github.com/GuanceCloud/cliutils@v1.1.21/pipeline/ptinput/funcs/md/json.en.md (about)

     1  ### `json()` {#fn-json}
     2  
     3  Function prototype: `fn json(input: str, json_path, newkey, trim_space: bool = true)`
     4  
     5  Function description: Extract the specified field in JSON and name it as a new field.
     6  
     7  Function parameters:
     8  
     9  - `input`: The JSON to be extracted can be the original text (`_`) or a `key` after the initial extraction
    10  - `json_path`: JSON path information
    11  - `newkey`：Write the data to the new key after extraction
    12  - `trim_space`: Delete the leading and trailing blank characters in the extracted characters, the default value is true
    13  - `delete_after_extract`: After extract delete the extracted info from input. Only map key and map value are deletable, list(array) are not supported. Default is `false'.
    14  
    15  ```python
    16  # Directly extract the x.y field in the original input json, and name it as a new field abc
    17  json(_, x.y, abc)
    18  
    19  # For a `key` that has been extracted, extract `x.y` again, and the extracted field name is `x.y`
    20  json(key, x.y) 
    21  ```
    22  
    23  Example 1:
    24  
    25  ```python
    26  # input data: 
    27  # {"info": {"age": 17, "name": "zhangsan", "height": 180}}
    28  
    29  # script:
    30  json(_, info, "zhangsan")
    31  json(zhangsan, name)
    32  json(zhangsan, age, "age")
    33  
    34  # result:
    35  {
    36    "age": 17,
    37    "message": "{\"info\": {\"age\": 17, \"name\": \"zhangsan\", \"height\": 180}}",
    38    "name": "zhangsan",
    39    "zhangsan": "{\"age\":17,\"height\":180,\"name\":\"zhangsan\"}"
    40  }
    41  ```
    42  
    43  Example 2:
    44  
    45  ```python
    46  # input data:
    47  #    data = {
    48  #        "name": {"first": "Tom", "last": "Anderson"},
    49  #        "age":37,
    50  #        "children": ["Sara","Alex","Jack"],
    51  #        "fav.movie": "Deer Hunter",
    52  #        "friends": [
    53  #            {"first": "Dale", "last": "Murphy", "age": 44, "nets": ["ig", "fb", "tw"]},
    54  #            {"first": "Roger", "last": "Craig", "age": 68, "nets": ["fb", "tw"]},
    55  #            {"first": "Jane", "last": "Murphy", "age": 47, "nets": ["ig", "tw"]}
    56  #        ]
    57  #    }
    58  
    59  # script:
    60  json(_, name) 
    61  json(name, first)
    62  ```
    63  
    64  Example 3:
    65  
    66  ```python
    67  # input data:
    68  #    [
    69  #            {"first": "Dale", "last": "Murphy", "age": 44, "nets": ["ig", "fb", "tw"]},
    70  #            {"first": "Roger", "last": "Craig", "age": 68, "nets": ["fb", "tw"]},
    71  #            {"first": "Jane", "last": "Murphy", "age": 47, "nets": ["ig", "tw"]}
    72  #    ]
    73      
    74  # script:
    75  json(_, .[0].nets[-1])
    76  ```
    77  
    78  Example 4:
    79  
    80  ```python
    81  # input data:
    82  {"item": " not_space ", "item2":{"item3": [123]}}
    83  
    84  # script:
    85  json(_, item2.item3, item, delete_after_extract = true)
    86  
    87  # result:
    88  {
    89    "item": "[123]",
    90    "message": "{\"item\":\" not_space \",\"item2\":{}}",
    91  }
    92  ```
    93  
    94  
    95  Example 5:
    96  
    97  ```python
    98  # input data:
    99  {"item": " not_space ", "item2":{"item3": [123]}}
   100  
   101  # If you try to remove a list element it will fail the script check.
   102  # Script:
   103  json(_, item2.item3[0], item, delete_after_extract = true)
   104  
   105  
   106  # test command:
   107  # datakit pipeline -P j2.p -T '{"item": " not_space ", "item2":{"item3": [123]}}'
   108  # report error:
   109  # [E] j2.p:1:54: does not support deleting elements in the list
   110  ```