diff --git a/src/deep_neurographs/utils/util.py b/src/deep_neurographs/utils/util.py
index 023b6a6..1413c60 100644
--- a/src/deep_neurographs/utils/util.py
+++ b/src/deep_neurographs/utils/util.py
@@ -477,7 +477,10 @@ def sample_once(my_container):
     sample
 
     """
-    return sample(my_container, 1)[0]
+    if type(my_container) is list:
+        return sample(my_container, 1)[0]
+    else:
+        return sample(list(my_container), 1)[0]
 
 
 # --- dictionary utils ---