One of the easiest ways to install a Python 3 distribution for iSpec on Linux without root permissions is by using Anaconda.
bash Anaconda3-2020.07-Linux-x86_64.sh
Follow the instructions, anaconda will be installed in /home/your_user/anaconda3/ by default. The installer will ask if you want to initialize/modify .bashrc or .bash_profile, select 'yes'. The installer should have added to your .bashrc or .bash_profile files (in your home directory) something like this:
# >>> conda initialize >>>
# !! Contents within this block are managed by 'conda init' !!
__conda_setup="$('/home/your_user/anaconda3/bin/conda' 'shell.bash' 'hook' 2> /dev/null)"
if [ $? -eq 0 ]; then
eval "$__conda_setup"
else
if [ -f "/home/your_user/anaconda3/etc/profile.d/conda.sh" ]; then
. "/home/your_user/anaconda3/etc/profile.d/conda.sh"
else
export PATH="/home/your_user/anaconda3/bin:$PATH"
fi
fi
unset __conda_setup
# <<< conda initialize <<<
Close all the terminals and open a new one in order to re-load this new setup.
Install a library that does not come by default and that it is needed by iSpec:
conda update conda
conda update --all
conda install lockfile dill
sudo apt install build-essential gfortran libgfortran3
make clean
make spectrum
make turbospectrum
make moog