WordNet in NLTK version up from 3.0 to 3.1

wn3.1.py

import os

nltkdata_wn = '/path/to/nltk_data/corpora/wordnet/'
wn31 = "http://wordnetcode.princeton.edu/wn3.1.dict.tar.gz"
if not os.path.exists(nltkdata_wn+'wn3.0'):
    os.mkdir(nltkdata_wn+'wn3.0')
os.system('mv '+nltkdata_wn+"* "+nltkdata_wn+"wn3.0/")
if not os.path.exists('wn3.1.dict.tar.gz'):
    os.system('wget '+wn31)
os.system("tar zxf wn3.1.dict.tar.gz -C "+nltkdata_wn)
os.system("mv "+nltkdata_wn+"dict/* "+nltkdata_wn)
os.rmdir(nltkdata_wn + 'dict')

# Creating lexnames file.

dbfiles = nltkdata_wn+'dbfiles'
with open(nltkdata_wn+'lexnames', 'w') as fout:
    for i,j in enumerate(sorted(os.listdir(dbfiles))):
        pos = j.partition('.')[0]
        if pos == "noun":
            syncat = 1
        elif pos == "verb":
            syncat = 2
        elif pos == "adj":
            syncat = 3
        elif pos == "adv":
            syncat = 4
        elif j == "cntlist":
            syncat = "cntlist"
        fout.write("\t".join([str(i).zfill(2),j,str(syncat)])+"\n")

from nltk.corpus import wordnet as wn

# Checking generated lexnames file.
for i, line in enumerate(open(nltkdata_wn + 'lexnames','r')):
    index, lexname, _ = line.split()
    ##print line.split(), int(index), i
    assert int(index) == i

# Testing wordnet function.
print(wn.synsets('dog'))
for i in wn.all_synsets():
    print(i, i.pos(), i.definition())