Frequently asked questions#

What is PyAnsys?#

PyAnsys is a set of open source technologies that let you interface with Ansys CFX, Fluent, Mechanical APDL, System Coupling, and other Ansys products and utilities using Python. You can use PyAnsys libraries in a Python environment of your choice along with external Python libraries.

What is PyCFX?#

PyCFX provides Python access to Ansys CFX. Its features let you seamlessly use CFX in the Python ecosystem and provide broad access to native CFX features for performing actions such as these:

  • Launch CFX using a local Ansys installation.

  • Connect to a CFX instance running on a remote machine.

PyCFX does not have a graphical user interface. You interact with PyCFX in the Python environment of your choice, either interactively or using Python scripts.

Who uses PyCFX?#

Engineers, product designers, consultants, and academia use PyCFX.

Which Python version should I use?#

PyCFX supports Python 3.10 through Python 3.14 on Windows and Linux.

You can use a suitable Python version from your Ansys installation. Python 3.10 ships with Ansys 2023 R2 and later. For example, in a 2025 R2 Windows installation, the executable file for Python 3.10 is typically located at: C:\Program Files\ANSYS Inc\v252\commonfiles\CPython\3_10\winx64\Release\python.exe.

If you use Python from an Ansys installation, install PyCFX in a Python virtual environment to prevent conflicts with Ansys Python packages.

Alternatively, you can download any compatible Python version directly from the Python downloads page. Run the Python executable file as an administrator and select the Add Python [version] to PATH checkbox on the first wizard page before proceeding with the installation. On the last wizard page, which indicates that Python is installed successfully, follow the instructions for disabling the path length limit if you have long file paths.

Where can I find source code and documentation?#

All PyAnsys public libraries are available on the Ansys GitHub account. The Repositories page displays the number of repositories, which you can search by name. For example, to find all PyCFX libraries, type pycfx in the search field.

The README.md file for the Ansys GitHub account lists the public PyAnsys libraries. The links in this list lead to the repositories for the respective libraries, where you can access their documentation. In addition to providing general usage information, the documentation for a library includes practical examples.

How does PyCFX find the location to launch CFX?#

PyCFX locates installed Ansys versions based on environment variables in the form AWP_ROOT<version>, where <version> is a release number such as 252 for Ansys 2025 R2. The corresponding environment variable is automatically configured on Windows systems when you install a new Ansys release. On Linux systems, you must configure the AWP_ROOT<version> environment variable to point to the absolute path of any Ansys installation that you want to use with PyCFX. For example:

set AWP_ROOT252=/apps/ansys_inc/v252

When PyCFX launches CFX, it determines which versions are available using these environment variables. The Ansys version selected (if more than one is installed) is based on the following, in decreasing order of precedence:

  1. The value of the product_version parameter passed to the function that launches a PyCFX session, such as from_install().

  2. The latest supported installed version.

How can I learn to use PyCFX?#

Depending on your preferences, you can use any or all of these methods to learn how to use PyCFX:

  • Review Examples.

  • Write scripts using capabilities such as these:

    • IntelliSense to show available options for any given command. For example, in JupyterLab, press the tab key.

    • Standard Python or PyAnsys tooling to print options related to a specified object. For example, use the dir (<object>) or help (<object>) functions.

How do I set up JupyterLab for better code completion with PyCFX?#

By default, JupyterLab ignores the static typing information provided by PyCFX and relies on dynamic lookup of the API for code completion. Because the dynamic lookup generally involves gRPC calls to the CFX server, it can be slow and often times out. To get a faster code completion experience based on the static typing information provided by PyCFX, install the JupyterLab extension jupyterlab-lsp along with a Python language server like python-lsp-server in your JupyterLab environment.

How can I get help for PyCFX?#

Because PyCFX libraries are open source, you can get support for issues, bugs, and feature requests in their respective GitHub repositories.

  • To log an issue for PyCFX, use the PyCFX Issues page.

  • For discussions about developer tools, engineering simulation, and physics for Ansys software, visit the Ansys Developer Portal.

The Ansys developer forum is where users, partners, students, and Ansys subject matter experts connect, share ideas, discuss the latest technologies, and ask questions to quickly get help and guidance. On this page, you can filter discussions by category or apply the CFX tag to view only CFX-related discussions.