When you work in Python projects you probably should use a **virtual environment** (or a similar mechanism) to isolate the packages you install for each project.

/// info

If you already know about virtual environments, how to create them and use them, you might want to skip this section. 🤓

///

/// tip

A **virtual environment** is different than an **environment variable**.

設定例:

* [VS Code](https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment)
* [PyCharm](https://www.jetbrains.com/help/pycharm/creating-virtual-environment.html)

/// tip | 豆知識

この設定は通常、仮想環境を作成した際に**一度だけ**行います。

///

## 仮想環境の無効化 { #deactivate-the-virtual-environment }

プロジェクトの作業が終了したら、その仮想環境を**無効化**できます。

<div class="termy">

```console

例如：

* [VS Code](https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment)
* [PyCharm](https://www.jetbrains.com/help/pycharm/creating-virtual-environment.html)

/// tip | 提示

通常你只需要在创建虚拟环境时执行此操作**一次**。

///

## 退出虚拟环境 { #deactivate-the-virtual-environment }

当你完成工作后，你可以**退出**虚拟环境。

<div class="termy">

```console
$ deactivate

Например:

* [VS Code](https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment)
* [PyCharm](https://www.jetbrains.com/help/pycharm/creating-virtual-environment.html)

/// tip | Подсказка

Обычно это нужно сделать только **один раз**, при создании виртуального окружения.

///

## Деактивация виртуального окружения { #deactivate-the-virtual-environment }

* [VS Code](https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment)
* [PyCharm](https://www.jetbrains.com/help/pycharm/creating-virtual-environment.html)

/// tip | Tipp

Normalerweise müssen Sie dies nur **einmal** tun, wenn Sie die virtuelle Umgebung erstellen.

///

## Die virtuelle Umgebung deaktivieren { #deactivate-the-virtual-environment }

* [VS Code](https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment)
* [PyCharm](https://www.jetbrains.com/help/pycharm/creating-virtual-environment.html)

/// tip | Astuce

Vous devez normalement faire cela une seule fois, lorsque vous créez l’environnement virtuel.

///

## Désactiver l’environnement virtuel { #deactivate-the-virtual-environment }

```

</div>

////

Bu komut, sonraki komutlarda kullanılabilecek bazı [environment variable](environment-variables.md)'ları oluşturur veya değiştirir.

Bunlardan biri `PATH` değişkenidir.

/// tip | İpucu

`PATH` environment variable hakkında daha fazla bilgiyi [Environment Variables](environment-variables.md#path-environment-variable) bölümünde bulabilirsiniz.

///

例如：

* [VS Code](https://code.visualstudio.com/docs/python/environments#_select-and-activate-an-environment)
* [PyCharm](https://www.jetbrains.com/help/pycharm/creating-virtual-environment.html)

/// tip

通常你只需要在建立虛擬環境時執行此操作**一次**。

///

## 退出虛擬環境 { #deactivate-the-virtual-environment }

當你完成工作後，你可以**退出**虛擬環境。

<div class="termy">

```console
$ deactivate

        // in test environments, we test that the method exists and can be invoked
        // without throwing unexpected exceptions
        try {
            // Create a new instance to ensure clean state
            SystemMonitorTarget testTarget = new SystemMonitorTarget();

            // Try to call the expired method
            // Note: This method may fail in test environments due to system dependencies

# Environment Variables { #environment-variables }

/// tip

If you already know what "environment variables" are and how to use them, feel free to skip this.

///

An environment variable (also known as "**env var**") is a variable that lives **outside** of the Python code, in the **operating system**, and could be read by your Python code (or by other programs as well).