input: Write a function to determine if a given number is an Armstrong number. If it is, return True; otherwise, return False. If the input number is empty, return False.
  
  def is_armstrong_number(num):
      if num == "":
          return False
      num = int(num)
      n = len(str(num))
      temp = num
      sum_of_digits = 0
      while temp > 0:
          digit = temp % 10
          sum_of_digits += digit ** n
          temp //= 10
      if num == sum_of_digits:
          return True
      else:
          return False
  
  assert is_armstrong_number(153)==True
  assert is_armstrong_number(9474)==True
  assert is_armstrong_number(1234)==False
  assert is_armstrong_number(0)==True
  assert is_armstrong_number("")==False
output: def is_armstrong_number(num):
      if num == "":
          return False
      num = int(num)
      n = len(str(num))
      temp = num
      sum_of_digits = 0
      while temp > 0:
          digit = temp % 10
          sum_of_digits += digit ** n
          temp //= 10
      if num == sum_of_digits:
          return True
      else:
          return False