+ if not data:
+ data = None
+ elif data.is_expired():
+ self.pop(key)
+ data = None
+ else:
+ data = data.get_data()
+ return data
+
+ def pop(self, key):
+ if key in self.cache:
+ self.cache.pop(key)
+
+ def dump(self):
+ result = {}
+ for key in self.cache:
+ result[key] = self.cache[key].__getstate__()
+ return result
+
+ def __str__(self):
+ return str(self.dump())
+
+ def tostring(self):
+ return self.__str()
+
+ def save_to_file(self, filename):
+ f = open(filename, 'wb')
+ pickle.dump(self.cache, f)
+
+ def load_from_file(self, filename):
+ f = open(filename, 'rb')
+ self.cache = pickle.load(f)