python - 如何使用Python截取Selenium中指定的WebElement

Question

我想截取Selenium中的一个元素，根据文档，每个WebElement都有一个功能:

screenshot(filename)

Saves a screenshot of the current element to a PNG image file. Returns False if there is any IOError, else returns True. Use full paths in your filename.

Args: filename: The full path you wish to save your screenshot to. This should end with a .png extension

Usage: element.screenshot(‘/Screenshots/foo.png’)

但是，当我在我的程序中使用这个函数时:

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from time import sleep


url='http://www.google.com'
browser = webdriver.Chrome()  
browser.get(url)
content = browser.find_element_by_id('searchform')
content.screenshot('/home/ding/Pictures/shot.png')

它引发这样的错误:

Traceback (most recent call last):

  File "<ipython-input-8-309cb404878d>", line 11, in <module>
    content.screenshot('/home/ding/Pictures/shot.png')

  File "/home/ding/anaconda3/lib/python3.6/site-packages/selenium/webdriver/remote/webelement.py", line 453, in screenshot
    png = self.screenshot_as_png

  File "/home/ding/anaconda3/lib/python3.6/site-packages/selenium/webdriver/remote/webelement.py", line 435, in screenshot_as_png
    return base64.b64decode(self.screenshot_as_base64.encode('ascii'))

  File "/home/ding/anaconda3/lib/python3.6/site-packages/selenium/webdriver/remote/webelement.py", line 425, in screenshot_as_base64
    return self._execute(Command.ELEMENT_SCREENSHOT)['value']

  File "/home/ding/anaconda3/lib/python3.6/site-packages/selenium/webdriver/remote/webelement.py", line 501, in _execute
    return self._parent.execute(command, params)

  File "/home/ding/anaconda3/lib/python3.6/site-packages/selenium/webdriver/remote/webdriver.py", line 308, in execute
    self.error_handler.check_response(response)

  File "/home/ding/anaconda3/lib/python3.6/site-packages/selenium/webdriver/remote/errorhandler.py", line 165, in check_response
    raise exception_class(value)

WebDriverException: unknown command: session/efbca24571c5332230f4d032ae04787c/element/0.7487814861441955-1/screenshot

我该如何解决这个问题并在 Python 中使用 Selenium 截取元素的屏幕截图？

Answer 1

此代码非常适用于截取 Firefox 浏览器中特定元素的屏幕截图。

from selenium import webdriver
import io
from PIL import Image

fox = webdriver.Firefox()
fox.get('http://stackoverflow.com/')
image = fox.find_element_by_id('hlogo').screenshot_as_png
imageStream = io.BytesIO(image)
im = Image.open(imageStream)
im.save(image_path)