all() is slow?

[OKB (not okblacke)]

    	I noticed this (Python 2.6.5 on Windows XP):

>>> import random, timeit
>>> def myAll(x):
...     for a in x:
...         if a not in (True, False):
...             return False
...     return True
>>> x = [random.choice([True, False]) for a in xrange(0, 5000000)]
>>> timeit.timeit('myAll(x)', 'from __main__ import myAll, x', 
number=10)
0: 9.7685158309226452
>>> timeit.timeit('all(a in (True, False) for a in x)', 'from __main__ 
import x', number=10)
1: 12.348196768024984
>>> x = [random.randint(0,100) for a in xrange(0, 5000000)]
>>> def myAll(x):
...     for a in x:
...         if not a <= 100:
...             return False
...     return True
>>> timeit.timeit('myAll(x)', 'from __main__ import myAll, x', 
number=10)
4: 2.8248207523582209
>>> timeit.timeit('all(a <= 100 for a in x)', 'gc.enable(); from 
__main__ import x', number=10)
5: 4.6433557896324942

    	What is the point of the all() function being a builtin if it's 
slower than writing a function to do the check myself?

-- 
--OKB (not okblacke)
Brendan Barnwell
"Do not follow where the path may lead.  Go, instead, where there is
no path, and leave a trail."
	--author unknown