帮我写一个完整的python爬取豆瓣top100电影的海报的完整代码

在Python中，我们可以使用requests库来获取网页内容，然后BeautifulSoup库解析HTML并提取我们需要的数据，最后使用`urllib.request.urlretrieve`保存图片到本地。这里是一个简单的示例，用于爬取豆瓣Top100电影的海报链接：

import requests
from bs4 import BeautifulSoup
import os

# 豆瓣Top100电影URL
url = "https://movie.douban.com/top250"

def download_image(title, img_url):
    # 定义保存路径，如果文件夹不存在就创建
    save_path = f"images/{title}.jpg"
    if not os.path.exists("images"):
        os.makedirs("images")
    
    try:
        response = requests.get(img_url, stream=True)
        response.raise_for_status()  # 检查请求是否成功
        
        with open(save_path, 'wb') as f:
            for chunk in response.iter_content(chunk_size=1024): 
                if chunk:  # filter out keep-alive new chunks
                    f.write(chunk)
        print(f"海报下载完成: {save_path}")
    except Exception as e:
        print(f"下载失败: {e}")

def main():
    response = requests.get(url)
    soup = BeautifulSoup(response.text, 'lxml')
    
    # 解析电影标题及海报链接
    movie_containers = soup.find_all('div', class_='hd')
    for container in movie_containers:
        title = container.find('span', itemprop='name').text.strip()
        img_url = container.find('img', alt=True)['src']
        
        # 下载海报
        download_image(title, img_url)

if __name__ == "__main__":
    main()