how to run or activate a virtual environment python code example

Example 1: virtual env create python

#------FOR LINUX/MAC---------#
#installing venv 
sudo apt-get install python3.6-venv
#creating virtual env
python3 -m venv env
#activating virtual env
source env/bin/activate


#-------FOR WINDOWS----------#
#installing venv
py -m pip install --user virtualenv
#creating virtual env
py -m venv env
#activating virtual env
.\env\Scripts\activate

Example 2: activate venv in python

(tutorial-env) $ python -m pip install --upgrade requests
Collecting requests
Installing collected packages: requests
  Found existing installation: requests 2.6.0
    Uninstalling requests-2.6.0:
      Successfully uninstalled requests-2.6.0
Successfully installed requests-2.7.0