SSL error downloading NLTK data

Question

I am trying to download NLTK 3.0 for use with Python 3.6 on Mac OS X 10.7.5, but am getting an SSL error:

import nltk
nltk.download()

Answer 1

In Finder, search for Python 3.6. It will appear under Application folder. Expand the Python 3.6 folder. Then install certificates using "Install Certificates.command".

Answer 2

To install in codestar only way is manually download modules and save them into nltk_data folder, create a lambda variable environment NLTK_DATA with valie ./nltk_data.

Answer 3

Please see answer by @doctorBroctor. It is more correct and safer to use. Leaving answer below as it might be useful for something else.

https://stackoverflow.com/a/42890688/1167890

---

This will work by disabling SSL checking.

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()

Answer 4

You don't need to disable SSL checking if you run the following terminal command:

/Applications/Python 3.6/Install Certificates.command

In the place of 3.6, put your version of Python if it's an earlier one. Then you should be able to open your Python interpreter (using the command python3) and successfully run nltk.download() there.

This is an issue wherein urllib uses an embedded version of OpenSSL that not in the system certificate store. Here's an answer with more information on what's going on.