Exception Handling

Handle errors gracefully to prevent program crashes.

Try-Except Basics

try:
    number = int(input("Enter number: "))
    result = 10 / number
    print(result)
except:
    print("An error occurred!")

Specific Exceptions

try:
    number = int(input("Enter number: "))
    result = 10 / number
except ValueError:
    print("Invalid number!")
except ZeroDivisionError:
    print("Cannot divide by zero!")
except Exception as e:
    print(f"Error: {e}")

Try-Except-Else-Finally

try:
    file = open('data.txt', 'r')
    content = file.read()
except FileNotFoundError:
    print("File not found!")
else:
    print("File read successfully!")
    print(content)
finally:
    print("Closing file...")
    try:
        file.close()
    except:
        pass

Raising Exceptions

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

try:
    result = divide(10, 0)
except ValueError as e:
    print(e)

Common Exceptions

Practice Exercises

1. Handle file reading errors
2. Validate user input with exceptions
3. Create custom exceptions
4. Use try-except with loops
5. Build robust error handling

Next Lesson: Debugging