pyappcache

Pyappcache is a library to make it easier to use application-level caching in Python.

• Allows putting arbitrary Python objects into the cache
• Uses PEP484 type hints to help you typecheck cache return values
• Supports Memcache, Redis and SQLite
• Supports working as a "read-through" and "write-through" cache
• Native support for key "namespacing"
• Provides a few handy extras
  • A plugin for the cachecontrol library so you can also use it as an HTTP cache with requests

A simple example

from datetime import date

from pyappcache.redis import RedisCache
from pyappcache.keys import Key, SimpleStringKey

cache = RedisCache()

# Annotate the type here to let mypy know this key is used for dates
key: Key[date] = SimpleStringKey("mifid start date")
cache.set(key, date(2018, 1, 3), ttl_seconds=3600)

... # later...

# This variable's type will be inferred as datetime.date
special_date = cache.get(key)

How it compares to alternatives

Using the redis/memcache/sqlite client directly

• Explicit key objects allow for type inference and encapsulation of keying
• Keys are prefix to help prevent collisions
• Optional, pluggable, compression
• Hopefully the overhead is small (not yet tested!)
• Portable between redis/memcache/sqlite, etc

dogpile.cache

• Explicit key objects allow for type inference and encapsulation of keying
• dogpile.cache provides locking, pyappcache does not
• Reduced temptation to use the problematic decorator pattern
  • This often causes import order problems as you need to have your cache at import time
• Pyappache doesn't provide DBM/file backends, SQLite instead