## GunicornとUvicornをインストールする

<div class="termy">

```console
$ pip install "uvicorn[standard]" gunicorn

---> 100%
```

</div>

これによりUvicornと（高性能を得るための）標準（`standard`）の追加パッケージとGunicornの両方がインストールされます。

## UvicornのワーカーとともにGunicornを実行する

Gunicornを以下のように起動させることができます:

<div class="termy">

```console
$ gunicorn main:app --workers 4 --worker-class uvicorn.workers.UvicornWorker --bind 0.0.0.0:80

  // This constant allows the deserialization code to set a final field. This holder class
  // makes sure it is not initialized unless an instance is deserialized.
  private static class FieldSettersHolder {
    static final FieldSetter<? super ConcurrentHashMultiset<?>> COUNT_MAP_FIELD_SETTER =
        Serialization.getFieldSetter(ConcurrentHashMultiset.class, "countMap");
  }

  /**

 *
 * @author George van den Driessche
 */
public final class MapTestSuiteBuilderTests extends TestCase {
  private MapTestSuiteBuilderTests() {}

  public static Test suite() {
    TestSuite suite = new TestSuite(MapTestSuiteBuilderTests.class.getSimpleName());
    suite.addTest(testsForHashMapNullKeysForbidden());
    suite.addTest(testsForHashMapNullValuesForbidden());

   * @return a time-limiting proxy
   * @throws IllegalArgumentException if {@code interfaceType} is a regular class, enum, or
   *     annotation type, rather than an interface
   */
  @SuppressWarnings("GoodTime") // should accept a java.time.Duration
  <T> T newProxy(T target, Class<T> interfaceType, long timeoutDuration, TimeUnit timeoutUnit);

  /**

        } catch (final IllegalArgumentException e) {
            final Class<?> clazz = field.getDeclaringClass();
            final Class<?> fieldClass = field.getType();
            final Class<?> valueClass = value == null ? null : value.getClass();
            final Class<?> targetClass = target == null ? field.getDeclaringClass() : target.getClass();

from typing import 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


class User(BaseModel):
    username: str
    full_name: Union[str, None] = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item, user: User):

from fastapi import Body, FastAPI
from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: str
    description: str | None = None
    price: float
    tax: float | None = None


class User(BaseModel):
    username: str
    full_name: str | None = None


@app.put("/items/{item_id}")
async def update_item(item_id: int, item: Item, user: User, importance: int = Body()):

from typing import List

from fastapi import FastAPI, Query
from pydantic import BaseModel, Field
from typing_extensions import Literal

app = FastAPI()


class FilterParams(BaseModel):
    class Config:
        extra = "forbid"

    limit: int = Field(100, gt=0, le=100)
    offset: int = Field(0, ge=0)
    order_by: Literal["created_at", "updated_at"] = "created_at"
    tags: List[str] = []


@app.get("/items/")

import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;

/**
 * Static meta-data about a class extracted from the source for the class.
 */
public class ClassMetaData extends AbstractLanguageElement implements Serializable, Attachable<ClassMetaData>, TypeContainer {
    private final String className;
    private String superClassName;

campo <a href="https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.5" class="external-link" target="_blank">`examples`</a>, mas o OpenAPI 3.0.3 é baseado numa versão mais antiga do JSON Schema que não tinha `examples`.

Por isso, o OpenAPI 3.0.3 definiu o seu próprio <a href="https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.3.md#fixed-fields-20" class="external-link" target="_blank">`example`</a> para a versão modificada do **JSON Schema** que...