## Run the code

All the code blocks can be copied and used directly (they are actually tested Python files).

To run any of the examples, copy the code to a file `main.py`, and start `fastapi dev` with:

<div class="termy">

```console
$ <font color="#4E9A06">fastapi</font> dev <u style="text-decoration-style:single">main.py</u>
<font color="#3465A4">INFO    </font> Using path <font color="#3465A4">main.py</font>

 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly if the last write <i>happens-before</i> any reads. To allow

import org.eclipse.aether.RepositorySystem;
import org.eclipse.aether.RepositorySystemSession;

import static org.apache.maven.internal.impl.Utils.map;
import static org.apache.maven.internal.impl.Utils.nonNull;

public class DefaultSession extends AbstractSession implements InternalMavenSession {

    private final MavenSession mavenSession;
    private final MavenRepositorySystem mavenRepositorySystem;

///

`status_code` 参数接收表示 HTTP 状态码的数字。

/// info | "说明"

`status_code` 还能接收 `IntEnum` 类型，比如 Python 的 <a href="https://docs.python.org/3/library/http.html#http.HTTPStatus" class="external-link" target="_blank">`http.HTTPStatus`</a>。

///

它可以：

* 在响应中返回状态码
* 在 OpenAPI 概图（及用户界面）中存档：

<img src="/img/tutorial/response-status-code/image01.png">

/// note | "笔记"

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import jakarta.annotation.Resource;

/**
 * @author shinsuke
 *
 */
public class DefaultResponseProcessor implements ResponseProcessor {
    private static final Logger logger = LoggerFactory.getLogger(DefaultResponseProcessor.class);

    @Resource
    protected CrawlerContainer crawlerContainer;

    protected Transformer transformer;

from typing import Union

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: Union[str, None] = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")

from typing import Annotated, Union

from fastapi import Depends, FastAPI

app = FastAPI()


fake_items_db = [{"item_name": "Foo"}, {"item_name": "Bar"}, {"item_name": "Baz"}]


class CommonQueryParams:
    def __init__(self, q: Union[str, None] = None, skip: int = 0, limit: int = 100):
        self.q = q
        self.skip = skip
        self.limit = limit


@app.get("/items/")

from typing import Annotated, Union

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


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


@app.put("/items/{item_id}")
async def update_item(
    *,
    item_id: int,
    item: Annotated[
        Item,
        Body(
            examples=[

*   Added `tf.keras.__internal__.KerasTensor`,`tf.keras.__internal__.SparseKerasTensor`, and `tf.keras.__internal__.RaggedKerasTensor` classes. You can use these classes to do instance type checking and type annotations for layer/model inputs and outputs.

 * @author Kevin Bourrillion
 * @since 2.0
 */
@GwtCompatible(serializable = true, emulated = true)
@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
public abstract class ImmutableList<E> extends ImmutableCollection<E>
    implements List<E>, RandomAccess {

  /**
   * Returns a {@code Collector} that accumulates the input elements into a new {@code
   * ImmutableList}, in encounter order.