Update README.md

hw5/README.md

@@ -123,9 +123,14 @@ We can similarly iterate over all of the flushed data (which optionally takes a
 for k,v in m.loadAll():
     print(k,v)
 ```
-There is also a way to iterate over all of the flushed keys (will strip out subkeys):
+
+Since there are some keys in memory and some flushed to disk there are two commands to iterate over keys.
+```
+m.keys() #returns all keys that are in memory
+```
+There is also a way to iterate over all of the flushed keys (will strip out any subkeys):
 ```
-m.flushed()
+m.flushed() #return keys that are flushed.
 ```
 
 ## Count Per Group