def calc_terms(self, kwargs, f_src):
# save the original corpus
corpus_temp = kwargs["corpus"]
groups = re.match(r'/home/aplm/nltk_data/corpora/c50/(.+)', corpus_temp.root.path)
kwargs["corpus"] = LazyCorpusLoader("c50_term_SFM_23/" + groups.group(1), CategorizedPlaintextCorpusReader, r'.+/.+', cat_pattern=r'(.+)/.+')
sfm_terms = Util.calc_SFM(kwargs["corpus"].raw(fileids=[f_src]))
# restore the original corpus
kwargs["corpus"] = corpus_temp
return sfm_terms
