CompDam can be compiled into a Python extension module, which allows many of the Fortran subroutines and functions in the for directory to be called from Python. The Python package f90wrap is used to automatically generate the Python extension modules that interface with the Fortran code. This Python extension module functionality is useful for development and debugging.
The python extension module requires some additional dependencies. First, the procedure only works on Linux using the bash shell. Windows users can use the Windows Subsystem for Linux (WSL). In addition, ifort or gfortran 4.6+ is required. Type gfortran --version to check if you have this available. The remaining dependencies are python packages and can be installed as follows. The Python extension module has been tested with Python 3.10.9. f90wrap = 0.2.16 is the most recent version found to be working properly as of April 2026.
Using Conda significantly simplifies the setup process, so it is assumed that you have a recent version of Conda available (see the Conda installation guide). Further, the bash scripts described below include calls to Conda, so they will not work correctly without installing and configuring Conda as follows. Add the Conda-Forge channel by typing:
$ conda config --add channels conda-forge
Conda stores Python packages in containers called environments. Create a new environment:
$ conda create --name compdam python=3.10.9
and switch to your new environment:
$ source activate compdam
which will add (compdam) to the prompt. Install numpy, matplotlib, and f90wrap by typing:
(compdam) $ conda install numpy matplotlib f90wrap=0.2.16
After typing 'y' in response to the prompt asking if you would like to proceed, Conda will install f90wrap and all of its dependencies. This completes the setup process. These steps only need to be executed once.
Note, you can exit the Conda environment by typing source deactivate. When you open a new session, you will need to activate the Conda environment by typing source activate compdam.
This section describes how to compile CompDam into a Python extension module and run a simple example.
The relevant files are in the pyextmod directory, so set pyextmod as your current working directory.
The bash shell is required. Type bash to open a bash shell session if you are using a different shell. Activate the environment in which you have installed the dependencies listed above, e.g. source activate compdam.
Next compile the python extension module by executing make in the pyextmod directory as follows:
(compdam) CompDam_DGD/pyextmod> make
When you execute make, the Fortran modules in the for directory are compiled to object files, the shared library _CompDam_DGD.so is built, and the Python extension module interface CompDam_DGD.py is created. A large amount of output is given in the terminal. After the module is created, most of the functionality of CompDam is available in python with import CompDam_DGD.
The file test_pyextmod_dgdevolve.py shows an example of how the python extension module can be used. Just as when CompDam_DGD is used in Abaqus, CompDam_DGD.py expects CompDam.parameters and props files (if provided) are located in the working directory. Note the test_pyextmod_dgdevolve.py loads a visualization tool that shows how the element deforms as equilibrium is sought by the DGD algorithm.
It is necessary to recompile the CompDam after making changes to the Fortran code. Recompile with the make command. It is a good idea to run make clean before rerunning make to remove old build files.
Note that portions of CompDam that are specific to Abaqus are hidden from f90wrap using the preprocessor directive #ifndef PYEXT.
In the tests directory the shell scripts pyextmod_compile.sh and pyextmod_run.sh are available to help streamline execution of the python extension module. These two scripts assume that Conda environment called compdam is available with abaverify and f90wrap. Both must be executed with the -i option. The script pyextmod_run.sh loads a debug file and executes the specified DGD routine. The DGD routine and the debug file are specified as arguments as follows:
$ bash -i pyextmod_run.sh dgdevolve <job-name>
The <job-name> is the Abaqus job name where it is assumed that the debug file resides in the testOutput folder with the name job-name-1-debug-0.py
In the pyextmod directory, the helpers.py file includes logic to load debug.py files.