使用NLTK与Open Multilingual Wordnet的语言显示异常问题

• 已下载wordnet和omw-1.4扩展包，但调用wnet.langs()仅返回['eng']，未按预期显示其他支持语言
• 查询葡萄牙语单词casa的synsets时，返回的是英文Synset对象，但调用synonyms()方法能正常返回葡萄牙语同义词结果

相关代码及输出： #

import nltk
nltk.download('wordnet')
nltk.download('omw-1.4')

# 下载日志输出
[nltk_data] Downloading package wordnet to /root/nltk_data...
[nltk_data]   Package wordnet is already up-to-date!
[nltk_data] Downloading package omw-1.4 to /root/nltk_data...
[nltk_data]   Package omw-1.4 is already up-to-date!
True

from nltk.corpus import wordnet as wnet
sorted(wnet.langs())
# 输出: ['eng']

wnet.synsets("casa", lang='por')
# 输出:
[Synset('apartment.n.01'),
 Synset('building.n.01'),
 Synset('chalet.n.01'),
 Synset('cringle.n.01'),
 Synset('detached_house.n.01'),
 Synset('dwelling.n.01'),
 Synset('house.n.01'),
 Synset('house.n.12'),
 Synset('housing.n.01'),
 Synset('theater.n.01'),
 Synset('house.n.06'),
 Synset('manufacturer.n.01'),
 Synset('family.n.01'),
 Synset('residence.n.01'),
 Synset('domicile.n.01'),
 Synset('home.n.01'),
 Synset('home.n.06'),
 Synset('home.n.07')]

wnet.synonyms("casa",lang='por')
# 输出:      
[['apartamento', 'aposentos'],
     ['edifício', 'edifícios', 'prédio'],
     ['chalé'],
     ['ilhó'],
     [],
     ['aposento',
      'domicílio',
      'habitação',
      'lar',
      'morada',
      'moradia',
      'residência'],
     ['Habitações',
      'edifícios_residenciais',
      'firma',
      'habitação',
      'teatro',
      'vivenda'],
     [],
     ['abrigo', 'abrigos', 'alojamentos'],
     ['teatro'],
     [],
     ['fabricante'],
     ['agregado_familiar',
      'classe',
      'família',
      'linhagem',
      'pessoa_da_família_que_mora_na_mesma_casa'],
     ['domicílio', 'residência'],
     ['domicílio'],
     ['Lar', 'lar'],
     ['lar'],
     ['lar']]

内容的提问来源于stack exchange，提问作者Douglas