Selenium 使用

中文文档:

https://selenium-python-zh.readthedocs.io/en/latest/installation.html

下载 chromedriver

https://sites.google.com/a/chromium.org/chromedriver/downloads

安装 导入

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

声明浏览器对象

from selenium import webdriver

browser = webdriver.Chrome()
browser = webdriver.Firefox()
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

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)

其他

find_element_by_name
find_element_by_xpath
find_element_by_link_text
find_element_by_partial_link_text
find_element_by_tag_name
find_element_by_class_name
find_element_by_css_selector

例子:

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()

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')

from selenium.webdriver.common.by import By #需要导入模块
lis = browser.find_elements(By.CSS_SELECTOR, '.service-bd li') #两种结果一样
print(lis) browser.close()

返回列表格式,
[<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-1")>, 
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-2")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-3")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-4")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-5")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-6")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-7")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-8")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-9")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-10")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-11")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-12")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-13")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-14")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-15")>,
<selenium.webdriver.remote.webelement.WebElement (session="c26290835d4457ebf7d96bfab3740d19", element="0.09221044033125603-16")>]
  • 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(1)
input.clear()
input.send_keys('iPad')
button = browser.find_element_by_class_name('btn-search')
button.click()

更多操作: http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.remote.webelement

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()

更多操作: http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.common.action_chains

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="e08c0f28d7f44d75ccd50df6bb676104", element="0.7236390660048155-1")>
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)
0.6822924344980397-1
{'y': 7, 'x': 774}
button
{'height': 32, 'width': 66}

Frame

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)

<selenium.webdriver.remote.webelement.WebElement (session="4bb8ac03ced4ecbdefef03ffdc0e4ccd", element="0.44746093888932004-1")>
NO LOGO
<selenium.webdriver.remote.webelement.WebElement (session="4bb8ac03ced4ecbdefef03ffdc0e4ccd", element="0.13792611320464965-2")>
RUNOOB.COM

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的异常, 换句话说,当查找元素或元素并没有立即出现的时候,隐式等待将等待一段时间再查找 DOM,默认的时间是0

from selenium import webdriver

browser = webdriver.Chrome()
browser.implicitly_wait(10)
browser.get('https://www.zhihu.com/explore')
input = browser.find_element_by_class_name('zu-top-add-question')
print(input)
<selenium.webdriver.remote.webelement.WebElement (session="b29214772d59e912f1ac52e96ed29abe", element="0.12886805191194894-1")>

显式等待

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="07dd2fbc2d5b1ce40e82b9754aba8fa8", element="0.5642646294074107-1")> 
<selenium.webdriver.remote.webelement.WebElement (session="07dd2fbc2d5b1ce40e82b9754aba8fa8", element="0.5642646294074107-2")>
  • 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 某个元素值包含某文字
  • 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,传入定位元组
  • element_selection_state_to_be 传入元素对象以及状态,相等返回True,否则返回False
  • element_located_selection_state_to_be 传入定位元组以及状态,相等返回True,否则返回False
  • alert_is_present 是否出现Alert

详细内容:http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.support.expected_conditions

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(1)
browser.forward()
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': 'germey'})
print(browser.get_cookies())
browser.delete_all_cookies()
print(browser.get_cookies())

选项卡管理

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])
browser.get('https://www.taobao.com')
time.sleep(1)
browser.switch_to_window(browser.window_handles[0])
browser.get('https://python.org')

['CDwindow-4f58e3a7-7167-4587-bedf-9cd8c867f435', 'CDwindow-6e05f076-6d77-453a-a36c-32baacc447df']

异常处理

from selenium import webdriver

browser = webdriver.Chrome()
browser.get('https://www.baidu.com')
browser.find_element_by_id('hello')

---------------------------------------------------------------------------
NoSuchElementException                    Traceback (most recent call last)
<ipython-input-23-978945848a1b> in <module>()
      3 browser = webdriver.Chrome()
      4 browser.get('https://www.baidu.com')
----> 5 browser.find_element_by_id('hello')

/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py in find_element_by_id(self, id_)
    267             driver.find_element_by_id('foo')
    268         """
--> 269         return self.find_element(by=By.ID, value=id_)
    270 
    271     def find_elements_by_id(self, id_):

/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py in find_element(self, by, value)
    750         return self.execute(Command.FIND_ELEMENT, {
    751             'using': by,
--> 752             'value': value})['value']
    753 
    754     def find_elements(self, by=By.ID, value=None):

/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/webdriver.py in execute(self, driver_command, params)
    234         response = self.command_executor.execute(driver_command, params)
    235         if response:
--> 236             self.error_handler.check_response(response)
    237             response['value'] = self._unwrap_value(
    238                 response.get('value', None))

/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/selenium/webdriver/remote/errorhandler.py in check_response(self, response)
    190         elif exception_class == UnexpectedAlertPresentException and 'alert' in value:
    191             raise exception_class(message, screen, stacktrace, value['alert'].get('text'))
--> 192         raise exception_class(message, screen, stacktrace)
    193 
    194     def _value_or_default(self, obj, key, default):

NoSuchElementException: Message: no such element: Unable to locate element: {"method":"id","selector":"hello"}
  (Session info: chrome=57.0.2987.133)
  (Driver info: chromedriver=2.27.440174 (e97a722caafc2d3a8b807ee115bfb307f7d2cfd9),platform=Mac OS X 10.12.3 x86_64)
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

详细文档:http://selenium-python.readthedocs.io/api.html#module-selenium.common.exceptions

原文地址:https://www.cnblogs.com/polly-ling/p/9910177.html