Created
April 16, 2014 01:53
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memoize class for memorizing / caching function calls in python along with reset and reset all memoized functions
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import collections | |
import functools | |
memoized = [] | |
def clearAllMemoized(): | |
[m.reset() for m in memoized] | |
class memoize(object): | |
'''Decorator. Caches a function's return value each time it is called. | |
If called later with the same arguments, the cached value is returned | |
(not reevaluated). | |
''' | |
def __init__(self, func): | |
self.func = func | |
self.cache = {} | |
memoized.append(self) | |
def __call__(self, *args): | |
if not isinstance(args, collections.Hashable): | |
# uncacheable. a list, for instance. | |
# better to not cache than blow up. | |
return self.func(*args) | |
if args in self.cache: | |
return self.cache[args] | |
else: | |
value = self.func(*args) | |
self.cache[args] = value | |
return value | |
def __repr__(self): | |
'''Return the function's docstring.''' | |
return self.func.__doc__ | |
def __get__(self, obj, objtype): | |
'''Support instance methods.''' | |
return functools.partial(self.__call__, obj) | |
def reset(self): | |
self.cache = {} |
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wrong, since
isinstance(args, collections.Hashable)
will always be True