code: def thousands(x):
      
      import locale
      try:
          locale.setlocale(locale.LC_ALL, "en_US.utf8")
      except Exception:
          locale.setlocale(locale.LC_ALL, "en_US.UTF-8")
      finally:
          s = '%d' % x
          groups = []
          while s and s[-1].isdigit():
              groups.append(s[-3:])
              s = s[:-3]
          return s + ','.join(reversed(groups))
      return locale.format('%d', x, True)
docs: >>> thousands(12345)
      '12,345'