Installation

Note

The steps in this documentation have been tested on Linux Ubuntu 24.04.2 LTS (which should also cover MacOS functionality in broad sense) and Windows 10 Pro.

The software is run by executing a series of commands in a terminal. When the software is installed with the steps below, the command line tools will be available in the terminal.

The installation process consists of the following steps:

  1. Create a clean Python environment (optional - but strongly recommended).

  2. Install the software using pip.

We provide both a quickgide for experienced python users and a more detailed guide for users who are new to Python environments.

Lastly, we also describe how to download and install an editable version of the software if you wish to contribute to the development of the software.

Quick guide for experienced python users

  1. Create a new Python 3.10 environment.

  2. Install using pip:

pip install pylongslit

Detailed guide for users new to Python environments

1. Create a clean Python environment

To ensure best possible stability of the software and to avoid version conflicts with other Python packages on your system, it is strongly recommended to create a clean Python environment for running the software. If you are unfamiliar with Python environments, see our quick introduction to Python environments. You can skip directly to installing the software if you prefer to not use a clean environment - in that case you might experience software bugs due to version conflicts that are not accounted for in this documentation.

Using Anaconda (conda) (recommeded):

To create a new virtual environment using Anaconda, run the following command in your terminal (if you are using Windows, do this and all following from the Anaconda Prompt):

conda create --name PyLongslit python=3.10

You can replace PyLongslit with any name you like. This will create a new environment with Python 3.10 installed.

To activate the environment, run:

conda activate PyLongslit

Using venv (standard Python):

To create a new virtual environment using venv (standard Python), make sure you have Python 3.10 installed, then run the following command in your terminal:

python3.10 -m venv PyLongslit

You can replace PyLongslit with any name you like. This will create a new environment with the Python version 3.10 installed.

Note

If you are using Windows, you might need to run the following command instead:

python -m venv PyLongslit

This is because the Python executable might not be named python3.10 on Windows. In that case, you can ensure that the correct version of Python is used by running:

python --version

If the Python version printed is not 3.10, you have several options:

  1. If your version is not 3.10, you most likely will be fine. Otherwise, try one of the following steps.

  2. Install Anaconda and create the environment using the conda command as described above.

  3. You can set the Python version to be used by the terminal by adding the Python installation directory to the PATH environment variable. See the following link for more information: How to set the path and environment variables in Windows.

To activate the environment, run:

For Linux/MacOS:

source PyLongslit/bin/activate

, where PyLongslit/bin/activate is the path to the activate script in the environment.

For Windows:

# In PowerShell
.\PyLongslit\Scripts\Activate.ps1


# In cmd.exe
.\PyLongslit\Scripts\Activate.bat

, where PyLongslit/Scripts is the path to the activate script in the environment.

Quick introduction to Python environments

The following is a quick introduction to Python environments for users who would like one. Feel free to skip to next section.

Python applications often depend on a specific version of Python and a specific set of Python packages. These packages can have dependencies on other packages, and these dependencies can have dependencies on other packages, and so on. This can lead to a situation where two applications require different versions of the same package, which can cause conflicts. By using Python environments, you can create isolated environments where you can install the specific versions of Python and Python packages that you need for a specific application. This helps ensure that only the needed packages are installed, and that they do not conflict with other applications on your system. Furtermore, this ensures that updates to any packages do not break the application, as the environment will not be updated unless you explicitly update it.

Note: The envirornment will need to be activated every time you open a new terminal. You can configure your terminal to automatically activate the environment upon startup. This will not be covered in this documentation - see documentation for your terminal for more information.

Example:

In bash (Linux/MacOS), using conda, prior to activating a specific environment, your terminal will start in the base environment:

(base) user@computer:~$

After activating the environment, the name of the environment will be shown in the terminal prompt:

(PyLongslit) user@computer:~$

2. Install the software using pip

To install the software and the required dependencies, run the following command in your terminal:

(if you are using a clean Python environment, make sure you activate it first.)

pip install pylongslit

After the installation is complete, you can perform a quick check to see if the software was installed by running the following command:

pylongslit_check_config --help

If the software was installed correctly, you should see a message like this in the terminal:

usage: pylongslit_check_config [-h] config

Run the pylongslit config-file checker.

positional arguments:
  config      Configuration file path

options:
  -h, --help  show this help message and exit

Developer installation

An editable version of the software can be installed if you plan on developing the code. This allows you to make changes to the software and see the changes reflected in the command line tools without having to reinstall the software.

The software can be downloaded from the GitHub repository website or cloned by using git.

Direct link to download from the repository website:

Download Source Code (ZIP)

Using git: (if you don’t know what git is just download the ZIP from link above)

SSH (recommended if you plan on developing)…

git clone git@github.com:KostasValeckas/PyLongslit.git

… or HTTPS (works too, but you will need to enter your username and password on every pull/push):

git clone https://github.com/KostasValeckas/PyLongslit.git

Then, when in clean python 3.10 environment, navigate to the directory where the software was downloaded (this is the directory with the file setup.py in it) and run the following command:

pip install -e .