我目前使用硒webdriver解析通过facebook用户的朋友页面,并从AJAX脚本提取所有id。但我需要向下滚动来找到所有的朋友。如何向下滚动硒。我正在使用python。


当前回答

这段代码滚动到底部,但不需要每次都等待。它会不断滚动,然后在底部停止(或超时)

from selenium import webdriver
import time

driver = webdriver.Chrome(executable_path='chromedriver.exe')
driver.get('https://example.com')

pre_scroll_height = driver.execute_script('return document.body.scrollHeight;')
run_time, max_run_time = 0, 1
while True:
    iteration_start = time.time()
    # Scroll webpage, the 100 allows for a more 'aggressive' scroll
    driver.execute_script('window.scrollTo(0, 100*document.body.scrollHeight);')

    post_scroll_height = driver.execute_script('return document.body.scrollHeight;')

    scrolled = post_scroll_height != pre_scroll_height
    timed_out = run_time >= max_run_time

    if scrolled:
        run_time = 0
        pre_scroll_height = post_scroll_height
    elif not scrolled and not timed_out:
        run_time += time.time() - iteration_start
    elif not scrolled and timed_out:
        break

# closing the driver is optional 
driver.close()

这比每次等待0.5-3秒的响应要快得多,因为每次响应可能需要0.1秒

其他回答

滚动加载页面。例如:medium, quora等

last_height = driver.execute_script("return document.body.scrollHeight")
    while True:
        driver.execute_script("window.scrollTo(0, document.body.scrollHeight-1000);")
        # Wait to load the page.
        driver.implicitly_wait(30) # seconds
        new_height = driver.execute_script("return document.body.scrollHeight")
    
        if new_height == last_height:
            break
        last_height = new_height
        # sleep for 30s
        driver.implicitly_wait(30) # seconds
    driver.quit()

如果你想滚动到无限页面的底部(如linkedin.com),你可以使用下面的代码:

SCROLL_PAUSE_TIME = 0.5

# Get scroll height
last_height = driver.execute_script("return document.body.scrollHeight")

while True:
    # Scroll down to bottom
    driver.execute_script("window.scrollTo(0, document.body.scrollHeight);")

    # Wait to load page
    time.sleep(SCROLL_PAUSE_TIME)

    # Calculate new scroll height and compare with last scroll height
    new_height = driver.execute_script("return document.body.scrollHeight")
    if new_height == last_height:
        break
    last_height = new_height

参考:https://stackoverflow.com/a/28928684/1316860

只是目前提供的解决方案的一个小变化:有时在刮痧中你必须满足以下要求:

一步一步地滚动。否则,如果你总是跳到底部,一些元素只作为容器/div加载,但它们的内容没有加载,因为它们从来都不可见(因为你直接跳到底部); 为加载内容留出足够的时间; 这不是一个无限滚动的页面,有一个终点,你必须确定什么时候到达终点;

下面是一个简单的实现:

from time import sleep
def keep_scrolling_to_the_bottom():
    while True:
        previous_scrollY = my_web_driver.execute_script( 'return window.scrollY' )
        my_web_driver.execute_script( 'window.scrollBy( 0, 230 )' )
        sleep( 0.4 )
        if previous_scrollY == my_web_driver.execute_script( 'return window.scrollY' ):
            print( 'job done, reached the bottom!' )
            break

测试和工作在Windows 7 x64, Python 3.8.0, selenium 4.1.3,谷歌Chrome 107.0.5304.107,物业租赁网站。

这段代码滚动到底部,但不需要每次都等待。它会不断滚动,然后在底部停止(或超时)

from selenium import webdriver
import time

driver = webdriver.Chrome(executable_path='chromedriver.exe')
driver.get('https://example.com')

pre_scroll_height = driver.execute_script('return document.body.scrollHeight;')
run_time, max_run_time = 0, 1
while True:
    iteration_start = time.time()
    # Scroll webpage, the 100 allows for a more 'aggressive' scroll
    driver.execute_script('window.scrollTo(0, 100*document.body.scrollHeight);')

    post_scroll_height = driver.execute_script('return document.body.scrollHeight;')

    scrolled = post_scroll_height != pre_scroll_height
    timed_out = run_time >= max_run_time

    if scrolled:
        run_time = 0
        pre_scroll_height = post_scroll_height
    elif not scrolled and not timed_out:
        run_time += time.time() - iteration_start
    elif not scrolled and timed_out:
        break

# closing the driver is optional 
driver.close()

这比每次等待0.5-3秒的响应要快得多,因为每次响应可能需要0.1秒

这是你如何向下滚动网页:

driver.execute_script("window.scrollTo(0, 1000);")