Redis Collections

redis-collections is a Python library that provides a high-level interface to Redis, the excellent key-value store.

Quickstart

Install the library with pip install redis-collections. Import the collections from the top-level redis_collections package.

Standard collections

The standard collections (e.g. Dict, List, Set) behave like their Python counterparts:

>>> from redis_collections import Dict, List, Set

>>> D = Dict()
>>> D['answer'] = 42
>>> D['answer']
42

Collection	Redis type	Description
`Dict`	Hash	Emulates Python's `dict`
`List`	List	Emulates Python's `list`
`Set`	Set	Emulates Python's `set`
`Counter`	Hash	Emulates Python's `collections.Counter`
`DefaultDict`	Hash	Emulates Python's `collections.defaultdict`
`Deque`	List	Emulates Python's `collections.deque`

Syncable collections

The syncable collections in this package provide types whose contents are kept in memory. When their sync method is called those contents are written to Redis:

>>> from redis_collections import SyncableDict

>>> with SyncableDict() as D:
...     D['a'] = 1  # No write to Redis
...     D['a'] += 1  # No read from or write to Redis
>>> D['a']  # D.sync() is called at the end of the with block
2

Collection	Python type	Description
`SyncableDict`	`dict`	Syncs to a Redis Hash
`SyncableList`	`list`	Syncs to a Redis List
`SyncableSet`	`set`	Syncs to a Redis Set
`SyncableCounter`	`collections.Counter`	Syncs to a Redis Hash
`SyncableDeque`	`collections.deque`	Syncs to a Redis List
`SyncableDefaultDict`	`collections.defaultdict`	Syncs to a Redis Hash

Other collections

The LRUDict collection stores recently used items in in memory. It pushes older items to Redis:

>>> from redis_collections import LRUDict

>>> D = LRUDict(maxsize=2)
>>> D['a'] = 1
>>> D['b'] = 2
>>> D['c'] = 2  # 'a' is pushed to Redis and 'c' is stored locally
>>> D['a']  # 'b' is pushed to Redis and 'a' is retrieved for local storage
1
>>> D.sync()  # All items are copied to Redis

The SortedSetCounter provides access to the Redis Sorted Set type:

>>> from redis_collections import SortedSetCounter

>>> ssc = SortedSetCounter([('earth', 300), ('mercury', 100)])
>>> ssc.set_score('venus', 200)
>>> ssc.get_score('venus')
200.0
>>> ssc.items()
[('mercury', 100.0), ('venus', 200.0), ('earth', 300.0)]