[Python-Dev] avoiding accidental shadowing of top-level libraries by the main module

[Michael Foord]

On 13/07/2010 14:00, Nick Coghlan wrote:
>> (Two different classes with the same name created - one from __main__ and
>> one from real_name.) Use cases for *genuinely* reimporting the same module
>> with different names (as different module objects rather than aliases) are
>> relatively rare, and the problem of modules *accidentally* reimporting
>> themselves not that rare.
>>      
> That particular issue can be resolved by automatically doing the
> shadowing at the sys.module level though (i.e. insert into sys.modules
> under the real module name as well as __main__ for
> runpy._run_module_as_main and just strip the directory and extension
> details from __file__ to determine where to insert the second
> reference for a directly executed script file).
>    

Sure - there are trivial workarounds which is why I don't think there 
are *many* genuine use cases for a module reimporting itself with a 
different name.

Michael

> Making sure both __main__ and the corresponding importable name refers
> to the same module object seems reasonable. Trying to special case
> shadowing detection just because the shadowing module happens to also
> be the main module seems ugly as hell :)
>
> Cheers,
> Nick.
>
>    


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