Playwright Python E2E Test Tutorial | Automate SauceDemo Login to Order Complete

E2E testing might sound complicated or hard to set up — but with Playwright, you can go from installation to running your first test in just a few minutes.

In this beginner-friendly guide, we’ll use SauceDemo — a popular demo e-commerce site built for test automation practice — as our target, and walk through automating the full user flow from login → add to cart → checkout → order complete → logout using Playwright and Python. We’ll cover all 10 test cases including negative tests.

What is Playwright?

Playwright is a browser automation library developed by Microsoft. It supports three browser engines — Chromium, Firefox, and WebKit — and works with multiple languages including Python, JavaScript, TypeScript, Java, and C#.

Like Selenium, it controls a real browser to run tests — but the setup is dramatically simpler, and it comes with built-in features like smart waiting, video recording, and slow-motion mode right out of the box.

What is E2E Testing?

E2E stands for End-to-End testing. It means automating the full sequence of actions a real user would take — like logging in, selecting a product, and completing a purchase. Unlike unit or integration tests, E2E tests control an actual browser to simulate real user behavior.

E2E tests are especially powerful as a final check before release, or as regression tests that automatically verify core flows haven’t broken after every deployment.

About the Test Target: SauceDemo

SauceDemo is a demo e-commerce site provided by Sauce Labs, designed specifically for practicing test automation. It includes all the core features of a real e-commerce site — login, product list, cart, and checkout — making it the perfect sandbox for E2E testing.

▲ SauceDemo login page — test usernames and the shared password are shown at the bottom

Setup (Python & Playwright)

Installation

Setting up Playwright takes just two commands. No manual ChromeDriver management required.

pip install playwright
playwright install chromium

Folder Structure

This project uses a simple single-file structure. The screenshots folder is created automatically on first run.

project/
├── test_saucedemo.py       # Main test script
└── screenshots/            # Auto-created on first run
    ├── ss_01_login_input.png
    ├── ss_02_after_login.png
    ├── ss_03_locked_user_error.png
    └── ...

Code Walkthrough

Let’s walk through the key parts of the code line by line. The goal is to make sure you understand not just what the code does, but why it’s written that way.

① Typing into a Form: fill()

page.fill("#user-name", "standard_user")
page.fill("#password", "secret_sauce")

fill() is Playwright’s method for typing text into an input field. #user-name is the CSS selector for the username input — it refers to the HTML element with id="user-name". It’s equivalent to Selenium’s send_keys(), but it automatically clears the field before typing, so you don’t need a separate clear step.

▲ Error message displayed when wrong credentials are entered (TC-03)

② Clicking a Button: click()

page.click("#login-button")

click() clicks the element matching the given selector. #login-button is the ID of the login button. Playwright automatically waits until the element is visible and clickable before acting — so unlike Selenium, you don’t need to write explicit wait logic just to click a button.

③ Waiting for Page Navigation: wait_for_url()

page.wait_for_url("**/inventory.html", timeout=8000)

wait_for_url() pauses execution until the page URL matches the given pattern. The ** wildcard matches any domain, so you can skip writing the full URL. timeout=8000 means it will throw an error if the page hasn’t navigated within 8 seconds. This replaces Selenium’s verbose WebDriverWait + expected_conditions combo in a single line.

④ Filtering Elements: filter()

item = page.locator(".inventory_item").filter(has_text="Sauce Labs Backpack")
item.locator("button").click()

locator() finds elements matching a selector, and filter(has_text=...) narrows the results to only those containing the specified text. This lets you target a specific product by name and click its button. It’s a very clean pattern for interacting with lists of similar elements.

⑤ Slowing Down Actions: slow_mo

browser = p.chromium.launch(
    headless=False,
    slow_mo=800,   # Add 800ms delay between each action
)

slow_mo is a Playwright-specific option that inserts a delay (in milliseconds) between every action. It’s great for debugging and demos — you can actually see what’s happening on screen. The recommended practice is to use slow_mo=0 (the default) in CI/CD and slow_mo=800 for local verification.

How to Run

Run Command

python test_saucedemo.py

Test Results

When you run the script, results stream to the terminal in real time section by section, with a full summary at the end. Screenshots are automatically saved to the screenshots/ folder.

==================================================
  SauceDemo Automated Test Suite [Playwright]
  Executed: 2025-07-01 10:00:00
==================================================

──────────────────────────────────────────────────
  TC-02: Login Failure - Locked User
──────────────────────────────────────────────────
  Error message: Epic sadface: Sorry, this user has been locked out.
    📸 screenshots/ss_03_locked_user_error.png

──────────────────────────────────────────────────
  TC-09: Order Completion
──────────────────────────────────────────────────
  Completion message: Thank you for your order!
    📸 screenshots/ss_10_order_complete.png

==================================================
  Test Result Summary
==================================================
  ✅ PASS  TC-02: Locked User Login Failure
           → Epic sadface: Sorry, this user has been locked out.
  ✅ PASS  TC-03: Wrong Password Login Failure
           → Epic sadface: Username and password do not match...
  ✅ PASS  TC-01: Login Success
           → //www.saucedemo.com/inventory.html
  ✅ PASS  TC-04: Product List Display (6 items)
           → 6 items displayed
  ✅ PASS  TC-05: Add 2 Items to Cart
           → Badge=2
  ✅ PASS  TC-06: Cart Contents Verification
           → Cart=2 / Added=2
  ✅ PASS  TC-07: Checkout Information Input
           → //www.saucedemo.com/checkout-step-two.html
  ✅ PASS  TC-08: Order Summary Verification
           → 2 items / Total: $19.42
  ✅ PASS  TC-09: Order Completion
           → Thank you for your order!
  ✅ PASS  TC-10: Logout
           → Redirected to login page
──────────────────────────────────────────────────
  Total: 10   ✅ 10 Passed   ❌ 0 Failed
  Result: ✅ All Tests PASSED 🎉
==================================================

If all 10 cases show PASS, you’re good to go! You should also find 11 screenshots automatically saved in the screenshots/ folder.

▲ Cart screen confirming 2 products were added correctly (TC-06)

▲ Order summary screen — item count, subtotal, tax, and total are automatically verified (TC-08)

▲ “Thank you for your order!” confirms the order was completed successfully (TC-09)

Ideas to Take It Further

Summary

In this article, we walked through how to automate a full E2E test suite for SauceDemo — from login to order completion — using Playwright and Python.

In real-world projects, this E2E test suite gets plugged into a CI/CD pipeline so the full purchase flow is automatically verified on every deployment. Playwright’s simpler syntax, built-in video recording, and slow_mo option make it a compelling upgrade from Selenium for modern QA workflows.

The full source code is available on GitHub — give it a try in your own environment!