Message 416690 - Python tracker

BZ2File doesn't have attribute name, unlike GzipFile which has it. Trying to access that attribute results in error.

PR is ready with code changes and tests which mimics what is already available for GzipFile (e.g. we do not take name from BytesIO() objects because they do not have it).
A similar PR is ready for LZMAFile as well (a different enhancement).