memoization_wrapper.py

from functools import wraps

def memoized(f):
    """Decorator that caches a function's return value each time it is
    called. If called later with the same arguments, the cached value
    is returned, and not re-evaluated.

    """
    cache = {}
    @wraps(f)
    def wrapped(*args):
        try:
            result = cache[args]
        except KeyError:
            result = cache[args] = f(*args)
        return result
    return wrapped