python 操作 jsonpath

一、简介

jsonpath-ng 和 jsonpath-rw 两个用于解析 JSONPath 表达式的 Python 库

 

jsonpath-ng

• 基本 JSONPath 语法（如根节点、子节点、通配符、数组索引、过滤表达式等）。
• 不支持过滤器中的正则表达式和脚本表达式。
• 不支持某些复杂的逻辑运算。

jsonpath-rw

• 更广泛的 JSONPath 语法，包括过滤器中的正则表达式和脚本表达式。
• 支持更复杂的逻辑运算和嵌套的过滤条件。
• 支持递归下降操作符 ..。

二、安装

pip install jsonpath-rw -i http://mirrors.aliyun.com/pypi/simple/ --trusted-host mirrors.aliyun.com　

pip install jsonpath-ng -i http://mirrors.aliyun.com/pypi/simple/ --trusted-host mirrors.aliyun.com

　　

三、基本用法

 3.1 获取所有书籍的标题：

from jsonpath_ng import jsonpath, parse


data = {
    "store": {
        "book": [
            {"category": "fiction", "title": "西游记", "author": "F. Scott Fitzgerald", "price": 10.99},
            {"category": "non-fiction", "title": "红楼梦", "author": "Yuval Noah Harari", "price": 15.99}
        ],
        "bicycle": {"color": "red", "price": 19.99}
    }
}

jsonpath_expression = parse('$.store.book[*].title')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

from jsonpath_rw import jsonpath, parse


data = {
    "store": {
        "book": [
            {"category": "fiction", "title": "西游记", "author": "F. Scott Fitzgerald", "price": 10.99},
            {"category": "non-fiction", "title": "红楼梦", "author": "Yuval Noah Harari", "price": 15.99}
        ],
        "bicycle": {"color": "red", "price": 19.99}
    }
}


jsonpath_expression = parse('$.store.book[*].title')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

3.2 获取所有书籍的价格：

jsonpath_expression = parse('$.store.book[*].price')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

3.3 获取某一类别的书籍：

jsonpath_expression = parse('$.store.book[?(@.category == "fiction")]')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

3.4 获取自行车的颜色：

jsonpath_expression = parse('$.store.bicycle.color')
results = [match.value for match in jsonpath_expression.find(data)][0]
print(results)

　　

四、处理嵌套结构

4.1 获取所有商店的名字：

from jsonpath_ng import jsonpath, parse

data = {
    "stores": [
        {
            "name": "张三",
            "items": [
                {"type": "book", "title": "红楼梦", "price": 10.99},
                {"type": "toy", "name": "1", "price": 5.99}
            ]
        },
        {
            "name": "李四",
            "items": [
                {"type": "book", "title": "西游记", "price": 12.99},
                {"type": "toy", "name": "2", "price": 6.99}
            ]
        }
    ]
}

jsonpath_expression = parse('$.stores[*].name')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

from jsonpath_rw import jsonpath, parse

data = {
    "stores": [
        {
            "name": "张三",
            "items": [
                {"type": "book", "title": "红楼梦", "price": 10.99},
                {"type": "toy", "name": "1", "price": 5.99}
            ]
        },
        {
            "name": "李四",
            "items": [
                {"type": "book", "title": "西游记", "price": 12.99},
                {"type": "toy", "name": "2", "price": 6.99}
            ]
        }
    ]
}

jsonpath_expression = parse('$.stores[*].name')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

4.2 获取所有书的标题和价格：　　

jsonpath_expression = parse('$.stores[*].items[?(@.type == "book")].{title: title, price: price}')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)　

五、高级用法

1. 过滤条件

 获取价格大于 10 的书籍：

jsonpath_expression = parse('$.store.book[?(@.price > 10)]')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

 

2. 投影（只返回指定的字段。这对于减少返回数据的大小非常有用）

jsonpath_expression = parse('$.store.book[*].{title: title, author: author}')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

　　

3. 组合查询

jsonpath_expression = parse('$.store.book[?(@.category == "non-fiction")].{title: title, price: price}')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

　　

4. 处理数组索引

jsonpath_expression = parse('$.stores[0].items[0]')
results = [match.value for match in jsonpath_expression.find(data)]
print(results)

　　

五、错误处理

可以使用 try-except 语句来捕获潜在的异常：

try:
    jsonpath_expression = parse('$.store.book[*].title')
    results = [match.value for match in jsonpath_expression.find(data)]
    print(results)
except Exception as e:
    print(f"An error occurred:{e}")