Redis/Python: store and combine data by date

Question

Objective (using Redis):

1. Cache data (as an object: example dict of string/pandas dataframe) by date
2. Retrieve data between date range (say 20101010 - 20151231)
3. Combine attributes of data between this date range (I'd like Redis to do this for me than combine it in python logic)

Example:

20101010: { "a" : dataframe_A1, "b" : "dataframe_B1 }, 
20101011: { "a" : dataframe_A2, "b" : "dataframe_B2 }

Output:

{"a" : dataframe_A1 concatenated with dataframe_A2, "b": dataframe_B1 concatenated with dataframe_B2}

One solution I've found is to use ZADD/ZRANGEBYSCORE technique, where I create an index on date in YYYYMMDD format, giving it a natural set ordering. This makes it trivial to retrieve data in a range (example: 20101010 - 20151231) (using: https://redis.io/topics/indexes)

Is there a way retrieve data in a combined format from Redis efficiently (#3) - see my example output above.

What sequence of operations/commands would most efficiently get me this information?

Note:

• The dict above is just an example. It can be an object as well, with a way to combine its attributes.
• Dataframes can be stored using to_msgpack format into Redis(How to set/get pandas.DataFrame to/from redis?)

Thanks