Arithmetic Formatter assertEqual error

Tell us what’s happening:
I don’t know what’s wrong with the code

The code

def arithmetic_arranger(problems, showResult = False):
  one = ''
  two = ''
  lines = ''
  third = ''
  for i in problems:
    if len(problems) > 5:
      return "Error: Too many problems."
    component = i.split(' ')
    first = component[0]
    op = component[1]
    second = component[2]
    if not first.isnumeric() or not second.isnumeric():
      return "Error: Numbers must only contain digits."
    if len(first) > 4 or len(second) > 4:
      return "Error: Numbers cannot be more than four digits."
    if op == "+" or op == "-":
      if op == "+":
        sum = str(int(first) + int(second))
      if op == "-":
        sum = str(int(first) - int(second))
    else:
      return "Error: Operator must be '+' or '-'."

    length = max(len(first), len(second)) + 2
    top = first.rjust(length)
    bottom  = op + second.rjust(length - 1)
    res = sum.rjust(length)
    line = ''
    for j in range(length):
      line += '-'

    if i != problems[-1]:
      one += top + '    '
      two += bottom + '    '
      lines += line + '    '
      third += res + '    '
    else:
      one += top
      two += bottom
      lines += line
      third += res

    if showResult:
      arranged_problems = one + '\n' + two + '\n' + lines + '\n' + third
    else:
      arranged_problems = one + '\n' + two + '\n' + lines + '\n'
  return arranged_problems

Log:

   32      3801      45      123
+ 698    -    2    + 43    +  49
-----    ------    ----    -----

F.....
======================================================================
FAIL: test_arrangement (test_module.UnitTests)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/runner/FatalFunctionalKeyboard/test_module.py", line 10, in test_arrangement
    self.assertEqual(actual, expected, 'Expected different output when calling "arithmetic_arranger()" with ["3 + 855", "3801 - 2", "45 + 43", "123 + 49"]')
AssertionError: '    [36 chars]   -    2    + 43    +  49\n-----    ------    ----    -----\n' != '    [36 chars]   -    2    + 43    +  49\n-----    ------    ----    -----'
      3      3801      45      123
  + 855    -    2    + 43    +  49
- -----    ------    ----    -----
?                                 -
+ -----    ------    ----    ----- : Expected different output when calling "arithmetic_arranger()" with ["3 + 855", "3801 - 2", "45 + 43", "123 + 49"]

----------------------------------------------------------------------
Ran 6 tests in 0.002s

FAILED (failures=1)

Challenge: Arithmetic Formatter

Link to the challenge:

it seems you have an extra character at the end, that’s what this part shows - the dash in the line starting with ? shows the difference between what you have and what you should have

oh yeah, thanks, I put a ‘/n’ after “+ lines” in the line arranged_problems = one + ‘\n’ + two + ‘\n’ + lines