python file cache decorators

file_cache.py

import os
import pickle
import hashlib
from functools import wraps, reduce


def default_filename_fn(args, kwargs):
    base = reduce(lambda acc,x: acc + str(x), args, "")
    return hashlib.sha1(base.encode()).hexdigest()


def dir_cache(directory, filename_fn=default_filename_fn):
    def decorator(function):
        @wraps(function)
        def wrapper(*args, **kwargs):
            if not os.path.exists(directory):
                os.makedirs(directory)
            filename = filename_fn(args, kwargs)
            path = os.path.join(directory, filename)
            if os.path.isfile(path):
                with open(path, "rb") as f:
                    result = pickle.load(f)
            else:
                result = function(*args, **kwargs)
                with open(path, "wb") as f:
                    pickle.dump(result, f)
            return result
        return wrapper
    return decorator


def file_cache(filename):
    def decorator(function):
        @wraps(function)
        def wrapper(*args, **kwargs):
            if os.path.isfile(filename):
                with open(filename, "rb") as f:
                    result = pickle.load(f)
            else:
                result = function(*args, **kwargs)
                with open(filename, "wb") as f:
                    pickle.dump(result, f)
            return result
        return wrapper
    return decorator