[Python-Dev] Default metaclass in Python 3.0 modules (original) (raw)

Ben Finney bignose+hates-spam at benfinney.id.au
Tue Jul 15 12:26:41 CEST 2008

Eric Smith <eric+python-dev at trueblade.com> writes:

Ben Finney wrote: > "Benjamin Peterson" <musiccomposition at gmail.com> writes: >> Line 94-95 in unittest.py (trunk): >> # All classes defined herein are 'new-style' classes, allowing use of 'super()' >> metaclass = type > > Hmm, you're right; I see that in Python 2.5.2 'unittest.py'. > > Why is it not there in 3.0's 'unittest.py'? Is this achieved some > other way?

In 3.0 there are only new-style classes, so nothing needs to be done there.

What makes that happen in the case where a class declares no superclass? Is there an invisible enforced "metaclass = type" for every module? Where can I read about this change?

-- \ “The apparent lesson of the Inquisition is that insistence on | `\ uniformity of belief is fatal to intellectual, moral, and | o) spiritual health.” —_The Uses Of The Past, Herbert J. Muller | Ben Finney

More information about the Python-Dev mailing list