documentation/Examples/Debian/Install Python.md

About

https://www.python.org/

Procedure

1. Sign in as root user

2. Run apt install python3 python3-venv to install Python 3.x, whichever version may be the latest

   !!! info "Info"

    The package `python3-venv` is included because it is in best practice to containerize Python projects and keep their dependencies isolated in environments where more than one application may be hosted
   

3. Run python3 --version to identify the version of Python installed

New Projects

1. Run mkdir myapp && cd myapp to create a new home for our Python project

2. Run python3 -m venv venv to create a virtual environment (venv)

3. Run source ./venv/bin/activate to activate

   !!! info "Info"

    Calling `python3` or `pip3` is no longer necessary. The alias `python` is symbolically linked to the correct executable and a copy of pip is included within the virtual environment. Installing packages using `pip install -r requirements.txt` or `pip install x` will install the downloaded libraries and modules local to this environment!
   

4. Run python -u myapp.py to run a script using our venv

   !!! tip "Tip"

    The `-u` in `python -u myapp.py` is instructing the Python interpreter to run in unbuffered output mode
   

Optional

1. Daemonize the Python application

   1. Create a new shell script via nano myapp.sh

      #!/bin/bash
      
      cd /root/myapp
      source ./venv/bin/activate
      python -u myapp.py
      

   2. Run chmod +x myapp.sh

   3. Learn about installing Node.js and PM2

   4. Run pm2 start myapp.sh && pm2 save