爬虫技巧汇总

一、UA大列表

USER_AGENT_LIST 是一个包含多个用户代理字符串的列表，用于模拟不同浏览器和设备的请求。以下是一些常见的用户代理字符串：

USER_AGENT_LIST = ['Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; Hot Lingo 2.0)','Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3451.0 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:57.0) Gecko/20100101 Firefox/57.0','Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.71 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.2999.0 Safari/537.36','Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.70 Safari/537.36','Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; rv:1.9.2.2) Gecko/20100316 Firefox/3.6.2','Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.155 Safari/537.36 OPR/31.0.1889.174','Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.1.4322; MS-RTC LM 8; InfoPath.2; Tablet PC 2.0)','Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36 TheWorld 7','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36 OPR/55.0.2994.61','Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; MATP; InfoPath.2; .NET4.0C; CIBA; Maxthon 2.0)','Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.814.0 Safari/535.1','Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ja-jp) AppleWebKit/418.9.1 (KHTML, like Gecko) Safari/419.3','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.134 Safari/537.36','Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0; Touch; MASMJS)','Mozilla/5.0 (X11; Linux i686) AppleWebKit/535.21 (KHTML, like Gecko) Chrome/19.0.1041.0 Safari/535.21','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36','Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; Trident/4.0; Hot Lingo 2.0)','Mozilla/5.0 (Windows NT 6.2; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3451.0 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:57.0) Gecko/20100101 Firefox/57.0','Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/28.0.1500.71 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.2999.0 Safari/537.36','Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.70 Safari/537.36','Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.4; en-US; rv:1.9.2.2) Gecko/20100316 Firefox/3.6.2','Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.155 Safari/537.36 OPR/31.0.1889.174','Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; .NET CLR 1.1.4322; MS-RTC LM 8; InfoPath.2; Tablet PC 2.0)','Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/48.0.2564.116 Safari/537.36 TheWorld 7','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.100 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36 OPR/55.0.2994.61','Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; MATP; InfoPath.2; .NET4.0C; CIBA; Maxthon 2.0)','Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.814.0 Safari/535.1','Mozilla/5.0 (Macintosh; U; PPC Mac OS X; ja-jp) AppleWebKit/418.9.1 (KHTML, like Gecko) Safari/419.3','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.134 Safari/537.36','Mozilla/5.0 (compatible; MSIE 10.0; Windows NT 6.1; Trident/6.0; Touch; MASMJS)','Mozilla/5.0 (X11; Linux i686) AppleWebKit/535.21 (KHTML, like Gecko) Chrome/19.0.1041.0 Safari/535.21','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/69.0.3497.100 Safari/537.36','Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4093.3 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko; compatible; Swurl) Chrome/77.0.3865.120 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36','Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Goanna/4.7 Firefox/68.0 PaleMoon/28.16.0','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.131 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/83.0.4086.0 Safari/537.36','Mozilla/5.0 (Windows NT 6.1; WOW64; rv:75.0) Gecko/20100101 Firefox/75.0','Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) coc_coc_browser/91.0.146 Chrome/85.0.4183.146 Safari/537.36','Mozilla/5.0 (Windows; U; Windows NT 5.2; en-US) AppleWebKit/537.36 (KHTML, like Gecko) Safari/537.36 VivoBrowser/8.4.72.0 Chrome/62.0.3202.84','Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.101 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36 Edg/87.0.664.60','Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:83.0) Gecko/20100101 Firefox/83.0','Mozilla/5.0 (X11; CrOS x86_64 13505.63.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:68.0) Gecko/20100101 Firefox/68.0','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.101 Safari/537.36','Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36','Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36 OPR/72.0.3815.400','Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.101 Safari/537.36',]

