Update u2/list_ops.py

u2/list_ops.py

@@ -38,5 +38,13 @@ def foldl(function, list, initial):
     return acc    
 
 def foldr(function, list, initial):
+    acc = initial
+    for acc in  list:
+        acc = function(acc, item)
+    return acc
 
 def reverse(list):
+    result = []
+    for item in list:
+        result = [item] + result
+    return result