Simplify parse method in label

backend/data_import/pipeline/label.py

@@ -2,7 +2,6 @@ import abc
 import uuid
 from typing import Any, Optional
 
-import pydantic.error_wrappers
 from pydantic import UUID4, BaseModel, validator
 
 from .label_types import LabelTypes
@@ -60,10 +59,7 @@ class CategoryLabel(Label):
 
     @classmethod
     def parse(cls, example_uuid: UUID4, obj: Any):
-        try:
-            return cls(example_uuid=example_uuid, label=obj)
-        except pydantic.error_wrappers.ValidationError:
-            return None
+        return cls(example_uuid=example_uuid, label=obj)
 
     def create_type(self, project: Project) -> Optional[LabelType]:
         return CategoryType(text=self.label, project=project)
@@ -82,15 +78,13 @@ class SpanLabel(Label):
 
     @classmethod
     def parse(cls, example_uuid: UUID4, obj: Any):
-        try:
-            if isinstance(obj, list) or isinstance(obj, tuple):
-                columns = ["start_offset", "end_offset", "label"]
-                obj = zip(columns, obj)
-                return cls(example_uuid=example_uuid, **dict(obj))
-            elif isinstance(obj, dict):
-                return cls(example_uuid=example_uuid, **obj)
-        except pydantic.error_wrappers.ValidationError:
-            return None
+        if isinstance(obj, list) or isinstance(obj, tuple):
+            columns = ["start_offset", "end_offset", "label"]
+            obj = zip(columns, obj)
+            return cls(example_uuid=example_uuid, **dict(obj))
+        elif isinstance(obj, dict):
+            return cls(example_uuid=example_uuid, **obj)
+        raise ValueError("SpanLabel.parse()")
 
     def create_type(self, project: Project) -> Optional[LabelType]:
         return SpanType(text=self.label, project=project)
@@ -114,10 +108,7 @@ class TextLabel(Label):
 
     @classmethod
     def parse(cls, example_uuid: UUID4, obj: Any):
-        try:
-            return cls(example_uuid=example_uuid, text=obj)
-        except pydantic.error_wrappers.ValidationError:
-            return None
+        return cls(example_uuid=example_uuid, text=obj)
 
     def create_type(self, project: Project) -> Optional[LabelType]:
         return None
@@ -136,10 +127,7 @@ class RelationLabel(Label):
 
     @classmethod
     def parse(cls, example_uuid: UUID4, obj: Any):
-        try:
-            return cls(example_uuid=example_uuid, **obj)
-        except pydantic.error_wrappers.ValidationError:
-            return None
+        return cls(example_uuid=example_uuid, **obj)
 
     def create_type(self, project: Project) -> Optional[LabelType]:
         return RelationType(text=self.type, project=project)

backend/data_import/tests/test_label.py

@@ -84,8 +84,8 @@ class TestSpanLabel(TestLabel):
 
     def test_parse_invalid_dict(self):
         example_uuid = uuid.uuid4()
-        span = SpanLabel.parse(example_uuid, obj={"label": "A", "start_offset": 0})
-        self.assertEqual(span, None)
+        with self.assertRaises(ValueError):
+            SpanLabel.parse(example_uuid, obj={"label": "A", "start_offset": 0})
 
     def test_create_type(self):
         span = SpanLabel(label="A", start_offset=0, end_offset=1, example_uuid=uuid.uuid4())
@@ -116,8 +116,8 @@ class TestTextLabel(TestLabel):
 
     def test_parse_invalid_data(self):
         example_uuid = uuid.uuid4()
-        text = TextLabel.parse(example_uuid, obj=[])
-        self.assertEqual(text, None)
+        with self.assertRaises(ValueError):
+            TextLabel.parse(example_uuid, obj=[])
 
     def test_create_type(self):
         text = TextLabel(text="A", example_uuid=uuid.uuid4())
@@ -148,8 +148,8 @@ class TestRelationLabel(TestLabel):
 
     def test_parse_invalid_data(self):
         example_uuid = uuid.uuid4()
-        relation = RelationLabel.parse(example_uuid, obj={"type": "A", "from_id": 0})
-        self.assertEqual(relation, None)
+        with self.assertRaises(ValueError):
+            RelationLabel.parse(example_uuid, obj={"type": "A", "from_id": 0})
 
     def test_create_type(self):
         relation = RelationLabel(type="A", from_id=0, to_id=1, example_uuid=uuid.uuid4())