http://docs.python.org/library/os.html#os.access

points out that I should use
try:
    fp = open("myfile")
except IOError as e:
    if e.errno == errno.EACCESS:
        return "some default data"
    # Not a permission error.
    raise
else:
    with fp:
        return fp.read()

but theres a typo the correct is errno.EACCES: not errno.EACCESS: