Exception Handling in Python

Exception handling in Python refers to the process of responding to the occurrence of exceptions—errors detected during execution.

• Python provides mechanisms like try, except, finally, and raise to handle exceptions gracefully.

• It helps in preventing program crashes and allows programs to handle error conditions more effectively.

Q.) What is the Use of Exception Handling in Python?

• It is used to gracefully manage and respond to errors that occur during the execution of a program, without crashing the program. It helps to detect runtime errors and take corrective action.

1.) try Block:

The try block is used to wrap code that might generate an exception.

• If an error occurs within the try block, the flow of control immediately moves to the except block.

Example: If the input cannot be converted to an integer (e.g., input is “abc”), an exception will be thrown and caught in the except block.

try:
    num = int(input("Enter a number: "))
    print("You entered:", num)

2.) except Block:

The except block contains the code that runs if an exception is raised in the try block.

• It can handle specific exception types.

Example:

try:
    value = 10 / 0
except ZeroDivisionError:
    print("Error: Cannot divide by zero.")

3.) finally Block:

The finally block will execute no matter what — whether or not an exception is raised.

• It’s typically used for cleanup tasks like closing files or database connections.

Example:

try:
    file = open("data.txt", "r")
    print(file.read())
except FileNotFoundError:
    print("File not found.")
finally:
    print("Closing file...")
    file.close()  # This will run whether or not an exception occurred

4.) raise Statement:

The raise statement is used to manually trigger an exception in a program.

• It is helpful for enforcing constraints or signaling unexpected conditions.

Example:

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

try:
    print(divide(10, 0))
except ZeroDivisionError as e:
    print("Caught an exception:", e)