Added error for lookup by primary key

tests/test_model_methods.py

@@ -22,6 +22,7 @@
     MultipleObjectsReturned,
     OperationalError,
     ParamsError,
+    ObjectDoesNotExistError,
     ValidationError,
 )
 from tortoise.expressions import F, Q
@@ -252,12 +253,26 @@ async def test_index_access(self):
         self.assertEqual(obj, self.mdl)
 
     async def test_index_badval(self):
-        with self.assertRaises(KeyError):
+        with self.assertRaises(ObjectDoesNotExistError) as cm:
             await self.cls[100000]
+        the_exception = cm.exception
+        # For compatibility reasons this should be an instance of KeyError
+        self.assertIsInstance(the_exception, KeyError)
+        self.assertIs(the_exception.model, self.cls)
+        self.assertEqual(the_exception.pk_name, "id")
+        self.assertEqual(the_exception.pk_val, 100000)
+        self.assertEqual(str(the_exception), f"{self.cls.__name__} has no object with id=100000")
 
     async def test_index_badtype(self):
-        with self.assertRaises(KeyError):
+        with self.assertRaises(ObjectDoesNotExistError) as cm:
             await self.cls["asdf"]
+        the_exception = cm.exception
+        # For compatibility reasons this should be an instance of KeyError
+        self.assertIsInstance(the_exception, KeyError)
+        self.assertIs(the_exception.model, self.cls)
+        self.assertEqual(the_exception.pk_name, "id")
+        self.assertEqual(the_exception.pk_val, "asdf")
+        self.assertEqual(str(the_exception), f"{self.cls.__name__} has no object with id=asdf")
 
     async def test_clone(self):
         mdl2 = self.mdl.clone()

tortoise/exceptions.py

@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, Any
 
 if TYPE_CHECKING:
     from tortoise import Model, Type
@@ -66,6 +66,20 @@ def __str__(self):
         return f'Multiple objects returned for "{self.model.__name__}", expected exactly one'
 
 
+class ObjectDoesNotExistError(OperationalError, KeyError):
+    """
+    The DoesNotExist exception is raised when an item with the passed primary key does not exist
+    """
+
+    def __init__(self, model: "Type[Model]", pk_name: str, pk_val: Any):
+        self.model: "Type[Model]" = model
+        self.pk_name: str = pk_name
+        self.pk_val: Any = pk_val
+
+    def __str__(self):
+        return f"{self.model.__name__} has no object with {self.pk_name}={self.pk_val}"
+
+
 class DoesNotExist(OperationalError):
     """
     The DoesNotExist exception is raised when expecting data, such as a ``.get()`` operation.

tortoise/models.py

@@ -32,6 +32,7 @@
     IntegrityError,
     OperationalError,
     ParamsError,
+    ObjectDoesNotExistError,
 )
 from tortoise.fields.base import Field
 from tortoise.fields.data import IntField
@@ -783,7 +784,7 @@ async def _getbypk(cls: Type[MODEL], key: Any) -> MODEL:
         try:
             return await cls.get(pk=key)
         except (DoesNotExist, ValueError):
-            raise KeyError(f"{cls._meta.full_name} has no object {repr(key)}")
+            raise ObjectDoesNotExistError(cls, cls._meta.pk_attr, key)
 
     def clone(self: MODEL, pk: Any = EMPTY) -> MODEL:
         """