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    selenium

    下载安装驱动
    https://selenium-python.readthedocs.io/index.html
    安装位置: python环境变量位置(D:Anaconda3Scripts)

    简单使用

    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')
        input.send_keys('Python')
        input.send_keys(Keys.ENTER)
        wait = WebDriverWait(browser, 10)
        wait.until(EC.presence_of_element_located((By.ID, 'content_left')))
        print(browser.current_url)
        print(browser.get_cookies())
        print(browser.page_source)
    finally:
        browser.close()
    

    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()
    

    元素查找

    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()
    
    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()
    

    多个元素查找

    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()
    
    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

    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()
    

    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'))
    
    # 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)
    
    # 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)
    

    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)
    

    等待

    隐式等待: 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)
    

    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)
    

    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

    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(标签页管理)

    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')
    

    异常处理

    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()
    

    不加载图片

    from selenium import wendriver
    
    chrome_options = webdriver.ChromeOptions()
    prefs = {"profile.managed_default_content_settings.images": 2}
    chrome_options.add_experimental_option("prefs", prefs)
    
    browser = webdriver.Chrome(chrome_options=chrome_options)
    
    class xxxSpider(Spider):
        ...
    
        def __init__(self):
            self.browser = webdriver.Chrome()
            super().__init__()
            dispatcher.connect(self.spider_closed, signal=signals.spider_closed)
    
        def spider_closed(self):
            self.browser.quit()
    
        ...
    

    下载中间件

    class JSPageMiddleware(object):
    
        def process_request(self, request, spider):
            if spider.name == "xxx":
                spider.browser.get(request.url)
    
                return HtmlResponse(url=spider.browser.current_url, body=spider.browser.page_source, encoding='utf-8')
    

    不显示浏览器界面

    安装pyvirtualdisplay,webdriver运行时不会显示
    pip install pyvirtualdisplay

    from pyvirtualdisplay import Display
    from selenium import webdriver
    
    display = Display(visible=0, size=(800, 600))
    display.start()
    
    # 现在firefox会运行在一个虚拟的屏幕之中. 
    # 你看不到它.
    browser = webdriver.Chrome()
    browser.get('http://www.baidu.com')
    print browser.title
    browser.quit()
    
    display.stop()
    
    
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  • 原文地址:https://www.cnblogs.com/gaoyongjian/p/9908231.html
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