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

当使用youtube时,浮动元素给出值“0”作为滚动高度 与其使用return document。body。scrollHeight"尝试使用这个"return document。documentelement。scrollHeight" 根据您的网速调整滚动暂停时间 否则它将只运行一次,然后在此之后中断。

SCROLL_PAUSE_TIME = 1

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

this dowsnt work due to floating web elements on youtube
"""

last_height = driver.execute_script("return document.documentElement.scrollHeight")
while True:
    # Scroll down to bottom
    driver.execute_script("window.scrollTo(0,document.documentElement.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.documentElement.scrollHeight")
    if new_height == last_height:
       print("break")
       break
    last_height = new_height

其他回答

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

我正在寻找一种滚动浏览动态网页的方法,并在到达页面末尾时自动停止,并找到了这个线程。

@Cuong Tran的这篇文章,有一个主要的修改,是我一直在寻找的答案。我认为其他人可能会发现这个修改很有帮助(它对代码的工作方式有明显的影响),因此写了这篇文章。

修改是将捕获最后一页高度的语句移动到循环内部(以便每个检查都与前一页高度进行比较)。

所以,下面的代码:

连续向下滚动一个动态网页(. scrollto()),只有在一次迭代中,页面高度保持相同时才停止。

(还有另一个修改,其中break语句在另一个条件(以防页面“卡住”)中,可以删除)。

    SCROLL_PAUSE_TIME = 0.5


    while True:

        # Get scroll height
        ### This is the difference. Moving this *inside* the loop
        ### means that it checks if scrollTo is still scrolling 
        last_height = driver.execute_script("return document.body.scrollHeight")

        # 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:

            # try again (can be removed)
            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")

            # check if the page height has remained the same
            if new_height == last_height:
                # if so, you are done
                break
            # if not, move on to the next loop
            else:
                last_height = new_height
                continue

当使用youtube时,浮动元素给出值“0”作为滚动高度 与其使用return document。body。scrollHeight"尝试使用这个"return document。documentelement。scrollHeight" 根据您的网速调整滚动暂停时间 否则它将只运行一次,然后在此之后中断。

SCROLL_PAUSE_TIME = 1

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

this dowsnt work due to floating web elements on youtube
"""

last_height = driver.execute_script("return document.documentElement.scrollHeight")
while True:
    # Scroll down to bottom
    driver.execute_script("window.scrollTo(0,document.documentElement.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.documentElement.scrollHeight")
    if new_height == last_height:
       print("break")
       break
    last_height = new_height

这是你如何向下滚动网页:

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

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