I recently noticed that I am running an old version of AWS CLI that is lacking some functionality I need:
$aws --version aws-cli/1.2.9 Python/3.4.3 Linux/3.1
Currently, using pip will get you the old version of awscli, 1.18.103.
1.18.103
The latest version of aws-cli, 2.0.33 is on the v2 branch. You can download the installer for Linux, Windows and macOS from here.
2.0.33
v2