Örneğin terminalde `python` yazdığınızda, işletim sistemi bu listedeki **ilk dizinde** `python` adlı bir program arar.

Bulursa **onu kullanır**. Bulamazsa **diğer dizinlerde** aramaya devam eder.

### Python Kurulumu ve `PATH`’in Güncellenmesi { #installing-python-and-updating-the-path }

Python’u kurarken, `PATH` ortam değişkenini güncellemek isteyip istemediğiniz sorulabilir.

        logging.info(f"Writing to {version_file}")
        version_file.write_text(content_format, encoding="utf-8")


@app.command()
def generate_docs_src_versions() -> None:
    """
    Generate Python version-specific files for all .py files in docs_src.
    """
    docs_src_path = Path("docs_src")
    for py_file in sorted(docs_src_path.rglob("*.py")):
        generate_docs_src_versions_for_file(py_file)

#
# This file is autogenerated by pip-compile with Python 3.10
# by the following command:
#
#    bazel run //ci/official/requirements_updater:requirements.update
#
absl-py==2.2.2 \
    --hash=sha256:bf25b2c2eed013ca456918c453d687eab4e8309fba81ee2f4c1a6aa2494175eb \
    --hash=sha256:e5797bc6abe45f64fd95dc06394ca3f2bedf3b5d895e9da691c9ee3397d70092
    # via
    #   keras-nightly
    #   tb-nightly
astor==0.7.1 \

#
# This file is autogenerated by pip-compile with Python 3.12
# by the following command:
#
#    bazel run //ci/official/requirements_updater:requirements.update
#
absl-py==2.2.2 \
    --hash=sha256:bf25b2c2eed013ca456918c453d687eab4e8309fba81ee2f4c1a6aa2494175eb \
    --hash=sha256:e5797bc6abe45f64fd95dc06394ca3f2bedf3b5d895e9da691c9ee3397d70092
    # via
    #   keras-nightly
    #   tb-nightly
astor==0.7.1 \

/home/user/code/awesome-project/.venv/bin/python
```

</div>

////

//// tab | Windows PowerShell

<div class="termy">

```console
$ Get-Command python

C:\Users\user\code\awesome-project\.venv\Scripts\python
```

</div>

////

Bu, kullanılacak `python` programının **virtual environment'in içindeki** Python olduğu anlamına gelir.

</div>

////

## Ler Variáveis de Ambiente no Python { #read-env-vars-in-python }

Você também pode criar variáveis de ambiente **fora** do Python, no terminal (ou com qualquer outro método) e depois **lê-las no Python**.

Por exemplo, você poderia ter um arquivo `main.py` com:

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip | Dica

Beachten Sie, wie wir `CommonQueryParams` im obigen Code zweimal schreiben:

//// tab | Python 3.10+

```Python
commons: Annotated[CommonQueryParams, Depends(CommonQueryParams)]
```

////

//// tab | Python 3.10+ nicht annotiert

/// tip | Tipp

Bevorzugen Sie die `Annotated`-Version, falls möglich.

///

```Python
commons: CommonQueryParams = Depends(CommonQueryParams)
```

////

#
# This file is autogenerated by pip-compile with Python 3.12
# by the following command:
#
#    bazel run //ci/official/requirements_updater:requirements.update
#
absl-py==2.2.2 \
    --hash=sha256:bf25b2c2eed013ca456918c453d687eab4e8309fba81ee2f4c1a6aa2494175eb \
    --hash=sha256:e5797bc6abe45f64fd95dc06394ca3f2bedf3b5d895e9da691c9ee3397d70092
    # via
    #   keras-nightly
    #   tb-nightly
astor==0.7.1 \

#
# This file is autogenerated by pip-compile with Python 3.11
# by the following command:
#
#    bazel run //ci/official/requirements_updater:requirements.update
#
absl-py==2.2.2 \
    --hash=sha256:bf25b2c2eed013ca456918c453d687eab4e8309fba81ee2f4c1a6aa2494175eb \
    --hash=sha256:e5797bc6abe45f64fd95dc06394ca3f2bedf3b5d895e9da691c9ee3397d70092
    # via
    #   keras-nightly
    #   tb-nightly
astor==0.7.1 \

<div class="termy">

```console
$ python -m venv .venv
```

</div>

/// details | Що означає ця команда

* `python`: використати програму з назвою `python`
* `-m`: викликати модуль як скрипт, далі ми вкажемо, який модуль
* `venv`: використати модуль з назвою `venv`, який зазвичай уже встановлено з Python