Python encountered a problem, many packages would be needed/required for a single package.
Thus the system Python (global installation) would get cluttered.
It also made distribution a big nightmare.
That’s where the Python Virtual Environment (pyvenv or venv) became invaluable.
With a pyvenv every package/module is stored local to the virtual environment.
You can follow this link to the official venv documentation.
Making a Virtual Environment
python3 -m venv . <env_name>
This also means you could destroy your pyvenv and rebuilt it, as it’s simply a directory.
Activating the Virtual Environment
# Unix/Linux
. <env_name>/bin/activate
Once active, all pip install commands instead of installing to the system python, it installs to the venv.
You’ll need to re-activate the venv everytime you close your shell/terminal.
Saving installed packages
# Unix/Linux
pip freeze > requirements.txt
This will save all the installed packages and their exact version info into the file.
Loading packages from requirements.txt
# Unix/Linux
pip install -r requirements.txt
This will load all the packages and their exact version info from the file into the venv.