nekto@darkstar:~/workspace/py3k$ time ./python test_first.py

real	0m1.004s
user	0m0.070s
sys	0m0.030s


nekto@darkstar:~/workspace/py3k$ time ./python test_first.py

real	0m26.106s
user	0m0.360s
sys	0m1.050s


nekto@darkstar:~/workspace/py3k$ cat test_first.py
import os

os.chdir('/tmp')


for i, entry in enumerate(os.listdir('.')):
	if i == 1000:
		break