如何为每个图像请求停止对数据库的调用？[完成]

import redis
import requests
from flask import Flask, send_file

app = Flask(__name__)
redis_client = redis.StrictRedis(host='localhost', port=6379, db=0)

@app.route('/image/<image_id>')
def get_image(image_id):
    # 尝试从Redis缓存中获取图像
    image_data = redis_client.get(f'image:{image_id}')
    
    if image_data is None:
        # 如果缓存中没有，从数据库或外部源获取
        response = requests.get(f'http://example.com/images/{image_id}')
        if response.status_code == 200:
            image_data = response.content
            # 将图像数据存入Redis缓存，设置过期时间为1小时
            redis_client.setex(f'image:{image_id}', 3600, image_data)
        else:
            return "Image not found", 404
    
    # 返回图像数据
    return send_file(
        io.BytesIO(image_data),
        mimetype='image/jpeg',
        as_attachment=True,
        attachment_filename=f'{image_id}.jpg'
    )

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