[Python-Dev] PEP 3003 - Python Language Moratorium

[Stefan Behnel]

Dino Viehland, 05.11.2009 19:35:
> Stefan wrote:
>> It /does/ make some static assumptions in that it considers builtins
>> true
>> builtins. However, it does not prevent you from replacing them in your
>> code, as long as you do it inside the module. Certainly a restriction
>> compared to Python, where you can import a module into a changed dict
>> environment that redefines 'object', but not a major restriction IMO,
>> and certainly not one that impacts much code.
> 
> To me this is a deal breaker which prevents Cython from being a Python
> implementation.  From a talk given by Colin Winter at the LLVM dev meeting
> (http://llvm.org/devmtg/2009-10/) it seems like Unladen Swallow wanted to
> do something like this as well and Guido said no.  In this case the breaking
> change is so subtle that I'd personally hate to run into something like 
> this porting code to Cython and having to figure out why it's not working.

I assume that this is artificially exaggerated to make a point, as this
behaviour is obviously not a technical requirement but an optimisation,
which could potentially be disabled.

Stefan