Indicate type of primary key using generics (bd46f183) · Commits · PoolPay Heidelberg / PoolPay

poolpay/model/Retrievable.py

+4 −5

Original line number	Diff line number	Diff line
		from __future__ import annotations

		from collections.abc import Sequence
		from typing import Any

		from sqlalchemy import select
		from sqlalchemy.orm import DeclarativeBase, MappedColumn
		@@ -9,7 +8,7 @@ from sqlalchemy.orm import DeclarativeBase, MappedColumn
		from poolpay import db


		class Retrievable(DeclarativeBase):
		class Retrievable[PrimaryKey](DeclarativeBase):
		"""
		A type whose instances can be retrieved from the database.

		@@ -30,7 +29,7 @@ class Retrievable(DeclarativeBase):
		return None

		@classmethod
		def get_all[T](cls: type[T]) -> Sequence[T]:
		def get_all[T: Retrievable](cls: type[T]) -> Sequence[T]:
		"""
		Return all instances of this type.
		"""
		@@ -44,7 +43,7 @@ class Retrievable(DeclarativeBase):
		)

		@classmethod
		def get_only[T](cls: type[T], primary_key: Any) -> T \| None:
		def get_only[T: Retrievable](cls: type[T], primary_key: PrimaryKey) -> T \| None:
		"""
		Return the instance of this type with the given primary key or None if it doesn't exist.
		"""
		@@ -54,7 +53,7 @@ class Retrievable(DeclarativeBase):
		return db.session.get(cls, primary_key)

		@property
		def primary_key(self) -> Any:
		def primary_key(self) -> PrimaryKey:
		"""
		Return the primary key that can be used to identify an instance of this class.
		"""