Storing a custom Python object in Redis

Question

I'm trying to store a custom, serializable python object in Redis, but have encountered some strange behavior. The set method seems to function, but the get method only returns the value of the object's __repr__ method. For instance...

import redis

# initialize the redis connection pool
rs = redis.Redis(host='localhost', port=6379)

# define a custom class
class SomeCustomObject(object):
    pass

When I try to set the SomeCustomObject as a value, it appears to work:

>>> rs.set('c', SomeCustomObject())
True

However, when I get the value back, it's just the __repr__ string:

>>> rs.get('c')
'<__main__.SomeCustomObject object at 0x102496710>'

How do I store/get the instance back? I've not had much luck finding any info on this in the documentation, but surely I'm not the first one to encounter this?

Answer 1

Use Pickle

Using the pickle module you can serialize and deserialize Python objects and pass them to Redis.

From this so answer - https://stackoverflow.com/a/20400288/4403600, it would look like this:

import pickle
import redis

# define a custom class
class SomeCustomObject(object):
    pass

# initialize the redis connection pool
rs = redis.Redis(host='localhost', port=6379)

# pickle and set in redis
rs.set('c', pickle.dumps(SomeCustomObject()))

# get from redis and unpickle
unpacked_object = pickle.loads(rs.get('c'))

Further reading - https://docs.python.org/2/library/pickle.html