一：介绍

selenium最初是一个自动化测试工具,而爬虫中使用它主要是为了解决requests无法直接执行JavaScript代码的问题selenium本质是通过驱动浏览器，完全模拟浏览器的操作，比如跳转、输入、点击、下拉等，来拿到网页渲染之后的结果，可支持多种浏览器from selenium import webdriverbrowser=webdriver.Chrome()browser=webdriver.Firefox()browser=webdriver.PhantomJS()browser=webdriver.Safari()browser=webdriver.Edge()

 

二：安装

#安装：selenium+chromedriverpip3 install selenium下载chromdriver.exe放到python安装路径的scripts目录中即可，注意最新版本是2.35，并非2.9国内镜像网站地址：http://npm.taobao.org/mirrors/chromedriver/最新的版本去官网找:https://sites.google.com/a/chromium.org/chromedriver/downloads#验证安装C:\Users\Administrator>python3Mac:/usr/local/binPython 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 18:41:36) [MSC v.1900 64 bit (AMD64)] on win32Type "help", "copyright", "credits" or "license" for more information.>>> from selenium import webdriver>>> driver=webdriver.Chrome() #弹出浏览器>>> driver.get('https://www.baidu.com')>>> driver.page_source#注意：selenium3默认支持的webdriver是Firfox，而Firefox需要安装geckodriver下载链接：https://github.com/mozilla/geckodriver/releases

#安装：selenium+phantomjspip3 install selenium下载phantomjs，解压后把phantomjs.exe所在的bin目录放到环境变量下载链接：http://phantomjs.org/download.html#验证安装C:\Users\Administrator>phantomjsphantomjs> console.log('egon gaga')egon gagaundefinedphantomjs> ^CC:\Users\Administrator>python3Python 3.6.1 (v3.6.1:69c0db5, Mar 21 2017, 18:41:36) [MSC v.1900 64 bit (AMD64)] on win32Type "help", "copyright", "credits" or "license" for more information.>>> from selenium import webdriver>>> driver=webdriver.PhantomJS() #无界面浏览器>>> driver.get('https://www.baidu.com')>>> driver.page_source

 

三：基本使用

from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素browser=webdriver.Chrome()try:    browser.get('https://www.baidu.com')    input_tag=browser.find_element_by_id('kw')    input_tag.send_keys('666') #python2中输入中文错误，字符串前加个u    input_tag.send_keys(Keys.ENTER) #输入回车    wait=WebDriverWait(browser,10)    wait.until(EC.presence_of_element_located((By.ID,'content_left'))) #等到id为content_left的元素加载完毕,最多等10秒    print(browser.page_source)    print(browser.current_url)    print(browser.get_cookies())finally:    browser.close()

 

四：选择器

　　1：基本用法

#官网链接：http://selenium-python.readthedocs.io/locating-elements.htmlfrom selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素import timedriver=webdriver.Chrome()driver.get('https://www.baidu.com')wait=WebDriverWait(driver,10)try:    #===============所有方法===================    # 1、find_element_by_id    # 2、find_element_by_link_text    # 3、find_element_by_partial_link_text    # 4、find_element_by_tag_name    # 5、find_element_by_class_name    # 6、find_element_by_name    # 7、find_element_by_css_selector    # 8、find_element_by_xpath    # 强调：    # 1、上述均可以改写成find_element(By.ID,'kw')的形式    # 2、find_elements_by_xxx的形式是查找到多个元素，结果为列表    #===============示范用法===================    # 1、find_element_by_id    print(driver.find_element_by_id('kw'))    # 2、find_element_by_link_text    # login=driver.find_element_by_link_text('登录')    # login.click()    # 3、find_element_by_partial_link_text    login=driver.find_elements_by_partial_link_text('录')[0]    login.click()    # 4、find_element_by_tag_name    print(driver.find_element_by_tag_name('a'))    # 5、find_element_by_class_name    button=wait.until(EC.element_to_be_clickable((By.CLASS_NAME,'tang-pass-footerBarULogin')))    button.click()    # 6、find_element_by_name    input_user=wait.until(EC.presence_of_element_located((By.NAME,'userName')))    input_pwd=wait.until(EC.presence_of_element_located((By.NAME,'password')))    commit=wait.until(EC.element_to_be_clickable((By.ID,'TANGRAM__PSP_10__submit')))    input_user.send_keys('18611453110')    input_pwd.send_keys('lhf@094573')    commit.click()    # 7、find_element_by_css_selector    driver.find_element_by_css_selector('#kw')    # 8、find_element_by_xpath    time.sleep(5)finally:    # driver.close()    driver.quit()  # 这个是杀掉进程。

