.. _python_setup:

Python Setup
============

In order to install the python library, it is recommended to create a python virtual environment where you can install
all dependencies. Therefore, you will first need a package management system to create the python environment. This way,
you can avoid package conflicts with packages you may need for different software projects. In general, we recommend
using uv_ due to its speed, but as many users are familiar with conda_, we also describe its usage as well.

uv
--

To install uv_ please follow the instructions on the `uv installation page
<https://docs.astral.sh/uv/getting-started/installation/>`_. No further requirements (like installing python) are
needed, as uv_ takes care of everything for you.

Creating a virtual environment with uv_ can be done via

.. code-block:: bash

    uv venv .venv --python 3.10

This will create a folder `.venv/` which contains all information on the virtual environment. Note, that you can choose
a different python version by simply changing the version number.

To activate the virtual environment, you can run

.. code-block:: bash

    # For Linux and MacOS users
    source .venv/bin/activate

    # For Windows users
    .venv\Scripts\activate

In order to install all build dependencies for pairinteraction, run

.. code-block:: bash

    uv pip install -r .build_requirements.txt

inside the pairinteraction repository.

If in addition you want to install all dependencies from the `pyproject.toml` file, you can use the following commands:

.. code-block:: bash

    uv pip compile pyproject.toml --all-extras > requirements.txt
    uv pip install -r requirements.txt

.. _uv: https://docs.astral.sh/uv/

Conda
-----

To install conda_ please follow the instructions on the `conda installation page
<https://docs.conda.io/projects/conda/en/latest/user-guide/install/index.html>`_.

Creating and activating a virtual environment that is able to use all pip functionality with conda_ can be done by
running the following commands:

.. code-block:: bash

    conda create --name venv python=3.10
    conda activate venv
    conda install pip-tools

In order to install all dependencies to build the package, you can run from inside the conda environment and the root
directory of the pairinteraction repository

.. code-block:: bash

    pip install -r .build_requirements.txt

If in addition you want to install all dependencies from the `pyproject.toml` file, you should use the following
commands:

.. code-block:: bash

    pip-compile pyproject.toml --all-extras --output-file=requirements.txt
    pip install -r requirements.txt

.. _conda: https://anaconda.org/anaconda/conda