metaclasses and performance

[Mirko Dziadzka]

Hi all

I'm playing around with metaclasses and noticed, that there is small
but mesurable a performance difference in the code shown below. With a 
more complex example I get a 5 percent performance penalty for using a
metaclass. Until today I assumed, that a metaclass has no performance
impact at all after class creation. 
Can someone explain me the performance difference between the two classes
test1 and test2

Thank's in advance

    Mirko

---- cut here -----

class meta(type):
    pass

class test1(object):
    __metaclass__ = meta                # using type via meta here
    def __init__(self):
        self.foo = 42
    def get_foo(self):
        return self.foo

class test2(object):
    __metaclass__ = type                # using type directly
    def __init__(self):
        self.foo = 42
    def get_foo(self):
        return self.foo

# and here the performance test code ... it's only 2% on my machine
import time
for c in [test1, test2] * 10:
    t = c()
    start = time.time()
    for i in xrange(10 * 1000 * 1000):
        t.get_foo()
    print c.__name__, time.time() - start

---- cut here -----