secure_https_url = 'https://{host}/{bucket}/{key}'.format(host=conn.
    server_name(), bucket='name-of-bucket', key='name_of_key')
http_url = 'http://{bucket}.{host}/{key}'.format(host=conn.server_name(),
    bucket='name-of-bucket', key='name_of_key')
Using Amazon s3 boto library, how can I get the URL of a saved key?