# RunPython

## xlwings アドイン

To get access to `Run main` (new in v0.16) button or the `RunPython` VBA function, you'll need the xlwings addin (or VBA module), see [Add-in & Settings](addin.md#add-in-settings).

For new projects, the easiest way to get started is by using the command line client with the quickstart command,
see [Command Line Client (CLI)](command_line.md#command-line-client-cli) for details:

```text
$ xlwings quickstart myproject
```

## "RunPython" でPythonを呼び出す

In the VBA Editor (`Alt-F11`), write the code below into a VBA module. `xlwings quickstart` automatically
adds a new module with a sample call. If you rather want to start from scratch, you can add a new module via `Insert > Module`.

```vb.net
Sub HelloWorld()
    RunPython "import hello; hello.world()"
End Sub
```

This calls the following code in `hello.py`:

```python
# hello.py
import numpy as np
import xlwings as xw

def world():
    wb = xw.Book.caller()
    wb.sheets[0]['A1'].value = 'Hello World!'
```

You can then attach `HelloWorld` to a button or run it directly in the VBA Editor by hitting `F5`.

#### NOTE
Place `xw.Book.caller()` within the function that is being called from Excel and not outside as
global variable. Otherwise it prevents Excel from shutting down properly upon exiting and
leaves you with a zombie process when you use `Use UDF Server = True`.

## 関数の引数および戻り値

While it's technically possible to include arguments in the function call within `RunPython`, it's not very convenient.
Also, `RunPython` does not allow you to return values. To overcome these issues, use UDFs, see [User Defined Functions (UDFs)](udfs.md#user-defined-functions-udfs) - however,
this is currently limited to Windows only.