在python3 json中通过值查找键

import json

def find_key(json_obj, target_value):
    for key, value in json_obj.items():
        if value == target_value:
            return key
        if isinstance(value, dict):
            result = find_key(value, target_value)
            if result is not None:
                return result
    return None

# 示例JSON对象
json_str = '''
{
    "name": "John",
    "age": 30,
    "address": {
        "street": "123 Street",
        "city": "New York",
        "state": "NY"
    }
}
'''

# 将JSON字符串解析为Python对象
data = json.loads(json_str)

# 查找值为"New York"的键
result = find_key(data, "New York")
print(result)  # 输出: "city"

import json

def find_key(json_obj, target_value):
    path = []  # 存储路径的列表
    stack = [(json_obj, path)]  # 使用栈来遍历JSON对象

    while stack:
        obj, path = stack.pop()
        for key, value in obj.items():
            current_path = path + [key]  # 当前路径
            if value == target_value:
                return current_path
            if isinstance(value, dict):
                stack.append((value, current_path))
    
    return None

# 示例JSON对象和目标值同上

# 查找值为"New York"的路径
result = find_key(data, "New York")
print(result)  # 输出: ["address", "city"]

import json

def find_key(json_obj, target_value):
    def find_path(obj, path):
        for key, value in obj.items():
            current_path = path + [key]  # 当前路径
            if value == target_value:
                yield current_path
            if isinstance(value, dict):
                yield from find_path(value, current_path)
    
    paths = find_path(json_obj, [])
    return next(paths, None)

# 示例JSON对象和目标值同上

# 查找值为"New York"的路径
result = find_key(data, "New York")
print(result)  # 输出: ["address", "city"]