♻️ raise exception if trait not found instead of returning None

Raising exception is more pythonic than returning just None. Also some changes in return type annotations.

client/ayon_core/pipeline/traits/trait.py

@@ -7,7 +7,7 @@ import sys
 import uuid
 from abc import ABC, abstractmethod
 from functools import lru_cache
-from typing import ClassVar, Optional, Type, Union
+from typing import ClassVar, Optional, Type, TypeVar, Union
 
 import pydantic.alias_generators
 from pydantic import (
@@ -105,6 +105,9 @@ class TraitBase(ABC, BaseModel):
         return re.sub(r"\.v\d+$", "", str(cls.id))
 
 
+T = TypeVar("T", bound=TraitBase)
+
+
 class Representation:
     """Representation of products.
 
@@ -287,7 +290,7 @@ class Representation:
             self.contains_trait_by_id(trait_id) for trait_id in trait_ids
         )
 
-    def get_trait(self, trait: Type[TraitBase]) -> Union[TraitBase, None]:
+    def get_trait(self, trait: Type[T]) -> Union[T]:
         """Get a trait from the representation.
 
         Args:
@@ -296,10 +299,17 @@ class Representation:
         Returns:
             TraitBase: Trait instance.
 
-        """
-        return self._data[trait.id] if self._data.get(trait.id) else None
+        Raises:
+            ValueError: If the trait is not found.
 
-    def get_trait_by_id(self, trait_id: str) -> Union[TraitBase, None]:
+        """
+        try:
+            return self._data[trait.id]
+        except KeyError as e:
+            msg = f"Trait with ID {trait.id} not found."
+            raise ValueError(msg) from e
+
+    def get_trait_by_id(self, trait_id: str) -> Union[T]:
         # sourcery skip: use-named-expression
         """Get a trait from the representation by id.
 
@@ -309,12 +319,19 @@ class Representation:
         Returns:
             TraitBase: Trait instance.
 
+        Raises:
+            ValueError: If the trait is not found.
+
         """
         version = _get_version_from_id(trait_id)
         if version:
-            return self._data.get(trait_id)
+            try:
+                return self._data[trait_id]
+            except KeyError as e:
+                msg = f"Trait with ID {trait_id} not found."
+                raise ValueError(msg) from e
 
-        return next(
+        result = next(
             (
                 self._data.get(trait_id)
                 for trait_id in self._data
@@ -322,9 +339,14 @@ class Representation:
             ),
             None,
         )
+        if not result:
+            msg = f"Trait with ID {trait_id} not found."
+            raise ValueError(msg)
+        return result
 
     def get_traits(self,
-                     traits: Optional[list[Type[TraitBase]]]=None) -> dict:
+                     traits: Optional[list[Type[TraitBase]]]=None
+                   ) -> dict[str, T]:
         """Get a list of traits from the representation.
 
         If no trait IDs or traits are provided, all traits will be returned.
@@ -346,7 +368,7 @@ class Representation:
              result[trait.id] = self.get_trait(trait=trait)
         return result
 
-    def get_traits_by_ids(self, trait_ids: list[str]) -> dict:
+    def get_traits_by_ids(self, trait_ids: list[str]) -> dict[str, T]:
         """Get a list of traits from the representation by their id.
 
         If no trait IDs or traits are provided, all traits will be returned.