Simplified python redis WRONGTYPE error

In [23]: k = p.keys()

In [24]: print k
['frontend:test.ufam.jp']

In [25]: p.type(k.pop())
Out[25]: 'string'

In [26]: k = p.keys()

In [27]: p.lrange(k.pop(),1,1)
---------------------------------------------------------------------------
ResponseError                             Traceback (most recent call last)
<ipython-input-27-3130ef3ccf8c> in <module>()
----> 1 p.lrange(k.pop(),1,1)

/usr/local/lib/python2.7/dist-packages/redis/client.pyc in lrange(self, name, start, end)
   1239         Python slicing notation
   1240         """
-> 1241         return self.execute_command('LRANGE', name, start, end)
   1242
   1243     def lrem(self, name, count, value):

/usr/local/lib/python2.7/dist-packages/redis/client.pyc in execute_command(self, *args, **options)
    571         try:
    572             connection.send_command(*args)
--> 573             return self.parse_response(connection, command_name, **options)
    574         except (ConnectionError, TimeoutError) as e:
    575             connection.disconnect()

/usr/local/lib/python2.7/dist-packages/redis/client.pyc in parse_response(self, connection, command_name, **options)
    583     def parse_response(self, connection, command_name, **options):
    584         "Parses a response from the Redis server"
--> 585         response = connection.read_response()
    586         if command_name in self.response_callbacks:
    587             return self.response_callbacks[command_name](response, **options)

/usr/local/lib/python2.7/dist-packages/redis/connection.pyc in read_response(self)
    580             raise
    581         if isinstance(response, ResponseError):
--> 582             raise response
    583         return response
    584

ResponseError: WRONGTYPE Operation against a key holding the wrong kind of value

In [28]: