Python Exception Handling – Complete
Study Notes
Introduction
Exception handling is an important concept in Python programming that allows developers
to manage runtime errors in a controlled manner. When a program encounters an
unexpected situation such as invalid input or a missing file, an exception may occur.
Without proper handling, such errors can cause the program to terminate abruptly.
Python provides built‑in mechanisms that help programmers detect and respond to errors
while the program is running. By handling exceptions, developers can prevent program
crashes and ensure that the application continues running smoothly.
In modern software systems, exception handling is essential for creating reliable and
user‑friendly applications because it allows programs to respond to errors gracefully.
Definition
An exception in Python is an event that occurs during program execution that disrupts the
normal flow of instructions. When Python encounters such an event, it creates an exception
object and stops normal execution.
Exception handling refers to the process of responding to these errors using special
constructs such as try, except, else, and finally.
These constructs allow programmers to identify potential problem areas in their code and
define alternative actions if an error occurs.
Types of Errors in Python
In Python programming, errors are generally categorized into syntax errors and runtime
errors.
Syntax errors occur when the program violates the rules of Python syntax, such as missing
parentheses or incorrect indentation.
Runtime errors occur while the program is running. These errors often generate exceptions
that can be handled using exception handling techniques.
Common Built‑in Exceptions
Python provides many built‑in exception types that represent different error situations.
