If you’re a QA engineer stepping into automation — or an SDET who just needs a quick refresher — this cheat sheet covers the Selenium + Python essentials you actually use at work.

No theory overload. No outdated patterns. Just practical examples you can copy, adapt, and scale.

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✅ Setup & Installation

Install Selenium:

pip install selenium

Make sure the correct browser driver is available in your system PATH:

Chrome → chromedriver

Firefox → geckodriver

Edge → msedgedriver

🚀 Starting the Browser

Launch Chrome
from selenium import webdriver

driver = webdriver.Chrome()

driver.get(”https://example.com”)

Headless Mode (Recommended for CI)

from selenium.webdriver.chrome.options import Options

options = Options()

options.add_argument(”--headless”)

options.add_argument(”--window-size=1920,1080”)

driver = webdriver.Chrome(options=options)

🔍 Locating Elements (The Most Important Skill)

Always prioritize reliable, stable locators.

from selenium.webdriver.common.by import By

Preferred Locators
driver.find_element(By.ID, “submit”)

driver.find_element(By.NAME, “email”)

driver.find_element(By.CSS_SELECTOR, “.login-button”)

driver.find_element(By.CSS_SELECTOR, “input[type=’password’]”)

XPath (Use Sparingly)

driver.find_element(By.XPATH, “//button[text()=’Login’]”)

✅ Tip: If your tests break often, your locators are probably the problem.

✍️ User Interactions

element.click()
element.send_keys(”user@test.com”)
element.clear()
Read values:
element.text
element.get_attribute(”value”)

⏳ Waiting for Elements (Non‑Negotiable)

Explicit Waits (Best Practice)
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
wait = WebDriverWait(driver, 10)
login_btn = wait.until(
EC.element_to_be_clickable((By.ID, “login”))
)

Common conditions:

EC.presence_of_element_located
EC.visibility_of_element_located
EC.element_to_be_clickable

❌ Avoid time.sleep() — it causes flaky tests.

📄 Forms & Dropdowns

from selenium.webdriver.support.ui import Select
dropdown = Select(driver.find_element(By.ID, “country”))
dropdown.select_by_visible_text(”India”)

🔔 Alerts, Frames & Windows

Alerts

alert = driver.switch_to.alert
alert.accept()

iFrames

driver.switch_to.frame(”frameName”)
driver.switch_to.default_content()

Multiple Tabs
driver.switch_to.window(driver.window_handles[1])

📜 Scrolling & JavaScript

driver.execute_script(”window.scrollTo(0, document.body.scrollHeight)”)
driver.execute_script(”arguments[0].scrollIntoView()”, element)

📷 Screenshots (For Failing Tests)

driver.save_screenshot(”failure.png”)
element.screenshot(”button.png”)

🧹 Cleanup
driver.close()
driver.quit()

🚀 Selenium + Pytest: Real‑World Automation Setup
Selenium alone isn’t enough. Pytest makes your automation scalable, readable, and CI‑ready.
**
✅ Install Pytest**

pip install pytest

🧱 Project Structure (Recommended)
tests/
├── pages/
│ └── login_page.py
├── conftest.py
├── test_login.py
└── pytest.ini

🔁 Pytest WebDriver Fixture

conftest.py
import pytest
from selenium import webdriver

@pytest.fixture
def driver():
driver = webdriver.Chrome()
driver.maximize_window()
yield driver
driver.quit()

✅ Automatically manages setup & teardown
✅ Cleaner than setUp() / tearDown()

🧪 Writing a Test

def test_valid_login(driver):
driver.get(”https://example.com/login”)
driver.find_element(By.ID, “username”).send_keys(”admin”)
driver.find_element(By.ID, “password”).send_keys(”password”)
driver.find_element(By.ID, “login”).click()
assert “Dashboard” in driver.title

🧠 Using Page Object Model with Pytest

pages/login_page.py

class LoginPage:
def init(self, driver):
self.driver = driver
def login(self, user, pwd):
self.driver.find_element(By.ID, “username”).send_keys(user)
self.driver.find_element(By.ID, “password”).send_keys(pwd)
self.driver.find_element(By.ID, “login”).click()

test_login.py

def test_login_success(driver):
page = LoginPage(driver)
page.login(”admin”, “password”)
assert “Dashboard” in driver.title

🏷️ Pytest Markers (Power Feature)

@pytest.mark.smoke
def test_smoke_login():
pass

Run specific tests:

pytest -m smoke

📊 HTML Reports (CI‑Friendly)

pip install pytest-html
pytest --html=report.html