Why are functions atomic?

[Alex Martelli]

Michael <michael.forbes at gmail.com> wrote:

> Is there a reason for using the closure here?  Using function defaults
> seems to give better performance:

What measurements show you that...?

brain:~ alex$ cat powi.py
def powerfactory1(exponent):
   def inner(x):
      return x**exponent
   return inner

def powerfactory2(exponent):
   def inner(x, exponent=exponent):
      return x**exponent
   return inner

brain:~ alex$ python -mtimeit -s'import powi; p=powi.powerfactory1(3)'
'p(27)'
1000000 loops, best of 3: 0.485 usec per loop

brain:~ alex$ python -mtimeit -s'import powi; p=powi.powerfactory2(3)'
'p(27)'
1000000 loops, best of 3: 0.482 usec per loop


Alex