selenium library of learning

selenium library steps

1. Import-related library, create an object webdriver

2. Access page

3. Objects created delays for WebDriverWait

4. Returns the HTML code

5. Find the relevant node is to mimic the clicking behavior simply to find other nodes using the library

Common applications: imitate the drop-down progress bar to load data

Common objects and methods

1. browser = webdriver.Chrome() <class 'selenium.webdriver.chrome.webdriver.WebDriver'

2. find_element() <class 'selenium.webdriver.remote.webelement.WebElement'>

3. wait = WebDriverWait(browser, 10) <class 'selenium.webdriver.support.wait.WebDriverWait'>

Import library preparation

from selenium import webdriver
from selenium.webdriver.common.by import By #class By类中包含find_element中by的方式
from selenium.webdriver.common.keys import Keys #class Set of special keys codes.
from selenium.webdriver.support import expected_conditions as EC #wait对象中until函数的等待条件
from selenium.webdriver.support.wait import WebDriverWait #class

Common exercises

from selenium import webdriver
from selenium.webdriver.common.by import By #class
from selenium.webdriver.common.keys import Keys #class
from selenium.webdriver.support import expected_conditions as EC
from selenium.webdriver.support.wait import WebDriverWait #class
import time
 
browser = webdriver.Chrome()
#print(type(browser))
#<class 'selenium.webdriver.chrome.webdriver.WebDriver'>
try:
    #访问页面
    browser.get('https://www.taobao.com')
    #<class 'NoneType'>

    #选择单个节点
    #-----------------------------------
    """
    find_element_by_id
    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
    find_element(By.ID, 'q')  查找方式By和值
    """
    #-----------------------------------
    #input_first = browser.find_element_by_id('q')
    #input_second = browser.find_element_by_css_selector('#q')
    input=browser.find_element_by_xpath(r'//input[contains(@type,"text") and @name="keyword"]')
    #<class 'selenium.webdriver.remote.webelement.WebElement'>

    #关键字搜索
    input.send_keys('龙虾')   #<class 'NoneType'>
    input.send_keys(Keys.ENTER)
    #input.clear() #清理搜索框

    #按钮点击，现在淘宝不行了需要登录
    button = browser.find_element_by_class_name('btn-search')
    button.click()
    
    #显式等待，创建wait对象
    wait = WebDriverWait(browser, 10)
    #<class 'selenium.webdriver.support.wait.WebDriverWait'>
    wait.until(EC.presence_of_element_located((By.ID, 'content_left')))
    #button = wait.until(EC.element_to_be_clickable((By.CSS_SELECTOR, '.btn-search')))
    print(browser.current_url)
    print(browser.get_cookies())

    #查找多个节点，返回结果为列表类型
    lis = browser.find_elements_by_css_selector('.service-bd li')
    #--------------------------------------
    """
    find_elements_by_id
    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
    find_elements(By.CSS_SELECTOR, '.service-bd li')
    """
    #--------------------------------------

    #下拉进度条
    from selenium import webdriver
    browser = webdriver.Chrome()
    browser.get('http://www.xiachufang.com/category/2918/')
    browser.execute_script('window.scrollTo(0, document.body.scrollHeight)')
    browser.execute_script('alert("To Bottom")')

    #前进和后退
    browser.back()
    time.sleep(1)
    browser.forward()
    #切换frame

    #cookies
    browser.get_cookies()
    browser.add_cookie({'name': 'name', 'domain': 'www.zhihu.com', 'value': 'germey'})
    browser.get_cookies()
    browser.delete_all_cookies()

finally:
    time.sleep(10)
    browser.close()