Martin Panter added the comment: It looks like the C _io close() implementations delegate to the wrapped object’s undocumented _dealloc_warn() method to emit the warning if “self->finalizing” is set. For wrapped objects like BytesIO that do not have it, I guess the error due to the missing method is ignored.
There is no Python implementation of FileIO yet (see Issue 21859), so the Python file wrapper classes still use the C FileIO implementation, which emits a resource warning. However for the wrapper classes, _pyio.IOBase.__del__() explicitly invokes the wrapper’s close() method, which will invoke FileIO.close() method, which bypasses the warning. Similarly, any object inheriting from the C implmentation’s _io.IOBase will also have close() explicitly invoked when being finalized, bypassing any warnings of the underlying wrapped object. The SocketIO instances returned by socket.makefile() are an example of this. ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue19829> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
