Python Selenium

Install

安装selenium

  $ pip install selenium
  # check:
  $ python3
  >>> from selenium import webdriver
  >>> help(webdriver)

安装browser驱动程序,eg: chrome的chromedrive
- download
- copy to path,eg: mac /usr/local/bin
- check: chromedriver -v

browser

def get_browser(slience=False):
    if not slience:
        return webdriver.Chrome()                           # 会弹出一个 chrome 浏览器
    else:
        chrome_options=Options()
        chrome_options.add_argument('--headless') 
        chrome_options.add_argument('--disable-gpu')
        browser=webdriver.Chrome(options=chrome_options)    # 创建的chrome浏览器是不可见的
        return browser

def test_browser(slience=False):
    browser=get_browser(slience)
    browser.get('http://www.baidu.com')
    print(browser.page_source)
    browser.close()

if __name__=='__main__':
    test_browser()
    # test_browser(slience=True)

查找元素

find_element_by_xxx(...),find_element(By.xxx,xxx): 返回匹配的第一个元素（WebElement类型对象），找不到则抛出异常
find_elements_by_xxx(...),find_elements(By.xxx,xxx): 返回所有匹配的元素列表，找不到则返回空列表
eg: find_elements(By.CSS_SELECTOR,'.service-bd li') = find_elements_by_css_selector(".service-bd li")
WebElement类型对象：
- .text 获取文本值（它与它的所有子孙节点的文字的组合，无则返回空字符串）
- .id
- .tag_name
- .location
- .size
- .get_attribute(attrName) 获取属性值（无则返回None）
- find_element_by_xxx / find_elements_by_xxx(...)
- find_element / find_elements(By.xxx,xxx)
使用:
- XPath
  - find_element_by_xpath / find_elements_by_xpath(xpath)
  - eg: find_element_by_xpath("//div[@class='detail']/a")
- CSS Selector
  - find_element_by_css_selector / find_elements_by_css_selector(css)
  - eg: find_element_by_css_selector("div[class='detail'] > div span")
- Tag
  - find_element_by_id(id): 一个或异常
  - find_element_by_tag_name / find_elements_by_tag_name(tagName)
  - find_element_by_class_name / find_elements_by_class_name(classValue): 使用元素的class值查找元素
  - find_element_by_name / find_elements_by_name(name): 通过name属性查找
  - find_element_by_link_text / find_elements_by_link_text(linkText): 文本值为linkText的超级链接元素<a>
  - find_element_by_partial_link_text / find_elements_by_partial_link_text(linkText): 文本值包含linkText的超级链接元素<a>
  - eg: find_element_by_class_name("p1") = find_elements_by_xpath("//*[@class='p1']") = find_elements_by_css_selector("*[class='p1']")

def test_element():
    browser=get_browser(slience=True)
    browser.get('http://www.baidu.com')

    print('--- input ---')
    input= browser.find_element_by_id('kw')
    print_element(input)

    print('--- searchBtn ---')
    #searchBtn = browser.find_element_by_id('su')
    searchBtn=browser.find_element(By.ID,'su')
    print_element(searchBtn)

def print_element(ele):
    print("id:",ele.id)
    print("tag_name:",ele.tag_name)
    print("location:",ele.location)
    print("size:",ele.size)
    print("text:",ele.text)
    print("class:",ele.get_attribute("class"))
    print("name:",ele.get_attribute("name"))
    print("type:",ele.get_attribute("type"))
    print("value:",ele.get_attribute("value"))
    print("id:",ele.get_attribute("id"))

交互操作

Refer to Action Chains

click,click_and_hold,double_click,context_click
drag_and_drop,drag_and_drop_by_offset
key_down,key_up
move_by_offset,move_to_element,move_to_element_with_offset
pause,perform,release,reset_actions
send_keys,send_keys_to_element

Sample1: action

browser=webdriver.Chrome()
input= browser.find_element_by_id('kw')
input.send_keys("MakBook")
searchBtn = browser.find_element_by_id('su')
searchBtn.click()
time.sleep(2)
input.clear()
input.send_keys("ipad")

Sample2: action_chains

from selenium.webdriver import ActionChains

browser=webdriver.Chrome()
browser.get("http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable")
time.sleep(1)

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()
time.sleep(1)

执行Javascript

execute_script(script)

browser=webdriver.Chrome()
browser.execute_script('window.scrollTo(0, document.body.scrollHeight)')
browser.execute_script('alert("To Bottom")')

