Getting adjective from an adverb in nltk or other NLP library

Question

Is there a way to get an adjective corresponding to a given adverb in NLTK or other python library. For example, for the adverb \"terribly\", I need to get

Answer 1

As MKoosej mentioned, nltk's lemmas is no longer an attribute but a method. I also made a little simplification to get the most possible word. Hope someone else can use it also:

wordtoinv = 'unduly'
s = []
winner = ""
for ss in wn.synsets(wordtoinv):
    for lemmas in ss.lemmas(): # all possible lemmas.
        s.append(lemmas)

for pers in s:
    posword = pers.pertainyms()[0].name()
    if posword[0:3] == wordtoinv[0:3]:
        winner = posword
        break

print winner # undue