diff --git a/src/metadata_review_lib.py b/src/metadata_review_lib.py
index 44f72f3..7627231 100644
--- a/src/metadata_review_lib.py
+++ b/src/metadata_review_lib.py
@@ -39,19 +39,18 @@ def get_review_status(filename_path):
             workflow_steps.append(line)
     return workflow_steps[-1]
 
-def parse_attribute(attr_value):
+def parse_attribute(attr_value : dict):
+    "Parse a dictionary attribute into an equivalent numpy structured array, which compatible with compound HDF5 type"
     dtype = []
     values_list = []
-    max_length = max(len(item) for item in attr_value.keys())
+    max_length = max(len(str(attr_value[key])) for key in attr_value.keys())
     for key in attr_value.keys():
         if (not key=='rename_as'):
             dtype.append((key,f'S{max_length}'))
             values_list.append(attr_value[key])  
 
-    if len(values_list)>1:
+    if values_list:
         new_attr_value = np.array([tuple(values_list)],dtype=dtype)
-    elif values_list:
-        new_attr_value = values_list[0]
     else:
         new_attr_value = 'missing'