updated contents from Atlas repo

decorators/average_py2.py

@@ -0,0 +1,28 @@
+"""
+>>> avg = make_averager()
+>>> avg(10)
+10.0
+>>> avg(11)
+10.5
+>>> avg(12)
+11.0
+>>> avg.__code__.co_varnames
+('new_value', 'total')
+>>> avg.__code__.co_freevars
+('series',)
+>>> avg.__closure__  # doctest: +ELLIPSIS
+(<cell at 0x...: list object at 0x...>,)
+>>> avg.__closure__[0].cell_contents
+[10, 11, 12]
+"""
+
+
+def make_averager():
+    series = []
+
+    def averager(new_value):
+        series.append(new_value)
+        total = sum(series)
+        return float(total)/len(series)
+
+    return averager