Boto3 has a pair of methods for file upload to an S3 bucket. The upload_file method accepts a file name, a bucket name, and an object name for handling large files. It does this by breaking down the files into chunks and uploading each bit in parallel.In addition, the upload_fileobj method accepts a readable file-like object which must be opened in binary mode (not text mode).
You can also learn more about uploading files in the Boto3 official documentation