input: Write a function to calculate the factorial of a given integer and then prints out the result. The function should handle both positive and non-positive integers.
  def factorial(num):
      if num <= 1:
          return 1
      else:
          return num * factorial(num - 1)
  
  n = int(input("Enter a number: "))
  print("Factorial of", n, "is", factorial(n))
  
  # Example test cases
  assert factorial(0) == 1
  assert factorial(1) == 1
  assert factorial(5) == 120
  assert factorial(7) == 5040
output: def factorial(num):
      if num <= 1:
          return 1
      else:
          return num * factorial(num - 1)