docs: def strip_symbols(s, pass_symbols=(u'й', u'Й', u'\n')):
      """ Strip ugly unicode symbols from a string """
      result = []
      for char in s:
          # Pass these symbols without processing
          if char in pass_symbols:
              result.append(char)
              continue
          for c in unicodedata.normalize('NFKC', char):
              if unicodedata.category(c) == 'Zs':
                  result.append(u' ')
                  continue
              if unicodedata.category(c) not in ['So', 'Mn', 'Lo', 'Cn', 'Co', 'Cf', 'Cc']:
                  result.append(c)
      return u"".join(result)