*   XLA reduction emitter is deterministic when the environment variable
        `TF_DETERMINISTIC_OPS` is set to "true" or "1". This extends
        deterministic `tf.nn.bias_add` back-prop functionality (and therefore
        also deterministic back-prop of bias-addition in Keras layers) to
        include when XLA JIT compilation is enabled.
    *   Fix problem, when running on a CUDA GPU and when either environment

Also allowing to have multiple alternative security schemes that are then checked in a single dependency instead of each one verifying and returning the error to the client automatically when not satisfied. PR [#134](https://github.com/tiangolo/fastapi/pull/134).

* Update [SQL Tutorial](https://fastapi.tiangolo.com/tutorial/sql-databases/#create-a-middleware-to-handle-sessions) to close database sessions even when there are exceptions. PR [#89](https://github.com/tiangolo/fastapi/pull/89)...

            TimeZone.setDefault(testTimeZone);

            // When
            DfFinalTimeZoneProvider provider = curtainBeforeHook.createFinalTimeZoneProvider();

            // Then
            // Provider should still use FessUserTimeZoneProcessProvider.centralTimeZone
            // which was set when the class was loaded
            TimeZone providedTimeZone = provider.provide();

* `C:\Windows\System32`

////

When you type a **command** in the terminal, the operating system **looks for** the program in **each of those directories** listed in the `PATH` environment variable.

For example, when you type `python` in the terminal, the operating system looks for a program called `python` in the **first directory** in that list.

And then, right after the `yield`, we unload the model. This code will be executed **after** the application **finishes handling requests**, right before the *shutdown*. This could, for example, release resources like memory or a GPU.

/// tip

The `shutdown` would happen when you are **stopping** the application.

In the dependency override we set a new value for the `admin_email` when creating the new `Settings` object, and then we return that new object.

Then we can test that it is used.

## Reading a `.env` file { #reading-a-env-file }

If you have many settings that possibly change a lot, maybe in different environments, it might be useful to put them on a file and then read them from it as if they were environment variables.

////

//// tab | Windows PowerShell

<div class="termy">

```console
$ Get-Command python

C:\Users\user\code\awesome-project\.venv\Scripts\python
```

</div>

If it shows the `python` binary at `.venv\Scripts\python`, inside of your project (in this case `awesome-project`), then it worked. 🎉

////

### Single Container { #single-container }

### About `__name__ == "__main__"` { #about-name-main }

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

<div class="termy">

```console
$ python myapp.py
```

</div>

but is not called when another file imports it, like in:

```Python
from myapp import app
```

#### More details { #more-details }

```

But the `Query` version declares it explicitly as being a query parameter.

Then, we can pass more parameters to `Query`. In this case, the `max_length` parameter that applies to strings:

```Python
q: str | None = Query(default=None, max_length=50)
```

This will validate the data, show a clear error when the data is not valid, and document the parameter in the OpenAPI schema *path operation*.