应对反爬:使用Selenium模拟浏览器抓取12306动态旅游产品
在当今数据驱动的时代,网络爬虫已成为获取互联网信息的重要手段。然而,许多网站如12306都实施了严格的反爬虫机制,特别是对于动态加载的内容。本文将详细介绍如何使用Selenium模拟真实浏览器行为,有效绕过这些限制,成功抓取12306旅游产品数据。
12306反爬机制分析
12306作为中国铁路官方售票平台,对其旅游产品数据实施了多层次防护:
- 动态内容加载:大量使用JavaScript异步加载数据,传统爬虫无法获取
- 验证码系统:复杂图片验证码和滑动验证码阻止自动化访问
- 请求头检测:验证User-Agent、Referer等头部信息
- 行为分析:检测鼠标移动、点击模式等人类特征
- IP限制:频繁请求会导致IP地址被暂时封锁
Selenium技术简介
Selenium是一个自动化Web测试工具,但其浏览器自动化能力使其成为应对反爬策略的利器:
- 真实浏览器环境:完全模拟用户操作,生成合法流量模式
- JavaScript执行:能够处理动态加载内容
- 元素交互:可以模拟点击、输入等用户行为
- 跨平台支持:支持Chrome、Firefox、Edge等主流浏览器
环境准备与配置
所需工具和库安装
首先确保安装以下Python库:
bash
pip install selenium beautifulsoup4 pandas webdriver-manager
WebDriver管理
Selenium需要对应浏览器的驱动程序。推荐使用webdriver-manager自动管理驱动:
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from webdriver_manager.chrome import ChromeDriverManager
from selenium.webdriver.chrome.options import Optionsdef setup_driver():chrome_options = Options()chrome_options.add_argument('--no-sandbox')chrome_options.add_argument('--disable-dev-shm-usage')chrome_options.add_argument('--disable-blink-features=AutomationControlled')chrome_options.add_experimental_option("excludeSwitches", ["enable-automation"])chrome_options.add_experimental_option('useAutomationExtension', False)chrome_options.add_argument('--start-maximized') # 最大化窗口# 使用webdriver-manager自动下载和管理ChromeDriverservice = Service(ChromeDriverManager().install())driver = webdriver.Chrome(service=service, options=chrome_options)# 执行CDP命令隐藏WebDriver特征driver.execute_script("Object.defineProperty(navigator, 'webdriver', {get: () => undefined})")driver.execute_cdp_cmd('Page.addScriptToEvaluateOnNewDocument', {'source': '''Object.defineProperty(navigator, 'webdriver', {get: () => undefined})'''})return driver
爬虫设计与实现
页面分析与等待策略
12306旅游产品页面(https://kyfw.12306.cn/otn/product/index.html)采用动态加载方式,需要合理设置等待时间:
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
import timedef wait_for_element(driver, by, value, timeout=10):"""等待元素出现"""try:element = WebDriverWait(driver, timeout).until(EC.presence_of_element_located((by, value)))return elementexcept Exception as e:print(f"元素加载超时: {value}")return Nonedef slow_scroll(driver, scroll_pause_time=0.5):"""模拟人类缓慢滚动页面"""last_height = driver.execute_script("return document.body.scrollHeight")while True:# 随机滚动距离,模拟人类行为scroll_height = random.randint(300, 800)driver.execute_script(f"window.scrollBy(0, {scroll_height});")time.sleep(scroll_pause_time)new_height = driver.execute_script("return document.body.scrollHeight")if new_height == last_height:breaklast_height = new_height
处理验证码挑战
当遇到验证码时,我们需要人工干预或使用OCR服务:
def handle_verification(driver):"""处理验证码挑战"""try:# 检查是否有验证码出现captcha_element = wait_for_element(driver, By.ID, "code", timeout=5)if captcha_element:print("验证码出现,请手动解决...")# 暂停程序,等待用户手动处理验证码input("解决验证码后按回车键继续...")return Trueexcept:passreturn False
数据提取实现
提取旅游产品信息的完整实现:
from bs4 import BeautifulSoup
import pandas as pd
import redef extract_tour_products(driver):"""提取旅游产品信息"""# 等待产品列表加载wait_for_element(driver, By.CLASS_NAME, "product-list", timeout=15)# 缓慢滚动加载所有内容slow_scroll(driver)# 获取页面源码并使用BeautifulSoup解析page_source = driver.page_sourcesoup = BeautifulSoup(page_source, 'html.parser')products = []product_items = soup.find_all('div', class_='product-item')for item in product_items:try:# 提取产品名称name_elem = item.find('div', class_='product-name')name = name_elem.text.strip() if name_elem else "未知产品"# 提取价格信息price_elem = item.find('div', class_='product-price')price_text = price_elem.text.strip() if price_elem else "0"price = re.search(r'(\d+)', price_text.replace(',', ''))price = int(price.group(1)) if price else 0# 提取出发地/目的地route_elem = item.find('div', class_='product-route')route = route_elem.text.strip() if route_elem else ""# 提取产品详情链接link_elem = item.find('a', href=True)link = "https://kyfw.12306.cn" + link_elem['href'] if link_elem else ""# 提取产品图片img_elem = item.find('img', src=True)img_url = img_elem['src'] if img_elem else ""products.append({'name': name,'price': price,'route': route,'link': link,'image_url': img_url,'crawled_time': pd.Timestamp.now()})except Exception as e:print(f"提取产品信息时出错: {e}")continuereturn products
完整爬虫流程
整合以上功能的完整实现:
import random
import json
from datetime import datetime
import time
import pandas as pd
from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from selenium.webdriver.chrome.options import Options
from webdriver_manager.chrome import ChromeDriverManager
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from bs4 import BeautifulSoup
import re# 代理信息
