app-json-file-cache 0.1.1

Simple user directory respecting JSON cache for expensive functions.

Provides a function decorator that caches the return value in a JSON file in the appropriate application cache directory.

It requires all function parameters and return values to be encodeable to JSON, so that the cache is human-readable.

It supports a “vary” guard value (e.g. a data model version) that protects against using old versions of cache.

Usage

Example usage:

from app_json_file_cache import AppCache
cache = AppCache("myapp")

@cache("expensive")
def expensive_function():
    return calculator()

More Example usage:

from app_json_file_cache import AppCache
cache = AppCache("myapp")

@cache("expensive", vary=VERSION)
def expensive_function(param):
    return calculator(param)

Caveats

• Names must be unique per app. If you reuse names, chaos ensues.

• Each set of function parameter values creates a new file. This may lead to too many files in a directory on some systems.

• Mixing positional and keyword arguments is not supported

• It’s your responsibility that return values are serializable to JSON.