selenium cheat sheet

Guri Bee

3 min read

·

22-10-2024

1

0

Share

Selenium Cheat Sheet: A Comprehensive Guide for Web Automation

Selenium is a powerful tool for automating web browsers, making it indispensable for tasks like web testing, scraping data, and managing multiple browser instances. This cheat sheet aims to guide you through the essentials of using Selenium, offering concise explanations, practical code examples, and insightful tips.

What is Selenium?

Selenium is a suite of tools designed to automate web browsers. It's primarily used for:

• Web Testing: Automate browser interactions to test website functionality and user flows.
• Web Scraping: Extract data from websites programmatically.
• Browser Automation: Control multiple browsers simultaneously for tasks like filling out forms, navigating websites, and managing cookies.

Getting Started with Selenium

1. Install Selenium:

   pip install selenium
   

2. Download WebDriver:

   Download the appropriate WebDriver for your browser from the Selenium WebDriver Downloads page.

3. Import Selenium:

   from selenium import webdriver
   

Core Components of Selenium

• WebDriver: The primary interface for controlling the browser.
• WebElement: Represents an individual element on a web page, such as a button, input field, or link.
• Locators: Used to identify and interact with web elements.

Locating Elements:

Finding the right element is crucial for effective automation. Selenium provides various locators:

• ID: driver.find_element(By.ID, "element_id")
• Name: driver.find_element(By.NAME, "element_name")
• Tag Name: driver.find_element(By.TAG_NAME, "tag_name")
• Class Name: driver.find_element(By.CLASS_NAME, "class_name")
• Link Text: driver.find_element(By.LINK_TEXT, "link_text")
• Partial Link Text: driver.find_element(By.PARTIAL_LINK_TEXT, "partial_text")
• CSS Selector: driver.find_element(By.CSS_SELECTOR, "css_selector")
• XPath: driver.find_element(By.XPATH, "xpath_expression")

Common Actions with Selenium

• Navigate:

  driver.get("https://www.example.com")
  

• Click:

  button = driver.find_element(By.ID, "login_button")
  button.click()
  

• Type Text:

  username_field = driver.find_element(By.NAME, "username")
  username_field.send_keys("your_username")
  

• Get Text:

  text = driver.find_element(By.XPATH, "//h1").text
  print(text)
  

• Submit Form:

  form = driver.find_element(By.TAG_NAME, "form")
  form.submit()
  

• Wait for Element:

  from selenium.webdriver.common.by import By
  from selenium.webdriver.support.ui import WebDriverWait
  from selenium.webdriver.support import expected_conditions as EC
  WebDriverWait(driver, 10).until(EC.presence_of_element_located((By.ID, "element_id")))
  

Handling Dynamic Content

Web pages often load dynamically, requiring you to wait for elements to appear before interacting with them. This is where explicit waits come in. They allow you to pause execution until a specific condition is met.

from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

# Wait for element to be clickable
element = WebDriverWait(driver, 10).until(
    EC.element_to_be_clickable((By.ID, "element_id"))
)
element.click()

Example: Automating a Login Form

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("/path/to/chromedriver")

driver.get("https://www.example.com/login")

# Wait for username field
username_field = WebDriverWait(driver, 10).until(
    EC.presence_of_element_located((By.ID, "username"))
)
username_field.send_keys("your_username")

# Wait for password field
password_field = WebDriverWait(driver, 10).until(
    EC.presence_of_element_located((By.ID, "password"))
)
password_field.send_keys("your_password")

# Wait for login button and click
login_button = WebDriverWait(driver, 10).until(
    EC.element_to_be_clickable((By.ID, "login_button"))
)
login_button.click()

# ... Perform further actions

Advanced Techniques:

• Handling Alerts: Use driver.switch_to.alert to interact with pop-up alerts.
• Working with Frames: Use driver.switch_to.frame("frame_name") to switch to a specific frame.
• Taking Screenshots: Use driver.get_screenshot_as_file("screenshot.png") to capture a snapshot of the current webpage.

Remember:

• Update WebDriver: Ensure your WebDriver version matches your browser version.
• Handle Exceptions: Use try...except blocks to gracefully handle errors during automation.
• Explore Selenium Documentation: Refer to the official documentation for comprehensive information and advanced techniques.

This cheat sheet provides a foundation for using Selenium. Remember to experiment, explore, and continuously learn to unlock the full potential of this powerful automation tool.