Checking if an element exists with Python Selenium

python

selenium

webdriver

explicit-wait

byAlex Kataev·Oct 23, 2024

Selenium provides methods like find_elements_by_* that return an empty list when no element matches the given identifier, preventing a NoSuchElementException.

from selenium import webdriver
from selenium.webdriver.common.by import By

driver = webdriver.Chrome()
driver.get("http://example.com")

# Remember to replace "element_id" with the actual ID
if driver.find_elements(By.ID, "element_id"):
    print("Element exists. Let's party 🎉")
else:
    print("Element does not exist. Better luck next time 😞")

Solid strategies for element locating

Embrace CSS selectors

Favour CSS selectors over the XPath for more efficient search and readability.

Generic function for the win

Craft a generic function to confirm if an element exists, regardless of the method used:

# Here's a life-saver helper function
def element_exists(driver, by_method, selector):
    return len(driver.find_elements(by_method, selector)) > 0

Explicit waits, the secret sauce

Explicit waits enhance reliability and beat time.sleep() any day of the week:

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

# Patience is a virtue, isn't it ? 😉
wait = WebDriverWait(driver, 10)
try:
    element = wait.until(EC.presence_of_element_located((By.ID, "element_id")))
    print("Element is visible! Rejoice 🎊")
except:
    print("Element is not visible. Time to rethink strategies 👩‍💻")

Gracefully handling exceptions like a pro

Embrace try-except blocks for the smooth handling of exceptions:

from selenium.common.exceptions import NoSuchElementException

try:
    # Mirage or Real - The ultimate truth
    driver.find_element(By.ID, "nonexistent_element")
    print("Element exists. Keep going, champ! 🥳")
except NoSuchElementException:
    print("Element does not exist. This is like finding a needle in a haystack 🙃")

More handy tips

Use ID or name to locate elements whenever possible.
Avoid LINK_TEXT due to potential localization or updates.
Harness the power of XPath for complex web structures.
Ensure correct script parameters to sidestep misfires.
Add debug statements to trace glitches during find_element().
Request developers to introduce unique IDs or names wherever feasible.
Mind to set the implicit wait back to default after any changes.

Performance-Boosting Tips

Write performant scripts. Remember, every millisecond counts.

Wait but wisely

Distinguish between implicit wait, explicit wait, and fluent wait in Selenium.

Implicit wait: The default waiting period before timing out when searching elements.
Explicit wait: Halts execution until a specific condition is met.
Fluent wait: Sets the maximum waiting time and polling frequency.

Best practices

Minimize the use of waits; use them judiciously for best results.
Prefer find_elements, it’s kinder—doesn’t throw an exception when elements are not found.
Always call driver.quit() when you're done to prevent leprechauns from wreaking havoc behind you! It's good housekeeping.

Going beyond existence

Checking an element's existence might not always suffice. Consider checking if it's visible and interact-able:

from selenium.webdriver.common.action_chains import ActionChains

# The true essence of existence - visibility!
visible = EC.visibility_of_element_located((By.ID, 'element_id'))
ActionChains(driver).move_to_element(wait.until(visible)).perform()