ICON4Py hosts Python implementations of various components from the ICON climate and weather model. Additionally, it includes icon4pytools, a collection of command-line interfaces (CLIs), and utilities required for the integration of ICON4Py code into the ICON Fortran model. ICON4Py leverages GT4Py to ensure efficient and performance portable implementations of these components.
The repository is organized into directories, each containing independent Python namespace packages for different ICON components or utility packages. These packages can be installed independently. Since these packages are not available from a package repository (yet), you need to specify the location of dependencies within this repository. This can be done by installing the required dependencies first. Refer to the Installation instructions below.
ICON4Py is licensed under the terms of the BSD-3-Clause.
A minimal installation of ICON4Py needs
- Python 3.10
- boost >= 1.85.0
You can install all packages at once by using the provided requirements.txt
or requirements-dev.txt
files in the root of the repository. For example:
The -dev.txt
file installs ICON4Py packages and GT4Py in editable mode, such that source changes are immediatly picked up and used in the virtual environment.
# Clone the repository
git clone [email protected]:C2SM/icon4py.git
cd icon4py
# Create a (Python 3.10) virtual environment (usually at `.venv`)
python3.10 -m venv .venv
# Activate the virtual environment and make sure that 'wheel' is installed
source .venv/bin/activate
pip install --upgrade wheel pip setuptools
# Install all the ICON4Py packages and its dependencies
# External dependencies would be checked out at './_external_src'
pip install --src _external_src -r requirements-dev.txt
# Finally, check that everything works
pytest -v
The --src _external_src
option tells pip
to use a specific folder as the base path for checked out sources, which is very convenient for development tasks involving changes in external dependencies like gt4py
. For convenience, ./_external_src
has been already added to the repository .gitignore
.
You can also use tox for the automatic installation of all packages in development mode in a single step:
# Clone the repository
git clone [email protected]:C2SM/icon4py.git
cd icon4py
# Use tox to create and set up a development environment (usually at `.venv`) in verbose mode
pip install tox
python -m tox -vv -e dev --devenv .venv
# Activate the virtual environment and check that everything works
source .venv/bin/activate
pytest -v
In case you only want to install a specific subpackage, use the actual subpackage requirements.txt
or requirements-dev.txt
files.
For example:
# Clone the repository
git clone [email protected]:C2SM/icon4py.git
cd icon4py
# Create a (Python 3.10) virtual environment (usually at `.venv`)
python3.10 -m venv .venv
# Activate the virtual environment and make sure that 'wheel' is installed
source .venv/bin/activate
pip install --upgrade wheel
# Install a specific ICON4Py subpackage and its dependencies
cd _SUBPACKAGE_ # where _SUBPACKAGE_ in model/atmosphere/dycore | tools | ...
pip install -r requirements-dev.txt
# or in the case of there being a pyproject.toml file
pip install .
After following the installation instructions above using the development requirements (*-dev.txt
files), an editable installation of all the packages will be active in the virtual environment. In this mode, code changes are immediately visible since source files are imported directly by the Python interpreter.
pre-commit is used to run several linting and checking tools. It should always be executed locally before opening a pull request. When executing pre-commit locally you can either run it for the model
or tools
folder:
For example to run code checks on all components in icon4py.model
you can do:
# running precommit for all components in model
cd model/
pre-commit run --all-files
pytest is used for testing and it also comes with a command tool to easily run tests:
# Run all tests (verbose mode)
pytest -v
# Run only tests in `path/to/test/folder`
pytest -v path/to/test/folder
Nonetheless, we also recommended to use tox
to run the complete test suite:
# Run test suite in the default environment
tox
# Run test suite in a specific environment (use `tox -a` to see list of envs)
tox -e py310
The default tox
environment is configured to generate HTML test coverage reports in _reports/coverage_html/
.
We use pytest-benchmark
to benchmark the execution time of stencils in icon4py. To disable benchmarking during testing you can use --benchmark-disable
when invoking pytest
.
The documentation is at a very early stage given the constant state of development. Some effort is ongoing to document the dycore and can be compiled as follows.
You can install the required packages by using the provided requirements-dev.txt
file in the root of the repository.
Then move to the dycore docs folder and build the html documentation with the provided makefile:
cd model/atmosphere/dycore/docs
make html
The documentation can then be accessed at docs/_build/html/index.html
For more information please consult the package specific READMEs found in the model
and tools
folders.