Selenium

Warnings

• breaking All find_element_by_*() shorthand methods removed in Selenium 4. driver.find_element_by_id(), find_element_by_xpath(), find_element_by_css_selector(), find_elements_by_class_name() etc. all raise AttributeError. Still the most common LLM-generated Selenium footgun.
  Fix: Replace find_element_by_id('x') with find_element(By.ID, 'x'). Replace find_element_by_css_selector('.x') with find_element(By.CSS_SELECTOR, '.x'). Import: from selenium.webdriver.common.by import By
• breaking Python 3.9 dropped in Selenium 4.33+. Now requires Python >=3.10.
  Fix: Pin selenium<4.33 for Python 3.9 environments.
• breaking desired_capabilities parameter deprecated and removed from WebDriver constructors. Passing desired_capabilities= raises TypeError in modern Selenium 4.
  Fix: Use Options objects instead: options = ChromeOptions(); options.set_capability('key', 'value'). Pass options= to the WebDriver constructor.
• breaking options.add_argument('--headless') (old Chrome headless) deprecated. Chrome switched to a new headless implementation — use --headless=new instead.
  Fix: Replace --headless with --headless=new in ChromeOptions. The new headless renders pages more like a real browser.
• gotcha Selenium Manager automatically downloads matching browser drivers since 4.6. Manually downloading chromedriver and putting it on PATH is no longer necessary — but if you have a stale chromedriver on PATH, it may conflict with Selenium Manager.
  Fix: Remove manually downloaded chromedriver from PATH and let Selenium Manager handle it. Or pin a specific driver version via Service(executable_path='...').
• gotcha Not using WebDriverWait causes flaky tests. Immediately calling find_element() after page navigation often fails because the element hasn't loaded yet.
  Fix: Always use WebDriverWait with expected_conditions: wait = WebDriverWait(driver, 10); element = wait.until(EC.presence_of_element_located((By.ID, 'element-id')))
• gotcha driver.quit() must be called to close the browser process. Using driver.close() only closes the current window but leaves the browser process running. Always use try/finally or context manager.
  Fix: Use try/finally: try: ... finally: driver.quit(). Or use with statement with a context manager wrapper.

Install

• pip install selenium Standard — Selenium Manager handles driver downloads automatically

Imports

• webdriver

  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
  
  # Selenium Manager handles chromedriver automatically
  driver = webdriver.Chrome()
  driver.get('https://example.com')
  
  # Correct element finding (Selenium 4)
  element = driver.find_element(By.ID, 'username')
  elements = driver.find_elements(By.CSS_SELECTOR, '.item')
  
  driver.quit()

  All find_element_by_*() and find_elements_by_*() shorthand methods were removed in Selenium 4. Use find_element(By.X, value) and find_elements(By.X, value) instead.

Quickstart

Modern Selenium 4 pattern. Selenium Manager handles chromedriver. Always use WebDriverWait.

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.webdriver.chrome.options import Options

# Selenium Manager downloads chromedriver automatically
options = Options()
options.add_argument('--headless=new')  # new headless mode
options.add_argument('--no-sandbox')
options.add_argument('--disable-dev-shm-usage')

driver = webdriver.Chrome(options=options)

try:
    driver.get('https://example.com')
    
    # Wait for element before interacting
    wait = WebDriverWait(driver, timeout=10)
    button = wait.until(
        EC.element_to_be_clickable((By.ID, 'submit-btn'))
    )
    button.click()
    
    # Find elements
    items = driver.find_elements(By.CSS_SELECTOR, '.product-item')
    print(f'Found {len(items)} items')
finally:
    driver.quit()