[Python-Dev] Challenge about print >> None

Vladimir Marangozov Vladimir.Marangozov@inrialpes.fr
Wed, 13 Sep 2000 15:58:53 +0200 (CEST)

Just van Rossum wrote:
> Amen.

The good thing is that we discussed this relatively in time. Like other
minor existing Python features, this one is probably going to die in
a dark corner due to the following conclusions:

1. print >> None generates multiple interpretations. It doesn't really
   matter which one is right or wrong. There is confusion. Face it.

2. For many users, "print >>None makes the '>>None' part disappear"
   is perceived as too magic and inconsistent in the face of general
   public knowledge on redirecting output. Honor that opinion.

3. Any specialization of None is bad. None == sys.stdout is no better
   than None == NullFile. A bug in users code may cause passing None
   which will dump the output to stdout, while it's meant to go into
   a file (say, a web log). This would be hard to catch and once this
   bites you, you'll start adding extra checks to make sure you're not
   passing None. (IOW, the same -1 on NullFile applies to sys.stdout)

A safe recommendation is to back this out and make it raise an exception.
No functionality of _extended_ print is lost.

whatever-the-outcome-is,-update-the-PEP'ly y'rs
       Vladimir MARANGOZOV          | Vladimir.Marangozov@inrialpes.fr
http://sirac.inrialpes.fr/~marangoz | tel:(+33-4)76615277 fax:76615252