> ## Documentation Index
> Fetch the complete documentation index at: https://docs.arc.cdata.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Third-Party Library Support

> Using third-party Python libraries with CData Arc, including SharedInterpreter and SubInterpreter configuration.

You can use third-party libraries when writing Python in Arc. In the Jep Java API, you can choose between two types of Python interpreters:

* SharedInterpreter
* SubInterpreter

Keep the following in mind when you configure your Arc environment to use Python.

**Use `SharedInterpreter` if:**

* You are new to running Python scripts in Arc.
* You are using third-party libraries like NumPy.

**Use `SubInterpreter` if:**

* You require parallel script execution.
* Full third-party library support is not important to you.

This behavior is controlled by the `SHARED_INTERPRETER` environment variable. If you set the environment variable `SHARED_INTERPRETER=false`, Arc uses `SubInterpreter`.

If you do not set the environment variable, or you explicitly set it to `true`, Arc defaults to `SharedInterpreter`.

> [!NOTE]
>
> While Arc restricts access to modules based on the value of [ScriptingEngineHardeningLevel](https://docs.arc.cdata.com/26.4/self-hosted/en/getting-started/administration/security-best-practices.md#hardening-server-security-settings), it cannot fully guarantee that third-party libraries installed on the system abide by these rules. Use this with caution in highly controlled environments.


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