Web Scraping Using Selenium - Explicit Wait for Presence of An Element

Selenium Wait - Explicit Wait For Presence of An Element

Waiting in selenium can be done in different ways. In this tutorial, we will use the explicit wait functionality for presence of an element given its locator. This is a way to check if the element already loaded.

But before that, please make sure you have read the first blog on this series to do the prerequisites.

Selenium Explicit Wait For Presence of An Elements Given Its Locator

1. Create a file seleniumwaitpresenceone.py and paste the following codes

   from selenium import webdriver
   from selenium.webdriver.common.by import By
   from selenium.webdriver.support.ui import WebDriverWait
   from selenium.webdriver.support import expected_conditions as EC
   from selenium.common.exceptions import TimeoutException
   from datetime import datetime
   

   The codes above imports the required library that we will use.
2. Add this line

   driver = webdriver.Firefox(executable_path="geckodriver.exe")
   

   The code above will create a webdriver instance for Firefox.
3. Add this line

   driver.get("https://slackingslacker.github.io/seleniumindex")
   

   The line will got to the website (https://slackingslacker.github.io/seleniumindex).
4. Add this function as is

   def wait_for_the_element(wait_time: int, el_id: str):
       try:
           print("[{}] Finding element {}".format(str(datetime.now()), el_id))
           WebDriverWait(driver, wait_time).until(
               EC.presence_of_all_elements_located((By.ID, el_id))
           )
           print("[{}] Element found".format(str(datetime.now())))
       except TimeoutException as e:
           print("[{}] Element did not load".format(str(datetime.now())))
   

   This method will wait for an element using locator to load at a given waiting time. It will print a message if the element loaded or not.
5. Add this line

   wait_for_the_element(3, "navMenuId")
   

   This line will call the method we created and will display Element found.
6. Add this line

   wait_for_the_element(6, "noneExistentId")
   

   This line will call the method we created and wait for 6 seconds until it gives an error.
7. Add this line

   wait_for_the_element(9, "anotherNoneExistentId")
   

   Again will call the method with a non existing element this time it is 9 seconds.
8. Add this line

   driver.close()
   

   The line will close the webdriver as well as the browser.
9. Run the seleniumwaitpresenceone.py. It should do the following:
   • Open the firefox browser
   • Browser goes to https://slackingslacker.github.io/seleniumindex
   • Call the Method 3 times which prints messages in the console
   • Closes the browser

 

Program Sample Output

[2020-06-01 13:52:53.817328] Finding element navMenuId
[2020-06-01 13:52:53.886479] Element found
[2020-06-01 13:52:53.886479] Finding element noneExistentId
[2020-06-01 13:53:00.019786] Element did not load
[2020-06-01 13:53:00.019786] Finding element anotherNoneExistentId
[2020-06-01 13:53:09.055716] Element did not load

Output explanations

1. The code looks for an element given the id navMenuId
2. The code found the element
3. The code looks for an element given the id noneExistentId
4. The code does not find the element within 6 seconds
5. The code looks for an element given the id anotherNoneExistentId
6. The code does not find the element within 9 seconds

As you may have noticed that the waiting time varies to what you have supplied to the WebDriverWait class.

 

Final Selenium Code

from selenium import webdriver
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from selenium.common.exceptions import TimeoutException
from datetime import datetime

driver = webdriver.Firefox(executable_path="geckodriver.exe")
driver.get("https://slackingslacker.github.io/seleniumindex")

def wait_for_the_element(wait_time: int, el_id: str):
    try:
        print("[{}] Finding element {}".format(str(datetime.now()), el_id))
        WebDriverWait(driver, wait_time).until(
            EC.presence_of_all_elements_located((By.ID, el_id))
        )
        print("[{}] Element found".format(str(datetime.now())))
    except TimeoutException as e:
        print("[{}] Element did not load".format(str(datetime.now())))

wait_for_the_element(3, "navMenuId")
wait_for_the_element(6, "noneExistentId")
wait_for_the_element(9, "anotherNoneExistentId")
driver.close()

 

Conclusion

Waiting time in selenium can be set to wait for an element given its locator.