爬虫案例实战

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一、窗口切换实战

案例实战：使用selenium实现打开百度和腾讯两个窗口并切换
知识点：用到selenium中execute_script()执行js代码及switch_to.window()方法
全部代码如下：

import time
import warnings
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.chrome.options import Optionswarnings.filterwarnings('ignore')
# 创建ChromeOptions对象
chrome_options = Options()
# 添加启动参数，禁用浏览器自动化控制提示
chrome_options.add_experimental_option('excludeSwitches', ['enable-automation'])driver = webdriver.Chrome(chrome_options)
driver.execute_cdp_cmd("Page.addScriptToEvaluateOnNewDocument",{"source": " Object.defineProperty(navigator, 'webdriver', { get: () => undefined }) "}
)
driver.maximize_window()
# 请求第1个网址：driver.get()
driver.get('https://www.baidu.com')
time.sleep(3)# 请求第2个网址：JS代码
js_code = 'window.open("https://www.qq.com")'
driver.execute_script(js_code)# 获取窗口
window_list = driver.window_handles# 切换窗口到百度
driver.switch_to.window(window_list[0])
driver.find_element(by=By.ID, value='kw').send_keys('风景')
driver.find_element(by=By.ID, value='su').click()
time.sleep(2)# 切换窗口到QQ
driver.switch_to.window(window_list[1])
driver.find_element(by=By.XPATH, value='//*[@id="qqhome-top-header"]/div/div/div[2]/div/input').send_keys('Python')
driver.find_element(by=By.XPATH, value='//*[@id="qqhome-top-header"]/div/div/div[2]/div/button/span').click()
input()

二、京东数据抓取

案例实战：使用selenium实现打开京东搜索商品并滑动页面获取数据
知识点：用到selenium中execute_script()执行js代码
全部代码如下：

import time
import warnings
from lxml import etree
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.chrome.options import Optionskeyword = '手机'
warnings.filterwarnings('ignore')
# 创建ChromeOptions对象
chrome_options = Options()
# 添加启动参数，禁用浏览器自动化控制提示
chrome_options.add_experimental_option('excludeSwitches', ['enable-automation'])driver = webdriver.Chrome(chrome_options)
driver.execute_cdp_cmd("Page.addScriptToEvaluateOnNewDocument",{"source": " Object.defineProperty(navigator, 'webdriver', { get: () => undefined }) "}
)
driver.maximize_window()def requests_url():# 访问京东首页start_url = r'https://www.jd.com/'driver.get(start_url)input_data()def input_data():# 输入数据driver.find_element(by=By.ID, value='key').send_keys(keyword)time.sleep(2)driver.find_element(by=By.CLASS_NAME, value='button').click()time.sleep(8)Down_Scroll()def Down_Scroll():# 控制鼠标滑到底部for i in range(1, 11):js_code = 'scrollTo(0, {})'.format(i * 600)driver.execute_script(js_code)time.sleep(1)time.sleep(3)get_goods_info()def get_goods_info():# 解析响应response = driver.page_sourcehtml_xpath = etree.HTML(response)li_list = html_xpath.xpath('//div[@id="J_goodsList"]/ul/li')for li in li_list:# 1、商品标题goods_name_1 = li.xpath(r'.//div[@class="p-name p-name-type-2"]/a/em/text()')goods_name_2 = li.xpath(r'.//div[@class="p-name p-name-type-2"]/a/@title')goods_name = goods_name_1 if goods_name_1 != [] else goods_name_2goods_name = ''.join(goods_name).replace('\n', '').replace(' ', '').replace('	', '')# 2、卖家名字sale_name = li.xpath(r'.//a[@class="curr-shop hd-shopname"]/@title')sale_name = ''.join(sale_name)# 3、商品价格goods_price = li.xpath(r'.//div/div[2]/strong/i/text()')goods_price = ''.join(goods_price)if goods_name != '':print(goods_name, sale_name, goods_price, sep=' | ')def main():requests_url()input()if __name__ == '__main__':main()