macos - SSL module in Python is not available (on OSX)

Question

I'm having trouble running pip install in a virtualenv on OSX 10.13. I already have run brew install openssl and the path /usr/local/include/openssl points to ../opt/openssl/include/openssl. Does anyone know how to fix this? This started happening after I reinstalled python using brew install.

pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available. Collecting Pillow Could not fetch URL https://pypi.python.org/simple/pillow/: There was a problem confirming the ssl certificate: Can't connect to HTTPS URL because the SSL module is not available. - skipping Could not find a version that satisfies the requirement Pillow (from versions: ) No matching distribution found for Pillow

UPDATE: Here's some more info:

? which python
/usr/local/opt/python/libexec/bin/python

? which pip
/usr/local/opt/python/libexec/bin/pip

? python --version
Python 3.7.4

? pip --version
pip 19.1.1 from /usr/local/lib/python3.7/site-packages/pip (python 3.7)

? brew info python
python: stable 3.7.4 (bottled), HEAD
Interpreted, interactive, object-oriented programming language
https://www.python.org/
/usr/local/Cellar/python/3.6.5_1 (4,795 files, 100.0MB)
  Poured from bottle on 2019-10-08 at 14:39:37
/usr/local/Cellar/python/3.7.4_1 (3,903 files, 60.6MB) *
  Poured from bottle on 2019-10-08 at 14:37:10
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/python.rb

Yes, I have both 3.6.5_1 and 3.7.4_1 installed as I may need to switch between the two at times.

? brew unlink openssl
Unlinking /usr/local/Cellar/openssl/1.0.2s... 0 symlinks removed

Answer 1

The ssl module as well as its underlying C extension appears to be a part of the python formula:

Mac-Admin:~ admin$ python3
Python 3.7.4 (default, Sep  7 2019, 18:27:02) 
[Clang 10.0.1 (clang-1001.0.46.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import ssl
>>> ssl
<module 'ssl' from '/usr/local/Cellar/python/3.7.4_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py'>
>>> import _ssl
>>> _ssl
<module '_ssl' from '/usr/local/Cellar/python/3.7.4_1/Frameworks/Python.framework/Versions/3.7/lib/python3.7/lib-dynload/_ssl.cpython-37m-darwin.so'>

so it being missing most probably means package installation corruption which brew reinstall python should fix.

---

Also note that while Homebrew allows multiple versions to coexist, its installation logic isn't quite designed to keep the alternative versions operational unless they are installed via a versioned formula (and e.g. routinely removes old versions in the regular brew cleanup).

So consider using pyenv (also available via brew) if you need to routinely switch between Python versions -- or some 3rd-party tap that offers versioned formulae for it.