Missing element of an array after loop and conditions. Result in an array with 3 elements instead of 4. 4 instead of 5, so on

You could call it a homework problem. I am doing a CodeWar challenge, basically, I get a string of numbers and I am supposed to return maximum and minimum values. I got this close of completing this problem but there is an issue. For example, "1 2 3 4 555" should return "555 1". I know about max and min functions but I don't need this yet.

I created a for loop for every x in a list of given string I made. For example "1 2 3 4 555" changed to list ["1", " ", "2", " ", "3", " ", "4", " ", "5", "5", "5"]. I have nested some if statements to add x or a number in string to new array with a few conditions. ["1", " ", "2", " ", "3", " ", "4", " ", "5", "5", "5"] --> [1, 2, 3, 555]. Instead I get [1, 2, 3]. I have gotten [1, 2, 3, 555] or any array without missing an element, now this.

This is my code. I want [1, 2, 3, 555] instead of [1, 2, 3]. Then I will use max and min functions to get min and max values.

def high_and_low(numbers):

  numbers = numbers

  toList = list(numbers)
  print(toList)

  newList = []
  string = ''

  for x in toList:
    if x != ' ': #number
      string += x
      print(string)
    else: #elif x == ' ': #anything that's not a number.  Space for example
      newList.append(int(string)) #we 'add' number to new list before space.  Converted number string to integar.

      #then

      string = '' #reset to empty so we can add next number to empty without worrying about adding number we do not need.
    print(newList) #[1,2,3] instead of [1, 2, 3, 555] is what I wanted.  If I called high_and_low("1 2 3 555 3"), I can get [1, 2, 3, 555]

high_and_low("1 2 3 555")  # return "555 1"

Same code without comments:

def high_and_low(numbers):

  numbers = numbers

  toList = list(numbers)
  print(toList)

  newList = []
  string = ''

  for x in toList:
    if x != ' ':
      string += x
      print(string)
    else: #elif x == ' ':
      newList.append(int(string))
      string = ''

    print(newList)

high_and_low("1 2 3 555")  # return "555 1"

I expect the output of [1, 2, 3, 555], but the actual output is [1, 2, 3]. If I called high_and_low("1 2 3 555 3"), I can get [1, 2, 3, 555].