python爬取网页中content-type: image/png的所有图片

在Python中，可以结合`requests`和`beautifulsoup4`库来爬取特定类型的图片（如`image/png`）。这里有一个示例，展示如何抓取指定Content-Type的PNG图片：

import requests
from bs4 import BeautifulSoup
import os

def get_image_links(url):
    response = requests.get(url)
    if response.status_code == 200:
        soup = BeautifulSoup(response.content, 'html.parser')
        
        def is_png(link):
            return link.lower().endswith('.png') and 'image/png' in response.headers['Content-Type']

        png_links = [a['href'] for a in soup.find_all('a', href=True) if is_png(a['href'])]
        return png_links

def download_images(png_links, save_path='images'):
    if not os.path.exists(save_path):
        os.makedirs(save_path)

    for link in png_links:
        try:
            img_data = requests.get(link).content
            with open(os.path.join(save_path, link.split('/')[-1]), 'wb') as f:
                f.write(img_data)
            print(f"已下载图片: {link}")
        except Exception as e:
            print(f"下载图片失败: {link} - {str(e)}")

# 示例使用
url = "https://example.com"  # 需要爬取的网站
links = get_image_links(url)
download_images(links)

这个脚本首先获取网页内容，然后解析HTML找寻包含PNG链接的`<a>`元素。接着，它检查每个链接的内容类型是否为`image/png`，如果是则下载。