We had this type annotation:

//// tab | Python 3.10+

```Python
q: str | None = None
```

////

//// tab | Python 3.9+

```Python
q: Union[str, None] = None
```

////

What we will do is wrap that with `Annotated`, so it becomes:

//// tab | Python 3.10+

```Python
q: Annotated[str | None] = None
```

////

//// tab | Python 3.9+

```Python

    /**
     * In case of complex XML structures, combining can be done based on id.
     */
    @Deprecated(since = "4.0.0", forRemoval = true)
    String ID_COMBINATION_MODE_ATTRIBUTE = XmlService.ID_COMBINATION_MODE_ATTRIBUTE;

    /**
     * In case of complex XML structures, combining can be done based on keys.
     * This is a comma separated list of attribute names.
     */

        // Test that empty args (except for goal) work correctly
        String[] args = {"apply"};
        CommonsCliUpgradeOptions options = CommonsCliUpgradeOptions.parse(args);

        // None of the optional flags should be present
        assertFalse(options.plugins().isPresent(), "--plugins should not be present by default");
        assertFalse(options.all().isPresent(), "--all should not be present by default");

                       var_name,
                       query_item,
                       enabled_by_default,
                       question=None,
                       yes_reply=None,
                       no_reply=None,
                       bazel_config_name=None):
  """Set boolean action_env variable.

  Ask user if query_item will be enabled. Default is used if no input is given.

			}
			err = next(resp.Msg)
			if err != nil {
				s.cancel(err)
				return err
			}
		}
	}
}

// Done will return a channel that will be closed when the stream is done.
// This mirrors context.Done().
func (s *Stream) Done() <-chan struct{} {
	return s.ctx.Done()
}

// Err will return the error that caused the stream to end.
// This mirrors context.Err().
func (s *Stream) Err() error {

```

/// tip

The second argument to <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> is the default value to return.

If not provided, it's `None` by default, here we provide `"World"` as the default value to use.

///

Then you could call that Python program:

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console

The way to describe this in OpenAPI, is to mark that field as **required**, because it will always be there.

Because of that, the JSON Schema for a model can be different depending on if it's used for **input or output**:

* for **input** the `description` will **not be required**
* for **output** it will be **required** (and possibly `None`, or in JSON terms, `null`)

# Used mainly to close files after the request is done, dependencies are closed
# in their own AsyncExitStack
class AsyncExitStackMiddleware:
    def __init__(
        self, app: ASGIApp, context_name: str = "fastapi_middleware_astack"
    ) -> None:
        self.app = app
        self.context_name = context_name

    async def __call__(self, scope: Scope, receive: Receive, send: Send) -> None:
        async with AsyncExitStack() as stack:

            """
        ),
    ]


class HTTPBase(SecurityBase):
    def __init__(
        self,
        *,
        scheme: str,
        scheme_name: Optional[str] = None,
        description: Optional[str] = None,
        auto_error: bool = True,
    ):
        self.model: HTTPBaseModel = HTTPBaseModel(
            scheme=scheme, description=description
        )

		b := make([]byte, 12)
		_, terr = deadlineconn.Read(b)
		if terr != nil {
			t.Errorf("failed to read from client. %v", terr)
			return
		}
		received := string(b)
		if received != "message one\n" {
			t.Errorf(`server: expected: "message one\n", got: %v`, received)
			return
		}

		// Wait for more than read timeout to simulate processing.
		time.Sleep(3 * time.Second)

		_, terr = deadlineconn.Read(b)
		if terr != nil {