[Python-3000] [Python-ideas] Namespaces are one honking great idea -- let's do more of those!

[Stephen J. Turnbull]

Christian Heimes writes:

 > > Having to type "python3.0" explicitly strikes me as unnecessarily verbose.
 > 
 > +1

It won't once python 3.1 is released.

 > > As for module file name extensions, what speaks against allowing (not
 > > mandating) "py3" for Python 3.x modules?

Namespace pollution, of various kinds.  Python 3.x modules will
already be placed in python3.x/site-packages anyway.

I know that in Emacs we have a registry for which mode should be used
by default for files with names matching a given regexp.  The initial
registry basically stabilized a few years back, because new
applications were bumping into extensions (the regexps are 95% of the
form "\\.abc$") previously claimed.

I think this is precisely analogous to recognizing which interpreter
should be used by extension, as well as being a practical case where
you're likely to get immediate pushback.

 > File extensions are only important on Windows. Or does anybody know a
 > system which starts scripts based on the extension like Windows does?

Mac OS X's open command does something according to extension:

chibi:tmp steve$ echo 'print "hello, world"' >> hello.py
chibi:tmp steve$ python hello.py 
hello, world
chibi:tmp steve$ open hello.py 
chibi:tmp steve$ 

I don't know what, though.  The disk spun, I waited a second, and then
the prompt returned. :-)

 > I see two ways to solve the program for Windows:
 > 
 > *  register additional file extensions for each Python version
 >    like .py26, .pyw26 (for pythonw.exe), .py30 etc.

FWIW, I can tell you that Skip will get pushback from me if he
proposes registering those extensions in XEmacs's auto-mode-alist.  I
won't absolutely veto it, but I'll certainly suggest to the other
reviewers that this is a bad idea.

 > * Write a wrapper for Windows which inspects the first line of
 >   a script, searches for "#! ... python2.6" or "#!python26" and
 >   starts the right interpreter.

How about a wrapper which (like the Unix shells) starts the
interpreter from the file named in the shebang if any, and provide a
tool for updating shebangs conveniently (for the user) and
automatically (for installers).

Of course you need to make sure that this wrapper doesn't use any
Python 3000 features.<wink>