import time
from collections.abc import Callable

from fastapi import APIRouter, FastAPI, Request, Response
from fastapi.routing import APIRoute


class TimedRoute(APIRoute):
    def get_route_handler(self) -> Callable:
        original_route_handler = super().get_route_handler()

        async def custom_route_handler(request: Request) -> Response:
            before = time.time()

그리고 `fluffy`를 만들기 위해 `Cat`을 "호출"하고 있습니다.

따라서 파이썬 클래스도 **호출 가능(callable)**합니다.

그러면 **FastAPI**에서는 파이썬 클래스를 의존성으로 사용할 수 있습니다.

FastAPI가 실제로 확인하는 것은 그것이 "호출 가능(callable)"(함수, 클래스, 또는 다른 무엇이든)한지와 정의된 매개변수들입니다.

**FastAPI**에서 "호출 가능(callable)"한 것을 의존성으로 넘기면, 그 "호출 가능(callable)"한 것의 매개변수들을 분석하고 *경로 처리 함수*의 매개변수와 동일한 방식으로 처리합니다. 하위 의존성도 포함해서요.

이것은 매개변수가 전혀 없는 callable에도 적용됩니다. 매개변수가 없는 *경로 처리 함수*에 적용되는 것과 동일합니다.

import warnings
from collections.abc import Callable, Sequence
from dataclasses import dataclass
from enum import Enum
from typing import Annotated, Any, Literal

from fastapi.exceptions import FastAPIDeprecationWarning
from fastapi.openapi.models import Example
from pydantic import AliasChoices, AliasPath
from pydantic.fields import FieldInfo
from typing_extensions import deprecated

from ._compat import (
    Undefined,
)

  ListenableScheduledFuture<?> schedule(Runnable command, long delay, TimeUnit unit);

  /**
   * @since 15.0 (previously returned ScheduledFuture)
   */
  @Override
  <V extends @Nullable Object> ListenableScheduledFuture<V> schedule(
      Callable<V> callable, long delay, TimeUnit unit);

  /**
   * @since 15.0 (previously returned ScheduledFuture)
   */
  @Override
  ListenableScheduledFuture<?> scheduleAtFixedRate(

    List<Callable<T>> tasks = ImmutableList.of();
    List<? extends Future<?>> unused = executor.invokeAll(tasks);
  }

  public void testListeningDecorator() throws Exception {
    ListeningExecutorService service = listeningDecorator(newDirectExecutorService());
    assertThat(listeningDecorator(service)).isSameInstanceAs(service);
    List<Callable<String>> callables = ImmutableList.of(Callables.returning("x"));

    set: list,
    UUID: str,
    Url: str,
    AnyUrl: str,
}


def generate_encoders_by_class_tuples(
    type_encoder_map: dict[Any, Callable[[Any], Any]],
) -> dict[Callable[[Any], Any], tuple[Any, ...]]:
    encoders_by_class_tuples: dict[Callable[[Any], Any], tuple[Any, ...]] = defaultdict(
        tuple
    )
    for type_, encoder in type_encoder_map.items():

            The parameter is available only for compatibility.
            """
        ),
    ] = ...,
    *,
    default_factory: Annotated[
        Callable[[], Any] | None,
        Doc(
            """
            A callable to generate the default value.

            This doesn't affect `Path` parameters as the value is always required.
            The parameter is available only for compatibility.

    assertThat(Duration.ofNanos(recordedDelay)).isEqualTo(Duration.ofSeconds(12));
  }

  public void testScheduleCallable() throws Exception {
    Callable<String> callable = () -> "hello";

    ListenableScheduledFuture<String> future =
        executorService.schedule(callable, Duration.ofMinutes(12));

    assertThat(future.get()).isEqualTo("hello");
    assertThat(recordedTimeUnit).isEqualTo(NANOSECONDS);

So, a Python class is also a **callable**.

Then, in **FastAPI**, you could use a Python class as a dependency.

What FastAPI actually checks is that it is a "callable" (function, class or anything else) and the parameters defined.

    Callable<@Nullable Void> completeSuccessfullyRunnable =
        () -> {
          if (currentFuture.get().set("set")) {
            numSuccessfulSetCalls.incrementAndGet();
          }
          awaitUnchecked(barrier);
          return null;
        };
    Callable<@Nullable Void> completeExceptionallyRunnable =
        new Callable<@Nullable Void>() {