Python爬虫 selenium
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库的安装
pip3 install selenium
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
查找单个元素的 element
* 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
查找多个元素的 elements
* 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
单个元素
第一种方式直接指定通过某种方式查找 find_element_by...
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()
第二种方式 通过 find_element(By.xx , ‘ ....‘)
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="1f209c0d11551c40d9d20ad964fef244", element="0.07914603542731591-1")> """
多个元素
第一种
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()
打印的结果如下
print(lis) browser.close() [<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")>]
第二种
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()
元素交互操作
以下操作往淘宝输入框中输入 iPhone 然后清空再输入 iPad 在点击搜索
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()
可了解更多可以查看: http://selenium-python.readthedocs.io/api.html#module-selenium.webdriver.remote.webelement
交互动作
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‘) # 选择iframe source = browser.find_element_by_css_selector(‘#draggable‘) target = browser.find_element_by_css_selector(‘#droppable‘) actions = ActionChains(browser) # 动作链 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
通过函数 execute_script()
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
1.获取属性 get_attribute()
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 """
2.获取文本值 text
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)
打印结果:
提问
获取ID、位置、标签名、大小等
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
切换 子Iframe switch_to.frame("iframe的id值")
切换回来 switch_to.parent_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
由于页面需要时间刷新，防止某些元素未刷新出来就访问导致出错，可设置等待时间
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) # 等待时间 browser.get(‘https://www.zhihu.com/explore‘) input = browser.find_element_by_class_name(‘zu-top-add-question‘) print(input)
打印结果:
<selenium.webdriver.remote.webelement.WebElement (session="b29214772d59e912f1ac52e96ed29abe", element="0.12886805191194894-1")>
显示等待
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) # 最长的等待时间 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)
打印结果:
<selenium.webdriver.remote.webelement.WebElement (session="07dd2fbc2d5b1ce40e82b9754aba8fa8", element="0.5642646294074107-1")> <selenium.webdriver.remote.webelement.WebElement (session="07dd2fbc2d5b1ce40e82b9754aba8fa8", element="0.5642646294074107-2")>
元素动作判断
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
前进与后退
与浏览器的交互 back() 后退 froward() 前进
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()
获取Cookies 以及添加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())
打印结果:
[{‘secure‘: False, ‘value‘: ‘"NGM0ZTM5NDAwMWEyNDQwNDk5ODlkZWY3OTkxY2I0NDY=|1491604091|236e34290a6f407bfbb517888849ea509ac366d0"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘l_cap_id‘, ‘expiry‘: 1494196091.403418}, {‘secure‘: False, ‘value‘: ‘"YWEyOGY4MmI1MzQ2NGY5MmFiMjgzZGUzZWJjYTgwYjY=|1491604091|ff946847ddb5881245bdb7a5e6401b70dc61013f"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘cap_id‘, ‘expiry‘: 1494196091.402855}, {‘secure‘: False, ‘value‘: ‘1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘l_n_c‘}, {‘secure‘: False, ‘value‘: ‘"MjcxMDE3YzU1YjI4NDljZjljNTQ4ZDIyOWJjZTBhNmY=|1491604091|8da4722b56a1545c2020dba97394a220c0eca8d9"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘r_cap_id‘, ‘expiry‘: 1494196091.402525}, {‘secure‘: False, ‘value‘: ‘51854390‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmc‘}, {‘secure‘: False, ‘value‘: ‘"AADCo7e1kguPTqvEOMieRUzwkA7ZUBhV-VY=|1491604091"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘d_c0‘, ‘expiry‘: 1586212091.344773}, {‘secure‘: False, ‘value‘: ‘51854390.1491604091.