如何在嵌套的JSON字符串中循环和提取newsid，headline的值

import json

def extract_values(data):
    newsids = []
    headlines = []

    if isinstance(data, list):
        for item in data:
            newsid, headline = extract_values(item)
            newsids.extend(newsid)
            headlines.extend(headline)
    elif isinstance(data, dict):
        if 'newsid' in data:
            newsids.append(data['newsid'])
        if 'headline' in data:
            headlines.append(data['headline'])
        
        for value in data.values():
            if isinstance(value, (list, dict)):
                newsid, headline = extract_values(value)
                newsids.extend(newsid)
                headlines.extend(headline)
    
    return newsids, headlines

# 示例JSON字符串
json_string = '''
{
    "newsid": "123",
    "headline": "Example Headline",
    "items": [
        {
            "newsid": "456",
            "headline": "Nested Headline 1"
        },
        {
            "newsid": "789",
            "headline": "Nested Headline 2"
        }
    ],
    "nested": {
        "newsid": "101112",
        "headline": "Nested Headline 3"
    }
}
'''

# 解析JSON字符串为字典
data = json.loads(json_string)

# 提取newsid和headline的值
newsids, headlines = extract_values(data)

# 打印结果
for newsid, headline in zip(newsids, headlines):
    print(f"newsid: {newsid}, headline: {headline}")

newsid: 123, headline: Example Headline
newsid: 456, headline: Nested Headline 1
newsid: 789, headline: Nested Headline 2
newsid: 101112, headline: Nested Headline 3