simple s3 file upload script

upload.py

import argparse
import os
import sys 
import threading

import boto3

from botocore.exceptions import ClientError

def get_buckets():
    return [b.name for b in boto3.resource('s3').buckets.all()]

def upload_file(file_name, bucket, object_name=None, extra_args=None):
    """Upload a file to an S3 bucket

    :param file_name: File to upload
    :param bucket: Bucket to upload to
    :param object_name: S3 object name. If not specified then file_name is used
    :return: True if file was uploaded, else False
    """

    # If S3 object_name was not specified, use file_name
    if object_name is None:
        object_name = file_name

    # Upload the file
    s3_client = boto3.client('s3')
    s3_client.upload_file(file_name, bucket, object_name,
                                     ExtraArgs=extra_args)
    location = s3_client.get_bucket_location(Bucket=bucket)['LocationConstraint']
    return f'https://{bucket}.s3-{location}.amazonaws.com/{object_name}'

def main():
    buckets = get_buckets()
    parser = argparse.ArgumentParser()
    parser.add_argument('file', help='File including latest status update for the week', nargs='?')
    parser.add_argument('bucket', help='S3 bucket to upload %(file) to', nargs='?', choices=buckets)
    parser.add_argument('--folder', help='Folder to put the file into. Example: "my-files"')
    parser.add_argument('--public-read', help='Make file readable by the public (default is not readable by the public', action='store_true')
    args = parser.parse_args()
    if args.file is None:
        args.file = input('File to upload: ')
    if args.bucket is None:
        print('Choose a bucket to upload your file to', file=sys.stderr)
        print('Buckets available:', file=sys.stderr)
        print(file=sys.stderr)
        for i, b in enumerate(buckets):
            print(f'({i+1}): {b}', file=sys.stderr)
        try:
            print(file=sys.stderr)
            idx = int(input(f'Enter your choice (1-{len(buckets)}): '))
            if idx > len(buckets):
                raise ValueError
        except (ValueError, EOFError):
            print('Invalid bucket', file=sys.stderr)
            exit(1)
        else:
            args.bucket = buckets[idx-1]
    object_name = None
    if args.folder is not None:
        object_name = f'{args.folder}/{args.file}'
    extra_args = {}
    if args.public_read is True:
        extra_args = {'ACL': 'public-read'}
    try:
        url = upload_file(args.file, args.bucket, object_name, extra_args)
        print(f'Success!!\nURL: {url}')
    except ClientError as e:
        print(f'FAILURE! Failed to upload "{args.file}" to bucket "{args.bucket}"', file=sys.stderr)
        raise e

if __name__ == '__main__':
    main()