exception in python

Python exception handling is a mechanism that allows a program to deal with unexpected situations or errors that occur during its execution. Instead of the program crashing, exception handling enables the program to catch and manage these errors gracefully, either by recovering from the error or by providing a meaningful error message.

Key Concepts in Python Exception Handling:

1. Exceptions: These are errors that occur at runtime. Common exceptions include ZeroDivisionError, ValueError, FileNotFoundError, etc.

2. try: The code block where you anticipate that an exception might occur. If an exception occurs within this block, the remaining code in the block is skipped, and the control moves to the except block.

   try:
       # Code that might raise an exception
       result = 10 / 0
   

3. except: This block handles the exception. You can specify the type of exception you want to catch.

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

4. else: The block of code inside the else statement will execute if no exception was raised in the try block.

   else:
       print("Division successful")
   

5. finally: This block will always execute, regardless of whether an exception occurred or not. It’s often used for cleanup actions like closing files or releasing resources.

   finally:
       print("Execution completed")
   

Example:

try:
    num = int(input("Enter a number: "))
    result = 10 / num
except ZeroDivisionError:
    print("Error: You cannot divide by zero.")
except ValueError:
    print("Error: Invalid input. Please enter a number.")
else:
    print(f"Result: {result}")
finally:
    print("This block always executes.")

Output Scenarios:

1. If you enter 0:

   • Output: "Error: You cannot divide by zero."
   • "This block always executes."

2. If you enter a non-numeric value:

   • Output: "Error: Invalid input. Please enter a number."
   • "This block always executes."

3. If you enter a valid number:

   • Output: "Result: (result of the division)"
   • "This block always executes."

Python's exception handling allows you to create more robust and error-tolerant programs by managing errors rather than letting them crash your program.