initial design idea

Author: mkrd

dictdatabase/orm.py

@@ -0,0 +1,90 @@
+from __future__ import annotations
+from abc import ABC
+from typing import get_type_hints, get_origin, get_args, TypeVar
+from types import UnionType, NoneType,
+from . import io_safe
+
+T = TypeVar('T')
+
+
+
+class FolderBase(ABC):
+	__folder__ = None
+	__file__base__ = None
+
+
+class FileDictBase(ABC):
+	"""
+		A file base refers to a file that is stored in the database.
+	"""
+
+	__file__ = None
+	__item_base__: T = None
+	__create_file_on_write__ = False
+
+
+	@classmethod
+	def get_by_key(cls, key) -> T:
+		"""
+			Gets an item by key.
+		"""
+		return cls.__item_base__.get_by_key(key)
+
+
+
+
+
+class FileDictItemBase(ABC):
+	@classmethod
+	def get_by_key(cls, key):
+		data = io_safe.partial_read(cls.__file__, key)
+		return cls.from_data(data)
+
+
+
+	@classmethod
+	def from_data(cls, data):
+
+		instance = cls()
+
+		for var_name, var_type in get_type_hints(cls).items():
+			# Check if variable is nullable (e.g. email: str | None)
+			nullable = get_origin(var_type) is UnionType and NoneType in get_args(var_name)
+			# When it is not nullable but not in the data, raise an error
+			if var_name not in data and not nullable:
+				raise RuntimeError(f"Missing variable '{var_name}' in file '{cls.__file__}'.")
+
+			setattr(instance, var_name, data.get(var_name, None))
+
+		return instance
+
+
+
+
+
+
+class User(FileDictItemBase):
+	first_name: str | None
+	last_name: str
+	email: str
+
+	def full_name(self):
+		return f"{self.first_name} {self.last_name}"
+
+
+class Users(FileDictBase):
+	__file__ = "users"
+	__item_base__ = User
+
+
+
+# Iterate FileDictBase
+# for user_id, user: User in Users.items():
+# 	print(user_id, user.first_name, user.last_name, user.email)
+
+# # Get one item
+# user: User = Users.get("user_id")
+
+
+# Get by lambda
+# users: Users = Users.where(lambda user: user.first_name != "John")