void testJoinSingleElement() {
        String result = StringUtil.join(",", "hello");
        assertEquals("hello", result);
    }

    @Test
    @DisplayName("Should join two elements with delimiter")
    void testJoinTwoElements() {
        String result = StringUtil.join(",", "hello", "world");
        assertEquals("hello,world", result);
    }

    @Test

```txt
Hello, World from Flask!
```

并且如果您访问 <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a>，您将会看到由 FastAPI 返回的响应：

```JSON
{
    "message": "Hello World"
}

def test_flask():
    response = client.get("/v1/")
    assert response.status_code == 200, response.text
    assert response.text == "Hello, World from Flask!"


def test_app():
    response = client.get("/v2")
    assert response.status_code == 200, response.text

	sep := []byte("/")
	for range b.N {
		for range SplitSeq(benchInputHard, sep) {
		}
	}
}

func BenchmarkSplitSeqMultiByteSeparator(b *testing.B) {
	sep := []byte("hello")
	for range b.N {
		for range SplitSeq(benchInputHard, sep) {
		}
	}
}

func BenchmarkSplitAfterSeqEmptySeparator(b *testing.B) {
	for range b.N {
		for range SplitAfterSeq(benchInputHard, nil) {
		}

            String originalString = "Hello World Test";
            byte[] allBytes = originalString.getBytes(StandardCharsets.UTF_16LE);
            int partialLength = "Hello World".getBytes(StandardCharsets.UTF_16LE).length;

            // When
            String result = Strings.fromUNIBytes(allBytes, 0, partialLength);

            // Then

        ):
            if q:
                return f"Hello {q}"
            else:
                return "Hello World"

    client = TestClient(app)
    return client


@needs_py310
def test_no_query():
    client = get_client()
    response = client.post("/items/")
    assert response.status_code == 200
    assert response.json() == "Hello World"


@needs_py310
def test_q_fixedquery():

            id="required-alias-and-validation-alias",
        ),
    ],
)
def test_success(path: str):
    client = TestClient(app)
    response = client.get(f"{path}/hello")
    assert response.status_code == 200, response.text

	}

	err = fs.AppendFile(context.Background(), "voldir", "/file", []byte("hello"))
	if err != nil {
		t.Fatal(err)
	}

	// Try to create a file that includes a file in its path components.
	// In *nix, this returns syscall.ENOTDIR while in windows we receive the following error.
	err = fs.AppendFile(context.Background(), "voldir", "/file/obj1", []byte("hello"))
	if err != errFileAccessDenied {

$ export MY_NAME="Wade Wilson"

// 然后您可以与其他程序一起使用它，例如
$ echo "Hello $MY_NAME"

Hello Wade Wilson
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

```console
// 创建一个名为 MY_NAME 的环境变量
$ $Env:MY_NAME = "Wade Wilson"

// 与其他程序一起使用它，例如
$ echo "Hello $Env:MY_NAME"

Hello Wade Wilson
```

</div>

////

### 在 Python 中读取环境变量

import pytest
from fastapi import FastAPI
from fastapi.testclient import TestClient

app = FastAPI()


@app.get("/a", responses={"hello": {"description": "Not a valid additional response"}})
async def a():
    pass  # pragma: no cover


openapi_schema = {
    "openapi": "3.1.0",
    "info": {"title": "FastAPI", "version": "0.1.0"},
    "paths": {
        "/a": {
            "get": {
                "responses": {