RemoveError: 'requests' is a dependency of conda and cannot be removed from conda's operating environment

running conda update conda before solved the problem for me

I had the same problem on Mac Mojave, and in my case run conda update --force conda first worked for me.

This worked for me on Linux:

1. Uninstall the package via pip:

   pip uninstall setuptools
   

2. Reinstall using the following command:

   conda install -c anaconda setuptools
   

Consider also that system packages (python3-setuptools, python-setuptools in Ubuntu) might need to be removed.