fun create(packageParts: List<Name>, classParts: List<Name>, callable: Name?): FqNameInterpretation {
            val packageName = FqName.fromSegments(packageParts.map { it.asString() })
            val relativeClassName = FqName.fromSegments(classParts.map { it.asString() })

            return when {
                classParts.isEmpty() && callable == null -> FqNameInterpretationAsPackage(packageName)

            The parameter is available only for compatibility.
            """
        ),
    ] = ...,
    *,
    default_factory: Annotated[
        Union[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.

import warnings
from enum import Enum
from typing import Any, Callable, Dict, List, Optional, Sequence, Union

from fastapi.openapi.models import Example
from pydantic.fields import FieldInfo
from typing_extensions import Annotated, deprecated

from ._compat import PYDANTIC_V2, PYDANTIC_VERSION, Undefined

_Unset: Any = Undefined


class ParamTypes(Enum):
    query = "query"
    header = "header"
    path = "path"

    return new WrappingExecutorService(service) {
      @Override
      protected <T extends @Nullable Object> Callable<T> wrapTask(Callable<T> callable) {
        return Callables.threadRenaming(callable, nameSupplier);
      }

      @Override
      protected Runnable wrapTask(Runnable command) {
        return Callables.threadRenaming(command, nameSupplier);
      }
    };
  }

  /**

def is_coroutine_callable(call: Callable[..., Any]) -> bool:
    if inspect.isroutine(call):
        return inspect.iscoroutinefunction(call)
    if inspect.isclass(call):
        return False
    dunder_call = getattr(call, "__call__", None)  # noqa: B004
    return inspect.iscoroutinefunction(dunder_call)


def is_async_gen_callable(call: Callable[..., Any]) -> bool:

   * @throws RejectedExecutionException if the task cannot be scheduled for execution
   * @since 28.2
   */
  public static <O extends @Nullable Object> ListenableFuture<O> submit(
      Callable<O> callable, Executor executor) {
    TrustedListenableFutureTask<O> task = TrustedListenableFutureTask.create(callable);
    executor.execute(task);
    return task;
  }

  /**

    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():
        encoders_by_class_tuples[encoder] += (type_,)

Eine Python-Klasse ist also auch ein **Callable**.

Darum können Sie in **FastAPI** auch eine Python-Klasse als Abhängigkeit verwenden.

Was FastAPI tatsächlich prüft, ist, ob es sich um ein „Callable“ (Funktion, Klasse oder irgendetwas anderes) handelt und ob die Parameter definiert sind.

     * @param <U> the type returned by the function
     */
    public interface ClosingFunction5<
        V1 extends @Nullable Object,
        V2 extends @Nullable Object,
        V3 extends @Nullable Object,
        V4 extends @Nullable Object,
        V5 extends @Nullable Object,
        U extends @Nullable Object> {
      /**
       * Applies this function to five inputs, or throws an exception if unable to do so.
       *

    assertFile(Relay.PREFIX_CLEAN, 20L, metadata.size, "abcdefghijklmnopqrst", metadata)
  }

  /** Returns a callable that reads all of source, closes it, and returns the bytes.  */
  private fun sourceReader(source: Source?): Callable<ByteString> {
    return Callable {
      val buffer = Buffer()
      while (source!!.read(buffer, 16384) != -1L) {
      }
      source.close()