json-builder 0.4

This module is built to provide straightforward way to build and modify json objects

json_builder

Build or modify json objects incrementally using json paths

Installation

The quick way:

pip install json_builder

Usage

Before start, check the json path syntax: https://goessner.net/articles/JsonPath/

Add new key

root_object = {"a": 10}
JsonBuilder.add(root_object, "$.b", 20)
JsonBuilder.add(root_object, "$.c.d.e", 30)
print(root_object)

Output:
{
  'a': 10,
  'b': 20,
  'c': {
    'd': {
      'e': 30
    }
  }
}

Modify existing key value

root_object = {
        'a': 10,
        'b': 20,
        'c': {
            'd': {
                'e': 30
            }
        }
    }
JsonBuilder.add(root_object, "$.c.d.e", "test")
print(root_object)

Output:
{
  'a': 10,
  'b': 20,
  'c': {
    'd': {
      'e': 'test'
    }
  }
}

Create a list

root_object = {
        'a': 10,
    }
JsonBuilder.add(root_object, "$.b[0]", "1")
JsonBuilder.add(root_object, "$.b[1]", "2")
JsonBuilder.add(root_object, "$.b[2]", {"c": 20})
print(root_object)

Output:
{
  'a': 10,
  'b': [
    '1',
    '2',
    {
      'c': 20
    }
  ]
}

Modify existing list index

root_object = {
        'a': 10,
        'b': [
            '1',
            '2',
            {
                'c': 20
            }
        ]
    }
JsonBuilder.add(root_object, "$.b[2]", '3')
print(root_object)

Output:
{
  'a': 10,
  'b': [
    '1',
    '2',
    '3'
  ]
}

Exceptions

Object is not json serializable

Values that are not json serializable are not allowed

root_object = object()
JsonBuilder.add(root_object, "$.b[4]", '3')
print(root_object)

root_object = {}
JsonBuilder.add(root_object, "$.b[4]", object())
print(root_object)

Output:
TypeError: Object <object object at 0x00000295240A4D20> is not JSON serializable.

Invalid json path

Check the json path syntax: https://goessner.net/articles/JsonPath/

root_object = {}
JsonBuilder.add(root_object, ".b[4]", 3)
print(root_object)

Output:
ValueError: Invalid json path ".b[4]". Check https://goessner.net/articles/JsonPath/ for more details.

Object is not a dictionary

root_object = {
  'a': []
}
JsonBuilder.add(root_object, "$.a.b", 1)
print(root_object)

Output:
Exception: Can't insert key "b", object is not a dictionary. Root: {'a': []}. Json path: $.a.b

Object is not a list

root_object = {
  'a': {}
}
JsonBuilder.add(root_object, "$.a[0]", 1)
print(root_object)

Output:
Exception: Can't insert on position "0", object is not a list. Root: {'a': {}}. Json path: $.a[0]

Previous list index not defined

List items must be added consecutively

root_object = {
  'a': []
}
JsonBuilder.add(root_object, "$.a[0]", 1)
JsonBuilder.add(root_object, "$.a[2]", 2)
print(root_object)

Output:
Exception: Index to big "2", previous list indexes not defined. Root: {'a': [1]}. Json path: $.a[2]

License

MIT