Python JSON Schema校验失败：如何获取错误节点路径？

问题场景 #

本地JSON文件与F5官方AS3 Schema校验时，正常校验功能正常，但当JSON存在错误（例如将declaration的class值从ADC改为ADC1），仅返回“不符合任一给定Schema”的模糊提示，无法通过e.path或e.json_path获取具体错误节点的路径（如.declaration.class）。

测试用错误JSON #

{
  "schema": "https://raw.githubusercontent.com/F5Networks/f5-appsvcs-extension/master/schema/latest/as3-schema.json",
  "class": "AS3",
  "action": "deploy",
  "persist": true,
  "declaration": {
    "class": "ADC1",
    "schemaVersion": "3.40.0",
    "target": {
      "hostname": "test.test.com"
    },
    "id": "version_21.0",
    "label": "211008",
    "remark": "CO_version_21.0"
  }
}

原校验脚本 #

import json
import requests
from jsonschema import Draft7Validator, ValidationError

def load_json_from_url(url):
   response = requests.get(url)
   return response.json()

def main():
   schema_url = 'https://raw.githubusercontent.com/F5Networks/f5-appsvcs-extension/master/schema/latest/as3-schema.json'
   schema = load_json_from_url(schema_url)
  
   schema['$id'] = schema['$id'].replace('urn:uuid:', '')

   with open('gtm1.json', 'r') as f:
       validJson = json.load(f)

   validator = Draft7Validator(schema)

   try:
       validator.validate(validJson)
       print('The JSON file is valid according to the schema.')
   except ValidationError as e:
       message = e.schema["error_msg"] if "error_msg" in e.schema else e.message
       print(f'Invalid data: {message}')

if __name__ == '__main__':
   main()

解决方案 #

核心原因 #

F5 AS3 Schema大量使用oneOf/anyOf复合校验规则，校验失败时顶层ValidationError仅会提示整体不符合任一Schema，具体错误细节（含节点路径）被存储在e.context属性的子错误对象中。

修改后校验脚本 #

修改异常处理逻辑，遍历子错误获取具体路径和信息：

import json
import requests
from jsonschema import Draft7Validator, ValidationError

def load_json_from_url(url):
   response = requests.get(url)
   return response.json()

def main():
   schema_url = 'https://raw.githubusercontent.com/F5Networks/f5-appsvcs-extension/master/schema/latest/as3-schema.json'
   schema = load_json_from_url(schema_url)
  
   schema['$id'] = schema['$id'].replace('urn:uuid:', '')

   with open('gtm1.json', 'r') as f:
       validJson = json.load(f)

   validator = Draft7Validator(schema)

   try:
       validator.validate(validJson)
       print('The JSON file is valid according to the schema.')
   except ValidationError as e:
       # 处理无嵌套错误的情况
       if not e.context:
           message = e.schema["error_msg"] if "error_msg" in e.schema else e.message
           print(f'Invalid data: {message}')
       else:
           # 遍历所有子错误，输出节点路径和错误详情
           print("Validation errors found:")
           for idx, err in enumerate(e.context, 1):
               error_path = err.json_path  # 如 .declaration.class
               error_msg = err.message
               print(f"{idx}. Path: {error_path}, Error: {error_msg}")

if __name__ == '__main__':
   main()

测试效果 #

针对ADC1的错误，运行后会输出：

Validation errors found:
1. Path: .declaration.class, Error: 'ADC1' is not one of ['ADC', 'ADC_F5']

直接定位到错误节点，并明确错误原因。

内容的提问来源于stack exchange，提问作者sundrys1