Sync fastapi docs from b5ca1324 on 2025-12-07

docs_src/body_nested_models/tutorial001.py

@@ -0,0 +1,20 @@
+from typing import Union
+
+from fastapi import FastAPI
+from pydantic import BaseModel
+
+app = FastAPI()
+
+
+class Item(BaseModel):
+    name: str
+    description: Union[str, None] = None
+    price: float
+    tax: Union[float, None] = None
+    tags: list = []
+
+
+@app.put("/items/{item_id}")
+async def update_item(item_id: int, item: Item):
+    results = {"item_id": item_id, "item": item}
+    return results