[Python-ideas] breaking out of module execution

[Ron Adam]

On 04/25/2012 02:31 PM, Georg Brandl wrote:
> On 25.04.2012 17:52, Ron Adam wrote:
>
>> Think of modules as a type of class where ...
>>
>>     import module
>>
>> is equivalent to ...
>>
>>     module module_name:
>>         <module file contents here>
>>
>> Like classes the module body would execute to define the module, and return
>> inside the module body would be a syntax error.
>
> No, sorry, that's not a good equivalence.  It reinforces the impression some
> people have of "import" working like "#include" in C or (God forbid) "require"
> in PHP.

Not quite the same thing, but I see how you would think that from the way I 
wrote the example.

I didn't mean the file to be inserted, but instead as if it was written in 
the module statement body.  That is, if we even had a "module" keyword, 
which we don't. ;-)

The point is that a module contents execute from beginning to end to create 
a module, in the same way a class's contents execute from beginning to end 
to create a class.

There are also differences, such as where a module is stored and how it's 
contents are accessed, and so they are not the same thing. You can't just 
change a class into a module and vise-versa by just changing it's header or 
moving it's body into a separate file.

I was just trying to point out a module is closer to a class than it is to 
a function, and that is a good thing.  Allowing a return or break in a 
module could make things more confusing.  Also, by not allowing return or 
breaks, it catches errors were the indentation is lost in functions or 
methods quicker.

Cheers,
   Ron