切换

switch_to.xxx
- window(windowName)
- frame(frameName)
- parent_frame()
- active_element()
- default_content()
- alert()
back(),forward()

Sample1: window tab切换

# 1. window tab切换：
# 执行js命令`window.open()`打开选项卡
# 不同的选项卡是存在`browser.window_handles`列表中
# eg: 通过`browser.window_handles[0]`可以操作第一个选项卡
def test_window():
    browser=get_browser()
    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.douban.com/')
    time.sleep(1)

    browser.switch_to.window(browser.window_handles[0])
    browser.get('https://python.org')
    time.sleep(1)

    # 浏览器的前进和后退: back(),forward()
    browser.back()
    time.sleep(1)
    browser.forward()
    time.sleep(1)

    browser.close()

Sample2: frame切换

def test_frame():
    browser=get_browser(slience=True)
    browser.get('http://www.runoob.com/try/try.php?filename=jqueryui-api-droppable')

    browser.switch_to.frame('iframeResult')
    source = browser.find_element_by_css_selector('div#draggable')
    print(source)
    print(source.text)
    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)

异常处理

selenium.common.exceptions

from selenium import webdriver
from selenium.common.exceptions import TimeoutException, NoSuchElementException

browser=webdriver.Chrome()
try:
    browser.get('http://www.baidu.com')
    input= browser.find_element_by_id('kw')
    input.send_keys("MakBook")
    searchBtn = browser.find_element_by_id('su')
    searchBtn.click()
    print("clicked!")
    span=browser.find_element_by_xpath("//div[@id='container']//div[@class='nums']/span[@class='nums_text']")
    print("result:",span.text)
except (TimeoutException,NoSuchElementException) as e:
    print("Occur Exception:",e)
except Exception as e:
    print("Unknow Exception:",type(e),e)
finally:
    print("close!")
    browser.close()

Cookie

get_cookie(name)
add_cookie(dict): required keys “name” and “value”
delete_cookie(name)
get_cookies()
delete_all_cookes()

def test_cookie():
    browser=get_browser(slience=True)
    browser.get('http://www.baidu.com')
    cookies=browser.get_cookies()
    print(cookies)
    browser.add_cookie({'name':'user','value':'Tom'})
    print(browser.get_cookie('user'))

等待元素

强制等待 time.sleep(seconds)

隐式等待 browser.implicitly_wait(seconds)

  browser=get_browser()
  browser.get('http://www.baidu.com')
  input= browser.find_element_by_id('kw')
  input.send_keys("MakBook")
  searchBtn = browser.find_element_by_id('su')
  searchBtn.click()

  browser.implicitly_wait(3)
  span=browser.find_element_by_xpath("//div[@id='container']//div[@class='nums']/span[@class='nums_text']")
  print(span.text)
  browser.close()

显示等待
```
  from selenium.webdriver.support.wait import WebDriverWait
  from selenium.webdriver.support import expected_conditions as EC

  browser=get_browser()
  browser.get('http://www.baidu.com')
  input= browser.find_element_by_id('kw')
  input.send_keys("MakBook")
  searchBtn = browser.find_element_by_id('su')
  searchBtn.click()

  wait=WebDriverWait(browser,10, 0.5)

  optionLocator = (By.XPATH, "//select/option")
  option=wait.until(EC.presence_of_element_located(optionLocator))
  print(option)

  btnLocator=(By.CSS_SELECTOR, '.btn-search')
  btn=wait.until(EC.element_to_be_clickable(btnLocator))
  print(btn)

  browser.close()
```
- EC 常用的判断条件：
  - title_is : 标题是某内容
  - title_contains : 标题包含某内容
  - visibility_of : 可见，传入元素对象
  - staleness_of : 判断一个元素是否仍在DOM，可判断页面是否已经刷新
  - alert_is_present : 是否出现Alert
  - frame_to_be_available_and_switch_to_it : frame加载并切换
  - 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
  - presence_of_element_located(locator) : 指定元素出现，传入定位元组，如(By.ID, 'p')
  - presence_of_all_elements_located(locator)
  - invisibility/visibility_of_element_located(locator): 指定元素不可见／可见
  - element_to_be_clickable(locator) : 指定元素可点击
  - element_located_to_be_selected(locator) : 指定元素可选择
  - element_to_be_selected(element)
  - text_to_be_present_in_element(locator,text) : 指定元素的文本包含指定文本
  - text_to_be_present_in_element_value(locator,text) : 指定元素值包含某文字

Python Selenium

Install

browser

查找元素

交互操作

执行Javascript

切换

异常处理

Cookie

等待元素

Reference