python vevnv code example

Example 1: virtual environment python

### VIRTUAL ENVIRONMENT 

pip install virtualenv

virtualenv pas # write the folder name 

.\foldername\Scripts\activate # to activate the virtual environment 

pip freeze # to get all the modules in the base interpretor / virtual env

pip freeze > requirements.txt # to set the modules and their versions in the requirement file 

pip install -r requirements.txt # to install all the modules with their respected versions in the virtual env

virtualenv --system-site-packages-foldername # this creates virtual env with all the modules and versions that are preinstalled on base python interpretor 

deactivate # to come out of the virtual env

Example 2: how to activate venv python

(tutorial-env) $ python -m pip install -r requirements.txt
Collecting novas==3.1.1.3 (from -r requirements.txt (line 1))
  ...
Collecting numpy==1.9.2 (from -r requirements.txt (line 2))
  ...
Collecting requests==2.7.0 (from -r requirements.txt (line 3))
  ...
Installing collected packages: novas, numpy, requests
  Running setup.py install for novas
Successfully installed novas-3.1.1.3 numpy-1.9.2 requests-2.7.0