Selenium Basics Explained for Complete Beginners

# 1. Check Python 3 is installed
python --version

# 2. Create and activate a virtual environment
python -m venv .venv
source .venv/bin/activate        # Windows: .venv\Scripts\activate

# 3. Install Selenium 4 and pytest
pip install selenium pytest

# 4. Confirm the version (should be 4.x)
python -c "import selenium; print(selenium.__version__)"

# first_test.py - open a page, read its title, close the browser
from selenium import webdriver

driver = webdriver.Chrome()   # Selenium Manager sets up chromedriver
try:
    driver.get("https://www.selenium.dev/selenium/web/web-form.html")
    print("Page title is:", driver.title)   # Web form
    assert driver.title == "Web form"
finally:
    driver.quit()                 # always close the browser

# Run with: python first_test.py

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

driver = webdriver.Chrome()
driver.get("https://www.selenium.dev/selenium/web/web-form.html")

text_box = driver.find_element(By.NAME, "my-text")
password = driver.find_element(By.NAME, "my-password")
textarea = driver.find_element(By.NAME, "my-textarea")
submit   = driver.find_element(By.CSS_SELECTOR, "button[type='submit']")

text_box.send_keys("Selenium")
password.send_keys("secret123")
textarea.send_keys("Learning locators")
submit.click()

message = driver.find_element(By.ID, "message")
print(message.text)   # Received!
driver.quit()

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

driver = webdriver.Chrome()
try:
    driver.get("https://www.selenium.dev/selenium/web/web-form.html")
    driver.find_element(By.NAME, "my-text").send_keys("Selenium")
    driver.find_element(By.CSS_SELECTOR, "button[type='submit']").click()

    # Wait up to 10 seconds for the confirmation text
    wait = WebDriverWait(driver, 10)
    message = wait.until(
        EC.visibility_of_element_located((By.ID, "message"))
    )
    assert message.text == "Received!"
finally:
    driver.quit()

# conftest.py - shared browser fixture
import pytest
from selenium import webdriver


@pytest.fixture
def driver():
    options = webdriver.ChromeOptions()
    options.add_argument("--headless=new")   # remove to watch the browser
    drv = webdriver.Chrome(options=options)
    yield drv
    drv.quit()


# pages/web_form.py - Page Object (add an empty pages/__init__.py)
from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC


class WebFormPage:
    URL = "https://www.selenium.dev/selenium/web/web-form.html"
    TEXT = (By.NAME, "my-text")
    SUBMIT = (By.CSS_SELECTOR, "button[type='submit']")
    MESSAGE = (By.ID, "message")

    def __init__(self, driver):
        self.driver = driver

    def open(self):
        self.driver.get(self.URL)
        return self

    def submit_text(self, value):
        self.driver.find_element(*self.TEXT).send_keys(value)
        self.driver.find_element(*self.SUBMIT).click()

    def message(self):
        wait = WebDriverWait(self.driver, 10)
        return wait.until(EC.visibility_of_element_located(self.MESSAGE)).text

# test_web_form.py - run with: python -m pytest -v
from pages.web_form import WebFormPage


def test_page_title(driver):
    WebFormPage(driver).open()
    assert driver.title == "Web form"


def test_submit_shows_confirmation(driver):
    page = WebFormPage(driver).open()
    page.submit_text("Hello Selenium")
    assert page.message() == "Received!"

SELENIUM + PYTEST PROJECT LAYOUT

selenium-basics/
  .venv/                 (not committed)
  pages/
    __init__.py
    web_form.py          Page Objects
  tests/
    test_web_form.py
  conftest.py            browser fixture
  requirements.txt       selenium, pytest
  pytest.ini             [pytest] testpaths = tests
  README.md              how to install and run
  .gitignore             .venv/ __pycache__/ .pytest_cache/

MANUAL TEST CASE -> AUTOMATION

ID            : TC_FORM_01
Title         : Submitting the web form shows confirmation
Pre-condition : Browser open, form page loaded
Steps         :
  1. Enter text in 'Text input'
  2. Click Submit
Expected      : Message 'Received!' is visible
Locators      : NAME=my-text, CSS=button[type='submit'], ID=message
Wait needed?  : Yes - visibility of #message
Automated in  : tests/test_web_form.py::test_submit_shows_confirmation

WHEN A SELENIUM TEST FAILS

[ ] Read the exception type
    NoSuchElementException -> locator wrong or page not ready
    TimeoutException       -> condition never became true
    ElementClickIntercepted -> something covers the element
    StaleElementReference  -> page re-rendered; find it again
[ ] Run without --headless and watch
[ ] Save a screenshot: driver.save_screenshot("fail.png")
[ ] Check the locator in browser DevTools (Ctrl+F in Elements)
[ ] Replace any time.sleep with an explicit wait
[ ] Confirm the element is not inside an iframe