update python in venv 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: python virtual environment

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

source env/bin/activate

#all this is on same directory

Example 3: venv upgrade python

python3 -m venv --upgrade ENV_DIR

Example 4: virtual env in python

pip install --user virtualenv
py -m venv env
.\env\Scripts\activate

Example 5: python virtual environment

source env/bin/activate