import nltk

nltk.download('punkt')    

 [nltk_data] Error loading Punkt: <urlopen error [SSL:

 [nltk_data]     CERTIFICATE_VERIFY_FAILED] certificate verify failed

 [nltk_data]     (_ssl.c:590)>

False

if __name__ == '__main__':

    import ssl

    try:

        _create_unverified_https_context = ssl._create_unverified_context

    except AttributeError:

        pass

    else:

        ssl._create_default_https_context = _create_unverified_https_context

    import nltk

    nltk.download('punkt')

    print('end')