This can be used as a quick shortcut if you have only one Pydantic model and want to remove some data from the output.

!!! tip
    But it is still recommended to use the ideas above, using multiple classes, instead of these parameters.

Using these ideas, JWT can be used for way more sophisticated scenarios.

In those cases, several of those entities could have the same ID, let's say `foo` (a user `foo`, a car `foo`, and a blog post `foo`).

User Guide** (what you are reading right now).

It's designed so that you can build a complete application with just the **Tutorial - User Guide**, and then extend it in different ways, depending on your needs, using some of the additional ideas from the **Advanced User Guide**....

!!! warning
    The supporting additional functions are just to demo a possible flow of the data, but they of course are not providing any real security.

## Reduce duplication

Reducing code duplication is one of the core ideas in **FastAPI**.

As code duplication increments the chances of bugs, security issues, code desynchronization issues (when you update in one place but not in the others), etc.

need to have a model with all the attributes marked as optional (with default values or `None`).

    To distinguish from the models with all optional values for **updates** and models with required values for **creation**, you can use the ideas described in [Extra Models](extra-models.md){.internal-link target=_blank}....

## Recap

You can use **Gunicorn** (or also Uvicorn) as a process manager with Uvicorn workers to take advantage of **multi-core CPUs**, to run **multiple processes in parallel**.

You could use these tools and ideas if you are setting up **your own deployment system** while taking care of the other deployment concepts yourself.

* Read what I write (or follow me) on <a href="https://dev.to/tiangolo" class="external-link" target="_blank">**Dev.to**</a> or <a href="https://medium.com/@tiangolo" class="external-link" target="_blank">**Medium**</a>.
    * Read other ideas, articles, and read about tools I have created.
    * Follow me to read when I publish something new.

## Tweet about **FastAPI**

    You can consider this a brief OpenAPI and JSON Schema **history lesson**. 🤓

!!! warning
    These are very technical details about the standards **JSON Schema** and **OpenAPI**.

    If the ideas above already work for you, that might be enough, and you probably don't need these details, feel free to skip them.

Before OpenAPI 3.1.0, OpenAPI used an older and modified version of **JSON Schema**.

    # to support it as a first class "feature"
    assert is_bytes_sequence_annotation(Union[List[str], List[bytes]])


def test_is_uploadfile_sequence_annotation():
    # For coverage
    # TODO: in theory this would allow declaring types that could be lists of UploadFile
    # and other types, but I'm not even sure it's a good idea to support it as a first
    # class "feature"

.idea
.ipynb_checkpoints
.mypy_cache
.vscode
__pycache__
.pytest_cache
htmlcov
dist
site
.coverage
coverage.xml
.netlify
test.db
log.txt
Pipfile.lock
env3.*
env
docs_build
site_build
venv
docs.zip
archive.zip

# vim temporary files
*~
.*.sw?
.cache

# macOS