Common python command

common-python-command.sh

# Create a virtual environment for a project:
cd repos
virtualenv project1

# To begin using the virtual environment, it needs to be activated:
source project1/bin/activate

# From now on, any package that you install using pip will be placed in the project1 folder, 
# isolated from the global Python installation.
# Install packages as usual, for example:
pip install django

# deactivate virtualenv
deactivate

# check if module django exist
python -m django --version

# Reference: 
# - https://docs.python-guide.org/dev/virtualenvs/#virtualenvironments-ref
# - https://docs.djangoproject.com/en/2.1/intro/tutorial01/