大观:
this 与 bind:JavaScript 中的“归属感”难题
反爬方法:
1. 请求头(Headers)验证
- 机制:检查
User-Agent
、Referer
、Cookie
等请求头 - 绕过方法:
headers = { "User-Agent": "Mozilla/5.0...", "Referer": "https://www.example.com", "Accept-Language": "zh-CN,zh;q=0.9" }
header:采用字典数据结构
request基础使用模板:
import requests headers = { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36 Edg/138.0.0.0" } url = "https://www.sogou.com/web" kw=input("请输入关键字") param={ 'query':kw } response = requests.get(url=url,headers=headers,params=param)
requests使用案例:
- [request+正则表达式爬取百度图片网的图片]
import requests import re url = "https://pic.netbian.com/" headers = { "user-agent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.90 Safari/537.36" } import os path = "彼岸图网图片获取" if not os.path.isdir(path): os.mkdir(path) response = requests.get(url=url,headers=headers) response.encoding = response.apparent_encoding # print(response.text) # 打印请求成功的网页源码,和在网页右键查看源代码的内容一样的 """ . 表示除空格外任意字符(除\n外) * 表示匹配字符零次或多次 ? 表示匹配字符零次或一次 .*? 非贪婪匹配 """ # src后面存放的是链接,alt后面是图片的名字 # 直接(.*?)也是可以可以直接获取到链接,但是会匹配到其他不是我们想要的图片 # 我们可以在前面图片信息看到链接都是/u····开头的,所以我们就设定限定条件(/u.*?)这样就能匹配到我们想要的 parr = re.compile('src="(/u.*?)".alt="(.*?)"') image = re.findall(parr,response.text) for content in image: print(content) # 对列表进行遍历 for i in image: link = i[0] # 获取链接 name = i[1] # 获取名字 """ 在文件夹下创建一个空jpg文件,打开方式以 'wb' 二进制读写方式 @param res:图片请求的结果 """ with open(path+"/{}.jpg".format(name),"wb") as img: res = requests.get("https://pic.netbian.com"+link) img.write(res.content) # 将图片请求的结果内容写到jpg文件中 img.close() # 关闭操作 print(name+".jpg 获取成功······")
- [在搜狗引擎搜索关键字,讲搜索后的页面生成html文件 ]
import requests headers = { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36 Edg/138.0.0.0" } url = "https://www.sogou.com/web" kw=input("请输入搜索的关键字") param={ 'query':kw } response = requests.get(url=url,headers=headers,params=param) page_text=response.text fileName=kw+".html" with open(fileName,'w',encoding='utf-8') as fp: fp.write(page_text) print(fileName,"保存成功")
- [requests爬取图片网站的图片 ]
import os import requests from urllib.parse import urljoin from bs4 import BeautifulSoup # 创建保存图片的目录 # os.makedirs('58pic_images', exist_ok=True) os.makedirs("110",) url = "https://www.58pic.com/tupian-tupian/so.html?n_order=dnum&n_page_type=2&n_more_free=?tid=922493&utm_source=baidu&sdclkid=AL2R15fNArDibLgpxOF&bd_vid=11560355579337041163" headers = { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36 Edg/138.0.0.0" } try: # 获取网页内容 response = requests.get(url, headers=headers) response.raise_for_status() html = response.text # 解析HTML soup = BeautifulSoup(html, "html.parser") # 查找所有img标签 img_tags = soup.find_all('img') print(f"找到 {len(img_tags)} 张图片") for i, img in enumerate(img_tags, start=1): # 获取图片URL(优先使用data-src,如果没有则用src) img_url = img.get('data-src') or img.get('src') if not img_url: continue # 处理相对URL img_url = urljoin(url, img_url) try: # 下载图片 img_data = requests.get(img_url, headers=headers, stream=True) img_data.raise_for_status() # 生成文件名 file_name = f"58pic_images/image_{i}.jpg" # 保存图片 with open(file_name, 'wb') as f: for chunk in img_data.iter_content(1024): f.write(chunk) print(f"已下载: {file_name}") except Exception as e: print(f"下载失败 {img_url}: {e}") except Exception as e: print(f"发生错误: {e}") print("下载完成!")
匹配方式汇总:
- css选择器
- 正则表达式(Regex)
- 使用如BeautifulSoup、PyQuery(基于Don树)
- XPath