Exception Handling in Python
Exception handling is an essential aspect of writing robust and reliable Python programs. Python, known for its simplicity and readability, also provides a powerful and flexible mechanism for dealing with errors and exceptions. In this blog post, we will dive deep into the world of exception handling in Python, exploring what exceptions are, how to handle them gracefully, and some best practices to ensure your code remains robust and maintainable.
In Python, an exception is an event that occurs during the execution of a program and disrupts the normal flow of code. These exceptions can be caused by various factors, such as invalid input, division by zero, or trying to access a non-existent file. When an exception is raised, Python creates an exception object that contains information about the error and looks for an appropriate exception handler to deal with it.
In the below PDF we discuss about Exception Handling in Python in detail in simple language, Hope this will help in better understanding.
Common Built-in Exceptions:
Python comes with a wide range of built-in exceptions that cover many common error scenarios. Some of the most frequently encountered exceptions include:
- SyntaxError: Raised when there’s a syntax error in your code.
- IndentationError: Occurs when the code is improperly indented.
- NameError: Raised when an undefined variable is used.
- TypeError: Occurs when an operation is performed on an inappropriate data type.
- ValueError: Raised when a function receives an argument of the correct type but an inappropriate value.
- ZeroDivisionError: Occurs when dividing by zero.
- FileNotFoundError: Raised when trying to access a file that doesn’t exist.
- KeyError: Raised when trying to access a non-existent dictionary key.
Python provides a structured way to handle exceptions using the try, except, else, and finally blocks.
- try: This block contains the code that might raise an exception.
- except: If an exception occurs inside the try block, this block is executed. You can specify which exceptions to catch.
- else: This block is executed if no exception is raised in the try block.
- finally: This block is executed regardless of whether an exception occurred or not, typically used for cleanup operations. Here’s an example of exception handling in Python:
# Code that might raise an exception
result = 10 / 0
# Handle the specific exception
print("Division by zero is not allowed.")
# Code to execute if no exception occurs
print("The result is:", result)
# Cleanup or finalization code
Exception handling in Python is a mechanism that allows you to gracefully handle errors and exceptions that occur during the execution of a program, preventing it from crashing.
An exception in Python is an event that disrupts the normal flow of a program’s execution. It occurs when an error or unexpected condition occurs during runtime.
Exceptions can be raised explicitly using the raise keyword or can occur implicitly when an error occurs in the program, such as dividing by zero or trying to access a non-existent file.
The finally block is used to specify code that should always be executed, whether an exception occurs or not. It is often used for cleanup operations, such as closing files or releasing resources.