Package: django-async-redis
Django Async RedisIntroductiondjango-async-redis is a full featured Redis cache and session backend for Django.Free software: Apache Software License 2.0Documentation:https://django-async-redis.readthedocs.io.RequirementsPython3.7+Django3.2+redis-py4.2+Redis server2.8+User guideInstallationInstall with pip:$python-mpipinstalldjango-async-redisConfigure as cache backendTo start using django-async-redis, you should change your Django cache settings to
something like:CACHES={"default":{"BACKEND":"django_async_redis.cache.RedisCache","LOCATION":"redis://127.0.0.1:6379/1","OPTIONS":{"CLIENT_CLASS":"django_async_redis.client.DefaultClient",}}}django-async-redis uses the aioredis native URL notation for connection strings, it
allows better interoperability and has a connection string in more “standard”
way. Some examples:redis://[:password]@localhost:6379/0rediss://[:password]@localhost:6379/0unix://[:password]@/path/to/socket.sock?db=0Three URL schemes are supported:redis://: creates a normal TCP socket connectionrediss://: creates a SSL wrapped TCP socket connectionunix://creates a Unix Domain Socket connectionThere are several ways to specify a database number:Adbquerystring option, e.g.redis://localhost?db=0If using theredis://scheme, the path argument of the URL, e.g.redis://localhost/0Advanced usagePickle versionFor almost all values, django-async-redis uses pickle to serialize objects.The latest available version of pickle is used by default. If you want set a
concrete version, you can do it, usingPICKLE_VERSIONoption:CACHES={"default":{# ..."OPTIONS":{"PICKLE_VERSION":-1# Use the latest protocol version}}}Memcached exceptions behaviorIn some situations, when Redis is only used for cache, you do not want
exceptions when Redis is down. This is default behavior in the memcached
backend and it can be emulated in django-async-redis.For setup memcached like behaviour (ignore connection exceptions), you should
setIGNORE_EXCEPTIONSsettings on your cache configuration:CACHES={"default":{# ..."OPTIONS":{"IGNORE_EXCEPTIONS":True,}}}Also, you can apply the same settings to all configured caches, you can set the global flag in
your settings:DJANGO_ASYNC_REDIS_IGNORE_EXCEPTIONS=TrueLog Ignored ExceptionsWhen ignoring exceptions withIGNORE_EXCEPTIONSorDJANGO_ASYNC_REDIS_IGNORE_EXCEPTIONS, you may optionally log exceptions using the
global variableDJANGO_ASYNC_REDIS_LOG_IGNORED_EXCEPTIONSin your settings file:DJANGO_ASYNC_REDIS_LOG_IGNORED_EXCEPTIONS = TrueIf you wish to specify the logger in which the exceptions are output, simply
set the global variableDJANGO_ASYNC_REDIS_LOGGERto the string name and/or path
of the desired logger. This will default to__name__if no logger is
specified andDJANGO_ASYNC_REDIS_LOG_IGNORED_EXCEPTIONSisTrue:DJANGO_ASYNC_REDIS_LOGGER = 'some.specified.logger'Infinite timeoutdjango-async-redis comes with infinite timeouts support out of the box.
And it behaves in the same way as the Django BaseCache backend specifies:timeout=0expires the value immediately.timeout=Noneinfinite timeoutawaitcache.aset("key","value",timeout=None)Get ttl (time-to-live) from keyWith Redis, you can access to ttl of any stored key, for it,
django-async-redis exposesattlfunction.It returns:0 if key does not exists (or already expired).None for keys that exists but does not have any expiration.ttl value for any volatile key (any key that has expiration).>>>fromdjango.core.cacheimportcache>>>awaitcache.aset("foo","value",timeout=25)>>>awaitcache.attl("foo")25>>>awaitcache.attl("not-existent")0Expire & PersistAdditionally to the simple ttl query, you can send persist a concrete key or
specify a new expiration timeout using theapersistandaexpiremethods:>>>awaitcache.aset("foo","bar",timeout=22)>>>awaitcache.attl("foo")22>>>awaitcache.apersist("foo")>>>awaitcache.attl("foo")None>>>awaitcache.aset("foo","bar",timeout=22)>>>awaitcache.aexpire("foo",timeout=5)>>>awaitcache.attl("foo")5Scan & Delete keys in bulkdjango-async-redis comes with some additional methods that help with searching or
deleting keys using glob patterns.>>>fromdjango.core.cacheimportcache>>>awaitcache.akeys("foo_*")["foo_1", "foo_2"]A simple search like this will return all matched values. In databases with a
large number of keys this isn’t suitable method. Instead, you can use theaiter_keysfunction that works like theakeysfunction but uses Redis
server side cursors. Callingaiter_keyswill return a generator that you can
then iterate over efficiently.>>>fromdjango.core.cacheimportcache>>>awaitcache.aiter_keys("foo_*")<async_generator object algo at 0x7ffa9c2713a8>>>>(awaitcache.aiter_keys("foo_*")).__anext__()"foo_1"For deleting keys, you should useadelete_patternwhich has the same glob
pattern syntax as theakeysfunction and returns the number of deleted keys.>>>fromdjango.core.cacheimportcache>>>awaitcache.adelete_pattern("foo_*")Redis native commandsdjango-async-redis has limited support for some Redis atomic operations, such as the
commandsSETNXandINCR.You can use theSETNXcommand through the backendaset()method with
thenxparameter:>>>fromdjango.core.cacheimportcache>>>awaitcache.aset("key","value1",nx=True)True>>>awaitcache.aset("key","value2",nx=True)False>>>awaitcache.aget("key")"value1"Also, theaincrandadecrmethods use Redis atomic
operations when the value that a key contains is suitable for it.Note that settingxxto True overrides thenxflag according
to aioredis.Connection poolsBehind the scenes, django-async-redis uses the underlying aioredis connection pool
implementation and exposes a simple way to configure it. Alternatively, you
can directly customize a connection/connection pool creation for a backend.The default aioredis behavior is to not close connections, recycling them when
possible.NotesSince the majority of this code was ported from django-redis, there was one
case that had needed a monkeypatch. Indjango_async_redis.util, we implementCacheKeywhich subclassesstrwhich helps us know if a cache key was
already created. Since aioredis, checks if the cache key is of type str
(and others), I had to monkeypatch that check so that a CacheKey instance could
also be accepted.CreditHey, I’m Andrew. I’m busy in college, but I wanted to help contribute
to Django’s async ecosystem.Lots of code and docs is taken from django-redis, including the tests.
I just needed to port everything to asyncio and aioredis.I used cookiecutter-pypackage to generate this project.Thank you to Python Discord server’s async topical chat
for helping me understand when to use coroutines over sync functions
and @Bast and @hmmmm in general because they’re OG.History0.1.0 (2020-09-25)First release on PyPI.