code: def ustr(x):
      '''py2/py3 unicode helper'''
  
      if sys.version_info < (3, 0, 0):
          from PyQt4.QtCore import QString
          if type(x) == str:
              return x.decode(DEFAULT_ENCODING)
          if type(x) == QString:
              #https://blog.csdn.net/friendan/article/details/51088476
              #https://blog.csdn.net/xxm524/article/details/74937308
              return unicode(x.toUtf8(), DEFAULT_ENCODING, 'ignore')
          return x
      else:
          return f ustr(x):
      '''py2/py3 unicode helper'''
  
      if sys.version_info < (3, 0, 0):
          from PyQt4.QtCore import QString
          if type(x) == str:
              return x.decode(DEFAULT_ENCODING)
          if type(x) == QString:
              #https://blog.csdn.net/friendan/article/details/51088476
              #https://blog.csdn.net/xxm524/article/details/74937308
              return unicode(x.toUtf8(), DEFAULT_ENCODING, 'ignore')
          return x
      else:
          return x
docs: py2/py3 unicode helper