硒蟒如何限制截图高度？

Question

我想用Selenium Python获得一个完整网页的截图。为了做到这一点，我用了这个答案。

但是现在我想分割截图，并将结果截图的高度限制在30000 px。例如，如果一个网页高度是40000 px，我想先一个30000 px的截图，然后一个10000 px的截图。

    raise exception_class(message, screen, stacktrace)
selenium.common.exceptions.WebDriverException: Message: [Exception... "Failure"  nsresult: "0x80004005 (NS_ERROR_FAILURE)"  location: "JS frame :: chrome://marionette/content/capture.js :: capture.canvas :: line 154"  data: no]

from selenium import webdriver
from selenium.webdriver.firefox.options import Options
from time import sleep

def save_screenshot(d, path):
    max_size = 30000
    original_size = d.get_window_size()
    required_width = d.execute_script('return document.body.parentNode.scrollWidth')+74
    required_height = d.execute_script('return document.body.parentNode.scrollHeight')+74
    if required_height <= max_size:
        d.set_window_size(required_width, required_height)
        d.find_element_by_tag_name('body').screenshot(path)  # avoids scrollbar
    else :
        for i in range(0,int(required_height/max_size)):
            d.set_window_position(0,max_size*i)
            d.set_window_size(required_width, max_size)
            d.find_element_by_tag_name('body').screenshot(path.replace(".png",str(i+1)+".png"))
        d.set_window_position(0,max_size*int(required_height/max_size))
        d.set_window_size(required_width, required_height%max_size)
        d.find_element_by_tag_name('body').screenshot(path.replace(".png",str(int(required_height/max_size)+1)+".png"))
        d.set_window_position(0,0)
    d.set_window_size(original_size['width'], original_size['height'])

if __name__ == '__main__':
    options = Options()
    options.headless = True
    driver = webdriver.Firefox(options=options,executable_path=r"C:/Users/path/geckodriver.exe")
    driver.get("http://www.lwb.com/")
    sleep(3)
    save_screenshot(driver,"C:/Users/path/test.png")
    driver.close()

谢谢，

米尔哈

Answer 1

您可以使用pillowPip install pillow裁剪保存的屏幕截图

def crop_image(img, img_limit):
    img_width, img_height = img.size
    crop_dim = (0, 0, img_width, img_limit) # left top right bottom
    cropped_img = img.crop(crop_dim)
    return cropped_img

执行save_screenshot(driver,“path/to/img”）后，执行以下操作：

from PIL import Image

img_limit = 30000 # your image size limit
img = Image.open("path/to/img")
img = crop_image(img, img_limit)
img.save("path/to/img")

如果在操作图像之前不想保存它，可以使用get_screenshot_as_png，它将返回二进制数据，而不是保存它：

from PIL import Image
from io import BytesIO

img_limit = 30000 # your image size limit
img_binary = driver.get_screenshot_as_png()
img = Image.open(BytesIO(img_binary))
img = crop_image(img, img_limit)
img.save("path/to/save")

from selenium import webdriver

DRIVER_PATH = "path/to/chrome/driver"
URL = "site.url"

options = webdriver.ChromeOptions()
options.add_argument("headless")
driver  =  webdriver.Chrome(executable_path = DRIVER_PATH, chrome_options = options)

# setting a long window height to take one full screenshot
driver.set_window_size(1920, 90000) # width , height
driver.get(URL)
driver.maximize_window()

img_binary = driver.get_screenshot_as_png()

PS：如果您使用此方法进行截图，您将不需要枕头。只需使用set_window_size设置所需窗口的高度和宽度，就可以在屏幕截图中获得相同的大小