Obtaining and installing PyRETIS¶

PyRETIS and its requirements can be installed using pip or using conda as described below. We also describe how PyRETIS can be installed in a virtual environment and how it can be installed directly from the source code using git.

Installing via `pip`¶

PyRETIS can be installed using pip with the following command:

pip install pyretis

Note: PyRETIS will only work with Python 3.5 and newer, but pip might actually try to install for Python 2 if that is your system default. In this case, use pip3 in the command above.

Installing via `conda`¶

PyRETIS can be installed using conda with the following command:

conda install pyretis -c conda-forge

Note: Since PyRETIS will only work with Python 3.5 and newer, please make sure that you are using an environment with a recent version of Python.

Optional: Setting up a virtual environment for pip¶

You can also install PyRETIS in a virtual environment. Using a virtual environment is recommended as it will help you maintain different versions of PyRETIS and it’s dependencies. The following steps are needed to set up a virtual environment:

Install the virtualenv package. This can be done using pip:
```
[sudo] pip install virtualenv
```
or using a package manager for your operative system, for instace apt if you are using a Debian-like Linux:
```
[sudo] apt-get install virtualenv
```
Create a folder dedicated to your virtual environments, for instance in your home directory:
```
mkdir ~/myenvfolder
cd ~/myenvfolder
```
Install the new environment with the desired Python3 interpreter, using the path to the desired Python executable (usually found in /usr/bin/), and a name for the virtual environment folder (python-3.5-env):
```
virtualenv -p /usr/bin/python3.5 ~/myenvfolder/python-3.5-env
```

Activate the environment:

source ~/myenvfolder/python-3.5-env/bin/activate

Install PyRETIS:
```
pip install pyretis
```

The folder ~/myenvfolder/python-3.5-env now contains a new Python environment where PyRETIS has been installed. Since you have sourced the virtual environment, pip will now refer to the version of pip installed in the environment and when you install packages, they will be installed inside the folder ~/myenvfolder/python-3.5-env.

Note: that you will have to source the environment each time you want to make use of it using the source command given above.

Optional: Installing from the PyRETIS git repository¶

Previous versions and the latest (possibly unstable) sources can be obtained using git:

git clone git@gitlab.com:pyretis/pyretis.git

or,

git clone https://gitlab.com/pyretis/pyretis.git

After cloning the repository, PyRETIS can be installed via pip (after navigating to the correct source directory):

pip install -e .

Requirements for PyRETIS¶

In order to run PyRETIS, the following Python libraries are needed:

SciPy, NumPy, and matplotlib (see also the information on installing the SciPy Stack).
Jinja2
Docutils
Sphinx and the Sphinx Bootstrap Theme (for building the documentation).
tqdm
colorama

These packages can be installed by:

pip install -r requirements.txt

using the requirements.txt file in the source code directory. This should be automatically done if you are installing PyRETIS using pip/conda.