Selenium with pyvirtualdisplay unable to locate element

问题

I have a working script that logs into a site using selenium like this:

script.py

from pyvirtualdisplay import Display
from selenium import webdriver

display = Display(visible=0, size=(1024, 768))
display.start()

browser = webdriver.Firefox()
actions = webdriver.ActionChains(browser)
browser.get('some_url_I_need')
content = browser.find_element_by_id('content') # Error on this line

running that script on an amazon ubuntu box through ssh where I installed firefox the following way: sudo apt-get install firefox

The error I get is:

selenium.common.exceptions.NoSuchElementException: Message: u'Unable to locate element: {"method":"id","selector":"content"}'

If I run the same script on another ubuntu box through ssh too, it runs fine, no error, but I don't know how firefox was installed on that box, what could be the cause of that error. Is is related firefox installation and how to properly install it to be used with pyvirtualdisplay and selenium ?

回答1:

If there is some dynamic content on the website you need to wait some time until you can retrieve the wished element. Try to following code examples:

Check Configuration

• Did you install a backend for pyvirtualdisplay like xvfb and xephyr? If not,

  try: sudo apt-get install xvfb xserver-xephyr

First try: Add a simple time.sleep()

import time
from pyvirtualdisplay import Display
from selenium import webdriver

display = Display(visible=0, size=(1024, 768))
display.start()

browser = webdriver.Firefox()
actions = webdriver.ActionChains(browser)
browser.get('some_url_I_need')
time.sleep(5) # sleep for 5 seconds
content = browser.find_element_by_id('content') # Error on this line

Second try: Add browser.implicitly_wait(30) to your Selenium webdriver.

from pyvirtualdisplay import Display
from selenium import webdriver

display = Display(visible=0, size=(1024, 768))
display.start()

browser = webdriver.Firefox()
browser.implicitly_wait(30) # seconds
actions = webdriver.ActionChains(browser)
browser.get('some_url_I_need')
content = browser.find_element_by_id('content') # Error on this line

回答2:

from pyvirtualdisplay import Display 

from selenium import webdriver

from selenium.webdriver.common.by import By

from selenium.webdriver.support.ui import Select

from selenium.webdriver.common.desired_capabilities import DesiredCapabilities

from selenium.common.exceptions import NoSuchElementException

from selenium.common.exceptions import NoAlertPresentException

from selenium.webdriver.common.keys import Keys

import unittest, time, re, random

capabilities = DesiredCapabilities.FIREFOX.copy()

capabilities['marionette'] = False

 #display = Display(visible=0, size=(1024, 768))
 #display.start()

driver = webdriver.Firefox(capabilities=capabilities)

driver.implicitly_wait(20)

base_url = "http://xxx.yyy.zzz.aaa/sss/sss-Login/login/main_login.php"

RANDINT = random.random()*10000

verificationErrors = []

driver.get(base_url + "")

username = driver.find_element_by_id("myusername")

username.send_keys("xxxxxxxx")

driver.implicitly_wait(20)

password = driver.find_element_by_id("mypassword")

 #password.send_keys("xxxxzz" + Keys.ENTER)

password.send_keys("xxxxzzc" )

driver.implicitly_wait(20)

driver.find_element_by_xpath("//*[@id='submit']").click() 


 # Click on category link 


driver.find_element_by_xpath("//*[@id='stylefour']/ul/li[3]/a").click()

driver.find_element_by_xpath("//*[@id='stylefour']/ul/li[1]/a").click()

driver.find_element_by_xpath("//*[@id='stylefour']/ul[2]/li[4]/a").click

 # Click on sub-category link

driver.find_element_by_xpath("//*[@id='top']/body/div/div[2]/div[2]/div/div[2]/ul/li[4]/a/span").click()

 # Click on product image

driver.find_element_by_xpath("//*[@id='product-collection-image-374']").click()

 # Click Checkout button

driver.find_element_by_xpath("//*[@id='checkout-button']/span/span").click()

driver.find_element_by_id("billing:firstname").clear()

driver.find_element_by_id("billing:firstname").send_keys("selenium", RANDINT, "_fname")

driver.find_element_by_id("billing:lastname").clear()

driver.find_element_by_id("billing:lastname").send_keys("selenium", RANDINT, "_lname")

 # Click Place Order

driver.find_element_by_xpath("//*[@id='order_submit_button']").click()



driver.quit()

display.stop()

来源：https://stackoverflow.com/questions/20485360/selenium-with-pyvirtualdisplay-unable-to-locate-element