Adding _init_private_attributes to SQLModel __init__ function.

sqlmodel/main.py

@@ -514,6 +514,7 @@ def __init__(__pydantic_self__, **data: Any) -> None:
         for key in non_pydantic_keys:
             if key in __pydantic_self__.__sqlmodel_relationships__:
                 setattr(__pydantic_self__, key, data[key])
+        __pydantic_self__._init_private_attributes()
 
     def __setattr__(self, name: str, value: Any) -> None:
         if name in {"_sa_instance_state"}:

tests/test_private_attributes.py

@@ -0,0 +1,18 @@
+from typing import Optional
+
+from pydantic import PrivateAttr
+from sqlmodel import Field, SQLModel
+
+
+def test_private_attribute():
+    class Hero(SQLModel, table=True):
+        primary_key: Optional[int] = Field(
+            default=None,
+            primary_key=True,
+        )
+        _private_attribute: str = PrivateAttr(default="my_private_attribute")
+
+    hero = Hero()
+    assert hero._private_attribute == "my_private_attribute"
+    assert "primary_key" in hero.dict()
+    assert "_private_attribute" not in hero.dict()