If you want to copy a python3 virtual environment to another location do the following:

sudo apt install -y python3-pip build-essential \
libssl-dev libffi-dev python3-dev python3-venv
mkdir Python-Envs
cd Python-Envs
python3.6 -m venv env

Make a entry point for the various projects

cd Python-Envs
mkdir src

To activate:

cd Python-Envs
source env/bin/activate

cd src[My project]

Do your stuff

to deactivate:

deactivate

In case you want to move a virt to another machine:
In the source env do:

pip3 freeze > requirements.txt

Copy that requirements.txt file to the other virt
in the other virt do:

pip3 install -r requirements.txt