　　

　　2：xpath

#官网链接：http://selenium-python.readthedocs.io/locating-elements.htmlfrom selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素import timedriver=webdriver.PhantomJS()driver.get('https://doc.scrapy.org/en/latest/_static/selectors-sample1.html')# wait=WebDriverWait(driver,3)driver.implicitly_wait(3) #使用隐式等待try:    # find_element_by_xpath    #//与/    # driver.find_element_by_xpath('//body/a')  # 开头的//代表从整篇文档中寻找,body之后的/代表body的儿子，这一行找不到就会报错了    driver.find_element_by_xpath('//body//a')  # 开头的//代表从整篇文档中寻找,body之后的//代表body的子子孙孙    driver.find_element_by_css_selector('body a')    #取第n个    res1=driver.find_elements_by_xpath('//body//a[1]') #取第一个a标签    print(res1[0].text)    #按照属性查找,下述三者查找效果一样    res1=driver.find_element_by_xpath('//a[5]')    res2=driver.find_element_by_xpath('//a[@href="image5.html"]')    res3=driver.find_element_by_xpath('//a[contains(@href,"image5")]') #模糊查找    print('==>', res1.text)    print('==>',res2.text)    print('==>',res3.text)    #其他    res1=driver.find_element_by_xpath('/html/body/div/a')    print(res1.text)    res2=driver.find_element_by_xpath('//a[img/@src="image3_thumb.jpg"]') #找到子标签img的src属性为image3_thumb.jpg的a标签    print(res2.tag_name,res2.text)    res3 = driver.find_element_by_xpath("//input[@name='continue'][@type='button']") #查看属性name为continue且属性type为button的input标签    res4 = driver.find_element_by_xpath("//*[@name='continue'][@type='button']") #查看属性name为continue且属性type为button的所有标签            time.sleep(5)finally:    # driver.close()    driver.quit()

 

　　3：获取标签属性

from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素browser=webdriver.Chrome()browser.get('https://www.amazon.cn/')wait=WebDriverWait(browser,10)wait.until(EC.presence_of_element_located((By.ID,'cc-lm-tcgShowImgContainer')))tag=browser.find_element(By.CSS_SELECTOR,'#cc-lm-tcgShowImgContainer img')#获取标签属性，print(tag.get_attribute('src'))#获取标签ID，位置，名称，大小（了解）print(tag.id)print(tag.location)print(tag.tag_name)print(tag.size)# browser.close() browser.quit()

 

五：等待元素被加载

#1、selenium只是模拟浏览器的行为，而浏览器解析页面是需要时间的（执行css，js），一些元素可能需要过一段时间才能加载出来，为了保证能查找到元素，必须等待#2、等待的方式分两种：隐式等待：在browser.get（'xxx'）前就设置，针对所有元素有效显式等待：在browser.get（'xxx'）之后设置，只针对某个元素有效

from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素browser=webdriver.Chrome()#隐式等待:在查找所有元素时，如果尚未被加载，则等10秒browser.implicitly_wait(10)browser.get('https://www.baidu.com')input_tag=browser.find_element_by_id('kw')input_tag.send_keys('美女')input_tag.send_keys(Keys.ENTER)contents=browser.find_element_by_id('content_left') #没有等待环节而直接查找，找不到则会报错print(contents)browser.close()

from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素browser=webdriver.Chrome()browser.get('https://www.baidu.com')input_tag=browser.find_element_by_id('kw')input_tag.send_keys('555')input_tag.send_keys(Keys.ENTER)#显式等待：显式地等待某个元素被加载wait=WebDriverWait(browser,10)wait.until(EC.presence_of_element_located((By.ID,'content_left')))contents=browser.find_element(By.CSS_SELECTOR,'#content_left')print(contents)browser.close()

