What are the Common Exceptions in Selenium?

When using Selenium for web automation testing, you may encounter various exceptions. Below are some of the most common exception types in Selenium, along with their usage scenarios and examples of solutions.

1. NoSuchElementException
   This exception is thrown when Selenium cannot find the specified element in the DOM. For example, if you attempt to click on a button that does not exist, you will encounter this issue.

   Solution Example:
   Ensure that the locators (such as ID, XPath, etc.) are correct. You can use explicit waits to wait for the element to appear.

   python
   from selenium.webdriver.common.by import By
   from selenium.webdriver.support.ui import WebDriverWait
   from selenium.webdriver.support import expected_conditions as EC
   
   try:
       element = WebDriverWait(driver, 10).until(
           EC.presence_of_element_located((By.ID, "myButton"))
       )
       element.click()
   except NoSuchElementException:
       print("Element not found")

2. TimeoutException
   This exception is thrown when an element does not appear within the specified time. It is typically used for waiting for certain elements to load.

   Solution Example:
   Increase the wait time or check if the webpage has asynchronous content affecting element loading.

   python
   try:
       element = WebDriverWait(driver, 20).until(
           EC.presence_of_element_located((By.ID, "myDynamicElement"))
       )
   except TimeoutException:
       print("Load timeout")

3. ElementNotVisibleException
   This exception is thrown when an element exists in the DOM but is not visible (e.g., because it is hidden).

   Solution Example:
   Check if the element is hidden by CSS properties (such as display: none) or covered by other elements.

   python
   try:
       element = WebDriverWait(driver, 10).until(
           EC.visibility_of_element_located((By.ID, "myHiddenElement"))
       )
       element.click()
   except ElementNotVisibleException:
       print("Element is not visible")

4. NoSuchWindowException
   If you attempt to switch to a non-existent window, Selenium will throw this exception.

   Solution Example:
   Verify that the window or tab exists before attempting to switch.

   python
   try:
       driver.switch_to.window("myWindowName")
   except NoSuchWindowException:
       print("Window does not exist")

5. NoSuchFrameException
   Similar to NoSuchWindowException, if you attempt to switch to a non-existent frame, this exception is thrown.

   Solution Example:
   Validate that the frame exists and that the name or ID is correct.

   python
   try:
       driver.switch_to.frame("myFrameName")
   except NoSuchFrameException:
       print("Frame does not exist")

These exception handling methods enhance the robustness and error handling capabilities of scripts, allowing for better management of unexpected situations during automated testing.