upload_file.py

import boto3
# other libs import

s3 = boto3.client(
    's3',
    aws_access_key_id=AWS_ACCESS_KEY,
    aws_secret_access_key=AWS_SECRET_KEY,
    region_name=AWS_REGION_NAME
)

file_extension = file_attachment.filename.rsplit('.', 1)[1].lower()
if '.' in file_attachment.filename and not file_extension in ALLOWED_FILE_EXTENSIONS:
    return {
        "message": "File extension is not one of our supported types."
    }, 400

filename = "%s_%s" % (int(time.time()), file_attachment.filename)
s3_path = "%s/%s/%s" % (datetime.now().year,
                        datetime.now().strftime('%m'), filename)

try:
    s3.upload_fileobj(
        file_attachment, S3_BUCKET_ATTACHMENT, s3_path)
except Exception as e:
    return {"message": str(e)}, 402

file_attachment = FileAttachment(
    user_id=current_user_id,
    file_name=file_attachment.filename,
    s3_path=s3_path
)