Merge pull request keon#6 from madhab-p/patch-1

update flatten.py

array/flatten.py

@@ -18,7 +18,7 @@ def list_flatten(l, a=None):
     a = list(a) if isinstance(a, (list, tuple)) else []
     for i in l:
         if isinstance(i, (list, tuple)):
-            list_flatten(i, a)
+            a = list_flatten(i, a)
         else:
             a.append(i)
     return a