在 json 文件中搜索字符串并提取其部分

Question

我想知道如何执行以下操作： 1.在 json 中搜索字符串并提取它们的嵌套组件。 给定：

"type": "blah",
"animals": [
    {
        "type": "dog1",
        "name": "oscar",
        }
    },
    {
        "type": "dog2",
        "name": "John",
        }
    },
    {
        "type": "cat1",
        "name": "Fred",
        "Colors": [
            "Red"
        ],
        "Contact_info": [
            {
                "Owner": "Jill",
                "Owner_number": "123"
            }
        ],
    
    },
    {
        "type": "cat3",
        "name": "Freddy",
        "Colors": [
            "Blue"
        ],
        "Contact_info": [
            {
                "Owner": "Ann",
                "Owner_number": "1323"
            }
        ],

从这个 json 中，我想提取所有 cat 类型的动物，如 cat1 和 cat2，以及该块中的所有信息。 就像我搜索 cat 它应该返回：

{
    "type": "cat1",
    "name": "Fred",
    "Colors": [
        "Red"
    ],
    "Contact_info": [
        {
            "Owner": "Jill",
            "Owner_number": "123"
        }
    ],

},
{
    "type": "cat3",
    "name": "Freddy",
    "Colors": [
        "Blue"
    ],
    "Contact_info": [
        {
            "Owner": "Ann",
            "Owner_number": "1323"
        }
    ],

不一定是那种格式，只是所有类型为 cat 的信息。 我试图在 json 文件中搜索对象并从该搜索中提取特征以及嵌套在其中的任何内容。 到目前为止，这是我的代码：

f = open('data.json')
 
# returns JSON object as
# a dictionary
data = json.load(f)
 
# Iterating through the json
# list
for i in data:
    if i['type'] == 'cat':
        print(i['name'])
        print(i['colors'])

        break
 
# Closing file
f.close()```

Answer 1

首先，我建议使用with语句创建运行时上下文，允许您在上下文管理器的控制下运行一组语句。

它更具可读性，并且允许您跳过关闭文件，因为上下文管理器将为您做所有事情。

转移到你的问题

假设您的文件名为animals.json

# Import json library to work with json files
import json

# Use context manager
with open("animals.json", "rb") as f:
    # Load animals list from json file
    animals = json.load(f)["animals"]

# Create a list of dictionaries if animal type contains "cat"
cats = [animal for animal in animals if "cat" in animal.get("type")]

# Write data to cats.json
json.dump(cats, open("cats.json", "w"), indent=4, sort_keys=False, ensure_ascii=False)

此代码输出带有所有必要元素的格式化cats.json文件：

[
    {
        "type": "cat1",
        "name": "Fred",
        "Colors": [
            "Red"
        ],
        "Contact_info": [
            {
                "Owner": "Jill",
                "Owner_number": "123"
            }
        ]
    },
    {
        "type": "cat3",
        "name": "Freddy",
        "Colors": [
            "Blue"
        ],
        "Contact_info": [
            {
                "Owner": "Ann",
                "Owner_number": "1323"
            }
        ]
    }
]