input: Write a function to check if a given number is an Armstrong number. If it is, return True. Otherwise, return False.
  def is_armstrong_number(num):
      order = len(str(num))
      sum = 0
      temp = num
      while temp > 0:
          digit = temp % 10
          sum += digit ** order
          temp //= 10
      return num == sum
  assert is_armstrong_number(153)==True
  assert is_armstrong_number(123)==False
  assert is_armstrong_number(370)==True
  assert is_armstrong_number(371)==True
  assert is_armstrong_number(407)==True
output: def is_armstrong_number(num):
      order = len(str(num))
      sum = 0
      temp = num
      while temp > 0:
          digit = temp % 10
          sum += digit ** order
          temp //= 10
      return num == sum