app = FastAPI()

items = {"foo": {"name": "Fighters", "size": 6}, "bar": {"name": "Tenders", "size": 3}}


@app.put("/items/{item_id}")
async def upsert_item(
    item_id: str,
    name: str | None = Body(default=None),
    size: int | None = Body(default=None),
):
    if item_id in items:
        item = items[item_id]
        item["name"] = name
        item["size"] = size
        return item
    else:

        final List<String> items = List.of("item1", "item2", "item3");
        chatApiManager.sendSseEvent(writer, "test", Map.of("items", items));

        final String output = stringWriter.toString();
        assertTrue(output.contains("event: test"));
        assertTrue(output.contains("["));
        assertTrue(output.contains("item1"));
        assertTrue(output.contains("item2"));

            "paths": {
                "/items/{item_id}": {
                    "put": {
                        "parameters": [
                            {
                                "in": "path",
                                "name": "item_id",
                                "required": True,
                                "schema": {
                                    "title": "Item Id",

Der Wert des Pfad-Parameters `item_id` wird Ihrer Funktion als das Argument `item_id` übergeben.

Wenn Sie dieses Beispiel ausführen und auf [http://127.0.0.1:8000/items/foo](http://127.0.0.1:8000/items/foo) gehen, sehen Sie als <abbr title="Response – Antwort: Daten, die der Server zum anfragenden Client zurücksendet">Response</abbr>:

```JSON
{"item_id":"foo"}
```

from fastapi import FastAPI, HTTPException

app = FastAPI()

items = {"foo": "The Foo Wrestlers"}


@app.get("/items/{item_id}")
async def read_item(item_id: str):
    if item_id not in items:
        raise HTTPException(status_code=404, detail="Item not found")

app = FastAPI()

items = {"foo": "The Foo Wrestlers"}


@app.get("/items-header/{item_id}")
async def read_item_header(item_id: str):
    if item_id not in items:
        raise HTTPException(
            status_code=404,
            detail="Item not found",
            headers={"X-Error": "There goes my error"},
        )

                        "summary": "Read Item",
                        "operationId": "read_item_items__item_id__get",
                        "parameters": [
                            {
                                "required": True,
                                "schema": {"title": "Item Id", "type": "string"},
                                "name": "item_id",
                                "in": "path",

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str | None = Query(min_length=3)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: str = Query(default="fixedquery", min_length=3)):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})

from typing import Annotated

from fastapi import FastAPI, Query

app = FastAPI()


@app.get("/items/")
async def read_items(q: Annotated[str, Query(min_length=3)]):
    results = {"items": [{"item_id": "Foo"}, {"item_id": "Bar"}]}
    if q:
        results.update({"q": q})