Selenium
自动化测试工具, 支持多种浏览器。 爬虫中主要用来解决JavaScript渲染的问题
驱动浏览器来做各种动作(跳转、查询、……)——支持主流浏览器
模拟浏览器访问,拿到浏览器渲染后的页面
安装
pip install selenium
基本使用
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.wait import WebDriverWait
browser = webdriver.Chrome()
try:
browser.get('https://www.baidu.com')
input = browser.find_element_by_id('kw') # 找到id 为kw的键
input.send_keys('Python') # 在这个键 中输入Python内容
input.send_keys(Keys.ENTER) # 回车
wait = WebDriverWait(browser, 10)
wait.until(EC.presence_of_element_located((By.ID,'content_left'))) # 等待id为content_left 的内容加载完毕
print(browser.current_url) # 打印url
print(browser.get_cookies()) # 打印cookies
print(browser.page_source) # 打印源代码
finally:
browser.close() # 关闭页面
声明浏览器对象
from selenium import webdriver
browser = webdriver.Chrome() # 声明一个CHrome浏览器对象
browser = webdriver.Firefox() # 声明
browser = webdriver.Edge()
browser = webdriver.PhantomJS()
browser = webdriver.Safari()
访问页面
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
print(browser.page_source)
browser.close()
查找元素
单个元素
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
input_first = browser.find_element_by_id('q')
input_second = browser.find_element_by_css_selector('#q')
input_third = browser.find_element_by_xpath('//*[@id="q"]')
print(input_first, input_second, input_third)
browser.close()
<selenium.webdriver.remote.webelement.WebElement (session="140e689c70a2e97e1c01ae7b5e54a03c", element="0.9239366371945823-1")> <selenium.webdriver.remote.webelement.WebElement (session="140e689c70a2e97e1c01ae7b5e54a03c", element="0.9239366371945823-1")> <selenium.webdriver.remote.webelement.WebElement (session="140e689c70a2e97e1c01ae7b5e54a03c", element="0.9239366371945823-1")>
- find_element_by_name
- find_element_by_xpath
- find_element_by_link_text
- find_element_by_tag_name
- find_element_by_class_name
- find_element_by_css_selector
from selenium import webdriver
from selenium.webdriver.common.by import By
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
input_first = browser.find_element(By.ID, 'q')
print(input_first)
browser.close()
<selenium.webdriver.remote.webelement.WebElement (session="2b9165a8730071b1c3b342eadb33f37d", element="0.26846444387513646-1")>
多个元素
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
lis = browser.find_elements_by_css_selector('.service-bd li')
print(lis)
browser.close()
[<selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-1")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-2")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-3")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-4")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-5")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-6")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-7")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-8")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-9")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-10")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-11")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-12")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-13")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-14")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-15")>, <selenium.webdriver.remote.webelement.WebElement (session="ece0ac0a8bc7840faaf9fa5b2537c35d", element="0.5686549757453516-16")>]
from selenium import webdriver
from selenium.webdriver.common.by import By
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
lis = browser.find_elements(By.CSS_SELECTOR, '.service-bd li')
print(lis)
browser.close()
[<selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-1")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-2")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-3")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-4")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-5")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-6")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-7")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-8")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-9")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-10")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-11")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-12")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-13")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-14")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-15")>, <selenium.webdriver.remote.webelement.WebElement (session="2fd570f9d8e1015e3b8dc935542db219", element="0.36423297915728003-16")>]
- find_elements_by_name
- find_elements_by_xpath
- find_elements_by_link_text
- find_elements_by_partial_link_text
- find_elements_by_tag_name
- find_elements_by_class_name
- find_elements_by_css_selector
元素交互操作
对获取的元素调用交互方法
from selenium import webdriver
import time
]
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
input = browser.find_element_by_id('q')
input.send_keys('iPhone')
time.sleep(5)
input.clear()
input.send_keys('iPad')
button = browser.find_element_by_class_name('btn-search')
button.click()
交互动作
将动作附加到动作链中串行执行
from selenium import webdriver
from selenium.webdriver import ActionChains
browser = webdriver.Chrome()
url = 'http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable'
browser.get(url)
browser.switch_to.frame('iframeResult')
source = browser.find_element_by_css_selector('#draggable')
target = browser.find_element_by_css_selector('#droppable')
actions = ActionChains(browser)
