Pydantic 덕분에 표준 Python 타입을 사용해 본문을 선언합니다.

```Python hl_lines="2  7-10 23-25"
from fastapi import FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    price: float
    is_offer: bool | None = None


@app.get("/")
def read_root():
    return {"Hello": "World"}


@app.get("/items/{item_id}")
def read_item(item_id: int, q: str | None = None):

   *
   * {@snippet :
   * static final ImmutableBiMap<String, Integer> WORD_TO_INT =
   *     new ImmutableBiMap.Builder<String, Integer>()
   *         .put("one", 1)
   *         .put("two", 2)
   *         .put("three", 3)
   *         .buildOrThrow();
   * }
   *
   * <p>For <i>small</i> immutable bimaps, the {@code ImmutableBiMap.of()} methods are even more
   * convenient.
   *

        assertFalse(emptyIterator.hasNext(), "Empty iterator should have no next element");

        // Note: Standard Iterator would throw NoSuchElementException, but this implementation returns null
        // This is a design choice for this specific implementation
        assertNull(emptyIterator.next(), "This implementation returns null instead of throwing");

        // Verify remove can be called (even though no-op)

                logger.trace("ChatApiManager.matches() returning false. ragChatEnabled={}", ragChatEnabled);
            }
            return false;
        }

        final String servletPath = request.getServletPath();
        final boolean matches = servletPath.startsWith(CHAT_API_PATH);
        if (logger.isTraceEnabled()) {

import jcifs.internal.smb1.com.SmbComNTCreateAndXResponse;

/**
 * This class will allow a Java program to read and write data to Named
 * Pipes and Transact NamedPipes.
 *
 * <p>
 * There are three Win32 function calls provided by the Windows SDK
 * that are important in the context of using jCIFS. They are:
 *
 * <ul>
 * <li><code>CallNamedPipe</code> A message-type pipe call that opens,

        String stackTrace = sw.toString();

        String fullMessage = message + "\n" + "Exception: "
                + e.getClass().getName() + "\n" + "Message: "
                + e.getMessage() + "\n" + "Stack trace:\n"
                + stackTrace;

        processingEnv.getMessager().printMessage(Diagnostic.Kind.ERROR, fullMessage);
    }

    }
  }

  public void testCopyOfDuplicateInconsistentWithEquals() {
    IntegerDiv10 three = new IntegerDiv10(3);
    IntegerDiv10 eleven = new IntegerDiv10(11);
    IntegerDiv10 twelve = new IntegerDiv10(12);
    IntegerDiv10 twenty = new IntegerDiv10(20);

    List<IntegerDiv10> original = ImmutableList.of(three, eleven, twelve, twenty);

    Multiset<IntegerDiv10> copy = ImmutableSortedMultiset.copyOf(original);

そして、それを属性の型として使用することができます:

{* ../../docs_src/body_nested_models/tutorial004_py310.py hl[18] *}

これは **FastAPI** が以下のようなボディを期待することを意味します:

```JSON
{
    "name": "Foo",
    "description": "The pretender",
    "price": 42.0,
    "tax": 3.2,
    "tags": ["rock", "metal", "bar"],
    "image": {
        "url": "http://example.com/baz.jpg",
        "name": "The Foo live"
    }
}
```

<img src="/img/tutorial/generate-clients/image02.png">

보낼 페이로드에 대해서도 자동 완성이 제공됩니다:

<img src="/img/tutorial/generate-clients/image03.png">

/// tip | 팁

`name`과 `price`에 대한 자동 완성은 FastAPI 애플리케이션에서 `Item` 모델에 정의된 내용입니다.

///

전송하는 데이터에 대해 인라인 오류도 표시됩니다:

<img src="/img/tutorial/generate-clients/image04.png">

응답 객체도 자동 완성을 제공합니다:

    List<Float> one = Arrays.asList(1.0f);
    assertThat(Floats.toArray(one)).isEqualTo(ARRAY1);

    float[] array = {0.0f, 1.0f, 3.0f};

    List<Float> three = Arrays.asList(0.0f, 1.0f, 3.0f);
    assertThat(Floats.toArray(three)).isEqualTo(array);

    assertThat(Floats.toArray(Floats.asList(array))).isEqualTo(array);
  }

  public void testToArray_threadSafe() {