how to enter my virtual environment python 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: 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