Minor refactoring

lib/core/decorators.py

@@ -0,0 +1,8 @@
+# Reference: http://code.activestate.com/recipes/325205-cache-decorator-in-python-24/
+def cachedmethod(f, cache={}):
+    def _(*args, **kwargs):
+        key = (f, tuple(args), frozenset(kwargs.items()))
+        if key not in cache:
+            cache[key] = f(*args, **kwargs)
+        return cache[key]
+    return _