[Python-Dev] python-dev Summary for 2004-10-16 through 2004-10-31 [draft]

Nick Coghlan ncoghlan at iinet.net.au
Sun Dec 12 05:10:59 CET 2004

Brett C. wrote:
> This also brought up the discussion of being able to specify a 'main' 
> function to take the place of the good old ``if __name__ == "__main__"`` 
> idiom.  Some liked the idea of allowing one to define a function named 
> 'main', others '__main__'.  But the discussion never went any farther.  
> This will require a PEP to ever even be seriously considered.

There's a PEP already - PEP 299.

The PEP actually describes a reasonable approach, since code using the current 
idiom is unlikely to define a __main__() function. However, it seems more like a 
Py3K idea, since if it's only in 2.5 and later, we'd see code like this to 
support earlier 2.x versions:

def __main__(*args):

if __name__ == "__main__":
   import sys as _sys
   if _sys.version_info < (2, 5):

Or, instead (using only the current idiom):

def _main(*args):

if __name__ == "__main__":
   import sys as _sys

So, to my mind, the backwards compatibility issue completely defeats the PEP's 
goal of finding a cleaner idiom than the current one.


Nick Coghlan   |   ncoghlan at email.com   |   Brisbane, Australia

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