from fastapi.routing import APIRoute

app = FastAPI()


@app.get("/items/")
async def read_items():
    return [{"item_id": "Foo"}]


def use_route_names_as_operation_ids(app: FastAPI) -> None:
    """
    Simplify operation IDs so that generated API clients have simpler function
    names.

    Should be called only after all routes have been added.
    """
    for route in app.routes:
        if isinstance(route, APIRoute):

We will create a FastAPI **dependency** with `yield` that will provide a new `Session` for each request. This is what ensures that we use a single session per request. 🤓

Then we create an `Annotated` dependency `SessionDep` to simplify the rest of the code that will use this dependency.

{* ../../docs_src/sql_databases/tutorial001_an_py310.py ln[25:30]  hl[25:27,30] *}

### Create Database Tables on Startup { #create-database-tables-on-startup }

{* ../../docs_src/bigger_applications/app_an_py39/dependencies.py hl[3,6:8] title["app/dependencies.py"] *}

/// tip

We are using an invented header to simplify this example.

But in real cases you will get better results using the integrated [Security utilities](security/index.md){.internal-link target=_blank}.

///

* ✅ Simplify tests for request_forms. PR [#13184](https://github.com/fastapi/fastapi/pull/13184) by [@alejsdev](https://github.com/alejsdev).
* ✅ Simplify tests for path_query_params. PR [#13181](https://github.com/fastapi/fastapi/pull/13181) by [@alejsdev](https://github.com/alejsdev).

## Recap { #recap }

You can use Pydantic Settings to handle the settings or configurations for your application, with all the power of Pydantic models.

* By using a dependency you can simplify testing.
* You can use `.env` files with it.

 *       smallest sensible numbers of threads, collection sizes, etc needed to check basic
 *       conformance.
 *   <li>The test classes currently do not declare inclusion in any particular package to simplify
 *       things for people integrating them in TCK test suites.
 *   <li>As a convenience, the {@code main} of this class (JSR166TestCase) runs all JSR166 unit
 *       tests.
 * </ul>
 */
@SuppressWarnings({

# TensorFlow Bazel configuration file.
# This file tries to group and simplify build options for TensorFlow
#
# ----CONFIG OPTIONS----
# Android options:
#    android:
#    android_arm:
#    android_arm64:
#    android_x86:
#    android_x86_64:
#
# iOS options:
#     ios:
#     ios_armv7:
#     ios_arm64:
#     ios_x86_64:
#     ios_fat:
#
# Macosx options
#     darwin_arm64:
#
# Compiler options:

[T int|string]               // = [T interface{int|string}]
type Constraint ~int         // illegal: ~int is not in a type parameter list
</pre>

<!--
We should be able to simplify the rules for comparable or delegate some of them
elsewhere since we have a section that clearly defines how interfaces implement
other interfaces based on their type sets. But this should get us going for now.
-->