Proper input value type verification for append method

CHANGELOG.md

@@ -22,6 +22,9 @@
 - Change run status to Active / Inactive ([#1233](https://github.com/neptune-ai/neptune-client/pull/1233))
 - Package renamed from `neptune-client` to `neptune` ([#1225](https://github.com/neptune-ai/neptune-client/pull/1225))
 
+### Fixes
+- Fixed input value type verification for `append()` method ([#1254](https://github.com/neptune-ai/neptune-client/pull/1254))
+
 ## neptune-client 0.16.18
 
 ### Fixes

src/neptune/handler.py

@@ -681,12 +681,7 @@ def validate_and_transform_to_extend_format(value):
         so work can be delegated to `extend` method."""
         if isinstance(value, Namespace) or is_dict_like(value):
             return {k: ExtendUtils.validate_and_transform_to_extend_format(v) for k, v in value.items()}
-        elif is_collection(value):
-            raise NeptuneUserApiInputException(
-                "Value cannot be a collection, if you want to `append` multiple values at once use `extend` method."
-            )
-        else:
-            return [value]
+        return [value]
 
     @staticmethod
     def validate_values_for_extend(values, steps, timestamps):

tests/unit/neptune/new/test_handler.py

@@ -50,6 +50,7 @@
 from neptune.exceptions import (
     FileNotFound,
     NeptuneUserApiInputException,
+    UnsupportedType,
 )
 from neptune.types import File as FileVal
 from neptune.types.atoms.artifact import Artifact
@@ -270,15 +271,15 @@ def test_log_many_values(self):
 
     def test_append_many_values_cause_error(self):
         with init_run(mode="debug", flush_period=0.5) as exp:
-            with self.assertRaises(NeptuneUserApiInputException):
+            with self.assertRaises(UnsupportedType):
                 exp["some/num/val"].append([])
-            with self.assertRaises(NeptuneUserApiInputException):
+            with self.assertRaises(UnsupportedType):
                 exp["some/num/val"].append([5, 10, 15])
-            with self.assertRaises(NeptuneUserApiInputException):
+            with self.assertRaises(UnsupportedType):
                 exp["some/str/val"].append(["some text", "other"])
-            with self.assertRaises(NeptuneUserApiInputException):
+            with self.assertRaises(UnsupportedType):
                 exp["some/num/val"].append({"key-a": [1, 2]})
-            with self.assertRaises(NeptuneUserApiInputException):
+            with self.assertRaises(UnsupportedType):
                 exp["some/img/val"].append(
                     [
                         FileVal.as_image(PIL.Image.new("RGB", (60, 30), color="red")),