proxyHost = "www.16yun.cn"
proxyPort = "5445"
proxyUser = "16QMSOML"
proxyPass = "280651"def get_proxy_url():"""生成带认证的代理URL"""return f"http://{proxyUser}:{proxyPass}@{proxyHost}:{proxyPort}"def setup_driver():"""设置带代理的浏览器实例"""chrome_options = Options()# 添加代理服务器配置(带认证)proxy_url = get_proxy_url()chrome_options.add_argument(f'--proxy-server={proxy_url}')# 其他配置chrome_options.add_argument('--no-sandbox')chrome_options.add_argument('--disable-dev-shm-usage')chrome_options.add_argument('--disable-blink-features=AutomationControlled')chrome_options.add_experimental_option("excludeSwitches", ["enable-automation"])chrome_options.add_experimental_option('useAutomationExtension', False)chrome_options.add_argument('--start-maximized')# 使用webdriver-manager自动下载和管理ChromeDriverservice = Service(ChromeDriverManager().install())driver = webdriver.Chrome(service=service, options=chrome_options)# 执行CDP命令隐藏WebDriver特征driver.execute_script("Object.defineProperty(navigator, 'webdriver', {get: () => undefined})")driver.execute_cdp_cmd('Page.addScriptToEvaluateOnNewDocument', {'source': '''Object.defineProperty(navigator, 'webdriver', {get: () => undefined})'''})return driverdef wait_for_element(driver, by, value, timeout=10):"""等待元素出现"""try:element = WebDriverWait(driver, timeout).until(EC.presence_of_element_located((by, value)))return elementexcept Exception as e:print(f"元素加载超时: {value}")return Nonedef slow_scroll(driver, scroll_pause_time=0.5):"""模拟人类缓慢滚动页面"""last_height = driver.execute_script("return document.body.scrollHeight")while True:# 随机滚动距离,模拟人类行为scroll_height = random.randint(300, 800)driver.execute_script(f"window.scrollBy(0, {scroll_height});")time.sleep(scroll_pause_time)new_height = driver.execute_script("return document.body.scrollHeight")if new_height == last_height:breaklast_height = new_heightdef handle_verification(driver):"""处理验证码挑战"""try:# 检查是否有验证码出现captcha_element = wait_for_element(driver, By.ID, "code", timeout=5)if captcha_element:print("验证码出现,请手动解决...")# 暂停程序,等待用户手动处理验证码input("解决验证码后按回车键继续...")return Trueexcept:passreturn Falsedef extract_tour_products(driver):"""提取旅游产品信息"""# 等待产品列表加载wait_for_element(driver, By.CLASS_NAME, "product-list", timeout=15)# 缓慢滚动加载所有内容slow_scroll(driver)# 获取页面源码并使用BeautifulSoup解析page_source = driver.page_sourcesoup = BeautifulSoup(page_source, 'html.parser')products = []product_items = soup.find_all('div', class_='product-item')for item in product_items:try:# 提取产品名称name_elem = item.find('div', class_='product-name')name = name_elem.text.strip() if name_elem else "未知产品"# 提取价格信息price_elem = item.find('div', class_='product-price')price_text = price_elem.text.strip() if price_elem else "0"price = re.search(r'(\d+)', price_text.replace(',', ''))price = int(price.group(1)) if price else 0# 提取出发地/目的地route_elem = item.find('div', class_='product-route')route = route_elem.text.strip() if route_elem else ""# 提取产品详情链接link_elem = item.find('a', href=True)link = "https://kyfw.12306.cn" + link_elem['href'] if link_elem else ""# 提取产品图片img_elem = item.find('img', src=True)img_url = img_elem['src'] if img_elem else ""products.append({'name': name,'price': price,'route': route,'link': link,'image_url': img_url,'crawled_time': pd.Timestamp.now()})except Exception as e:print(f"提取产品信息时出错: {e}")continuereturn productsdef crawl_12306_tours():"""爬取12306旅游产品的完整流程"""print("启动浏览器(使用代理服务器)...")print(f"代理服务器: {proxyHost}:{proxyPort}")driver = setup_driver()try:# 访问12306旅游产品页面print("访问12306旅游产品页面...")driver.get("https://kyfw.12306.cn/otn/product/index.html")# 等待页面加载time.sleep(3)# 检查并处理验证码if handle_verification(driver):# 验证码处理后重新等待页面加载time.sleep(3)# 提取产品信息print("正在提取旅游产品信息...")products = extract_tour_products(driver)# 保存数据if products:df = pd.DataFrame(products)timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")filename = f"12306_tours_{timestamp}.csv"df.to_csv(filename, index=False, encoding='utf-8-sig')print(f"成功提取 {len(products)} 个旅游产品,已保存到 {filename}")# 同时保存JSON格式json_filename = f"12306_tours_{timestamp}.json"with open(json_filename, 'w', encoding='utf-8') as f:json.dump(products, f, ensure_ascii=False, indent=2)print(f"JSON数据已保存到 {json_filename}")else:print("未找到旅游产品信息")return productsexcept Exception as e:print(f"爬取过程中发生错误: {e}")return []finally:# 关闭浏览器driver.quit()print("浏览器已关闭")# 执行爬虫
if __name__ == "__main__":crawl_12306_tours()
道德与法律考量
在使用Selenium爬取12306数据时,必须注意以下道德和法律问题:
- 遵守robots.txt:检查目标网站的爬虫政策
- 控制请求频率:避免对服务器造成过大压力
- 数据使用限制:仅将数据用于个人学习和研究目的
- 用户隐私保护:不收集、存储或分享任何用户个人信息
- 版权尊重:遵守12306网站上内容的版权声明