selenium cannot screenshot a web element

Question

I can screenshot a whole page using Firefox.get_screenshot_as_file(\'2.png\'),but when I screenshot a web element using passage.screenshot(\'1.png\'),it alway raise

Answer 1

The screenshot of a web element is not implemented in the Firefox driver. A workaround would be to crop the targeted element from the screenshot:

import StringIO
from selenium import webdriver
from PIL import Image

driver = webdriver.Firefox()
driver.get('http://stackoverflow.com')

# get the logo element
element = driver.find_element_by_id('hlogo')

# crop to the logo from the screenshot
rect = element.rect
points = [rect['x'], rect['y'], rect['x'] + rect['width'], rect['y'] + rect['height']]
with Image.open(StringIO.StringIO(driver.get_screenshot_as_png())) as img :
    with img.crop(points) as imgsub :
        imgsub.save("c:\\temp\\logo.png", 'PNG')

Answer 2

You're getting this exception because you cannot take a screenshot of just an element in selenium without some third-party libraries or your own code to handle this. See This stackoverflow post

Which uses a library called PIL to do it:

from selenium import webdriver
from PIL import Image

fox = webdriver.Firefox()
fox.get('https://stackoverflow.com/')

# now that we have the preliminary stuff out of the way time to get that image :D
element = fox.find_element_by_id('hlogo') # find part of the page you want image of
location = element.location
size = element.size
fox.save_screenshot('screenshot.png') # saves screenshot of entire page
fox.quit()

im = Image.open('screenshot.png') # uses PIL library to open image in memory

left = location['x']
top = location['y']
right = location['x'] + size['width']
bottom = location['y'] + size['height']


im = im.crop((left, top, right, bottom)) # defines crop points
im.save('screenshot.png') # saves new cropped image