Hello, On Thu, 16 Oct 2014 07:50:02 -0700 Guido van Rossum <gu...@python.org> wrote:
[] > > > So, how readline() should behave in this case, and can that be > > > specified in the Library Reference? > > > > Well, the problem is that it's not obvious how to implement such > > methods in a non-blocking context. > > > > Let's says some data is received but there isn't a complete line. > > Should readline() return just that data (an incomplete line)? That > > breaks the API's contract. Should readline() buffer the incomplete > > line and keep it for the next readline() call? But then the > > internal buffer becomes unbounded: perhaps there is no new line in > > the next 4GB of incoming data... > > > > And besides, raw I/O objects *shouldn't* have an internal buffer. > > That's the role of the buffered I/O layer. > > > [] > (if any). If the underlying stream returns None, I think it makes > sense for readline() to return None too -- attempting to read more > will just turn into a busy-wait loop, and that's the opposite of what > should happen. > [] > > (Alternatively, we could raise BlockingIOError, which is that the OS > level read() raises if there's no data immediately available on a > non-blocking FD; but it seems that streams have already gotten a Yes, that's the choices I had in mind - either return None, or raise an exception. Thanks for confirming that None is a better choice here, that's what I implemented in MicroPython. Thanks for other points and commentary too. -- Best regards, Paul mailto:pmis...@gmail.com _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
