✨ Add first version of Pydantic model generator from SQLAlchemy model

tiangolo · tiangolo · commit 67dcde061b65 · 2020-05-02T18:14:57.000+02:00
diff --git a/pydantic_sqlalchemy/__init__.py b/pydantic_sqlalchemy/__init__.py
@@ -0,0 +1,5 @@
+from importlib_metadata import version
+
+__version__ = version(__package__)
+
+from .main import sqlalchemy_to_pydantic
diff --git a/pydantic_sqlalchemy/main.py b/pydantic_sqlalchemy/main.py
@@ -0,0 +1,28 @@
+from typing import Type
+
+from pydantic import BaseConfig, BaseModel, create_model
+from sqlalchemy.inspection import inspect
+from sqlalchemy.orm.properties import ColumnProperty
+
+
+class OrmConfig(BaseConfig):
+    orm_config = True
+
+
+def sqlalchemy_to_pydantic(db_model: Type) -> Type[BaseModel]:
+    mapper = inspect(db_model)
+    fields = {}
+    for attr in mapper.attrs:
+        if isinstance(attr, ColumnProperty):
+            if attr.columns:
+                column = attr.columns[0]
+                python_type = column.type.python_type
+                name = attr.key
+                default = column.default
+                if default is None and not column.nullable:
+                    default = ...
+                fields[name] = (python_type, default)
+    pydantic_model = create_model(
+        db_model.__name__, __config__=OrmConfig, **fields  # type: ignore
+    )
+    return pydantic_model
