David Nesting added the comment:
Thanks, Lars. And this does make complete sense to me in retrospect.
Better documentation here would help a lot. I'm happy to take a stab at this.
Short of labeling methods as "safe for streaming" versus "unsafe for
streaming"
New submission from David Nesting :
When opening a tarfile with mode "r|" (streaming mode), extractfile("filename")
and extractfile(mytarfile.getmembers()[0]) raise "tarfile.StreamError: seeking
backwards is not allowed". extractfile(mytarfile.next()) succeed
