selenium窗口截图操作

#窗口截图操作
#coding utf-8

from selenium import webdriver
from time import sleep

driver = webdriver.Firefox()

url = "http://www.baidu.com"

driver.get(url)

driver.find_element_by_id('kw').send_keys('selenium python')
driver.find_element_by_id('su').click()

sleep(2)

driver.get_screenshot_as_file("D:\\baidu_error.jpg")

driver.quit()

file type. It should end with a `.png` extension
  "type. It should end with a `.png` extension", UserWarning)