def check_lowercase_bucketname(n):
    if not (n + 'a').islower():
        raise BotoClientError("Bucket names cannot contain upper-case " \
            "characters when using either the sub-domain or virtual " \
            "hosting calling format.")
    return True
Bucket names must not contain uppercase characters. We check for
dataset/ETHPy150Open darcyliu/storyboard/boto/s3/connection.py/check_lowercase_bucketname