def lemmatise(self, word):
lemmas = list(self._mongo_db.lemmatiser.find({'<STR_LIT>': word}))<EOL>if lemmas:<EOL><INDENT>return [lemma['<STR_LIT>'] for lemma in lemmas]<EOL><DEDENT>else:<EOL><INDENT>return [word]<EOL><DEDENT>
Tries to find the base form (lemma) of the given word, using
the data provided by the Projekt deutscher Wortschatz.  This
method returns a list of potential lemmas.

>>> gn.lemmatise(u'Männer')
[u'Mann']
>>> gn.lemmatise(u'XYZ123')
[u'XYZ123']