python - 如何递归访问 JSON 中的 $ref 以完成整个 JSON？

Question

我有这个架构，其中有 $ref 。我需要递归(假设没有无限循环)填写引用。也就是说，只要 $ref 出现，整个对象就会被它所指向的内容替换。

注意，我无法使用任何库，需要自己编写类/函数。我确实看到了jsonref但无法理解 LazyLoad 和回调。

可以用更简单的方式来完成吗？几天来我一直在尝试这样做。

{
  "definitions": {
    "pet": {
      "type": "object",
      "properties": {
        "name":  { "type": "string" },
        "breed": { "type": "string" },
        "age":  { "type": "string" }
      },
      "required": ["name", "breed", "age"]
    }
  },
  "type": "object",
  "properties": {
    "cat": { "$ref": "#/definitions/pet" },
    "dog": { "$ref": "#/definitions/pet" }
  }
}

变成，

{
  "definitions": {
    "pet": {
      "type": "object",
      "properties": {
        "name": {
          "type": "string"
        },
        "breed": {
          "type": "string"
        },
        "age": {
          "type": "string"
        }
      },
      "required": [
        "name",
        "breed",
        "age"
      ]
    }
  },
  "type": "object",
  "properties": {
    "cat": {
      "type": "object",
      "properties": {
        "name": {
          "type": "string"
        },
        "breed": {
          "type": "string"
        },
        "age": {
          "type": "string"
        }
      },
      "required": [
        "name",
        "breed",
        "age"
      ]
    },
    "dog": {
      "type": "object",
      "properties": {
        "name": {
          "type": "string"
        },
        "breed": {
          "type": "string"
        },
        "age": {
          "type": "string"
        }
      },
      "required": [
        "name",
        "breed",
        "age"
      ]
    }
  }
}

这是我正在尝试解决的 JSON，谢谢。

{
  "$id": "https://example.com/nested-schema.json",
  "title": "nested-schema",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "required": [
    "Music",
    "MusicID",
    "Composer"
  ],
  "properties": {
    "MusicID": {
      "type": "string",
      "minLength": 0,
      "maxLength": 0
    },
    "Music": {
      "$ref": "#/definitions/Music"
    },
    "Composer": {
      "type": "integer",
      "minimum": 0,
      "maximum": 0
    }
  },
  "definitions": {
    "Music": {
      "type": "object",
      "required": [
        "Date"
      ],
      "properties": {
        "Date": {
          "type": "string",
          "format": "date"
        },
        "Artist": {
          "$ref": "#/definitions/AlbumInformation"
        }
      }
    },
    "AlbumInformation": {
      "type": "object",
      "required": [
        "Name"
      ],
      "properties": {
        "Name": {
          "type": "string",
          "minLength": 5
        }
      }
    }
  },
  "description": "nested-schema"
}

非常感谢您的帮助，谢谢。

我一直在尝试的一些代码:

@classmethod
def replace_refs(cls, obj, _recursive=False, **kwargs):
    kwargs["_recursive"] = True
    path = list(kwargs.pop("_path", ()))
    if isinstance(obj, Mapping):
        for k, v in obj.items():
            if isinstance(v, dict):
                if '$ref' in v:
                    import pdb
                    print(k, v)
            cls.replace_refs(v)
    return obj

Answer 1

仅需要递归来爬取文档。实际上解决 ref 可以迭代地完成。解决循环问题留给学生作为练习。

import json

obj = {
  "$id": "https://example.com/nested-schema.json",
  "title": "nested-schema",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "required": [
    "Music",
    "MusicID",
    "Composer"
  ],
  "properties": {
    "MusicID": {
      "type": "string",
      "minLength": 0,
      "maxLength": 0
    },
    "Music": {
      "$ref": "#/definitions/Music"
    },
    "Composer": {
      "type": "integer",
      "minimum": 0,
      "maximum": 0
    }
  },
  "definitions": {
    "Music": {
      "type": "object",
      "required": [
        "Date"
      ],
      "properties": {
        "Date": {
          "type": "string",
          "format": "date"
        },
        "Artist": {
          "$ref": "#/definitions/AlbumInformation"
        }
      }
    },
    "AlbumInformation": {
      "type": "object",
      "required": [
        "Name"
      ],
      "properties": {
        "Name": {
          "type": "string",
          "minLength": 5
        }
      }
    }
  },
  "description": "nested-schema"
}

def resolveRef(ref):
  refpath = ref["$ref"].split("/")[1:]
  refobj = obj
  for node in refpath:
    refobj = refobj[node]
  resolveRefs(refobj)
  return refobj

def resolveRefs(j):
  for k,v in j.items():
    if type(v) == dict and "$ref" in v:
      j[k] = resolveRef(v)
    elif type(v) == dict:
      resolveRefs(j[k])

resolveRefs(obj)
print(json.dumps(obj, indent=4))

示例:https://repl.it/repls/WarmKnottySupport