安裝 Python 時，可能會詢問你是否要更新 `PATH` 環境變數。

//// tab | Linux, macOS

假設你安裝了 Python，並將其安裝在目錄 `/opt/custompython/bin` 中。

如果你選擇更新 `PATH` 環境變數，那麼安裝程式會將 `/opt/custompython/bin` 加入到 `PATH` 環境變數中。

它看起來大致會是這樣：

```plaintext
/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/opt/custompython/bin
```

如此一來，當你在終端機輸入 `python` 時，系統會在 `/opt/custompython/bin` 中找到 Python 程式（最後一個目錄）並使用它。

////

//// tab | Windows

    val perfTestJavaVersion: JvmVersion = JvmVersion.JAVA_17,
    val defaultArch: Arch = Arch.AMD64,
) {
    LINUX(
        "Linux",
        androidHome = "/opt/android/sdk",
        jprofilerHome = "/opt/jprofiler/jprofiler11.1.4",
    ),
    ALPINE(
        "Linux",
        androidHome = "/not/supported",
        jprofilerHome = "/not/supported",
    ),
    WINDOWS(
        "Windows",

		}
	}

	var skipAfterInitialize bool
	for _, opt := range opts {
		if opt != nil {
			if applyErr := opt.Apply(config); applyErr != nil {
				return nil, applyErr
			}
			defer func(opt Option) {
				if skipAfterInitialize {
					return
				}
				if errr := opt.AfterInitialize(db); errr != nil {
					err = errr
				}
			}(opt)
		}
	}

func (db *PreparedStmtDB) BeginTx(ctx context.Context, opt *sql.TxOptions) (ConnPool, error) {
	if beginner, ok := db.ConnPool.(TxBeginner); ok {
		tx, err := beginner.BeginTx(ctx, opt)
		return &PreparedStmtTX{PreparedStmtDB: db, Tx: tx}, err
	}

	beginner, ok := db.ConnPool.(ConnPoolBeginner)
	if !ok {
		return nil, ErrInvalidTransaction
	}

	connPool, err := beginner.BeginTx(ctx, opt)
	if err != nil {
		return nil, err
	}

    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception
        handler -->> client: HTTP error response
    end
    dep ->> operation: Run dependency, e.g. DB session
    opt raise
        operation -->> dep: Raise Exception (e.g. HTTPException)
        opt handle

    client ->> dep: Start request
    Note over dep: Run code up to yield
    opt raise Exception
        dep -->> handler: Raise Exception
        handler -->> client: HTTP error response
    end
    dep ->> operation: Run dependency, e.g. DB session
    opt raise
        operation -->> dep: Raise Exception (e.g. HTTPException)
        opt handle

                when (os) {
                    Os.WINDOWS -> param("env.PATH", "%env.PATH%;C:/Program Files/7-zip")
                    else -> param("env.PATH", "%env.PATH%:/opt/swift/4.2.3/usr/bin:/opt/swift/4.2.4-RELEASE-ubuntu18.04/usr/bin")
                }
            }
            failureConditions {
                // We have test-retry to handle the crash in tests
                javaCrash = false

    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> dep: Raise other exception
    end
    Note over dep: After yield
    opt Handle other exception
        dep -->> dep: Handle exception, can't change response. E.g. close DB session.
    end
```

    Note over dep: Führt den Code bis zum yield aus
    opt Löst Exception aus
        dep -->> handler: Löst Exception aus
        handler -->> client: HTTP-Error-Response
    end
    dep ->> operation: Führt Abhängigkeit aus, z. B. DB-Session
    opt Löst aus
        operation -->> dep: Löst Exception aus (z. B. HTTPException)
        opt Handhabt

    Note over dep: Ejecutar código hasta yield
    opt raise Exception
        dep -->> handler: Lanzar Exception
        handler -->> client: Response HTTP de error
    end
    dep ->> operation: Ejecutar dependencia, por ejemplo, sesión de BD
    opt raise
        operation -->> dep: Lanzar Exception (por ejemplo, HTTPException)
        opt handle