file_cache.py

from pathlib import Path
import pickle
import functools
import hashlib


def hash_args(args, kwargs):
    assert all(isinstance(s, str) for s in kwargs.values())
    assert all(isinstance(s, str) for s in args)

    m = hashlib.md5()
    for s in args:
        m.update(s.encode())
    for k, v in kwargs:
        m.update(k.encode())
        m.update(v.encode())
    return m.hexdigest()


def file_cache(func):
    """
    Caches the result of this function call on the filesystem by hashing the arguments.
    """
    path = Path("./.file_cache/")
    path.mkdir(exist_ok=True)

    @functools.wraps(func)
    def wrapper(*args, **kwargs):
        file_path = path / (func.__name__ + "_" + str(hash_args(args, kwargs)))
        file_path = file_path.with_suffix(".pckl")

        if file_path.exists():
            with open(file_path, "rb") as f:
                output = pickle.load(f)  
            return output

        output = func(*args, **kwargs)
        with open(file_path, "wb") as f:
            pickle.dump(output, f)

        return output

    return wrapper