def _memoize(func, *args, **kw): if kw: # frozenset is used to ensure hashability key = args, frozenset(kw.items()) else: key = args cache = func.cache # attribute added by memoize if key not in cache: cache[key] = func(*args, **kw) return cache[key] def memoize(f): """ A simple memoize implementation. It works by adding a .cache dictionary to the decorated function. The cache will grow indefinitely, so it is your responsability to clear it, if needed. """ f.cache = {} return decorate(f, _memoize) >>> @memoize ... def heavy_computation(): ... time.sleep(2) ... return "done" >>> print(getargspec(heavy_computation)) ArgSpec(args=[], varargs=None, varkw=None, defaults=None)
使用decorator模块可以防止更改signature,这样decorator符合一个signature-preserving decorators的要求:Callable objects which accept a function as input and return a function as output, with the same signature.
时间: 2024-10-07 05:03:15