Reference:
https://uoa-eresearch.github.io/eresearch-cookbook/recipe/2014/11/20/conda/
I\'ve run the following commands to install conda and create a virtual env
You can overwrite the existing enviroment by adding the --force option.
--force
So:
conda create -n ENV1 python=2.7.12 anaconda --force
Make sure that you have updated you anaconda because it is a recent function.