六：元素交互操作

from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素browser=webdriver.Chrome()browser.get('https://www.amazon.cn/')wait=WebDriverWait(browser,10)input_tag=wait.until(EC.presence_of_element_located((By.ID,'twotabsearchtextbox')))input_tag.send_keys('iphone 8')button=browser.find_element_by_css_selector('#nav-search > form > div.nav-right > div > input')button.click()import timetime.sleep(3)input_tag=browser.find_element_by_id('twotabsearchtextbox')input_tag.clear() #清空输入框input_tag.send_keys('iphone7plus')button=browser.find_element_by_css_selector('#nav-search > form > div.nav-right > div > input')button.click()# browser.close()

from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By  # 按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys  # 键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait  # 等待页面加载某些元素import timedriver = webdriver.Chrome()driver.get('http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable')wait=WebDriverWait(driver,3)# driver.implicitly_wait(3)  # 使用隐式等待try:    driver.switch_to.frame('iframeResult') ##切换到iframeResult    sourse=driver.find_element_by_id('draggable')    target=driver.find_element_by_id('droppable')    #方式一：基于同一个动作链串行执行    # actions=ActionChains(driver) #拿到动作链对象    # actions.drag_and_drop(sourse,target) #把动作放到动作链中，准备串行执行    # actions.perform()    #方式二：不同的动作链，每次移动的位移都不同    ActionChains(driver).click_and_hold(sourse).perform()    distance=target.location['x']-sourse.location['x']    track=0    while track < distance:        ActionChains(driver).move_by_offset(xoffset=2,yoffset=0).perform()        track+=2    ActionChains(driver).release().perform()    time.sleep(10)finally:    driver.close()Action Chains

from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素try:    browser=webdriver.Chrome()    browser.get('https://www.baidu.com')    browser.execute_script('alert("hello world")') #打印警告finally:    browser.close()在交互动作比较难实现的时候可以自己写JS（万能方法）

#frame相当于一个单独的网页，在父frame里是无法直接查看到子frame的元素的，必须switch_to_frame切到该frame下，才能进一步查找from selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素try:    browser=webdriver.Chrome()    browser.get('http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable')    browser.switch_to.frame('iframeResult') #切换到id为iframeResult的frame    tag1=browser.find_element_by_id('droppable')    print(tag1)    # tag2=browser.find_element_by_id('textareaCode') #报错，在子frame里无法查看到父frame的元素    browser.switch_to.parent_frame() #切回父frame,就可以查找到了    tag2=browser.find_element_by_id('textareaCode')    print(tag2)finally:    browser.close()补充:frame的切换

 

七：其他

#模拟浏览器的前进后退import timefrom selenium import webdriverbrowser=webdriver.Chrome()browser.get('https://www.baidu.com')browser.get('https://www.taobao.com')browser.get('http://www.sina.com.cn/')browser.back()time.sleep(10)browser.forward()browser.close()

#cookiesfrom selenium import webdriverbrowser=webdriver.Chrome()browser.get('https://www.zhihu.com/explore')print(browser.get_cookies())browser.add_cookie({
    'k1':'xxx','k2':'yyy'})print(browser.get_cookies())# browser.delete_all_cookies()cookies

#选项卡管理：切换选项卡，有js的方式windows.open,有windows快捷键：ctrl+t等，最通用的就是js的方式import timefrom selenium import webdriverbrowser=webdriver.Chrome()browser.get('https://www.baidu.com')browser.execute_script('window.open()')print(browser.window_handles) #获取所有的选项卡browser.switch_to_window(browser.window_handles[1])browser.get('https://www.taobao.com')time.sleep(10)browser.switch_to_window(browser.window_handles[0])browser.get('https://www.sina.com.cn')browser.close()选项卡管理

from selenium import webdriverfrom selenium.common.exceptions import TimeoutException,NoSuchElementException,NoSuchFrameExceptiontry:    browser=webdriver.Chrome()    browser.get('http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable')    browser.switch_to.frame('iframssseResult')except TimeoutException as e:    print(e)except NoSuchFrameException as e:    print(e)finally:    browser.close()异常处理

 

