# `Response` class

You can declare a parameter in a *path operation function* or dependency to be of type `Response` and then you can set data for the response like headers or cookies.

You can also use it directly to create an instance of it and return it from your *path operations*.

You can import it directly from `fastapi`:

```python
from fastapi import Response
```

from typing import List, Union

from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: Union[str, None] = None
    price: float
    tax: Union[float, None] = None
    tags: List[str] = []


@app.post("/items/")
async def create_item(item: Item) -> Item:
    return item


@app.get("/items/")
async def read_items() -> List[Item]:

    assertThrows(IllegalArgumentException.class, () -> base64().withSeparator("=", 3));

    assertThrows(
        IllegalArgumentException.class, () -> base64().withPadChar('#').withSeparator("!#!", 3));
  }

  public void testAtMostOneSeparator() {
    BaseEncoding separated = base64().withSeparator("\n", 3);
    assertThrows(UnsupportedOperationException.class, () -> separated.withSeparator("$", 4));
  }

<a href="https://www.starlette.io/background/" class="external-link" target="_blank">`Starlette의 공식 문서`</a>에서 백그라운드 작업에 대한 자세한 내용을 확인할 수 있습니다.

## 경고

만약 무거운 백그라운드 작업을 수행해야하고 동일한 프로세스에서 실행할 필요가 없는 경우 (예: 메모리, 변수 등을 공유할 필요가 없음) <a href="https://docs.celeryq.dev" class="external-link" target="_blank">`Celery`</a>와 같은 큰 도구를 사용하면 도움이 될 수 있습니다.

import org.codelibs.fess.dict.DictionaryFile;
import org.codelibs.fess.dict.DictionaryItem;

import jakarta.annotation.PostConstruct;

public class KuromojiCreator extends DictionaryCreator {
    private static final Logger logger = LogManager.getLogger(KuromojiCreator.class);

    public KuromojiCreator() {
        super("kuromoji.*\\.txt");
    }

    @PostConstruct
    public void register() {

import org.codelibs.fess.dict.DictionaryFile;
import org.codelibs.fess.dict.DictionaryItem;

import jakarta.annotation.PostConstruct;

public class CharMappingCreator extends DictionaryCreator {
    private static final Logger logger = LogManager.getLogger(CharMappingCreator.class);

    public CharMappingCreator() {
        super("mapping.*\\.txt");
    }

    @PostConstruct
    public void register() {

import org.codelibs.fess.dict.DictionaryFile;
import org.codelibs.fess.dict.DictionaryItem;

import jakarta.annotation.PostConstruct;

public class StemmerOverrideCreator extends DictionaryCreator {
    private static final Logger logger = LogManager.getLogger(StemmerOverrideCreator.class);

    public StemmerOverrideCreator() {
        super("stemmer_override.*\\.txt");
    }

    @PostConstruct
    public void register() {

class AsyncRequestBody : RequestBody() {
  private val requestBodySinks: BlockingQueue<BufferedSink> = LinkedBlockingQueue()

  override fun contentType(): MediaType? = null

  override fun writeTo(sink: BufferedSink) {
    requestBodySinks.add(sink)
  }

  override fun isDuplex(): Boolean = true

  @Throws(InterruptedException::class)
  fun takeSink(): BufferedSink {

import com.google.common.eventbus.Subscribe;
import com.google.common.eventbus.outside.BaseSubscriberFinderTest.Subscriber;
import java.util.List;

public class BaseSubscriberFinderTest extends AbstractEventBusTest<Subscriber> {
  static class Subscriber {
    final List<Object> nonSubscriberEvents = Lists.newArrayList();
    final List<Object> subscriberEvents = Lists.newArrayList();

import com.google.common.annotations.GwtCompatible;
import java.io.Serializable;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Simple base class to verify that we handle generics correctly.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
public class BaseComparable implements Comparable<BaseComparable>, Serializable {
  private final String s;

  public BaseComparable(String s) {
    this.s = s;
  }