def add_object(bucket, obj):
    """
    Upload a local file to an S3 bucket.

    :type bucket: :class:`boto.s3.bucket.Bucket`
    :param bucket: The :class:`~boto.s3.bucket.Bucket` that the file will be uploaded to.

    :type obj: string
    :param obj: The local filename.
    """
    key = bucket.new_key(obj)
    key.set_contents_from_filename(obj, policy='private')
