fix: list index out of range error caused by calling LayoutElements.from_list() with empty list (#398)

error coming from
https://github.com/Unstructured-IO/core-product/actions/runs/11510770484/job/32043653203?pr=662#step:5:718
or lmk if there are better way to fix error w/o changing here :)

Author: yuming-long

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 0.8.1
+* fix: fix list index out of range error caused by calling LayoutElements.from_list() with empty list
+
 ## 0.8.0
 
 * fix: fix missing source after cleaning layout elements

test_unstructured_inference/test_elements.py

@@ -436,3 +436,8 @@ def test_layoutelements_to_list_and_back(test_layoutelements):
         test_layoutelements.element_class_id_map[idx]
         for idx in test_layoutelements.element_class_ids
     ] == [back.element_class_id_map[idx] for idx in back.element_class_ids]
+
+
+def test_layoutelements_from_list_no_elements():
+    back = LayoutElements.from_list(elements=[])
+    assert back.source is None

unstructured_inference/__version__.py

@@ -1 +1 @@
-__version__ = "0.8.0"  # pragma: no cover
+__version__ = "0.8.1"  # pragma: no cover

unstructured_inference/inference/layoutelement.py

@@ -145,7 +145,7 @@ def from_list(cls, elements: list):
             element_probs=np.array(class_probs),
             element_class_ids=class_ids,
             element_class_id_map=dict(zip(range(len(unique_ids)), unique_ids)),
-            source=elements[0].source,
+            source=elements[0].source if len_ele else None,
         )