NLTK download SSL: Certificate verify failed

Solution 1:

TLDR: Here is a better solution: https://github.com/gunthercox/ChatterBot/issues/930#issuecomment-322111087

Note that when you run nltk.download(), a window will pop up and let you select which packages to download (Download is not automatically started right away).

To complement the accepted answer, the following is a complete list of directories that will be searched on Mac (not limited to the one mentioned in the accepted answer): - '/Users/YOUR_USERNAME/nltk_data' - '/usr/share/nltk_data' - '/usr/local/share/nltk_data' - '/usr/lib/nltk_data' - '/usr/local/lib/nltk_data' - '/Users/YOUR_USERNAME/YOUR_VIRTUAL_ENV_DIRECTORY/nltk_data' - '/Users/YOUR_USERNAME/YOUR_VIRTUAL_ENV_DIRECTORY/share/nltk_data' - '/Users/YOUR_USERNAME/YOUR_VIRTUAL_ENV_DIRECTORY/lib/nltk_data'

In case the link above dies, here is the solution pasted in its entirety:

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()

Run the above code in your favourite Python IDE or via the command line.

Solution 2:

This works by disabling SSL check!

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()

Solution 3:

Run the Python interpreter and type the commands:

import nltk
nltk.download()

from here: http://www.nltk.org/data.html

if you get an SSL/Certificate error, run the following command

bash /Applications/Python 3.6/Install Certificates.command

from here: ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749)

Solution 4:

The downloader script is broken. As a temporal workaround can manually download the punkt tokenizer from here and then place the unzipped folder in the corresponding location. The default folders for each OS are:

• Windows: C:\nltk_data\tokenizers
• OSX: /usr/local/share/nltk_data/tokenizers
• Unix: /usr/share/nltk_data/tokenizers