CubitPy

Utility functions and 4C related functionality for the Cubit and Coreform python interface, Especially for the creation of input files for 4C.

Usage

A tutorial can be found in the /tutorial directory.

Contributing

If you are interested in contributing to CubitPy, we welcome your collaboration. For general questions, feature request and bug reports please open an issue.

If you contribute actual code, fork the repository and make the changes in a feature branch. Depending on the topic and amount of changes you also might want to open an issue. To merge your changes into the CubitPy repository, create a pull request to the main branch. A few things to keep in mind:

• It is highly encouraged to add tests covering the functionality of your changes, see the test suite in tests/.
• CubitPy uses black to format python code. Make sure to apply black to the changed source files.
• Feel free to add yourself to the CONTRIBUTORS file.

Installation

CubitPy is developed with python3.13. Other versions of Python might lead to issues. It is recommended to use a python environment container such as conda or venv.

• conda: A conda environment can be created and loaded with

  conda create -n cubitpy python=3.13
  conda activate cubitpy
  

• venv: Chose an appropriate directory for this, e.g., /home/user/opt. A virtual environment can be setup with
  • On Debian systems the following packages have to be installed:

    sudo apt-get install python3-venv python3-dev
    

  • Create and load the environment

    cd <path-to-env-folder>
    python -m venv cubitpy-env
    source cubitpy-env/bin/activate
    

To install cubitpy go to the repository root directory

cd path_to_cubitpy

And install cubitpy via pip

pip install .

If you intend to actively develop cubitpy, install it in editable mode

pip install -e ".[dev]"

To run CubitPy it is required to provide a CubitPy configuration file. This file should look like:

cubitpy_mode: "local"  # "local" or "remote"
local_config:
  cubit_path: "/Users/username/opt/Cubit-15.2/Cubit.app"
remote_config:
  user: "username"
  host: "hostname"
  platform: "windows"
  cubit_path: "C:\\Coreform_Cubit_2025.8"

To run CubitPy one can either provide the configuration file then initializing CubitPy, or set an environment variable with the path to the configuration file.

export CUBITPY_CONFIG_PATH=path_to_cubitpy_config.yaml

If you are using a Cubit version that still runs on python2, you need to specify a path to a valid python2.7 executable

export CUBITPY_PYTHON2=path_to_python2.7

Note: for IMCS workstations this path is "/imcs/public/compsim/opt/Python-2.7.18/python".

To check if everything worked as expected, run the test suite (from the root directory)

cd path_to_cubitpy/tests
pytest

If you intend to actively develop CubitPy, please make sure to install the pre-commit hook within the python environment to follow our style guides:

pre-commit install

Debugging in VS Code and PyCharm

When debugging, IDEs may try to attach to subprocesses, which can cause issues. The instructions below show how to disable this behavior in VS Code and PyCharm.

VS Code

To prevent the debugger from attaching to subprocesses, add the following to your .vscode/launch.json:

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "Python: Launch current file",
      "type": "debugpy",
      "request": "launch",
      "program": "${file}", // Launches the currently open file
      "console": "integratedTerminal", // or "externalTerminal" if needed
      "subProcess":false, // Disables debugging for subprocesses and libraries
    }
  ]
}

PyCharm

To disable subprocess debugging:

1. Go to File > Settings
2. Navigate to: Build, Execution, Deployment > Python Debugger
3. Uncheck: Attach to subprocess automatically while debugging