https://docs.anaconda.com/anaconda/user-guide/tasks/switch-environment/
first, you need to install miniconda (minimal installer for conda)
https://docs.conda.io/en/latest/miniconda.html
1. create python 2.7 environment
[lee@ko44 ~]$ conda create --name py2 python=2.7
2. create python 3.7 environment
[lee@ko44 ~]$ conda create --name py3 python=3.7
3. activate python 2 environment
[lee@ko44 ~]$ conda activate py2
then, you can see (py2) in terminal
(py2) [lee@ko44 ~]$
4. deactivate python 2 environment
(py2) [lee@ko44 ~]$ conda deactivate
then, you will not see (py2) in terminal
[lee@ko44 ~]$
