I did some quick measures out of curiosity. Performances seems clearly filesystem and O.S. dependent (and are likely deployment/configuration dependent). I did each test 3 times to ensure measure where consistent. Tests were done with ActivePython 2.6.3.7. * AIX 5.3: python26 -m timeit -s 'def f(): pass' 'f()' 1000000 loops, best of 3: 0.336 usec per loop cwd is NFS mount: users/baplepil/sandbox> python26 -m timeit -s 'from os import getcwd' 'getcwd()' 1000 loops, best of 3: 1.09 msec per loop cwd is /tmp: /tmp> python26 -m timeit -s 'from os import getcwd' 'getcwd()' 1000 loops, best of 3: 323 usec per loop * Solaris 10 (Sparc): python26 -m timeit -s 'def f(): pass' 'f()' 1000000 loops, best of 3: 0.495 usec per loop cwd is NFS mount: users/baplepil/sandbox> python26 -m timeit -s 'from os import getcwd' 'getcwd()' 100000 loops, best of 3: 12.1 usec per loop cwd is /tmp: /tmp> python26 -m timeit -s 'from os import getcwd' 'getcwd()' 100000 loops, best of 3: 4.58 usec per loop * Windows XP SP2: python -m timeit -s "def f(): pass; f()" 10000000 loops, best of 3: 0.0531 usec per loop cwd is network drive (same as previous NFS mount): R:\...\users\baplepil>python -m timeit -s "from os import getcwd" "getcwd()" 100000 loops, best of 3: 5.14 usec per loop cwd is C:\temp>: C:\temp>python -m timeit -s "from os import getcwd" "getcwd()" 100000 loops, best of 3: 4.27 usec per loop 2010/2/17 Dan Villiom Podlaski Christiansen <danchr@gmail.com>
On 7 Feb 2010, at 05:27, exarkun@twistedmatrix.com wrote:
Do you know of a case where it's actually slow? If not, how convincing should this argument really be? Perhaps we can measure it on a few platforms before passing judgement.