Add handling for lists with just one or zero entries

test/collection/test_filter.py

@@ -32,3 +32,21 @@ def test_filter_lists() -> None:
     or_direct = f1 | f2
     assert isinstance(or_list, _FilterOr)
     assert or_list.filters == or_direct.filters
+
+
+def test_filter_lists_one_entry() -> None:
+    f1 = wvc.query.Filter.by_property("test").equal("test")
+
+    and_list = wvc.query.Filter.all_of([f1])
+    assert and_list == f1
+
+    or_list = wvc.query.Filter.any_of([f1])
+    assert or_list == f1
+
+
+def test_filter_lists_empty() -> None:
+    with pytest.raises(weaviate.exceptions.WeaviateInvalidInputError):
+        wvc.query.Filter.all_of([])
+
+    with pytest.raises(weaviate.exceptions.WeaviateInvalidInputError):
+        wvc.query.Filter.any_of([])

weaviate/collections/classes/filters.py

@@ -564,11 +564,19 @@ def by_property(name: str, length: bool = False) -> _FilterByProperty:
     @staticmethod
     def all_of(filters: List[_Filters]) -> _Filters:
         """Combine all filters in the input list with an AND operator."""
+        if len(filters) == 1:
+            return filters[0]
+        elif len(filters) == 0:
+            raise WeaviateInvalidInputError("Filter.all_of must have at least one filter")
         return _FilterAnd(filters)
 
     @staticmethod
     def any_of(filters: List[_Filters]) -> _Filters:
         """Combine all filters in the input list with an OR operator."""
+        if len(filters) == 1:
+            return filters[0]
+        elif len(filters) == 0:
+            raise WeaviateInvalidInputError("Filter.any_of must have at least one filter")
         return _FilterOr(filters)