What are the features of exception handling in…

Exceptions in Python are events that disrupt the normal flow of program execution. They are objects that represent errors.

Features:

Hierarchy of exceptions: All built-in exceptions are classes organized in a hierarchy based on inheritance from the base class BaseException.

# Example hierarchy
# BaseException -> Exception -> StandardError -> ...
#                  Exception -> ArithmeticError -> ZeroDivisionError

try...except... blocks: The main mechanism for handling exceptions.

try:
    # Code that might raise an exception
    result = 10 / 0
except ZeroDivisionError:
    # Handling a specific exception
    print("Division by zero!")
except Exception as e:
    # Handling other exceptions
    print(f"An error occurred: {e}")

Multiple except blocks: Allow handling different types of exceptions differently.

try:
    # Code
    value = int("abc")
except ValueError:
    print("Invalid number format.")
except TypeError:
    print("Invalid data type.")

else block: Executes if the try block completes without exceptions.

try:
    # Code
    result = 10 / 2
except ZeroDivisionError:
    print("Division by zero!")
else:
    print("Operation completed successfully.")

finally block: Always executes, regardless of whether an exception occurred or not. Used for resource cleanup.

file = None
try:
    file = open("myfile.txt", "r")
    # Reading from file
except FileNotFoundError:
    print("File not found.")
finally:
    if file:
        file.close() # Guaranteed file closure

raise operator: Used to explicitly raise an exception.

def divide(a, b):
    if b == 0:
        raise ZeroDivisionError("Cannot divide by zero")
    return a / b

try:
    divide(10, 0)
except ZeroDivisionError as e:
    print(f"Error: {e}")

Custom exceptions: You can create your own exception classes by inheriting from Exception or another existing exception class.

class CustomError(Exception):
    pass

def process_data(data):
    if not data:
        raise CustomError("Data is empty")

try:
    process_data([])
except CustomError as e:
    print(f"Error: {e}")

Handling exceptions with the with context manager: Simplifies working with resources that require explicit closing (e.g., files).

try:
    with open("myfile.txt", "r") as file:
        # Working with the file
        content = file.read()
except FileNotFoundError:
    print("File not found.")
# The file is automatically closed when exiting the 'with' block

Chaining exceptions: When handling an exception, you can preserve information about a previous exception (implicitly or using raise Exception from another_exception).

These features provide a flexible and powerful error handling mechanism in Python, allowing for the creation of more reliable and fault-tolerant programs.

What are the features of exception handling in Python?