actions.drag_and_drop(source, target)
actions.perform()
执行JavaScript
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.zhihu.com/explore')
browser.execute_script('window.scrollTo(0, document.body.scrollHeight)')
browser.execute_script('alert("To Bottom")')
获取元素信息
获取属性
from selenium import webdriver
from selenium.webdriver import ActionChains
browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
logo = browser.find_element_by_id('zh-top-link-logo')
print(logo)
print(logo.get_attribute('class'))
<selenium.webdriver.remote.webelement.WebElement (session="dbcb58c81f345e6baefe14f449a81559", element="0.23926475887966325-1")>
zu-top-link-logo
获取文本值
from selenium import webdriver
browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
input = browser.find_element_by_class_name('zu-top-add-question')
print(input.text)
提问
获取ID、位置、标签名、大小
from selenium import webdriver
browser = webdriver.Chrome()
url = 'https://www.zhihu.com/explore'
browser.get(url)
input = browser.find_element_by_class_name('zu-top-add-question')
print(input.id)
print(input.location)
print(input.tag_name)
print(input.size)
0.6622234120324215-1
{'x': 758, 'y': 7}
button
{'height': 32, 'width': 66}
Frame
相当于一个独立的网页嵌入,如果在父级Frame想查找子级Frame 必须将页面切换到子级Frame 才能进行查找
import time
from selenium import webdriver
from selenium.common.exceptions import NoSuchElementException
browser = webdriver.Chrome()
url = 'http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable'
browser.get(url)
browser.switch_to.frame('iframeResult')
source = browser.find_element_by_css_selector('#draggable')
print(source)
try:
logo = browser.find_element_by_class_name('logo')
except NoSuchElementException:
print('No Logo')
browser.switch_to.parent_frame()
logo = browser.find_element_by_class_name('logo')
print(logo)
print(logo.text)
print(logo.get_attribute('class'))
<selenium.webdriver.remote.webelement.WebElement (session="3babf5d126171225ac7e648935c6cdbc", element="0.5865806992227736-1")>
No Logo
<selenium.webdriver.remote.webelement.WebElement (session="3babf5d126171225ac7e648935c6cdbc", element="0.8736718201387208-2")>
RUNOOB.COM
navbar-header logo
等待
隐式等待
当使用了隐式等待执行测试的时候,如果WebDriver没有在DOM中找到元素,将继续等待,超出设定时间后则抛出找不到元素异常,换句话说当查找元素或元素没有立即出现的时候,隐式等待将等待一段时间再查找DOM,默认时间为0
from selenium import webdriver
browser = webdriver.Chrome()
browser.implicitly_wait(10)
browser.get('https://zhihu.com/explore')
input = browser.find_element_by_class_name('zu-top-add-question')
print(input)
<selenium.webdriver.remote.webelement.WebElement (session="50f05e319852de6a485f641d13b4c35a", element="0.22632707900120286-1")>
显示等待
指定一个等待条件和最长等待时间,会在等待时间中判断条件是否成立,如果成立则会立即返回,如果不成立则会一直等待,如果超过等待时间 则会抛出异常
from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
browser = webdriver.Chrome()
browser.get('https://www.taobao.com')
wait = WebDriverWait(browser, 10)
input = wait.until(EC.presence_of_element_located((By.ID,'q')))
button = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR,'.btn-search')))
print(input, button)
<selenium.webdriver.remote.webelement.WebElement (session="72a244279181ef8f8e2c9157bd8e64a6", element="0.7878713628776868-1")> <selenium.webdriver.remote.webelement.WebElement (session="72a244279181ef8f8e2c9157bd8e64a6", element="0.7878713628776868-2")>
- title_is 标题是某内容
- title_contains 标题包含某内容
- presence_of_element_located 元素加载出,传入定位元组, 如(By.ID,’p’)
- visibility_of_element_located 元素可见,传入定位元组
- visibility_of 可见, 传入元素对象
- presence_of_all_elements_located 所有元素加载出
- text_to_be_present_in_element 某个元素文本包含某文字
- text_to_be_present_in_element_value 某个元素包含某文字
- frame_to_be_available_and_switch_to_it frame加载并切换
- invisibility_of_element_located 元素不可见
- element_to_be_clickable 元素可点击
- staleness_of 判断一个元素是否仍在DOM,可判断页面是否已经刷新
- element_to_be_selected 元素可选择,传元素对象
- element_located_to_be_selected 元素可选择,传定位元组
- element_selection_state_to_be 传入元素对象及状态,相等返回Ture,否则返回False
- alert_is_present 是否出现Alert
前进后退
import time
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.get('https://www.taobao.com')
browser.get('https://www.python.org')
browser.back()
time.sleep(10)
browser.forward()
time.sleep(10)
browser.close()
Cookies
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.zhihu.com/explore')
print(browser.get_cookies())
browser.add_cookie({'name': 'name', 'domain': 'www.zhihu.com','value': 'Night'})
print(browser.get_cookies())
browser.delete_all_cookies()
print(browser.get_cookies())
管理选项卡
通过js手动打开一个新页面
然后通过 browser.switch_to_window() 跳转 选项卡
在打开页面
import time
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.execute_script('window.open()')
print(browser.window_handles)
browser.switch_to_window(browser.window_handles[1]) # 设置当前选项卡
browser.get('https://www.taobao.com')
time.sleep(1)
browser.switch_to_window(browser.window_handles[0])
browser.get('https://python.org')
['CDwindow-(5C5B79F87A42E4CA1B11BC99B5F22E82)', 'CDwindow-(AC524DF290CE5D4847C861BDA5A0978)']
异常处理
from selenium import webdriver
browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.find_element_by_id('hello')
NoSuchElementException: Message: no such element: Unable to locate element: {"method":"id","selector":"hello"}
from selenium import webdriver
from selenium.common.exceptions import TimeoutException, NoSuchElementException
browser = webdriver.Chrome()
try:
browser.get('https://www.baidu.com')
except TimeoutException:
print('Time Out')
try:
browser.find_element_by_id('hello')
except NoSuchElementException:
print('No Element')
finally:
browser.close()
No Element