How to handle errors in Python?

In Python, error handling is primarily managed using **exceptions**, which are runtime errors that can be caught and handled to prevent your program from crashing. The most common way to handle errors is with the `try-except` block. Here is a basic example: ```python try: # Code that might raise an error result = 10 / 0 except ZeroDivisionError: # Handle the specific error print("Cannot divide by zero!") ``` In this example, the code inside the `try` block raises a `ZeroDivisionError`. The `except` block catches this error and allows the program to continue running gracefully by printing a message instead of crashing. You can also catch multiple exceptions by specifying them in a tuple: ```python try: value = int(input("Enter a number: ")) result = 10 / value except (ValueError, ZeroDivisionError) as e: print(f"An error occurred: {e}") ``` Besides `try-except`, Python provides additional keywords for more granular control: - `else`: Runs if the `try` block did **not** raise an exception. - `finally`: Runs no matter what, useful for cleanup actions like closing files. Example with `else` and `finally`: ```python try: file = open('data.txt', 'r') data = file.read() except FileNotFoundError: print("File not found.") else: print("File read successfully.") finally: file.close() ``` This structure helps you handle errors effectively while keeping your programs robust and user-friendly. For more advanced error handling, you can also define your own custom exception classes by subclassing `Exception`.

In Python, error handling is primarily done using **exception handling** with `try`, `except`, `else`, and `finally` blocks. This allows your program to respond gracefully to unexpected situations (errors) without crashing abruptly. ### Basic Error Handling with try-except The most common way to handle errors is by wrapping code that might raise an exception inside a `try` block and then catching specific exceptions with one or more `except` blocks. For example: ```python try: result = 10 / 0 # This will raise a ZeroDivisionError except ZeroDivisionError: print("Cannot divide by zero!") ``` In this example, when dividing by zero occurs, the program catches the `ZeroDivisionError` and prints a message instead of stopping execution. ### Using else and finally - The `else` block runs if no exceptions occur in the `try` block. - The `finally` block runs no matter what, often used for cleanup actions like closing files or releasing resources. Example: ```python try: file = open("data.txt", "r") data = file.read() except FileNotFoundError: print("File not found.") else: print("File read successfully.") finally: file.close() print("File closed.") ``` ### Catching Multiple Exceptions You can handle multiple exceptions in one `except` clause by specifying a tuple: ```python try: # some code except (ValueError, TypeError): print("Value or type error occurred.") ``` ### Raising Exceptions You can also raise exceptions intentionally using the `raise` statement, useful when you want to enforce certain conditions: ```python def set_age(age): if age < 0: raise ValueError("Age cannot be negative.") ``` ### Best Practices - Catch only exceptions you expect and know how to handle. - Avoid using a bare `except:` clause, as it catches all exceptions, including system-exiting ones. - Use specific exception classes to make debugging easier. - Clean up resources in `finally` or use context managers (`with` statement) when working with files or network connections. --- In summary, Python’s exception handling mechanism with `try-except-else-finally` blocks provides a powerful and flexible way to handle errors gracefully, improving the robustness and user experience of your programs.