How to uninstall aws-cli
I had a similar issue. Answering in case someone else does too. I think I had originally installed it without pip like this: https://docs.aws.amazon.com/cli/latest/userguide/awscli-install-bundle.html. So you just need to uninstall it like this (as instructed in above link):
$ sudo rm -rf /usr/local/aws
$ sudo rm /usr/local/bin/aws
Then you can re-install it with pip3: https://docs.aws.amazon.com/cli/latest/userguide/cli-install-macos.html
Basically:
pip3 install awscli --upgrade --user
Then add it to your path
export PATH=/Users/yourname/Library/Python/3.6/bin/:$PATH
On ubuntu :
sudo apt-get remove --auto-remove awscli
ln -s /home/ubuntu/.local/bin/aws /usr/bin/aws