jsonpath是类似xpath的路径查找工具，可以方便地从JSON数据里查找到数据。

安装

pip install jsonpath

使用

测试数据

import jsonpath
import json

json_data = '''
{ "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
    }
  }
}
'''

data = json.loads(json_data)

从根目录递归

# 从根目录递归匹配键bicycle
bicycle = jsonpath.jsonpath(data, '$..bicycle')
print(bicycle)
# [{'color': 'red', 'price': 19.95}]

$表示根目录，..表示遍历。

键过滤

# 从根目录递归匹配book，并且当前子键是isbn
isbn = jsonpath.jsonpath(data, '$..book[?(@.isbn)]')
print(isbn)
# [{'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}]

?()用来过滤。

取值

author = jsonpath.jsonpath(data, '$..author')
print(author)
# ['Nigel Rees', 'Evelyn Waugh', 'Herman Melville', 'J. R. R. Tolkien']

author下面是键值对的值。

多选

#提取bicycle中color,price
color = jsonpath.jsonpath(data, '$..bicycle[color,price]]')
print(color)
# ['red', 19.95]

[,]可以填写多个键，用来多选。

[]和.写法

# 跟$..bicycle.price一样
price = jsonpath.jsonpath(data, '$..bicycle[price]')
print(price)
#[19.95]

.不能多选。

值过滤

# 取价格小于15的book
price = jsonpath.jsonpath(data, '$..book[?(@.price<15)]')
print(price)
# [{'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}]

第几个

# 取第二个
book1 = jsonpath.jsonpath(data, '$..book[1]')
print(book1)
# [{'category': 'fiction', 'author': 'Evelyn Waugh', 'title': 'Sword of Honour', 'price': 12.99}]

# 取前两个
book2 = jsonpath.jsonpath(data, '$..book[:2]')
print(book2)
# [{'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}]

[]里的数字从0开始。

参考

https://goessner.net/articles/JsonPath/