code: def _replace_tabs(s, ts=8):
      
      result = ''
      for c in s:
          if c == '\t':
              while True:
                  result += ' '
                  if len(result) % ts == 0:
                      break
          else:
              result += c
      return result
docs: Replace the tabs in 's' and keep its original alignment with the tab-stop
      equals to 'ts'