[Python-Dev] New lines, carriage returns, and Windows (original) (raw)

Nick Maclaren nmm1 at cus.cam.ac.uk
Sun Sep 30 15:38:12 CEST 2007

skip at pobox.com wrote:

I've been thinking about this some more (in lieu of actually writing up any sort of proposal ;-) and I'm not so sure it would be all that useful. If you've opened a file in text mode you should only be writing newlines as '\n' anyway. If you want to translate a text file imported from another system to use the current system's line ending just open both the input and output files in text mode.

I.e. at least \r, \f and \v are discouraged - i.e. system-dependent, at best. That works.

With universal newlines mode for output, should writing '\r\n' result in one or two newlines (or one-and-a-half)? Depending on the platform you can argue that it should write out '\r\r', '\r\n\r\n' or '\n\n' or if on Windows that it should be left alone as '\r\n'. There is, of course, the current '\r\r\n' behavior as well. I don't think there's obviously one best answer.

Quite. And it has nothing to do with the format the outside system uses - your first question is purely a matter of what the semantics of the Python program are. The question applies as much to zOS as to any of the systems Python supports.

If you want to do something esoteric, open the file in binary mode and do whatever you like.

Er, no. That's the Unix mistake. It works, provided two things are true:

1) You don't need to write portable formatting.

2) The 'outside system' uses the control characters of a byte

stream for formatting.

Let's skip (1) - but (2) is universally true, nowadays, isn't it? Er, no. Consider reading and writing to an X window (NOT an xterm). Such formatting is out-of-band (sorry, I used out-of-bound in a previous posting).

Ouch.

Regards, Nick Maclaren, University of Cambridge Computing Service, New Museums Site, Pembroke Street, Cambridge CB2 3QH, England. Email: nmm1 at cam.ac.uk Tel.: +44 1223 334761 Fax: +44 1223 334679

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