Here's some example code:
from mockredis import MockRedis
from redis import Redis
real_redis = Redis()
mock_redis = MockRedis()
real_redis.hset('answer', 'ultimate', 42)
mock_redis.hset('answer', 'ultimate', 42)
assert(real_redis.hget('answer', 'ultimate') == mock_redis.hget('answer', 'ultimate'))
mock_redis returns the integer 42, and real_redis returns the string '42', since everything in Redis is a string.
MockRedis should convert all values to strings.