@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

{!../../../docs_src/path_params/tutorial001.py!}
```

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

Wenn Sie dieses Beispiel ausführen und auf <a href="http://127.0.0.1:8000/items/foo" class="external-link" target="_blank">http://127.0.0.1:8000/items/foo</a> gehen, sehen Sie als Response:

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

## Pfad-Parameter mit Typen

defaultConfig:
  discoveryAddress: istiod-rev-1.istio-system.svc:15012
  proxyMetadata:
    CANONICAL_REVISION: latest
    CANONICAL_SERVICE: foo
    CLUSTER_MESH_CONFIG_VALUE: foo
    ISTIO_META_CLUSTER_ID: Kubernetes
    ISTIO_META_DNS_CAPTURE: "true"
    ISTIO_META_MESH_ID: ""
    ISTIO_META_NETWORK: ""
    ISTIO_META_WORKLOAD_NAME: foo
    ISTIO_METAJSON_LABELS: '{"service.istio.io/canonical-name":"foo","service.istio.io/canonical-revision":"latest"}'

defaultConfig:
  discoveryAddress: istiod-rev-1.istio-system.svc:15012
  proxyMetadata:
    CANONICAL_REVISION: latest
    CANONICAL_SERVICE: foo
    CLUSTER_MESH_CONFIG_VALUE: foo
    ISTIO_META_CLUSTER_ID: Kubernetes
    ISTIO_META_DNS_CAPTURE: "true"
    ISTIO_META_MESH_ID: ""
    ISTIO_META_NETWORK: ""
    ISTIO_META_WORKLOAD_NAME: foo
    ISTIO_METAJSON_LABELS: '{"service.istio.io/canonical-name":"foo","service.istio.io/canonical-revision":"latest"}'

ISTIO_INBOUND_PORTS='*'
ISTIO_LOCAL_EXCLUDE_PORTS='22,15090,15021,15020'
ISTIO_METAJSON_LABELS='{"service.istio.io/canonical-name":"foo","service.istio.io/canonical-revision":"latest"}'
ISTIO_META_CLUSTER_ID='Kubernetes'
ISTIO_META_DNS_CAPTURE='true'
ISTIO_META_MESH_ID=''
ISTIO_META_NETWORK=''
ISTIO_META_WORKLOAD_NAME='foo'
ISTIO_NAMESPACE='bar'
ISTIO_SERVICE='foo.bar'
ISTIO_SERVICE_CIDR='*'
ISTIO_SVC_IP='10.10.10.10'
POD_NAMESPACE='bar'

@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Optional[str] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```

@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}


@app.put("/items/{item_id}")
def update_item(item_id: int, item: Item):
    return {"item_name": item.name, "item_id": item_id}
```