[Tutor] creating objects in a loop

[Erik Price]

On Tuesday, April 2, 2002, at 11:22  PM, Kirby Urner wrote:

> or do that same import at the top of some *other* module, then
> the __name__ = '__main__' condition won't be true, and no code
> will actually execute, which is good, because when I import this
> way, I'm not supplying arguments to any function and I don't want
> to actually generate a sinewave.  I'll maybe do that later, by invoking
> an internal function explicitly.

I see.  It hadn't crossed my mind that you might have a script that is 
useful both as an executable and as a library of code.  So this test 
lets you put executable code into a "protected" area that only runs if 
the script is run as a script, and not imported (because an import will 
automatically execute all code that is -not- protected in this fashion, 
won't it).  I understand now.

> The __name__ = '__main__' code block is sometimes used to
> write tests of the module's main functions.  This is in cases where
> the module is really designed to function as a module.  The only
> reason you'd run it as a standalone script is precisely to invoke
> these tests, which will confirm or disconfirm that everything is
> working properly as far as this module is concerned.

I see -- another, different use for this test.  You put "echo value" or 
something in the if __name__ = "__main__" to make sure that the function 
is declared properly, or the value was indeed created.

Are tests like this native to Python?  I mean, I understand that these 
names may be unique to Python, but do people use similar techniques to 
this in Java and C?


Erik