In all the docs there are examples compatible with each version of Python (when there's a difference).

For example "**Python 3.6+**" means it's compatible with Python 3.6 or above (including 3.7, 3.8, 3.9, 3.10, etc). And "**Python 3.9+**" means it's compatible with Python 3.9 or above (including 3.10, etc).

to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

So, you can just let **FastAPI** use the correct Starlette version.

## About Pydantic

Pydantic includes the tests for **FastAPI** with its own tests, so new versions of Pydantic (above `1.0.0`) are always compatible with FastAPI.

You can pin Pydantic to any version above `1.0.0` that works for you and below `2.0.0`.

For example:

```txt
pydantic>=1.2.0,<2.0.0

async with lifespan(app):
    await do_stuff()
```

When you create a context manager or an async context manager like above, what it does is that, before entering the `with` block, it will execute the code before the `yield`, and after exiting the `with` block, it will execute the code after the `yield`.

In our code example above, we don't use it directly, but we pass it to FastAPI for it to use it.

### Technical Details: `root_path`

When you mount a sub-application as described above, FastAPI will take care of communicating the mount path for the sub-application using a mechanism from the ASGI specification called a `root_path`.

That way, the sub-application will know to use that path prefix for the docs UI.

The TLS Termination Proxy would have access to one or more **TLS certificates** (HTTPS certificates).

Using the **SNI extension** discussed above, the TLS Termination Proxy would check which of the TLS (HTTPS) certificates available it should use for this connection, using the one that matches the domain expected by the client.

So, even with the code above that doesn't use Pydantic explicitly, FastAPI is using Pydantic to convert those standard dataclasses to Pydantic's own flavor of dataclasses.

And of course, it supports the same:

* data validation
* data serialization

</div>

It will also auto-sort all your imports.

For it to sort them correctly, you need to have FastAPI installed locally in your environment, with the command in the section above using `-e`.

## Docs

First, make sure you set up your environment as described above, that will install all the requirements.

### Docs live

During local development, there is a script that builds the site and checks for any changes, live-reloading:

**FastAPI**는 각 경우에 수행할 작업과 동일한 개체를 내부적으로 재사용하기에, 모든 백그라운드 작업이 함께 병합되고 나중에 백그라운드에서 실행됩니다.

=== "Python 3.6 and above"

    ```Python hl_lines="13  15  22  25"
    {!> ../../../docs_src/background_tasks/tutorial002.py!}
    ```

=== "Python 3.10 and above"

    ```Python hl_lines="11  13  20  23"
    {!> ../../../docs_src/background_tasks/tutorial002_py310.py!}
    ```

]
```

These are **JavaScript** objects, not strings, so you can't pass them from Python code directly.