add parse_obj

layercake/layercake/dynamodb.py

@@ -5,7 +5,7 @@ from base64 import urlsafe_b64decode, urlsafe_b64encode
 from dataclasses import dataclass
 from datetime import datetime
 from ipaddress import IPv4Address
-from typing import TYPE_CHECKING, Any, Type, TypedDict
+from typing import TYPE_CHECKING, Any, Self, Type, TypedDict
 from urllib.parse import quote, unquote
 from uuid import UUID
 
@@ -251,6 +251,19 @@ class KeyPair(Key):
             ':sk': self[SK],
         }
 
+    @classmethod
+    def parse_obj(cls, obj: Any) -> Self | None:
+        if not obj:
+            return None
+
+        match obj:
+            case dict():
+                pair = obj.values()
+            case _:
+                pair = obj
+
+        return cls(*pair)
+
 
 class TransactItems:
     def __init__(self, table_name: str) -> None: