举例说明jsonpath方法的使用

假设我们有如下的JSON数据：

{
   "store": {
      "book": [
         {
            "category": "reference",
            "author": "Nigel Rees",
            "title": "Sayings of the Century",
            "price": 8.95
         },
         {
            "category": "fiction",
            "author": "Evelyn Waugh",
            "title": "Sword of Honour",
            "price": 12.99
         },
         {
            "category": "fiction",
            "author": "Herman Melville",
            "title": "Moby Dick",
            "isbn": "0-553-21311-3",
            "price": 8.99
         },
         {
            "category": "fiction",
            "author": "J. R. R. Tolkien",
            "title": "The Lord of the Rings",
            "isbn": "0-395-19395-8",
            "price": 22.99
         }
      ],
      "bicycle": {
         "color": "red",
         "price": 19.95
      }
   }
}

现在我们想要获取所有图书的价格，我们可以使用jsonpath方法来实现：

import json
from jsonpath_ng import jsonpath, parse

# 解析JSON数据
data = json.loads('''
{
   "store": {
      "book": [
         {
            "category": "reference",
            "author": "Nigel Rees",
            "title": "Sayings of the Century",
            "price": 8.95
         },
         {
            "category": "fiction",
            "author": "Evelyn Waugh",
            "title": "Sword of Honour",
            "price": 12.99
         },
         {
            "category": "fiction",
            "author": "Herman Melville",
            "title": "Moby Dick",
            "isbn": "0-553-21311-3",
            "price": 8.99
         },
         {
            "category": "fiction",
            "author": "J. R. R. Tolkien",
            "title": "The Lord of the Rings",
            "isbn": "0-395-19395-8",
            "price": 22.99
         }
      ],
      "bicycle": {
         "color": "red",
         "price": 19.95
      }
   }
}
''')

# 解析jsonpath表达式
expression = parse('$.store.book[*].price')

# 使用jsonpath表达式获取数据
for match in expression.find(data):
    print(match.value)

运行上述代码，会输出所有图书的价格：

8.95
12.99
8.99
22.99