Python Exception Handling

📌 What is Exception Handling?

Exception Handling allows your program to deal with unexpected errors gracefully, without crashing. Common errors like dividing by zero, accessing unavailable files, or invalid user input can be caught and managed using try, except, and finally.

💡 Keywords Explained:

• try: Code that may cause an exception
• except: Block that executes if an exception occurs
• finally: Executes no matter what — used for cleanup code (e.g. closing files)

🧪 Example:

try:
    num = int(input("Enter a number: "))
    result = 100 / num
    print("Result:", result)

except ZeroDivisionError:
    print("You can't divide by zero!")

except ValueError:
    print("Please enter a valid number!")

finally:
    print("This block runs no matter what.")

🔍 Breakdown:

• ZeroDivisionError: Triggered if the user enters 0
• ValueError: Triggered if the user enters non-numeric input
• finally: This message always prints regardless of exception or not

🛠️ Use Cases

• Handling file read/write errors
• Managing user input validation
• Working with APIs or network calls that may fail
• Dealing with database errors

📎 Real World Example (File Handling):

try:
    with open("data.txt", "r") as file:
        content = file.read()
        print(content)

except FileNotFoundError:
    print("The file doesn't exist.")

finally:
    print("Execution completed.")