Web automation: how to realize browser window scrolling in 8.3 selenium

Window scrolling is not a web page operation , It belongs to window behavior . Realize window scrolling , Need to be in selenium Sent in js Instructions （ Reference resources ：8.2 selenium How to send js Instructions ）
Use scenarios ：
1、 There are lazy loaded products ： You don't load everything at once , Something must be done before something new comes out （ Such as ： Scroll bar drop-down , Will load new things ）
2、 Want to click or manipulate an element , But this element is not visible in the page . You need to pull the element into the visual range first , To click .

Introduce 3 A method of window scrolling ：

Method 1 ： Coordinate method

But we rarely use this method , Because generally, I don't know how many pixels of the element I'm positioning .
window.scrollTo(0,1000) # f（x,y） x： Abscissa ,y: Ordinate , Company ：xp( Pixel point )

practice 1

from selenium import webdriver
import time

driver = webdriver.Chrome()  #  Initialize a Google browser 
driver.maximize_window()  #  Maximize browser windows 
driver.get("https://readhub.cn/topics")   #  Open a web page with lazy loading 

time.sleep(5)   #  Wait for a while , Wait until the page is loaded js Code 

#  Method 1 ： Coordinate method 
driver.execute_script('window.scrollTo(0,1000)')   #  The abscissa does not change , Ordinate   Scroll to 1000 Pixel point 
time.sleep(2)   #  Wait for a while , Easy to see the effect of scrolling 
driver.execute_script('window.scrollTo(0,2000)')   #  Scroll again 
time.sleep(2)  #  Wait for a while , Easy to see the effect of scrolling 

Method 2 ： Scroll to the bottom of the window , Then locate the element to be found

window.scrollTo(0,document.body.scrollHeight) # document.body.scrollHeight The height of the current window

practice 2

from selenium import webdriver
import time

driver = webdriver.Chrome()  #  Initialize a Google browser 
driver.maximize_window()  #  Maximize browser windows 
driver.get("https://readhub.cn/topics")   #  Open a web page with lazy loading 

time.sleep(5)   #  Wait for a while , Wait until the page is loaded js Code 

#  Method 2 ： Scroll to the bottom of the window 
#  Pull to bottom , But with a new load, it will return to the two-thirds position ; After loading it, it jumps to the quarter position 
driver.execute_script('window.scrollTo(0,document.body.scrollHeight)')
time.sleep(2)   #  Wait for a while , Easy to see the effect of scrolling 
driver.execute_script('window.scrollTo(0,document.body.scrollHeight)')  #  Continue scrolling 

Method 3 ： Scroll elements to the visible range

scene ： Sometimes elements are under comparison , You need to scroll down the page to see the element and click
document.getElementById(“id”).scrollIntoView()
Or write in two lines ：
el = document.getElementById(“id”)
el.scrollIntoView()

practice 3

from selenium import webdriver
import time

driver = webdriver.Chrome()  #  Initialize a Google browser 
driver.maximize_window()  #  Maximize browser windows 
driver.get("https://www.baidu.com/s?ie=UTF-8&wd=%E8%8A%B1%E9%9D%99%E9%80%B8")   #  Open Baidu search “ Hua Jingyi ” The results page 

time.sleep(5)   #  Wait for a while , Wait until the page is loaded js Code 

# document.getElementsByClassName("pc")[1] # js Instructions ： Baidu search results page , Locate the flipping element at the bottom of the page “2”
driver.execute_script('document.getElementsByClassName("pc")[1].scrollIntoView()')

#  Or write in two lines 
driver.execute_script('el = document.getElementsByClassName("pc")[1]')
driver.execute_script('el.scrollIntoView()')

Be careful ： practice 3 There's a hole in it
getElementsByClassName Navigate to a set of elements , We need to index （ from 0 Start ） To get the element “2”