## Call `uvicorn` { #call-uvicorn }

In your FastAPI application, import and run `uvicorn` directly:

{* ../../docs_src/debugging/tutorial001_py310.py hl[1,15] *}

### About `__name__ == "__main__"` { #about-name-main }

The main purpose of the `__name__ == "__main__"` is to have some code that is executed when your file is called with:

<div class="termy">

```console
$ python myapp.py
```

</div>

router_a_a = APIRouter()
router_a_b_override = APIRouter()  # Overrides default class
router_b_override = APIRouter()  # Overrides default class
router_b_a = APIRouter()
router_b_a_c_override = APIRouter()  # Overrides default class again


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


@app.get("/override", response_class=PlainTextResponse)
def get_path_override():
    return "Hello World"


@router_a.get("/")

		l.IDMap[id] = prev
		shouldLog = false
	}
	l.Unlock()

	if shouldLog {
		logIf(ctx, subsystem, err, errKind...)
	}
}

// Cleanup the map every one hour so that the log message is printed again for the user to notice.
func (l *logOnceType) cleanupRoutine() {
	for {
		time.Sleep(time.Hour)

		l.Lock()
		l.IDMap = make(map[string]onceErr)
		l.Unlock()
	}
}

// Returns logOnceType

        // /tmp/junit-16591192886395443631/.m2/extensions.xml:3
        // [main] WARNING org.apache.maven.cling.invoker.PlexusContainerCapsuleFactory -
        // [main] WARNING org.apache.maven.cling.invoker.PlexusContainerCapsuleFactory - Order of core extensions
        // precedence is project > user > installation. Selected extensions are:
        // [main] WARNING org.apache.maven.cling.invoker.PlexusContainerCapsuleFactory - *

Par exemple, vous pourriez avoir un fichier `config.py` avec :

{* ../../docs_src/settings/app01_py310/config.py *}

Puis l'utiliser dans un fichier `main.py` :

{* ../../docs_src/settings/app01_py310/main.py hl[3,11:13] *}

/// tip | Astuce

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// 여기서는 아직 환경 변수를 설정하지 않습니다
$ python main.py

// 환경 변수를 설정하지 않았으므로 기본값이 사용됩니다

Hello World from Python

// 하지만 먼저 환경 변수를 생성하면
$ export MY_NAME="Wade Wilson"

// 그리고 프로그램을 다시 실행하면
$ python main.py

// 이제 환경 변수를 읽을 수 있습니다

Hello Wade Wilson from Python
```

</div>

////

然后你可以调用这个 Python 程序：

//// tab | Linux, macOS, Windows Bash

<div class="termy">

```console
// 这里我们还没有设置环境变量
$ python main.py

// 因为我们没有设置环境变量，所以我们得到的是默认值

Hello World from Python

// 但是如果我们事先创建过一个环境变量
$ export MY_NAME="Wade Wilson"

// 然后再次调用程序
$ python main.py

// 现在就可以读取到环境变量了

Hello Wade Wilson from Python
```

</div>

////

//// tab | Windows PowerShell

import re
import sys
from datetime import date

RELEASE_NOTES_FILE = "docs/en/docs/release-notes.md"
RELEASE_HEADER_PATTERN = re.compile(r"^## (\d+\.\d+\.\d+)\s*(\(.*\))?\s*$")


def main() -> None:
    with open(RELEASE_NOTES_FILE) as f:
        lines = f.readlines()

    for i, line in enumerate(lines):
        match = RELEASE_HEADER_PATTERN.match(line)
        if not match:
            continue

	export GOOS=$os
	export GOARCH=$arch
	export GO111MODULE=on
	go build -trimpath -tags kqueue -o /dev/null
}

function main() {
	echo "Testing builds for OS/Arch: ${SUPPORTED_OSARCH}"
	for each_osarch in ${SUPPORTED_OSARCH}; do
		_build "${each_osarch}"
	done
}

//go:build ignore

// Compute Fibonacci numbers with two goroutines
// that pass integers back and forth.  No actual
// concurrency, just threads and synchronization
// and foreign code on multiple pthreads.

package main

import (
	big "."
	"runtime"
)

func fibber(c chan *big.Int, out chan string, n int64) {
	// Keep the fibbers in dedicated operating system
	// threads, so that this program tests coordination