双十一专家服务购买

// 使用懒加载技术减少初始页面加载时间
document.addEventListener("DOMContentLoaded", function() {
  let lazyImages = [].slice.call(document.querySelectorAll("img.lazy"));
  if ("IntersectionObserver" in window) {
    let lazyImageObserver = new IntersectionObserver(function(entries, observer) {
      entries.forEach(function(entry) {
        if (entry.isIntersecting) {
          let lazyImage = entry.target;
          lazyImage.src = lazyImage.dataset.src;
          lazyImage.classList.remove("lazy");
          lazyImageObserver.unobserve(lazyImage);
        }
      });
    });
    lazyImages.forEach(function(lazyImage) {
      lazyImageObserver.observe(lazyImage);
    });
  }
});

# 使用Flask框架的示例，增加缓存机制
from flask import Flask, jsonify
from flask_caching import Cache

app = Flask(__name__)
cache = Cache(app, config={'CACHE_TYPE': 'simple'})

@app.route('/data')
@cache.cached(timeout=50)
def get_data():
    # 假设这里是从数据库获取数据
    data = fetch_from_database()
    return jsonify(data)

if __name__ == '__main__':
    app.run(debug=True)