# 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).

```console
$ C:\opt\custompython\bin\python
```

</div>

///

この情報は、[Virtual Environments](virtual-environments.md) について学ぶ際にも役立ちます。

## まとめ

これで、**環境変数**とは何か、Pythonでどのように使用するかについて、基本的な理解が得られたはずです。

環境変数についての詳細は、<a href="https://en.wikipedia.org/wiki/Environment_variable" class="external-link" target="_blank">Wikipedia: Environment Variable</a> を参照してください。

        // 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

$ python main.py

// As we didn't set the env var, we get the default value

Hello World from Python

// But if we create an environment variable first
$ export MY_NAME="Wade Wilson"

// And then call the program again
$ python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

<div class="termy">

```console
$ C:\opt\custompython\bin\python
```

</div>

////

Deze informatie is handig wanneer je meer wilt weten over [virtuele omgevingen](virtual-environments.md){.internal-link target=_blank}.

## Conclusion

Hiermee heb je basiskennis van wat **omgevingsvariabelen** zijn en hoe je ze in Python kunt gebruiken.

/// info

To use `TestClient`, first install <a href="https://www.python-httpx.org" class="external-link" target="_blank">`httpx`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install httpx
```

///

Import `TestClient`.

about just retrofitting monolithic applications onto modern container based compute environment. A cloud-native application is portable and resilient by design, and can scale horizontally by simply replicating. Modern orchestration platforms like Kubernetes, DC/OS make replicating and managing containers in huge clusters easier than ever.

While containers provide isolated application execution environment, orchestration platforms allow seamless scaling by helping replicate and manage containers....

// CHECKSTYLE_OFF: RegexpHeader
/**
 * Provides classes for managing Maven toolchains, which allow projects to use specific
 * tool installations (like JDKs, compilers, or other build tools) across different
 * environments without hardcoding paths.
 *
 * @since 4.0.0
 */

/// info

To use forms, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

```console
$ pip install python-multipart
```

///

/// note

<div class="termy">

```console
$ C:\opt\custompython\bin\python
```

</div>

////

Essas informações serão úteis ao aprender sobre [Ambientes Virtuais](virtual-environments.md){.internal-link target=_blank}.

## Conclusão

Com isso, você deve ter uma compreensão básica do que são **variáveis ​​de ambiente** e como usá-las em Python.