script.py

import PyQt4.QtCore as QtCore

from PyKDE4.nepomuk import Nepomuk
from PyKDE4.kdecore import KUrl


filename = 'file'
tag = 'tag1'


absolute_path = QtCore.QFileInfo(filename).absoluteFilePath()
resource = Nepomuk.File(KUrl(absolute_path))

nepomuk_tag = Nepomuk.Tag(tag)
nepomuk_tag.setLabel(tag)
resource.addTag(nepomuk_tag)