八：项目练习

import timefrom selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素# 该代码生效与 2018-01-18     不知道什么时候会变。重在学习流程。# username = '1111111'# password = '2222222'## try:#     browser = webdriver.Chrome()#     browser.get('https://mail.163.com')#     browser.implicitly_wait(5)#     frame = browser.find_element_by_id('x-URS-iframe')  # 这个163有点骚气，需要进入到该id下的iframe#     browser.switch_to.frame(frame)##     user_tag = browser.find_element_by_id('auto-id-1516274652838')#     user_tag.send_keys(username)#     pwd_tag = browser.find_element_by_id('auto-id-1516274652839')#     pwd_tag.send_keys(password)##     pwd_tag.send_keys(Keys.ENTER)#     login = browser.find_elements_by_id('dologin')##     # 这里如果有验证码。。。  原谅我，我还在学习破解该验证码方式。#     # 。。。略略略browser = webdriver.Chrome()try:    browser.get('http://mail.163.com/')    wait = WebDriverWait(browser, 5)    frame = wait.until(EC.presence_of_element_located((By.ID, 'x-URS-iframe')))    browser.switch_to.frame(frame)    wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, '.m-container')))    inp_user = browser.find_element_by_name('email')    inp_pwd = browser.find_element_by_name('password')    button = browser.find_element_by_id('dologin')    inp_user.send_keys('66666')    inp_pwd.send_keys('xxxx')    button.click()    wait.until(EC.presence_of_element_located((By.ID, 'dvNavTop')))    write_msg = browser.find_elements_by_css_selector('#dvNavTop li')[1]  # 获取第二个li标签就是“写信”了    write_msg.click()    wait.until(EC.presence_of_element_located((By.CLASS_NAME, 'tH0')))    recv_man = browser.find_element_by_class_name('nui-editableAddr-ipt')    title = browser.find_element_by_css_selector('.dG0 .nui-ipt-input')    recv_man.send_keys('666@qq.com')    title.send_keys('8787')    print(title.tag_name)    frame = wait.until(EC.presence_of_element_located((By.CLASS_NAME, 'APP-editor-iframe')))    browser.switch_to.frame(frame)    body = browser.find_element(By.CSS_SELECTOR, 'body')    body.send_keys('666，wenwenwen')    browser.switch_to.parent_frame()  # 切回他爹    send_button = browser.find_element_by_class_name('nui-toolbar-item')    send_button.click()    # 可以睡时间久一点别让浏览器关掉，看看发送成功没有    import time    time.sleep(100)except Exception as e:    print(e)finally:    browser.quit()

import timefrom selenium import webdriverfrom selenium.webdriver import ActionChainsfrom selenium.webdriver.common.by import By #按照什么方式查找，By.ID,By.CSS_SELECTORfrom selenium.webdriver.common.keys import Keys #键盘按键操作from selenium.webdriver.support import expected_conditions as ECfrom selenium.webdriver.support.wait import WebDriverWait #等待页面加载某些元素# 爬取天猫撸撸杯def get_goods(browser):    goods = browser.find_elements_by_class_name('J_MouserOnverReq')    # print(goods)    msgs=[]    for detail_good in goods:        tag_a = detail_good.find_element_by_css_selector('.pic > .pic-link')        detail_url =tag_a.get_attribute('href')        detail_name = tag_a.find_element_by_tag_name('img').get_attribute('alt')        detail_price = tag_a.get_attribute('trace-price')        detail_pic = tag_a.find_element_by_tag_name('img').get_attribute('src')        msg="""            ?????            商品名称：{0},            商品链接：{1},            商品价钱：{2}，            商品图片：{3}             """.format(detail_name,detail_url,detail_price,detail_pic)        msgs.append(msg)    with open('saosao','w') as f :        for x in msgs:            f.write(x)def spider(url,keyword):    try:        browser = webdriver.Chrome()        browser.get(url)        browser.implicitly_wait(10)        # 找到搜索框，并输入关键字        # browser.find_element_by_css_selector('div .s-combobox-input > input')        search_tag = browser.find_element_by_id('q')        search_tag.send_keys(keyword)        search_tag.send_keys(Keys.ENTER)        get_goods(browser)        time.sleep(50)        # print(browser)    finally:        browser.quit()url='https://www.taobao.com'keyword = '撸撸杯'# 执行if __name__ == '__main__':    spider(url,keyword)