diskoize 0.1.2

A memoize-like decorator that caches to disk.

diskoize:memoize::disk:memory

What is this

When I use @functools.lru_cache, I often want to persist data between python process restarts. This library accomplishes that.

import diskoize
import requests

@diskoize.diskoize("scrape_cache.db")
def scrape(url):
  return requests.request(url)


scrape("google.com") # <-- will run only once, even after rerunning this script.

You need to manually delete the cache if you change the function's input-output behavior.

Tests

We use pytest for testing. To run the tests, you can use the following command:

pytest

This will run all the tests in the tests directory. You can also run a specific test file by providing the path to the file:

pytest tests/test_file.py

Development

Make a temporary pip install: pip install -e . Now you can use the library from any python script, and edits to the local diskoize/ folder will be reflected.

Remarks

• There is a tension between making this library understandable and making it easy to use. -- we always give the option of explicitly naming the backing sqlite database file. -- for autonaming, we currently create or reuse a file in the system temp directory which is based based on the diskoized function's name. It is up to the user to delete invalidated caches. So autonaming should probably only be used for quick-and-dirty experiments where we don't expect to come back to the code after a long while.

TODOs

• add option in_memory (default False) to store the cache in memory, always with persistent backing.
• make the tests actually test separate processes accessing the same cache
• add methods for interacting with the cache
• add more examples
• add flush() method, and a lru_cache to support it
• fix _make_key