Sync fastapi docs from 50fa3f7c on 2026-01-11

docs_src/query_params_str_validations/tutorial001_py39.py

@@ -0,0 +1,13 @@
+from typing import Union
+
+from fastapi import FastAPI
+
+app = FastAPI()
+
+
+@app.get("/items/")
+async def read_items(q: Union[str, None] = None):
+    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
+    if q:
+        results.update({"q": q})
+    return results