display: inline-block;
}

a.external-link::after {
  /* \00A0 is a non-breaking space
        to make the mark be on the same line as the link
    */
  content: "\00A0[↪]";
}

a.internal-link::after {
  /* \00A0 is a non-breaking space
        to make the mark be on the same line as the link
    */
  content: "\00A0↪";
}

.shadow {
  box-shadow: 5px 5px 10px #999;
}

    "W",  # pycodestyle warnings
    "F",  # pyflakes
    "I",  # isort
    "B",  # flake8-bugbear
    "C4",  # flake8-comprehensions
    "UP",  # pyupgrade
]
ignore = [
    "E501",  # line too long, handled by black
    "B008",  # do not perform function calls in argument defaults
    "C901",  # too complex
    "W191",  # indentation contains tabs
]

[tool.ruff.lint.per-file-ignores]

👆 💪 ✍ 🌐 🔢 🕴 🎯 📋 👼, 👈 🕴 💪 👈 📋, & 🕴 🚮 📐.

👈, ✍ ⚫️ ▶️️ ⏭ 📋 ⚫️, 🔛 🎏 ⏸:

<div class="termy">

```console
// Create an env var MY_NAME in line for this program call
$ MY_NAME="Wade Wilson" python main.py

// Now it can read the environment variable

Hello Wade Wilson from Python

// The env var no longer exists afterwards
$ python main.py

```

!!! tip
    There are several `__init__.py` files: one in each directory or subdirectory.

    This is what allows importing code from one file into another.

    For example, in `app/main.py` you could have a line like:

    ```
    from app.routers import items
    ```

* The `app` directory contains everything. And it has an empty file `app/__init__.py`, so it is a "Python package" (a collection of "Python modules"): `app`.

But, sadly, you get nothing useful:

<img src="/img/python-types/image01.png">

### Add types

Let's modify a single line from the previous version.

We will change exactly this fragment, the parameters of the function, from:

```Python
    first_name, last_name
```

to:

```Python
    first_name: str, last_name: str

## **Typer**, CLI এর জন্য FastAPI

<a href="https://typer.tiangolo.com" target="_blank"><img src="https://typer.tiangolo.com/img/logo-margin/logo-margin-vector.svg" style="width: 20%;"></a>

আপনি যদি <abbr title="Command Line Interface">CLI</abbr> অ্যাপ বানাতে চান, যা কিনা ওয়েব API এর পরিবর্তে টার্মিনালে ব্যবহার হবে, তাহলে দেখুন<a href="https://typer.tiangolo.com/" class="external-link" target="_blank">**Typer**</a>.

* 📝 Update usage of Token model in security docs. PR [#9313](https://github.com/tiangolo/fastapi/pull/9313) by [@piotrszacilowski](https://github.com/piotrszacilowski).
* ✏️ Update highlighted line in `docs/en/docs/tutorial/bigger-applications.md`. PR [#5490](https://github.com/tiangolo/fastapi/pull/5490) by [@papb](https://github.com/papb).

```

## 创建免费 Deta 账号

创建<a href="https://www.deta.sh/?ref=fastapi" class="external-link" target="_blank">免费的 Deta 账号</a>，只需要电子邮件和密码。

甚至不需要信用卡。

## 安装 CLI

创建账号后，安装 Deta <abbr title="Command Line Interface application">CLI</abbr>：

=== "Linux, macOS"

    <div class="termy">

    ```console
    $ curl -fsSL https://get.deta.dev/cli.sh | sh
    ```

    </div>

=== "Windows PowerShell"

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

Here, the `shutdown` event handler function will write a text line `"Application shutdown"` to a file `log.txt`.

!!! info
    In the `open()` function, the `mode="a"` means "append", so, the line will be added after whatever is on that file, without overwriting the previous contents.

!!! tip

<a href="https://typer.tiangolo.com" target="_blank"><img src="https://typer.tiangolo.com/img/logo-margin/logo-margin-vector.svg" style="width: 20%;"></a>

If you are building a <abbr title="Command Line Interface">CLI</abbr> app to be used in the terminal instead of a web API, check out <a href="https://typer.tiangolo.com/" class="external-link" target="_blank">**Typer**</a>.