relative path to open in py2app'ed.

can't open file even if

$py2app test.py ./hello/world.txt

to build test.app .
Can not use relative path?!
But wx.Image can handle relative path. why??
test.py

#!/usr/bin/env python
# -*- coding: us-ascii -*-
# vim: syntax=python
#

f = file('./hello/world.txt')
print f.read()
f.close()