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I think this may be because in Python 2, there is a coupling between stdin and stderr (in the C stdlib code) that flushes stdout when you read stdin. This doesn't seem to be required by the C std, but most implementations seem to do it. http://stackoverflow.com/questions/2123528/does-reading-from-stdin-flush-stdout
I think it was a nice feature but I can see problems with it; apps that want this behavior ought to bite the bullet and flush stdout.
Posting to python-dev as it is no more relates to the idea of improving print().sys.stdout.write() in Python 3 causes backwards incompatible behavior that breaks recipe for�unbuffered character reading from stdin on Linux -�http://code.activestate.com/recipes/134892/� At first I though that the problem is in the new�print() function, but�it appeared that the culprit is sys.stdout.write()
Attached is a test script which is a stripped down version of the recipe above.If executed with Python 2, you can see the prompt to press a key (even though output on Linux is buffered in Python 2).With Python 3, there is not prompt until you press a key.Is it a bug or intended behavior? What is the cause of this break?--�anatoly t.
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