SSLError using Requests and Python 3.6 - python-3.x

Question

I'm getting an SSLError while submitting a request against https://myaccount.xcelenergy.com (and am not nearly enough of an SSL expert to understand why). Can you help me see what the issue is (and how to address it)?
Environment
macOS 10.13.2
LibreSSL 2.2.7 (installed via Homebrew)
Python 3.6.4 (installed via Homebrew)
Requests 2.18.4 (installed via pipenv)
Certifi 2017.11.5 (installed via pipenv)
Code
import requests
requests.get('https://myaccount.xcelenergy.com')
Stacktrace
Traceback (most recent call last):
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/urllib3/connectionpool.py", line 595, in urlopen
self._prepare_proxy(conn)
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/urllib3/connectionpool.py", line 816, in _prepare_proxy
conn.connect()
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/urllib3/connection.py", line 326, in connect
ssl_context=context)
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/urllib3/util/ssl_.py", line 329, in ssl_wrap_socket
return context.wrap_socket(sock, server_hostname=server_hostname)
File "/usr/local/Cellar/python3/3.6.4/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 407, in wrap_socket
_context=self, _session=session)
File "/usr/local/Cellar/python3/3.6.4/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 814, in __init__
self.do_handshake()
File "/usr/local/Cellar/python3/3.6.4/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 1068, in do_handshake
self._sslobj.do_handshake()
File "/usr/local/Cellar/python3/3.6.4/Frameworks/Python.framework/Versions/3.6/lib/python3.6/ssl.py", line 689, in do_handshake
self._sslobj.do_handshake()
ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/requests/adapters.py", line 440, in send
timeout=timeout
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/urllib3/connectionpool.py", line 639, in urlopen
_stacktrace=sys.exc_info()[2])
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/urllib3/util/retry.py", line 388, in increment
raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='myaccount.xcelenergy.com', port=443): Max retries exceeded with url: / (Caused by SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),))
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/requests/api.py", line 72, in get
return request('get', url, params=params, **kwargs)
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/requests/api.py", line 58, in request
return session.request(method=method, url=url, **kwargs)
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/requests/sessions.py", line 508, in request
resp = self.send(prep, **send_kwargs)
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/requests/sessions.py", line 618, in send
r = adapter.send(request, **kwargs)
File "/Users/abach/.local/share/virtualenvs/pyxcel-PG9DCiyE/lib/python3.6/site-packages/requests/adapters.py", line 506, in send
raise SSLError(e, request=request)
requests.exceptions.SSLError: HTTPSConnectionPool(host='myaccount.xcelenergy.com', port=443): Max retries exceeded with url: / (Caused by SSLError(SSLError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)'),))
What I've Tried (to no avail)
# Specifically calling out local cert chain:
requests.get('https://myaccount.xcelenergy.com', verify='/usr/local/etc/openssl/cert.pem')
# Using Certifi's old chain:
requests.get('https://myaccount.xcelenergy.com', verify=certifi.old_where())

Answer 1

There is currently a known issue with OSX's Python3.6 and OpenSSL that might be related to what you're seeing. I was able to fix it by installing certifi, then making a symlink in OpenSSL's directory. All of that can be done for you by running the following from bash:
Applications/Python 3.6/Install Certificates.command
See this related question: ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:747) on OS X