20_exceptions_tutorial.py

def divide_numbers(a, b):
    try:
        # Trying to execute the operation
        result = a / b
    except ZeroDivisionError:
        # Handling a specific error: division by zero
        return "Error: Cannot divide by zero!"
    except TypeError:
        # Handling another error: incorrect data type
        return "Error: Only numbers should be entered!"
    except Exception as e:
        # Catching any other unexpected errors
        return f"An unexpected error occurred: {e}"
    else:
        # Executes if no exceptions occurred in the try block
        return f"Result: {result}"
    finally:
        # Executes ALWAYS (useful for closing files or connections)
        print("Completing division operation.")

# Usage examples
print(divide_numbers(10, 2))    # Success
print(divide_numbers(10, 0))    # ZeroDivisionError
print(divide_numbers(10, "2"))  # TypeError

print("-" * 20)

# How to handle multiple errors in one block
def multi_catch_example(value):
    try:
        # Let's say we're trying to convert to int and divide
        res = 100 / int(value)
        print(f"Result: {res}")
    except (ValueError, ZeroDivisionError) as e:
        # Catching either a value error or division by zero
        print(f"Input data '{value}' caused an error: {e}")

multi_catch_example("abc") # ValueError
multi_catch_example("0")   # ZeroDivisionError

print("-" * 20)

# Example with raising a custom error
def check_age(age):
    if age < 0:
        raise ValueError("Age cannot be negative!")
    return f"Age accepted: {age}"

try:
    print(check_age(-5))
except ValueError as e:
    print(f"Caught exception: {e}")