如何从JSON文件中高效提取多类动物数据并生成字典列表

需要从JSON文档中提取类型包含cat或snail的动物数据，并导出到单独文件。当前代码仅能提取单类（cat）数据，无法实现多类提取，同时希望找到高效实现方法。

示例数据 #

{
    "type": "blah",
    "animals": [
        {
            "type": "dog1",
            "name": "oscar"
        },
        {
            "type": "dog2",
            "name": "John"
        },
        {
            "type": "snail1",
            "name": "Fred",
            "Colors": ["Red"],
            "Contact_info": [{"Owner": "Jill", "Owner_number": "123"}]
        },
        {
            "type": "cat3",
            "name": "Freddy",
            "Colors": ["Blue"],
            "Contact_info": [{"Owner": "Ann", "Owner_number": "1323"}]
        }
    ]
}

预期结果 #

[
    {
        "type": "snail1",
        "name": "Fred",
        "Colors": ["Red"],
        "Contact_info": [{"Owner": "Jill", "Owner_number": "123"}]
    },
    {
        "type": "cat3",
        "name": "Freddy",
        "Colors": ["Blue"],
        "Contact_info": [{"Owner": "Ann", "Owner_number": "1323"}]
    }
]

现有问题代码 #

import json

with open("data.json", "rb") as f:
    # Load obj list
    data = json.load(f)["animals"]

# Create a list of dictionaries if obj type contains "snail" or cat
animal= [a for a in data if "snail" in a.get("type")]
animal = [a for a in data if "cat" in a.get("type")]

1. 修复基础逻辑错误 #

现有代码的问题在于两次赋值animal变量，第二次的列表推导式完全覆盖了第一次的结果，最终只保留了cat类型的数据。需要把两个条件合并到同一个推导式中：

import json

with open("data.json", "r", encoding="utf-8") as f:
    data = json.load(f)["animals"]

# 合并两个条件，提取包含snail或cat的条目
animals = [a for a in data if "snail" in a.get("type", "") or "cat" in a.get("type", "")]

2. 高效扩展方案（适合多关键词场景） #

如果后续需要匹配更多关键词，直接写多个or会冗余。可以用集合存储关键词，通过检查动物类型是否包含集合中的任意关键词实现，扩展性更强，数据量大时效率更高：

import json

# 定义需要匹配的关键词集合
TARGET_TYPES = {"snail", "cat"}

with open("data.json", "r", encoding="utf-8") as f:
    data = json.load(f)["animals"]

# 高效筛选：检查动物type中是否包含任意目标关键词
animals = [
    a for a in data 
    if any(keyword in a.get("type", "") for keyword in TARGET_TYPES)
]

3. 导出结果到文件 #

提取完成后，用json.dump将结果写入目标文件，设置ensure_ascii=False和indent=4保证中文显示正常且格式美观：

# 导出到结果文件
with open("filtered_animals.json", "w", encoding="utf-8") as f:
    json.dump(animals, f, ensure_ascii=False, indent=4)

内容的提问来源于stack exchange，提问作者user18774110