NLTK下载SSL:证书验证失败

import nltk
nltk.download()

尝试为nltk安装Punkt时出现以下错误:

nltk.download('punkt') [nltk_data] Error loading Punkt: False

如果上面的链接死掉,这里是完整粘贴的解决方案:

import nltk
import ssl

try:
    _create_unverified_https_context = ssl._create_unverified_context
except AttributeError:
    pass
else:
    ssl._create_default_https_context = _create_unverified_https_context

nltk.download()

Python IDE中或通过命令行运行上面的代码.