import os
import fileinput

_path = "C://Documents and Settings//user//Desktop//file.nk"
_passes = [ 'file "BTY"','file "PUZ"','file "OCCLU"','file "MVE"','file "DPF"','file "NRM"','file "GRU"','file "FRESNEL MAT"',
 'file "SKIN REFL SPC"','file "SKIN GLOSSY REFL"','file "SKIN BRDF SPC"','file "SKIN MAT"','file "OILY SPC"','file "SCENE EYES SPEC"','file "PUZ2"',
 'file "SPEC"','file "REFL"','file "SSS"','file "ALB"','file "AMB"','file "DIF"','file "DET"']

_replaceby = " file Y:/Production/xxx/shots/here/versions/v026/version.tga"

fopen = open(_path).read()
for passe in _passeFettel:
    fopen.write(re.sub(passe, _fileFettel)