Tags
When I need to cache some data between runs or share a cache accross multiple
processes my go to library in python is diskcache
. It's built on sqlite with
just enough cacheing niceties that make it very worth it.
install diskcache
Install diskcache into your virtual environement of choice using pip from your command line.
python -m pip install diskcache
setup the cache
There are a couple of different types of cache, Cache
, FanoutCache
,
and DjangoCache
, you can read more about those in the
docs
from diskcache import Cache cache = FanoutCache('.mycache', statistics=True)
Adding to the cache
Adding to the cache only needs a key and value.
cache.add('me', 'waylonwalker' )
Set the expire time
Optionally you can set the seconds before it expires. The cache invalidation tools like this is what really makes diskcache shine over using raw sqlite or any sort of static file.
cache.add('me', 'waylonwalker', expire=60)
tagging
Diskcache supports tagging entries added to the cache.
# add an item to the cache with a tag cache.add('me', 'waylonwalker', expire=60, tag='people')
This seems to let you do a few new things like getting items from the cache by both key and tag, or evict all tags from the cache.
# evict all items tagged as 'people' from the cache cache.evict(tag='people')
Reading from the cache
You can read from the cache by using the .get
method and giving it the key
you want to retrieve.
who = cache.get('me') # who == 'waylonwalker'
Cache Misses
Cache misses will return a None
just like any dictionary .get
miss.
missed = cache.get('missing') # missed == None
⭐
Give Grant some love and give grantjenks/python-diskcache a ⭐.