old_contents: """
  An Armstrong number is a number that is equal to the sum of the cubes of its digits.
  For example, 370 is an Armstrong number because 3*3*3 + 7*7*7 + 0*0*0 = 370.
  An Armstrong number is often called Narcissistic number.
  """
  
  
  def armstrong_number(n: int) -> bool:
      """
      This function checks if a number is Armstrong or not.
  
      >>> armstrong_number(153)
      True
      >>> armstrong_number(200)
      False
      >>> armstrong_number(1634)
      True
      >>> armstrong_number(0)
      False
      >>> armstrong_number(-1)
      False
      >>> armstrong_number(1.2)
      False
      """
      if not isinstance(n, int) or n < 1:
          return False
      
      # Initialization of sum and number of digits.
      sum = 0
      number_of_digits = 0
      temp = n
      # Calculation of digits of the number
      while temp > 0:
          number_of_digits += 1
          temp //= 10
      # Dividing number into separate digits and find Armstrong number
      temp = n
      while temp > 0:
          rem = temp % 10
          sum += (rem ** number_of_digits)
          temp //= 10
      return n == sum
  
  
  # In main function user inputs a number to find out if it's an Armstrong or not. Th function armstrong_number is called.
  def main():
      num = int(input("Enter an integer number to check if it is Armstrong or not: ").strip())
      print(f"{num} is {'' if armstrong_number(num) else 'not '}an Armstrong number.")
  
  
  if __name__ == '__main__':
      import doctest
  
      doctest.testmod()
      main()
  
new_contents: """
  An Armstrong number is equal to the sum of the cubes of its digits.
  For example, 370 is an Armstrong number because 3*3*3 + 7*7*7 + 0*0*0 = 370.
  An Armstrong number is often called Narcissistic number.
  """
  
  
  def armstrong_number(n: int) -> bool:
      """
      Return True if n is an Armstrong number or False if it is not.
  
      >>> armstrong_number(153)
      True
      >>> armstrong_number(200)
      False
      >>> armstrong_number(1634)
      True
      >>> armstrong_number(0)
      False
      >>> armstrong_number(-1)
      False
      >>> armstrong_number(1.2)
      False
      """
      if not isinstance(n, int) or n < 1:
          return False
      
      # Initialization of sum and number of digits.
      sum = 0
      number_of_digits = 0
      temp = n
      # Calculation of digits of the number
      while temp > 0:
          number_of_digits += 1
          temp //= 10
      # Dividing number into separate digits and find Armstrong number
      temp = n
      while temp > 0:
          rem = temp % 10
          sum += (rem ** number_of_digits)
          temp //= 10
      return n == sum
  
  
  def main():
      """
      Request that user input an integer and tell them if it is Armstrong number.
      """
      num = int(input("Enter an integer to see if it is an Armstrong number: ").strip())
      print(f"{num} is {'' if armstrong_number(num) else 'not '}an Armstrong number.")
  
  
  if __name__ == '__main__':
      import doctest
  
      doctest.testmod()
      main()
  
subject: fix comment (#1710)