Let's say that you want to declare the query parameter `q` as a required `str`.

And you don't need to declare anything else for that parameter, so you don't really need to use `Query`.

But you still need to use `Path` for the `item_id` path parameter. And you don't want to use `Annotated` for some reason.

# Dependencies in path operation decorators

In some cases you don't really need the return value of a dependency inside your *path operation function*.

Or the dependency doesn't return a value.

But you still need it to be executed/solved.

For those cases, instead of declaring a *path operation function* parameter with `Depends`, you can add a `list` of `dependencies` to the *path operation decorator*.

## Shortcut to remember the names

Let's see the previous example again:

```Python hl_lines="6"
{!../../../docs_src/response_status_code/tutorial001.py!}
```

`201` is the status code for "Created".

But you don't have to memorize what each of these codes mean.

You can use the convenience variables from `fastapi.status`.

```Python hl_lines="1  6"
{!../../../docs_src/response_status_code/tutorial002.py!}
```

Let's imagine that loading the model can **take quite some time**, because it has to read a lot of **data from disk**. So you don't want to do it for every request.

    ```

=== "Python 3.8+"

    ```Python hl_lines="21"
    {!> ../../../docs_src/separate_openapi_schemas/tutorial001.py!}
    ```

...then because `description` has a default value, if you **don't return anything** for that field, it will still have that **default value**.

### Model for Output Response Data

    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:

<div class="termy">

```console
// Here we don't set the env var yet
$ python main.py

// As we didn't set the env var, we get the default value

Hello World from Python

// But if we create an environment variable first
$ export MY_NAME="Wade Wilson"

We are going to override the internal parts of Peewee that use `threading.local` and replace them with `contextvars`, with the corresponding updates.

This might seem a bit complex (and it actually is), you don't really need to completely understand how it works to use it.

We will create a `PeeweeConnectionState`:

```Python hl_lines="10-19"
{!../../../docs_src/sql_databases_peewee/sql_app/database.py!}
```

from fastapi import FastAPI
from pydantic import BaseModel, EmailStr

app = FastAPI()


class UserIn(BaseModel):
    username: str
    password: str
    email: EmailStr
    full_name: str | None = None


# Don't do this in production!
@app.post("/user/")
async def create_user(user: UserIn) -> UserIn:

    results = some_library()
    return results
```

---

If your application (somehow) doesn't have to communicate with anything else and wait for it to respond, use `async def`.

---

If you just don't know, use normal `def`.

---

**Note**: You can mix `def` and `async def` in your *path operation functions* as much as you need and define each one using the best option for you. FastAPI will do the right thing with them.

     * @param {string} options.cursor – Character to use for cursor, defaults to ▋.
     * @param {Object[]} lineData - Dynamically loaded line data objects.
     * @param {boolean} options.noInit - Don't initialise the animation.
     */
    constructor(container = '#termynal', options = {}) {
        this.container = (typeof container === 'string') ? document.querySelector(container) : container;