二、反爬解决方案

随机替换UA
通过随机选择UA字符串来模拟不同用户请求，避免被网站识别为爬虫。
```
import random
ua = random.choice(USER_AGENT_LIST)
headers = {'User-Agent': ua}
```
随机延时
在请求之间添加随机延时，模拟人类操作，避免频繁请求被封锁。
```
import random
import time
time.sleep(random.randint(3, 5))
```
随机代理IP
使用代理IP池来隐藏真实IP地址，避免IP被封禁。推荐使用快代理等代理服务。
```
proxies = {'http': 'http://ip:port','https': 'https://ip:port',
}
requests.get(url, proxies=proxies)
```

Selenium防检测方法
使用Selenium时，可以通过以下方法绕过检测：

方法一：禁用自动化标志。

from selenium.webdriver.chrome.options import Options
options = Options()
options.add_experimental_option("excludeSwitches", ["enable-automation"])
driver = webdriver.Chrome(options=options)

方法二：通过CDP命令隐藏WebDriver属性。

driver.execute_cdp_cmd("Page.addScriptToEvaluateOnNewDocument", {"source": """Object.defineProperty(navigator, 'webdriver', {get: () => undefined})"""
})

三、Scrapy日志保存

Scrapy的日志可以通过以下方式进行配置：

终端日志显示控制
在settings.py中设置日志级别，控制终端输出的日志信息。
```
LOG_LEVEL = 'WARNING'  # 只显示警告及以上级别的日志
```

日志文件输出
将日志保存到文件中，便于后续分析。

import os
import datetimeos_path = os.getcwd() + '/log/'
if not os.path.exists(os_path):os.mkdir(os_path)to_day = datetime.datetime.now()
log_file_path = f'log/scrapy_{to_day.year}_{to_day.month}_{to_day.day}.log'
LOG_FILE = log_file_path

四、逆向方法

逆向工程是爬虫中常用的技术，尤其是面对复杂的反爬机制时。常见的逆向方法包括：

JavaScript逆向：通过分析网页的JavaScript代码，找到数据加载的逻辑。
API接口分析：直接调用网站的后端API接口获取数据。
加密算法破解：分析并破解网站使用的加密算法，如AES、RSA等。

五、Scrapy中Cookie值

在Scrapy中，可以通过以下方式处理Cookie：

禁用Cookie
在settings.py中禁用Cookie。
```
COOKIES_ENABLED = False
```

手动设置Cookie
在请求头中手动添加Cookie。

DEFAULT_REQUEST_HEADERS = {'Accept': 'text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8','Accept-Language': 'en','cookie': 'your_cookie_here',
}

动态生成Cookie
在爬虫中动态生成并传递Cookie。

cookies = {'key': 'value'}
yield scrapy.Request(url, cookies=cookies)

六、如何挂外网代理

SOCKS代理
使用SOCKS代理进行网络请求。

import socket
import sockssocks.set_default_proxy(socks.SOCKS5, 'ip', port)
socket.socket = socks.socksocket

HTTP代理
使用HTTP代理进行网络请求。

proxy = {'http': 'http://ip:port','https': 'https://ip:port',
}
requests.get(url, proxies=proxy)

七、解析方法

常见的网页解析方法包括：

BeautifulSoup4：适合解析HTML文档，语法简单易用。
XPath：强大的路径表达式语言，适合复杂的HTML结构。
PyQuery：类似于jQuery的语法，适合熟悉jQuery的开发者。
正则表达式：适合处理简单的文本匹配和提取。

对于JSON数据，可以使用jsonpath进行解析。

八、其他技巧

分布式爬虫
使用Scrapy-Redis等工具实现分布式爬虫，提高爬取效率。
数据存储
将爬取的数据存储到数据库（如MySQL、MongoDB）或文件中（如CSV、JSON）。
反反爬虫策略
- 使用Headless浏览器（如Puppeteer）模拟真实用户操作。
- 定期更换IP和UA，避免被封禁。
- 使用验证码识别服务（如打码平台）处理验证码。
异步爬虫
使用aiohttp或httpx等异步HTTP库，提高爬取速度。