CondaValueError: Value error: prefix already exists:

Question

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

Answer 1

The next time you open the terminal and the prompt is (base) C:\Users\whatever> Just type: (base) C:\Users\whatever> conda activate ENV1

Your prompt should change to: (ENV1) C:\Users\whatever>

And once your work is done just say: (ENV1) C:\Users\whatever> conda deactivate

Because it's obviously inconvenient to keep deleting the folder over and over

Answer 2

I simply deleted folder C:\Program Files\Miniconda2\envs\ENV1\.

Answer 3

When the conda environment was previously removed, but the actual directory still exists (for some reason), then the "conda env remove -n ENV1" will do nothing:

$ conda-env list

  # conda environments:
  #
  base                  *  /home/nmanos/miniconda
  test-env                 /home/nmanos/miniconda/envs/test-env

$ conda-env remove -n ENV1
# Nothing was removed (exit code zero)   

$ ls /home/nmanos/miniconda/envs/ENV1  
  bin  conda-meta  etc  go
# Directory still exists

So you can remove the actual ENV1 directory, as follow:

$ ENV_BASE=$(conda-env list | awk '/base/ { print $NF }')
$ echo $ENV_BASE
  /home/nmanos/miniconda

$ rm -rf "$ENV_BASE/envs/ENV1"

Answer 4

You can overwrite the existing enviroment by adding the --force option.

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.