通过授权账号（ AppID 和 AppSecret）爬取微信公众号【某个具体的公众号】中所有的文章内容存放到本地D盘

使用https://api.weixin.qq.com/cgi-bin/material/get_material?access_token=ACCESS_TOKEN 接口获取
但在获取过程中发现获取的文章数量不全，总共有84篇文章，多次调试始终只获取到早期的32篇，请问问题出在哪里？
具体代码详情如下：

import requests
import os
import re
import time

# 替换为你的公众号 AppID 和 AppSecret
APP_ID = 'AppID '
APP_SECRET = 'AppSecret'
# 存储文章的本地目录
SAVE_DIR = 'D:/wechat_articles'


def get_access_token():
    """
    获取微信公众号的 Access Token
    """
    url = f'https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid={APP_ID}&secret={APP_SECRET}'
    response = requests.get(url)
    result = response.json()
    if 'access_token' in result:
        print(result['access_token'])
        return result['access_token']
    else:
        print(f"获取 Access Token 失败: {result}")
        return None


def sanitize_filename(filename):
    """
    处理文件名中的非法字符，并确保编码正确
    """
    # 移除非法字符
    invalid_chars = r'[<>:"/\\|?*\x00-\x1F]'
    sanitized = re.sub(invalid_chars, '_', filename)
    return sanitized


def save_article(title, content):
    """
    将文章保存到本地文件
    """
    # 处理文件名
    safe_title = sanitize_filename(title)
    file_path = os.path.join(SAVE_DIR, f'{safe_title}.html')

    try:
        with open(file_path, 'w', encoding='utf-8') as f:
            f.write(content)
        print(f"文章 {title} 已保存到 {file_path}")
    except Exception as e:
        print(f"保存文章 {title} 失败: {e}")


def get_articles(access_token):
    """
    获取公众号的所有图文素材并保存到本地
    """
    if not os.path.exists(SAVE_DIR):
        os.makedirs(SAVE_DIR)

    url = 'https://api.weixin.qq.com/cgi-bin/material/batchget_material'
    offset = 0
    count = 20
    #start_date = "2020-01-01"
    #end_date = "2025-04-21"  # 微信接口仅支持查询到昨日

    while True:
        data = {
            "type": "news",
            "offset": offset,
            "count": count
        }
        response = requests.post(url, params={'access_token': access_token}, json=data)
        # 确保响应使用正确的编码
        response.encoding = 'utf-8'
        result = response.json()
        #print(result)
        if 'total_count' in result:
            print(result['total_count'])
        else:
            print(f"响应中未包含 total_count 字段: {result}")
        total_articles = 0

        if 'item' in result:
            items = result['item']
            if not items:
                break
            for item in items:
                article_info = item['content']['news_item']
                total_articles += len(article_info)
                for article in article_info:
                    title = article['title']
                    content = article['content']

                    save_article(title, content)
            offset += count
            # 防止触发频率限制
            time.sleep(1)  # 适当延时，建议1秒以上
        else:
            print(f"获取文章列表失败: {result}")
            break
        print(f"实际保存的文章总数: {total_articles}")

if __name__ == "__main__":
    access_token = get_access_token()
    if access_token:
        get_articles(access_token)