It gives you all the flexibility to choose the ones that fit your project the best.

And you can use directly many well maintained and widely used packages like `passlib` and `PyJWT`, because **FastAPI** doesn't require any complex mechanisms to integrate external packages.

But it provides you the tools to simplify the process as much as possible without compromising flexibility, robustness, or security.

```

////

/// tip

We'll discuss the `@lru_cache` in a bit.

For now you can assume `get_settings()` is a normal function.

///

And then we can require it from the *path operation function* as a dependency and use it anywhere we need it.

//// tab | Python 3.9+

```Python hl_lines="17  19-21"
{!> ../../docs_src/settings/app02_an_py39/main.py!}
```

////

| Params     | Value    |
| :--        | :--      |
| *Type*     | *String* |
| *Required* | *No*     |

### RoleArn

The role ARN to use. This must be specified if and only if the web identity provider is configured with a role policy.

| Params     | Value    |
| :--        | :--      |
| *Type*     | *String* |
| *Required* | *No*     |

### Version

# SQL (Relational) Databases

**FastAPI** doesn't require you to use a SQL (relational) database. But you can use **any database** that you want.

Here we'll see an example using <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a>.

   * type. That said, we could *accept* a `@Nullable T[]` (which, given that we treat arrays as
   * covariant, would still permit a plain `T[]`) and return a plain `T[]`. But of course that would
   * require its own suppression, since it is also unsound. toArray(T[]) is just a mess from a
   * nullness perspective. The signature below at least has the virtue of being relatively simple.
   */
  @SuppressWarnings("nullness")

                    problems,
                    Severity.FATAL,
                    Version.V40,
                    "model",
                    null,
                    "the model contains elements that require a model version of " + minVersion,
                    m);
        }

        Parent parent = m.getParent();

        if (parent != null) {
            validateStringNotEmpty(

    duplex request bodies. Such interceptors should check `RequestBody.isDuplex()` and avoid
    accessing the request body when it is.

    Duplex calls require HTTP/2. If HTTP/1 is established instead the duplex call will fail. The
    most common use of duplex calls is [gRPC][grpc_http2].

	if err != nil {
		err = msgp.WrapError(err, "set")
		return
	}
	return
}

// MarshalMsg implements msgp.Marshaler
func (z *listPathOptions) MarshalMsg(b []byte) (o []byte, err error) {
	o = msgp.Require(b, z.Msgsize())
	// map header, size 19
	// string "ID"
	o = append(o, 0xde, 0x0, 0x13, 0xa2, 0x49, 0x44)
	o = msgp.AppendString(o, z.ID)
	// string "Bucket"
	o = append(o, 0xa6, 0x42, 0x75, 0x63, 0x6b, 0x65, 0x74)

*   Include unit tests when you contribute new features, as they help to a)
    prove that your code works correctly, and b) guard against future breaking
    changes to lower the maintenance cost.
*   Bug fixes also generally require unit tests, because the presence of bugs
    usually indicates insufficient test coverage.
*   Keep API compatibility in mind when you change code in core TensorFlow,
    e.g., code in

### Bug or Regression

- Fix error when trying to expand a volume that does not require node expansion ([#123055](https://github.com/kubernetes/kubernetes/pull/123055), [@gnufied](https://github.com/gnufied)) [SIG Node and Storage]