Day 12: Python exercise that involves calculating the factorial of a number using a loop.

def factorial(n): if n < 0: 
      return "Factorial is not defined for negative numbers."

result = 1 
        for i in range(1, n + 1): 
        result *= i return result

Test the factorial function

number = int(input("Enter a non-negative integer: ")) 
print(f"The factorial of {number} is {factorial(number)}")