Puedes crear dependencias que tengan **sub-dependencias**.

Pueden ser tan **profundas** como necesites.

**FastAPI** se encargará de resolverlas.

## Primera dependencia "dependable" { #first-dependency-dependable }

Podrías crear una primera dependencia ("dependable") así:

{* ../../docs_src/dependencies/tutorial005_an_py310.py hl[8:9] *}

Entonces el código de Python en tu aplicación equivaldría a algo como:

```Python
if "johndoe" == "stanleyjobson" and "love123" == "swordfish":
    ...
```

def process_items(prices: dict[str, float]):
    for item_name, item_price in prices.items():
        print(item_name)

///

### Función de Lifespan { #lifespan-function }

Lo primero que hay que notar es que estamos definiendo una función asíncrona con `yield`. Esto es muy similar a las Dependencias con `yield`.

{* ../../docs_src/events/tutorial003_py39.py hl[14:19] *}

La primera parte de la función, antes del `yield`, será ejecutada **antes** de que la aplicación comience.

A stand-alone MinIO server would go down if the server hosting the drives goes offline. In contrast, a distributed MinIO setup with _m_ servers and _n_ drives will have your data safe as long as _m/2_ servers or _m*n_/2 or more drives are online.

For example, an 16-server distributed setup with 200 drives per node would continue serving files, up to 4 servers can be offline in default configuration i.e around 800 drives down MinIO would continue to read and write objects.

    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + eventType;
        result = prime * result + ((exception == null) ? 0 : exception.hashCode());
        result = prime * result + ((localFile == null) ? 0 : localFile.hashCode());
        result = prime * result + requestType;
        return result;
    }

    @Override

				Name:    v.Name,
				Deleted: v.Created,
			})
		}
		return true
	})

	return buckets, nil
}

func cloneDrives(drives map[string]StorageAPI) []StorageAPI {
	copyDrives := make([]StorageAPI, 0, len(drives))
	for _, drive := range drives {
		copyDrives = append(copyDrives, drive)
	}
	return copyDrives
}

		"Count of offline drives in the cluster")
	healthDrivesOnlineCountMD = NewGaugeMD(healthDrivesOnlineCount,
		"Count of online drives in the cluster")
	healthDrivesCountMD = NewGaugeMD(healthDrivesCount,
		"Count of all drives in the cluster")
)

// loadClusterHealthDriveMetrics - `MetricsLoaderFn` for cluster storage drive metrics
// such as online, offline and total drives.

on 16 drive MinIO deployment. If you use eight data and eight parity drives, the file space usage will be approximately twice, i.e. 100 MiB
file will take 200 MiB space. But, if you use ten data and six parity drives, same 100 MiB file takes around 160 MiB. If you use 14 data and
two parity drives, 100 MiB file takes only approximately 114 MiB.

- We limited the number of drives to 16 for erasure set because, erasure code shards more than 16 can become chatty and do not have any performance advantages. Additionally since 16 drive erasure set gives you tolerance of 8 drives per object by default which is plenty in any practical scenario.