KurumiPy

KurumiPy is an enhanced memoization library.

Kurumi stands for walnut in Japanese. They say walnuts improve memory.

Features

Usual memoizations keep return values associated with arguments only. KurumiPy provides an enhanced memoization with features following.

• Changes in your function
  • KurumiPy automatically invalidates cache when you change implementation of the target function. It is useful for test-driven development.
• Changes in dependent variables
  • KurumiPy automatically invalidates cache when any dependent variables of the target function have been changed. It is useful if you modify parameters and re-execute your program.
• Inter-process
  • KurumiPy shares cache amoung processes. Even if your program runs in multiple processes, KurumiPy handles cache correctly.

Setting up

Python 3

Supported versions of Python are 3.x.

Installing dependent packages

Please install fasteners 0.14.1.

pip install fasteners==0.14.1

or

Add 'fasteners==0.14.1' to your 'requirements.txt' and install.

How to apply to your project

Copy 'memoization' folder to your project, then import the module. Write a decorator to functions to enable memoization.

from memoization.memo_decorator import memo

@memo
def your_function(n):
    # ...

Functions should meet the restrictions following.

• Pure functions
• Arguments are string type, numeric type, etc. (Not supported: list type, dict type, set type, file objects etc.)
• Not supported: Mutual recursive function in multiple threads (Dining Philosophers Problem).

Cache files will be stored in the folder following.

• ./memoization/memocache

Disabling salt

Python 3.3 enables "salt" on hash of str, bytes and datetime objects by default. See https://docs.python.org/3/reference/datamodel.html#object.__hash__ for details. Salt prevents consistent hash values across processes. You need to disable it before running Python programs.

# bash
export PYTHONHASHSEED=0
# Command prompt
set PYTHONHASHSEED=0

You have to set environment variable only once until you exit bash or command prompt.

Test

# bash
python -m unittest discover -p '*_test.py'
# Command prompt
python -m unittest discover -p *_test.py

python main.py

Related project

• IncPy

License

Apache License 2.0