how meny python env's i have code example

Example 1: python virtual environment

python3 -m venv env
python -m virtualenv env #py2

source env/bin/activate

#all this is on same directory

Example 2: python virtual environment

python3 -m pip install --user virtualenv

Example 3: python virtual environment

source env/bin/activate

Example 4: virtual environment python

python3 -m venv tutorial-env