STINNER Victor <vstin...@python.org> added the comment:
cc Antoine Pitrou who was involved in io module design. Currently, the io.TextIOWrapper implementation doesn't handle partial write: it doesn't fully support an unbuffered 'buffer' object. It should either handle partial write internally, or it should inject a buffered writer between itself (TextIOWrapper) and the unbuffered buffer so handling partial writes who be handled by the buffered writer. The socket.socket class has a sendall() method which helps to handle such problem. In the io module, sometimes write() can do a partial write (unbuffered writer like FileIO), sometimes it doesn't (buffered writer like BufferedWriter). == C implementation == Modules/_io/text.c. The _io_TextIOWrapper_write_impl() function puts the encoded string into an internal pending_bytes list. If needed, it calls flush(): _textiowrapper_writeflush(). The pseudo-code of _textiowrapper_writeflush() is to call "self.buffer.write(b)" where b is made of all "pending bytes". write() result is ignored: partial write is silently ignored. == Python implementation == _pyio.TextIOWrapper.write() simply calls: "self.buffer.write(b)". It ignores partial write silently. ---------- nosy: +pitrou title: Output of print() might get truncated in unbuffered mode -> io.TextIOWrapper ignores silently partial write if buffer is unbuffered _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue41221> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