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmz‘, ‘expiry‘: 1507372091}, {‘secure‘: False, ‘value‘: ‘3cc99fc5-8706-43fc-90ac-3ad991bd1a25‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘_zap‘, ‘expiry‘: 1554676091}, {‘secure‘: False, ‘value‘: ‘97cb00128ccb46659728f7c69cc191b0|1491604091000|1491604091000‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘q_c1‘, ‘expiry‘: 1586212091.401644}, {‘secure‘: False, ‘value‘: ‘51854390.2.10.1491604091‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmb‘, ‘expiry‘: 1491605891}, {‘secure‘: False, ‘value‘: ‘1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘n_c‘}, {‘secure‘: False, ‘value‘: ‘51854390.000--|3=entry_date=20170408=1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmv‘, ‘expiry‘: 1554676091}, {‘secure‘: False, ‘value‘: ‘51854390.669300758.1491604091.1491604091.1491604091.1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utma‘, ‘expiry‘: 1554676091}, {‘secure‘: False, ‘value‘: ‘1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmt‘, ‘expiry‘: 1491604691}, {‘secure‘: False, ‘value‘: ‘AQAAALCZuwh+dgIAeu3PPHA+csDPnXvT‘, ‘domain‘: ‘www.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: True, ‘name‘: ‘aliyungf_tc‘}]
[{‘secure‘: False, ‘value‘: ‘germey‘, ‘domain‘: ‘.www.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘name‘}, {‘secure‘: False, ‘value‘: ‘"NGM0ZTM5NDAwMWEyNDQwNDk5ODlkZWY3OTkxY2I0NDY=|1491604091|236e34290a6f407bfbb517888849ea509ac366d0"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘l_cap_id‘, ‘expiry‘: 1494196091.403418}, {‘secure‘: False, ‘value‘: ‘"YWEyOGY4MmI1MzQ2NGY5MmFiMjgzZGUzZWJjYTgwYjY=|1491604091|ff946847ddb5881245bdb7a5e6401b70dc61013f"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘cap_id‘, ‘expiry‘: 1494196091.402855}, {‘secure‘: False, ‘value‘: ‘1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘l_n_c‘}, {‘secure‘: False, ‘value‘: ‘"MjcxMDE3YzU1YjI4NDljZjljNTQ4ZDIyOWJjZTBhNmY=|1491604091|8da4722b56a1545c2020dba97394a220c0eca8d9"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘r_cap_id‘, ‘expiry‘: 1494196091.402525}, {‘secure‘: False, ‘value‘: ‘51854390‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmc‘}, {‘secure‘: False, ‘value‘: ‘"AADCo7e1kguPTqvEOMieRUzwkA7ZUBhV-VY=|1491604091"‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘d_c0‘, ‘expiry‘: 1586212091.344773}, {‘secure‘: False, ‘value‘: ‘51854390.1491604091.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmz‘, ‘expiry‘: 1507372091}, {‘secure‘: False, ‘value‘: ‘3cc99fc5-8706-43fc-90ac-3ad991bd1a25‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘_zap‘, ‘expiry‘: 1554676091}, {‘secure‘: False, ‘value‘: ‘97cb00128ccb46659728f7c69cc191b0|1491604091000|1491604091000‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘q_c1‘, ‘expiry‘: 1586212091.401644}, {‘secure‘: False, ‘value‘: ‘51854390.2.10.1491604091‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmb‘, ‘expiry‘: 1491605891}, {‘secure‘: False, ‘value‘: ‘1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘n_c‘}, {‘secure‘: False, ‘value‘: ‘51854390.000--|3=entry_date=20170408=1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmv‘, ‘expiry‘: 1554676091}, {‘secure‘: False, ‘value‘: ‘51854390.669300758.1491604091.1491604091.1491604091.1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utma‘, ‘expiry‘: 1554676091}, {‘secure‘: False, ‘value‘: ‘1‘, ‘domain‘: ‘.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: False, ‘name‘: ‘__utmt‘, ‘expiry‘: 1491604691}, {‘secure‘: False, ‘value‘: ‘AQAAALCZuwh+dgIAeu3PPHA+csDPnXvT‘, ‘domain‘: ‘www.zhihu.com‘, ‘path‘: ‘/‘, ‘httpOnly‘: True, ‘name‘: ‘aliyungf_tc‘}]
[]
浏览器选项卡的管理
通过switch_to_window(browser.window_handles[])
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‘)
打印结果:
[‘CDwindow-4f58e3a7-7167-4587-bedf-9cd8c867f435‘, ‘CDwindow-6e05f076-6d77-453a-a36c-32baacc447df‘]
异常处理
比如下面的元素不存在的处理 打印肯定会报错的啦
from selenium import webdriver browser = webdriver.Chrome() browser.get(‘https://www.baidu.com‘) browser.find_element_by_id(‘hello‘)
处理方式:
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()
打印结果:
No Element
详细文档：http://selenium-python.readthedocs.io/api.html#module-selenium.common.exceptions
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