How to make Python use CA certificates from Mac OS TrustStore?

Mac brew install python env.

$ python3
Python 3.7.3 (v3.7.3:ef4ec6ed12, Mar 25 2019, 16:52:21) 
[Clang 6.0 (clang-600.0.57)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import certifi
>>> certifi.where()
'/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/certifi/cacert.pem'
>>> 

Or from the command line:

$ python -m certifi

then need link cacert.pem as cert.pem

$ ln -s /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/certifi/cacert.pem cert.pem
$ pwd
/Library/Frameworks/Python.framework/Versions/3.7/etc/openssl

rehash

then work fine.

This is also a problem in Python 3.6 with MacOS Sierrra. I know your use case is different. But I stumbled upon this thread while investigating this problem. So if anyone is also having this article is worth checking out:

http://www.cdotson.com/2017/01/sslerror-with-python-3-6-x-on-macos-sierra/

In a nutshell: Python 3.6 does not rely on MacOS' openSSL anymore. It comes with its own openSSL bundled and doesn't have access on MacOS' root certificates.

You have two options:

Run an install command shipped with Python 3.6

cd /Applications/Python\ 3.6/
./Install\ Certificates.command

or

Install the certifi package with

pip install certifi

I chose the first option and it worked.

Run this to set the appropriate variables. This is a combination of the answers that have already been given here. Put it in your ~/.bash_profile to make it permanent.

CERT_PATH=$(python -m certifi)
export SSL_CERT_FILE=${CERT_PATH}
export REQUESTS_CA_BUNDLE=${CERT_PATH}