On 3/28/06, Georg Brandl wrote:

since I found myself writing "if __name__ == '__main__'" often these days, I wondered whether PEP 299 could be pronounced upon. I'm not proposing putting it into 2.5, but it should be relatively small a change.

If you're asking for a quick pronouncement, it's going to be "no". It's not worth the change (in docs, user habits, etc.) and there's nothing particularly broken. -- --Guido van Rossum (home page: http://www.python.org/~guido/)

On 3/28/06, Charles Cazabon wrote:

It might be worth instead adding an option flag to the executable that implies "from the loaded module, run __main__() with sys.argv as its argument(s)", so the user can get this behaviour with `python -X somemodule.py`.

You can do "python -x somemodule" as long as somemodule.py uses the if __name__=='__main__' convention. What does your proposal add? -- --Guido van Rossum (home page: http://www.python.org/~guido/)

Guido van Rossum wrote:

On 3/28/06, Charles Cazabon wrote:

...

It might be worth instead adding an option flag to the executable that implies "from the loaded module, run __main__() with sys.argv as its argument(s)", so the user can get this behaviour with `python -X somemodule.py`.

You can do "python -m somemodule" as long as somemodule.py uses the if __name__=='__main__' convention. What does your proposal add?

Well, it's not really my proposal. I'm just suggesting the behaviour in PEP299 could be added via a commandline option so that it doesn't introduce backward-incompatibility. I don't see any particular benefit to PEP299 myself -- I'd rather just add an entry to the style guide about standardizing the "executable stanza" and main() function. Charles -- ----------------------------------------------------------------------- Charles Cazabon GPL'ed software available at: http://pyropus.ca/software/ -----------------------------------------------------------------------

Guido van Rossum wrote:

On 3/28/06, Charles Cazabon wrote:

...

It might be worth instead adding an option flag to the executable that implies "from the loaded module, run __main__() with sys.argv as its argument(s)", so the user can get this behaviour with `python -X somemodule.py`.

You can do "python -x somemodule" as long as somemodule.py uses the if __name__=='__main__' convention. What does your proposal add?

FWIW, you can already (Python 2.4) do something like: ------- x.py --------- import sys if __name__ == __main__: del sys.argv[0] # Get rid of reference to ourselves mod_name = sys.argv[0] # First arg is now module to be run mod = __import__(mod_name) # Run the top level module code main = mod.__main__ # Grab the main function sys.modules["__main__"] = mod # Make that module the __main__ one try: sys.argv[0] = mod.__file__ # Try to set argv[0] properly except AttributeError: pass sys.exit(main(*sys.argv)) # Run the function ------------------------- Put that in site-packages and "python -mx somemodule" will do exactly as Charles describes. Getting it to work with a filename instead of a module name would be a bit trickier, but not a lot. However, I think PEP 299 is mainly a holdover from C/C++/Java where the top level of a module is a play area for the compiler that the runtime never really gets to see. I know I found PEP 299 appealing when I first seriously started using Python, but the appeal faded over time as I got used to the idea of being able to have control logic at the top level of a module (to the point where the idea is now thoroughly *un*appealing). PEP 299's other 'use case' (trying to run another program's main function from within the current program) seems like a recipe for disaster - far better to use the subprocess module instead (since, strangely enough, application initialisation code has this tendency to assume it has sole control of the interpreter). Cheers, Nick. -- Nick Coghlan | ncoghlan@gmail.com | Brisbane, Australia --------------------------------------------------------------- http://www.boredomandlaziness.org

Guido van Rossum wrote:

Die, thread.

Do I personally have to go into svn and reject this PEP?

After my latest channeling disaster, I was cautious about this one ;) I'll reject it now. Georg