockarea","orientation":"none","scratchpad_state":"none","percent":null,"urgent":false,"focused":false,"layout":"dockarea","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":-1,"rect":{"x":0,"y":1061,"width":1920,"height":19},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":0,"height":0},"geometry":{"x":0,"y":0,"width":0,"height":0},"name":"bottomdock","window":null,"nodes":[{"id":10891392,"type":"con","orientation":"none","scratchpad_state":"none","percent":1.0,"urgent":false,"focused":false,"layout":"splith","workspace_layout":"default","last_split_layout":"splith","border":"pixel","current_border_width":1,"rect":{"x":0,"y":1061,"width":1920,"height":19},"deco_rect":{"x":0,"y":0,"width":0,"height":0},"window_rect":{"x":0,"y":0,"width":1920,"height":19},"geometry":{"x":0,"y":1061,"width":3840,"height":19},"name":"i3bar for output VNC-0","window":14680070,"window_properties":{"class":"i3bar","instance":"i3bar","title":"i3bar for output VNC-0","transient_for":null},"nodes":[],"floating_nodes":[],"focus":[],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[]}],"floating_nodes":[],"focus":[10891392],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[{"dock":3,"insert_where":2}]}],"floating_nodes":[],"focus":[10887648,10886944,10888352],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[]}],"floating_nodes":[],"focus":[10886256,10883568],"fullscreen_mode":0,"sticky":false,"floating":"auto_off","swallows":[]}

【问题讨论】：

标签： python json jq

【解决方案1】：

当然，jq 可以做到这一点！

首先，我们使用递归运算符.. 递归遍历所有内容。然后，我们得到所有的.nodes 和.floating_nodes，我们使用? 来忽略尝试从数字、字符串或对象获取属性时可能出现的错误。然后，我们用[] 获取这些数组中的所有元素。同样，忽略上一步中的错误留下了一些nulls，因此我们忽略了尝试在nulls 上使用[] 和? 的错误。最后，我们将所有内容通过管道传输到 select(.window != null)，并将每个结果包装在一个数组中以便于处理。

jq '[.. | .floating_nodes?, .nodes? | .[]? | select(.window != null)]'

【讨论】：

谢谢。麻烦的是，jq 抛出错误：error: Invalid numeric literal (while parsing '..') [.. | .floating_nodes?, .nodes? | .[]? | select(.window != null)] ^^ error: Invalid character 我的 jq 是 1.3 版
我建议为此购买 jq 1.5。如果不是，.. 应在早期版本中定义为 recurse。

【解决方案2】：

如果window 属性只能出现在node 或floating_node 对象上，您可以通过搜索所有具有window 属性的对象来简化操作。

.. | objects | select(.window != null)

【讨论】：

谢谢。麻烦的是，jq 抛出错误：错误：对象未定义。 |对象 | select(.window != null) ^^^^^^^ 1 编译错误我的jq是1.3版

【解决方案3】：

解决圣地亚哥的解决方案并尝试回填 jq-1.3 中可能缺少的内容，我得到了这个工作：

jq 'recurse(.[]) | .floating_nodes, .nodes | .[] | select(.window != null) | select(.focused == true) | .name'

...它还给出了很多错误消息，例如：

jq: error: Cannot iterate over number
jq: error: Cannot iterate over null
jq: error: Cannot iterate over null
jq: error: Cannot index number with string

【讨论】：

【解决方案4】：

以下内容已使用 jq 1.3、1.4 和 1.5 进行了测试：

recurse(if type == "object" or type == "array" then .[] else empty end)
| select(type == "object")
| ( select(.nodes|type == "array") | .nodes[]),
  ( select(.floating_nodes|type == "array") | .floating_nodes[])
| select( .window != null )

使用给定输入的“完整版”，jq 1.3 产生以下输出：

{
  "swallows": [],
  "floating": "auto_off",
  "sticky": false,
  "fullscreen_mode": 0,
  "focus": [],
  "floating_nodes": [],
  "nodes": [],
  "window_properties": {
    "transient_for": null,
    "title": "16:11 bhepple:.../~ — Konsole",
    "instance": "konsole",
    "class": "konsole"
  },
  "window": 8388613,
  "name": "16:11 bhepple:.../~ — Konsole",
  "layout": "splith",
  "focused": true,
  "urgent": false,
  "percent": 1,
  "scratchpad_state": "none",
  "orientation": "none",
  "type": "con",
  "id": 10895664,
  "workspace_layout": "default",
  "last_split_layout": "splith",
  "border": "pixel",
  "current_border_width": 1,
  "rect": {
    "height": 1061,
    "width": 1920,
    "y": 0,
    "x": 0
  },
  "deco_rect": {
    "height": 0,
    "width": 0,
    "y": 0,
    "x": 0
  },
  "window_rect": {
    "height": 1059,
    "width": 1918,
    "y": 1,
    "x": 1
  },
  "geometry": {
    "height": 1059,
    "width": 958,
    "y": 0,
    "x": 0
  }
}
{
  "swallows": [],
  "floating": "auto_off",
  "sticky": false,
  "fullscreen_mode": 0,
  "focus": [],
  "floating_nodes": [],
  "nodes": [],
  "window_properties": {
    "transient_for": null,
    "title": "i3bar for output VNC-0",
    "instance": "i3bar",
    "class": "i3bar"
  },
  "window": 14680070,
  "name": "i3bar for output VNC-0",
  "layout": "splith",
  "focused": false,
  "urgent": false,
  "percent": 1,
  "scratchpad_state": "none",
  "orientation": "none",
  "type": "con",
  "id": 10891392,
  "workspace_layout": "default",
  "last_split_layout": "splith",
  "border": "pixel",
  "current_border_width": 1,
  "rect": {
    "height": 19,
    "width": 1920,
    "y": 1061,
    "x": 0
  },
  "deco_rect": {
    "height": 0,
    "width": 0,
    "y": 0,
    "x": 0
  },
  "window_rect": {
    "height": 19,
    "width": 1920,
    "y": 0,
    "x": 0
  },
  "geometry": {
    "height": 19,
    "width": 3840,
    "y": 1061,
    "x": 0
  }
}

【讨论】：

【解决方案5】：

这是一个解决方案，它使用 tostream 从给定的输入中扫描 [path,value] 数组流。然后它使用 select 只挑选出以“window”结尾且其对应值不为空的路径。最后，它使用 foreach 和 getpath 来生成包含对象的流。

foreach (   tostream
          | select(length == 2 and .[0][-1] == "window" and .[1] != null)
        ) as $p (
    .
  ; .
  ; getpath($p[0][:-1])
)

编辑：我现在意识到foreach E as $X (.; .; R) 形式的过滤器几乎总是可以重写为E as $X | R 所以上面真的只是

  ( tostream | select(length == 2 and .[0][-1] == "window" and .[1] != null) ) as $p
|  getpath($p[0][:-1])

【讨论】：

使用 jq-1.5 给出语法错误：~/ $ i3-msg -t get_tree | jq 'foreach ( tostream | select(length == 2 and .[0][-1] == "window" and .[1] != null) ) as $p ( . ; . ; getpath($p[0][:-1])' jq: error: syntax error, unexpected $end (Unix shell quoting issues?) at <top-level>, line 6: ; getpath($p[0][:-1]) jq: 1 compile error
看起来你还需要一个）在最后一个'之前。