---
title: Install Python custom runtime
description: Learn how to install a Python custom runtime for SQL Server using Language Extensions. The Python custom runtime can run machine learning scripts.
ms.prod: sql
ms.technology: machine-learning-services
ms.date: 02/08/2021
ms.topic: how-to
author: dphansen
ms.author: davidph
ms.custom: seo-lt-2019
zone_pivot_groups: sqlml-platforms
monikerRange: ">=sql-server-ver15||>=sql-server-linux-ver15"
---
# Install a Python custom runtime for SQL Server
[!INCLUDE [SQL Server 2019 and later](../../includes/applies-to-version/sqlserver2019.md)]

Learn how to install a Python custom runtime for running external Python scripts with SQL Server on:

+ Windows
+ Ubuntu Linux
+ Red Hat Enterprise Linux (RHEL)
+ SUSE Linux Enterprise Server (SLES)

The custom runtime can run machine learning scripts and uses the [SQL Server Language Extensions](../../language-extensions/language-extensions-overview.md).

Use your own version of the Python runtime with SQL Server, instead of the default runtime version installed with [SQL Server Machine Learning Services](../sql-server-machine-learning-services.md).

::: zone pivot="platform-windows"
[!INCLUDE [Python custom runtime - Windows](includes/custom-runtime-python-windows.md)]
::: zone-end

::: zone pivot="platform-linux-ubuntu"
[!INCLUDE [Python custom runtime - Linux - Prerequisites](includes/custom-runtime-python-linux-prerequisites.md)]

[!INCLUDE [Python custom runtime - Linux - Ubuntu specific steps](includes/custom-runtime-python-linux-ubuntu.md)]

[!INCLUDE [Python custom runtime on Linux - Common steps](includes/custom-runtime-python-linux-common.md)]
::: zone-end

::: zone pivot="platform-linux-rhel"
[!INCLUDE [Python custom runtime - Linux - Prerequisites](includes/custom-runtime-python-linux-prerequisites.md)]

[!INCLUDE [Python custom runtime - Linux - RHEL specific steps](includes/custom-runtime-python-linux-rhel.md)]

[!INCLUDE [Python custom runtime on Linux - Common steps](includes/custom-runtime-python-linux-common.md)]
::: zone-end

::: zone pivot="platform-linux-sles"
[!INCLUDE [Python custom runtime - Linux - Prerequisites](includes/custom-runtime-python-linux-prerequisites.md)]

[!INCLUDE [Python custom runtime - Linux - SLES specific steps](includes/custom-runtime-python-linux-sles.md)]

[!INCLUDE [Python custom runtime on Linux - Common steps](includes/custom-runtime-python-linux-common.md)]
::: zone-end

## Enable external script

You can execute a Python external script with the stored procedure [sp_execute_external script](../../relational-databases/system-stored-procedures/sp-execute-external-script-transact-sql.md).

To enable external scripts, use [Azure Data Studio](../../azure-data-studio/what-is-azure-data-studio.md) to execute the statement below.

```sql
sp_configure 'external scripts enabled', 1;
RECONFIGURE WITH OVERRIDE;  
```

## Verify installation

Use the following SQL script to verify the installation and functionality of the Python custom runtime.

```sql
EXEC sp_execute_external_script
@language =N'myPython',
@script=N'
import sys
print(sys.path)
print(sys.version)
print(sys.executable)'
```

## Next steps

+ [Install an R custom runtime for SQL Server](custom-runtime-r.md)
+ [Extensibility framework in SQL Server](../concepts/extensibility-framework.md)
+ [Language Extensions Overview](../../language-extensions/language-extensions-overview.md)