input: 
  def is_armstrong_number(num):
      """ Check if a given number is an Armstrong number.
      An Armstrong number of 'n' digits is a number that is equal to the sum of its own 
      digits each raised to the power of 'n'.
      >>> is_armstrong_number(153)
      True
      >>> is_armstrong_number(123)
      False
      """
      n = len(str(num))
      temp = num
      sum_of_digits = 0
      
      while temp > 0:
          digit = temp % 10
          sum_of_digits += digit ** n
          temp //= 10
      
      return num == sum_of_digits
  
output:     n = len(str(num))
      temp = num
      sum_of_digits = 0
      
      while temp > 0:
          digit = temp % 10
          sum_of_digits += digit ** n
          temp //= 10
      
      return num == sum_of_digits