[Python-Dev] extended print statement, uPre-PEP

Paul Prescod paul@prescod.net
Sun, 23 Jul 2000 10:10:00 -0500

"Barry A. Warsaw" wrote:
> >>>>> "PP" == Paul Prescod <paul@prescod.net> writes:
>     PP> I don't see what proposal you are promoting that doesn't have
>     PP> "@" in it?
> Forget about @, let's use >> instead.  

Okay, but we're still inventing a new token that doesn't exist otherwise
in the language.

There are two reasons I oppose this. 

1. On the one hand, we are making the print statement even more of a
special "syntax region" than it already is. In my opinion that's newbie
*unfriendly*. They learn how ">>" works in one place and then when they
look around for somewhere else to use it, they won't find it. I think
that that is profoundly unpythonic.

2. On the other hand, I oppose special case hacks *in general* because
when you solve a problem in one place, it doesn't solve it elsewhere.
The benefits of print are:

 * no requirement for parens
 * newline by default
 * easy string coercion and interpolation
 * less thinking about whitepspace

Okay, but what about when I want these features elsewhere in the Python
language? At least the last three should should be available everywhere
in Python.

In fact, we can do better than print:


print >> sys.stdout, 'post to', listname, 'from', sender, \
                          'size=', len(msg)

My proposal:

writeln( $"post to ${listname} from ${sender} size=${len(msg)}" )


log.writeln( $"post to ${listname} from ${sender} size=${len(msg)}")

Note that I have more control over whitespace than in your example. I am
also reusing conventions from other popular languages. The interpolation
is available *wherever* string processing is done and it uses standard
Python features to redirect the output.

 Paul Prescod - Not encumbered by corporate consensus
New from Computer Associates: "Software that can 'think', sold by 
marketers who choose not to."