[Python-Dev] [IronPython] Exception for setting attributes of built-in type

[Guido van Rossum]

On Mon, Jun 15, 2009 at 9:10 AM, Michael Foord<fuzzyman at voidspace.org.uk> wrote:
> Dino Viehland wrote:
>> Guido wrote:
>>> I should add that this policy is also forced somewhat by the existence
>>> of the "multiple interpreters in one address space" feature, which is
>>> used e.g. by mod_python. This feature attempts to provide isolation
>>> between interpreters to the point that each one can have a completely
>>> different set of modules loaded and can be working on a totally
>>> different application. The implementation of CPython shares built-in
>>> types between multiple interpreters (and it wouldn't be easy to change
>>> this); if you were able to modify a built-in type from one
>>> interpreter, all other interpreters would see that same modification.

>> IronPython is in the exact same boat here - we share built-in types
>> Across multiple Python engines as well.

> And indeed it is needed - if you are working with multiple interpreters
> (engines in IronPython) you don't want isinstance(something, dict) to fail
> because it is a dictionary from a different interpreter...

Ah, but that suggests you have sharing between different interpreters.
If you're doing that, perhaps you shouldn't be using multiple
interpreters, but instead multiple threads?

-- 
--Guido van Rossum (home page: http://www.python.org/~guido/)