35 lines
959 B
Python
35 lines
959 B
Python
import collections
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import functools
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class memoized(object):
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'''Decorator. Caches a function's return value each time it is called.
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If called later with the same arguments, the cached value is returned
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(not reevaluated).
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'''
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def __init__(self, func):
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self.func = func
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self.cache = {}
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def __call__(self, *args):
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if not isinstance(args, collections.Hashable):
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# uncacheable. a list, for instance.
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# better to not cache than blow up.
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return self.func(*args)
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if args in self.cache:
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return self.cache[args]
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else:
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value = self.func(*args)
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self.cache[args] = value
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return value
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def __repr__(self):
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'''Return the function's docstring.'''
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return self.func.__doc__
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def __get__(self, obj, objtype):
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'''Support instance methods.'''
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return functools.partial(self.__call__, obj)
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