def set_cookie(self, name, value, expires=None):
if expires is None:
self.response.headers.add_header('Set-Cookie', '%s=%s; Path=/' % (name, Hash.hash_cookie(str(value))))
else:
self.response.headers.add_header('Set-Cookie', '%s=%s; Path=/; Expires=%s' % (name, Hash.hash_cookie(str(value)), expires))
