[Python-ideas] making a module callable

[Steven D'Aprano]

On Fri, Nov 22, 2013 at 10:02:56PM +0100, Philipp A. wrote:
> we’re all accustomed to it, but objectively, it’s horribly implicit and
> unobvious.

Certainly you are correct that it is unobvious, but the "if __name__" 
idiom is anything but implicit. It's the opposite, you are *explicitly* 
testing whether the module is being run as the main module (__name__ == 
"__main__") and if so, you explicitly run some code.

Of course you can also run code only when *not* the main module:

if __name__ != '__main__':
    print "Module is being imported"
else:
    print "Module is being executed"

And you aren't limited to a single "main function", you can dot such 
tests all throughout your code, including inside functions.

Aside: perhaps it would have been better to have an explicit ismain() 
function that returns True when running as the main module, that's more 
discoverable.



-- 
Steven