硒下载的验证码图片与浏览器中的图片不同

Question

我正在尝试使用Selenium下载一个验证码图像，但是，下载的图像与浏览器中显示的图像不同。如果我尝试在不更改浏览器的情况下再次下载该图像，则会得到另一种图像。

有什么想法吗？

from selenium import webdriver
import urllib


driver = webdriver.Firefox()
driver.get("http://sistemas.cvm.gov.br/?fundosreg")

# Change frame.
driver.switch_to.frame("Main")


# Download image/captcha.
img = driver.find_element_by_xpath(".//*[@id='trRandom3']/td[2]/img")
src = img.get_attribute('src')
urllib.request.urlretrieve(src, "captcha.jpeg")

Answer 1

因为图片的链接会在您打开该链接后src为您提供随机的 新验证 码图片！

src可以从屏幕快照中截取屏幕快照，而不是从图像的上下载文件。但是，您需要下载Pillow（pip install Pillow）并按照此答案中提到的方式使用它：

from PIL import Image
from selenium import webdriver

def get_captcha(driver, element, path):
    # now that we have the preliminary stuff out of the way time to get that image :D
    location = element.location
    size = element.size
    # saves screenshot of entire page
    driver.save_screenshot(path)

    # uses PIL library to open image in memory
    image = Image.open(path)

    left = location['x']
    top = location['y'] + 140
    right = location['x'] + size['width']
    bottom = location['y'] + size['height'] + 140

    image = image.crop((left, top, right, bottom))  # defines crop points
    image.save(path, 'jpeg')  # saves new cropped image


driver = webdriver.Firefox()
driver.get("http://sistemas.cvm.gov.br/?fundosreg")

# change frame
driver.switch_to.frame("Main")

# download image/captcha
img = driver.find_element_by_xpath(".//*[@id='trRandom3']/td[2]/img")
get_captcha(driver, img, "captcha.jpeg")



driver = webdriver.Firefox()
driver.get("http://sistemas.cvm.gov.br/?fundosreg")

# change frame
driver.switch_to.frame("Main")

# download image/captcha
img = driver.find_element_by_xpath(".//*[@id='trRandom3']/td[2]/img")
get_captcha(driver, img, "captcha.jpeg")

（请注意，我对代码进行了一些更改，因此可以在您的情况下使用。）