本教程将一步步向你展示如何使用 **FastAPI** 的绝大部分特性。

各个章节的内容循序渐进，但是又围绕着单独的主题，所以你可以直接跳转到某个章节以解决你的特定需求。

本教程同样可以作为将来的参考手册。

你可以随时回到本教程并查阅你需要的内容。

## 运行代码

所有代码片段都可以复制后直接使用（它们实际上是经过测试的 Python 文件）。

要运行任何示例，请将代码复制到 `main.py` 文件中，然后使用以下命令启动 `uvicorn`：

<div class="termy">

```console
$ uvicorn main:app --reload

<span style="color: green;">INFO</span>:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)

    destinationFile = futurePluginVersionsPropertiesFile
}
val futurePluginVersionsDestDir = futurePluginVersionsPropertiesFile.map { it.asFile.parentFile }
sourceSets.main {
    output.dir(mapOf("builtBy" to writeFuturePluginVersions), futurePluginVersionsDestDir)
}
configurations.runtimeElements {
    outgoing {
        variants.named("resources") {

        if (getContainer().hasComponent(ProjectBuilder.class, "test")) {
            projectBuilder = getContainer().lookup(ProjectBuilder.class, "test");
        } else {
            // default over to the main project builder...
            projectBuilder = getContainer().lookup(ProjectBuilder.class);
        }
    }

    protected ProjectBuilder getProjectBuilder() {
        return projectBuilder;
    }

 *       conformance.
 *   <li>The test classes currently do not declare inclusion in any particular package to simplify
 *       things for people integrating them in TCK test suites.
 *   <li>As a convenience, the {@code main} of this class (JSR166TestCase) runs all JSR166 unit
 *       tests.
 * </ul>
 */
// We call threadUnexpectedException, which does the right thing for errors.
@SuppressWarnings("AssertionFailureIgnored")

		var nf int // Bytes written in fragment
		dataStart, dataEnd := sw.sp[0].Offset, sw.sp[0].endOffset()
		if sw.pos < dataStart { // In a hole fragment
			bf := b[:min(int64(len(b)), dataStart-sw.pos)]
			nf, err = zeroWriter{}.Write(bf)
		} else { // In a data fragment
			bf := b[:min(int64(len(b)), dataEnd-sw.pos)]
			nf, err = sw.fw.Write(bf)
		}
		b = b[nf:]
		sw.pos += int64(nf)
		if sw.pos >= dataEnd && len(sw.sp) > 1 {

Including how to handle lifespan state that can be used in other areas of your code.

///

## Sub Applications

			return
		}
	}

	// Validate table name
	err = validateTableName(selectAST.From)
	if err != nil {
		return
	}

	// Analyze main select expression
	stmt.selectQProp = selectAST.Expression.analyze(&selectAST)
	err = stmt.selectQProp.err
	if err != nil {
		err = errQueryAnalysisFailure(err)
	}

	// Set table alias

package dsync

import (
	"context"
	"fmt"
	"runtime"
	"sync/atomic"
	"testing"
	"time"
)

const (
	id     = "1234-5678"
	source = "main.go"
)

func testSimpleWriteLock(t *testing.T, duration time.Duration) (locked bool) {
	drwm1 := NewDRWMutex(ds, "simplelock")
	ctx1, cancel1 := context.WithCancel(context.Background())

**FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette.

///

### `Response`

The main `Response` class, all the other responses inherit from it.

You can return it directly.

It accepts the following parameters:

* `content` - A `str` or `bytes`.
* `status_code` - An `int` HTTP status code.

// additional allocation tweaks reproduced using GODEBUG=allocfreetrace=1
// original file https://github.com/golang-jwt/jwt/blob/main/parser.go
// borrowed under MIT License https://github.com/golang-jwt/jwt/blob/main/LICENSE

import (
	"bytes"
	"crypto"
	"crypto/hmac"
	"encoding/base64"
	"errors"
	"fmt"
	"hash"
	"sync"
	"time"

	"github.com/buger/jsonparser"