added safe_insert

python/database.py

@@ -0,0 +1,57 @@
+from __future__ import annotations
+
+import logging
+from typing import TYPE_CHECKING
+
+from sqlalchemy import inspect
+from sqlalchemy.exc import NoInspectionAvailable
+
+if TYPE_CHECKING:
+    from collections.abc import Sequence
+
+    from sqlalchemy.orm import Session
+
+logger = logging.getLogger(__name__)
+
+
+def safe_insert(orm_objects: Sequence[object], session: Session) -> list[tuple[Exception, object]]:
+    """Safer insert at allows for partial rollbacks.
+
+    Args:
+        orm_objects (Sequence[object]): Tables to insert.
+        session (Session): Database session.
+    """
+    if unmapped := [orm_object for orm_object in orm_objects if not _is_mapped_instance(orm_object)]:
+        error = f"binary_search_insert expects ORM-mapped instances {unmapped}"
+        raise TypeError(error)
+    return _safe_insert(orm_objects, session)
+
+
+def _safe_insert(objects: Sequence[object], session: Session) -> list[tuple[Exception, object]]:
+    exceptions: list[tuple[Exception, object]] = []
+    try:
+        session.add_all(objects)
+        session.commit()
+
+    except Exception as error:
+        session.rollback()
+
+        objects_len = len(objects)
+        if objects_len == 1:
+            logger.exception(objects)
+            return [(error, objects[0])]
+
+        middle = objects_len // 2
+        exceptions.extend(_safe_insert(objects=objects[:middle], session=session))
+        exceptions.extend(_safe_insert(objects=objects[middle:], session=session))
+    return exceptions
+
+
+def _is_mapped_instance(obj: object) -> bool:
+    """Return True if `obj` is a SQLAlchemy ORM-mapped instance."""
+    try:
+        inspect(obj)  # raises NoInspectionAvailable if not mapped
+    except NoInspectionAvailable:
+        return False
+    else:
+        return True