RPC passwords cannot contain some characters

I have an RPC password of the form "LiJgWqrKPi+OuIDPkyfW5rJ5L5ubE+R6ofs1/gJuKWM". When using this password in a call to "connect_to_remote", the following error occurs:

>>> conn = litecoinrpc.connect_to_remote("Redacted", 'LiJgWqrKPi+OuIDPkyfW5rJ5L5ubE+R6ofs1/gJuKWM', host='localhost', port=6669)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "build/bdist.linux-x86_64/egg/litecoinrpc/__init__.py", line 54, in connect_to_remote

  File "build/bdist.linux-x86_64/egg/litecoinrpc/connection.py", line 53, in __init__
  File "build/bdist.linux-x86_64/egg/litecoinrpc/proxy.py", line 138, in __init__
  File "build/bdist.linux-x86_64/egg/litecoinrpc/proxy.py", line 51, in __init__
  File "/usr/lib/python2.7/urlparse.py", line 107, in port
    return int(port, 10)
ValueError: invalid literal for int() with base 10: 'LiJgWqrKPi+OuIDPkyfW5rJ5L5ubE+R6ofs1/gJuKWM'

If I remove the '+' and '/' characters from the RPC password (from LiJgWqrKPi+OuIDPkyfW5rJ5L5ubE+R6ofs1/gJuKWM to LiJgWqrKPiOuIDPkyfW5rJ5L5ubER6ofs1gJuKWM), then the function succeeds.