original_route_handler = super().get_route_handler()

        async def custom_route_handler(request: Request) -> Response:
            before = time.time()
            response: Response = await original_route_handler(request)
            duration = time.time() - before
            response.headers["X-Response-Time"] = str(duration)
            print(f"route duration: {duration}")

# Reference

Here's the reference or code API, the classes, functions, parameters, attributes, and
all the FastAPI parts you can use in your applications.

If you want to **learn FastAPI** you are much better off reading the

/// tip

Do you want to understand what's all that above?

Continue reading. 👇🤓

///

## Why Virtual Environments { #why-virtual-environments }

To work with FastAPI you need to install <a href="https://www.python.org/" class="external-link" target="_blank">Python</a>.

After that, you would need to **install** FastAPI and any other **packages** you want to use.

{* ../../docs_src/path_operation_advanced_configuration/tutorial001_py39.py hl[6] *}

### Using the *path operation function* name as the operationId { #using-the-path-operation-function-name-as-the-operationid }

If you want to use your APIs' function names as `operationId`s, you can iterate over all of them and override each *path operation's* `operation_id` using their `APIRoute.name`.

You should do it after adding all your *path operations*.

All the dependencies we have seen are a fixed function or class.

But there could be cases where you want to be able to set parameters on the dependency, without having to declare many different functions or classes.

Let's imagine that we want to have a dependency that checks if the query parameter `q` contains some fixed content.

But we want to be able to parameterize that fixed content.

## A "callable" instance { #a-callable-instance }

Notice that the default value is still `None`, so the parameter is still optional.

But now, having `Query(max_length=50)` inside of `Annotated`, we are telling FastAPI that we want it to have **additional validation** for this value, we want it to have maximum 50 characters. 😎

/// tip

# Files that should be ignored by tools which do not want to consider generated
# code.
#
# https://github.com/kubernetes/test-infra/blob/master/prow/plugins/size/size.go
#
# This file is a series of lines, each of the form:
#     <type> <name>
#
# Type can be:
#    path - an exact path to a single file
#    file-name - an exact leaf filename, regardless of path
#    path-prefix - a prefix match on the file path

---
name: Question
about: Use Stack Overflow instead
title: "\U0001F649"
labels: ''
assignees: ''

---

🛑 𝙎𝙏𝙊𝙋

This issue tracker is not the place for questions!

If you want to ask how to do something, or to understand why something isn't working the way you expect it to, use Stack Overflow. https://stackoverflow.com/questions/tagged/okhttp

from .main import app


@pytest.mark.anyio
async def test_root():
    async with AsyncClient(
        transport=ASGITransport(app=app), base_url="http://test"
    ) as ac:
        response = await ac.get("/")
    assert response.status_code == 200

{* ../../docs_src/async_tests/app_a_py39/test_main.py hl[9:12] *}

Это эквивалентно следующему:

```Python
response = client.get('/')
```

...которое мы использовали для отправки наших запросов с `TestClient`.

/// tip | Подсказка

Обратите внимание, что мы используем async/await с `AsyncClient` - запрос асинхронный.

///