这是Alex Martelli Python Cookbook中的示例，展示了如何使用cPickle为带有可变参数（ ）的函数创建备忘录装饰器：
import cPickle
class MemoizeMutable:
def __init__(self, fn):
self.fn = fn
self.memo = {}
def __call__(self, *args, **kwds):
import cPickle
str = cPickle.dumps(args, 1)+cPickle.dumps(kwds, 1)
if not self.memo.has_key(str):
print "miss" # DEBUG INFO
self.memo[str] = self.fn(*args, **kwds)
else:
print "hit" # DEBUG INFO
return self.memo[str]
使用您给定的代码和此备忘录装饰器：
_level = MemoizeMutable(_level)
equirements = {'a': [],
'b': [],
'c': ['a'],
'd': ['a','b'],
'e': ['c','d'],
'f': ['e']
}
print uses_hierarchy(equirements)
我能够重现此：
miss
miss
hit
miss
miss
hit
miss
hit
hit
hit
miss
hit
{0: ['a', 'b'], 1: ['c', 'd'], 2: ['e'], 3: ['f']}
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