If you are writing a shell script for deploying your website you can probably use s3cmd and AWS CLI because these two are command line tools.
AWS CLI help you in copying files through S3 command, which would be helpful to deploy your website to an S3 bucket.
s3cmd supports all the functionalities that AWS CLI has and also has additional functionalities over it.
bott is a Python library- official AWS Python SDK which would be helpful if you are writing your website deployment scripts in Python.
Keep Learning :)