a Go translation.  C arithmetic types translate to precisely-sized Go
arithmetic types.  A C struct translates to a Go struct, field by
field; unrepresentable fields are replaced with opaque byte arrays.  A
C union translates into a struct containing the first union member and
perhaps additional padding.  C arrays become Go arrays.  C pointers
become Go pointers.  C function pointers become Go's uintptr.
C void pointers become Go's unsafe.Pointer.

То же самое произошло бы, если бы у вас было что-то вроде <abbr title='Union разных типов буквально означает "любой из перечисленных типов".'>Union</abbr> различных типов и один или несколько из них не являлись бы допустимыми типами для Pydantic. Например, такой вариант приведет к ошибке 💥:

//// tab | Python 3.10+

      return ((Multiset<?>) elements).elementSet().size();
    }
    return 11; // initial capacity will be rounded up to 16
  }

  /**
   * Returns an unmodifiable view of the union of two multisets. In the returned multiset, the count
   * of each element is the <i>maximum</i> of its counts in the two backing multisets. The iteration

      return ((Multiset<?>) elements).elementSet().size();
    }
    return 11; // initial capacity will be rounded up to 16
  }

  /**
   * Returns an unmodifiable view of the union of two multisets. In the returned multiset, the count
   * of each element is the <i>maximum</i> of its counts in the two backing multisets. The iteration

## 必須にする

これ以上、バリデーションやメタデータを宣言する必要のない場合は、デフォルト値を指定しないだけでクエリパラメータ`q`を必須にすることができます。以下のように:

```Python
q: str
```

以下の代わりに:

```Python
q: Union[str, None] = None
```

現在は以下の例のように`Query`で宣言しています:

```Python
q: Union[str, None] = Query(default=None, min_length=3)
```

そのため、`Query`を使用して必須の値を宣言する必要がある場合は、第一引数に`...`を使用することができます:

```Python hl_lines="7"

* 만약 매개변수가 **Pydantic 모델** 타입으로 선언되어 있으면, 요청 **본문**으로 해석될 것입니다.

/// note | "참고"

FastAPI는 `q`의 값이 필요없음을 알게 될 것입니다. 기본 값이 `= None`이기 때문입니다.

`Union[str, None]`에 있는 `Union`은 FastAPI에 의해 사용된 것이 아니지만, 편집기로 하여금 더 나은 지원과 에러 탐지를 지원할 것입니다.

///

## Pydantic없이

from functools import lru_cache
from http.server import HTTPServer, SimpleHTTPRequestHandler
from importlib import metadata
from multiprocessing import Pool
from pathlib import Path
from typing import Any, Dict, List, Optional, Union

import mkdocs.utils
import typer
import yaml
from jinja2 import Template
from ruff.__main__ import find_ruff_bin

logging.basicConfig(level=logging.INFO)

app = typer.Typer()

		{NewTargetIDSet(TargetID{"1", "webhook"}), NewTargetIDSet(TargetID{"1", "webhook"}), NewTargetIDSet(TargetID{"1", "webhook"})},
	}

	for i, testCase := range testCases {
		result := testCase.set.Union(testCase.setToAdd)

		if !reflect.DeepEqual(testCase.expectedResult, result) {
			t.Fatalf("test %v: result: expected: %v, got: %v", i+1, testCase.expectedResult, result)
		}
	}
}

### ایجاد کنید
* فایلی به نام `main.py` با محتوای زیر ایجاد کنید:

```Python
from typing import Union

from fastapi import FastAPI

app = FastAPI()


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


@app.get("/items/{item_id}")
def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">

  // well-known group names.
  // Required.
  optional string name = 1;
}

// LimitResponse defines how to handle requests that can not be executed right now.
// +union
message LimitResponse {
  // `type` is "Queue" or "Reject".
  // "Queue" means that requests that can not be executed upon arrival
  // are held in a queue until they can be executed or a queuing limit
  // is reached.