You could have custom internal logic to separate it by colon caracters (`:`) or
    similar, and get the two parts `items` and `read`. Many applications do that to
    group and organize permissions, you could do it as well in your application, just
    know that that it is application specific, it's not part of the specification.
    """

    def __init__(
        self,
        *,
        grant_type: Annotated[

It can't handle nested models very well. So, if the JSON body in the request is a JSON object that has inner fields that in turn are nested JSON objects, it cannot be properly documented and validated.

!!! check "Inspired **FastAPI** to"

---

**FastAPI** doesn't make any compromise with any database, data model or tool.

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 `python-jose`, because **FastAPI** doesn't require any complex mechanisms to integrate external packages.

<img src="/img/deployment/concepts/process-ram.svg">

And of course, the same machine would probably have **other processes** running as well, apart from your application.

An interesting detail is that the percentage of the **CPU used** by each process can **vary** a lot over time, but the **memory (RAM)** normally stays more or less **stable**.

Keep in mind that this means that the whole contents will be stored in memory. This will work well for small files.

But there are several cases in which you might benefit from using `UploadFile`.

## File Parameters with `UploadFile`

Define a file parameter with a type of `UploadFile`:

=== "Python 3.9+"

* If the PR can be simplified in a way, you can ask for that, but there's no need to be too picky, there might be a lot of subjective points of view (and I will have my own as well 🙈), so it's better if you can focus on the fundamental things.

### Tests

* Help me check that the PR has **tests**.

* Check that the tests **fail** before the PR. 🚨

    Feel free to skip this.

    Peewee is not recommended with FastAPI as it doesn't play well with anything async Python. There are several better alternatives.

!!! info
    These docs assume Pydantic v1.

    Because Pewee doesn't play well with anything async and there are better alternatives, I won't update these docs for Pydantic v2, they are kept for now only for historical purposes.

But if you want to use `async` / `await` without FastAPI, you can do it as well.

### Write your own async code

You can create and use environment variables in the shell, without needing Python:

=== "Linux, macOS, Windows Bash"

    <div class="termy">

    ```console
    // You could create an env var MY_NAME with

    The new docs will include Pydantic v2 and will use <a href="https://sqlmodel.tiangolo.com/" class="external-link" target="_blank">SQLModel</a> (which is also based on SQLAlchemy) once it is updated to use Pydantic v2 as well.

**FastAPI** doesn't require you to use a SQL (relational) database.

But you can use any relational database that you want.