FIX: for SSLCertVerificationError on Mac OSX

[kodymoodley]

Hi,

For those on Mac OSX, you may receive an SSLCertVerificationError error when downloading the srl.pt tensorflow model. For example, when I run the following command stanza.Pipeline(lang='nl', processors='srl'), I get the following error:

Downloading https://raw.githubusercontent.com/stanfordnlp/stanza-resources/main/resources_1.4.0.json: 154kB [00:00, 33.1MB/s]
2022-05-19 15:09:31 INFO: Loading these models for language: nl (Dutch):
=======================
| Processor | Package |
-----------------------
| srl       | default |
=======================

2022-05-19 15:09:31 INFO: Use device: cpu
2022-05-19 15:09:31 INFO: Loading: srl
---------------------------------------------------------------------------
SSLCertVerificationError                  Traceback (most recent call last)
File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/urllib/request.py:1350, in AbstractHTTPHandler.do_open(self, http_class, req, **http_conn_args)
   1349 try:
-> 1350     h.request(req.get_method(), req.selector, req.data, headers,
   1351               encode_chunked=req.has_header('Transfer-encoding'))
   1352 except OSError as err: # timeout error

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py:1240, in HTTPConnection.request(self, method, url, body, headers, encode_chunked)
   1239 """Send a complete request to the server."""
-> 1240 self._send_request(method, url, body, headers, encode_chunked)

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py:1286, in HTTPConnection._send_request(self, method, url, body, headers, encode_chunked)
   1285     body = _encode(body, 'body')
-> 1286 self.endheaders(body, encode_chunked=encode_chunked)

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py:1235, in HTTPConnection.endheaders(self, message_body, encode_chunked)
   1234     raise CannotSendHeader()
-> 1235 self._send_output(message_body, encode_chunked=encode_chunked)

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py:1006, in HTTPConnection._send_output(self, message_body, encode_chunked)
   1005 del self._buffer[:]
-> 1006 self.send(msg)
   1008 if message_body is not None:
   1009 
   1010     # create a consistent interface to message_body

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py:946, in HTTPConnection.send(self, data)
    945 if self.auto_open:
--> 946     self.connect()
    947 else:

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/http/client.py:1409, in HTTPSConnection.connect(self)
   1407     server_hostname = self.host
-> 1409 self.sock = self._context.wrap_socket(self.sock,
   1410                                       server_hostname=server_hostname)

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py:500, in SSLContext.wrap_socket(self, sock, server_side, do_handshake_on_connect, suppress_ragged_eofs, server_hostname, session)
    494 def wrap_socket(self, sock, server_side=False,
    495                 do_handshake_on_connect=True,
    496                 suppress_ragged_eofs=True,
    497                 server_hostname=None, session=None):
    498     # SSLSocket class handles server_hostname encoding before it calls
    499     # ctx._wrap_socket()
--> 500     return self.sslsocket_class._create(
    501         sock=sock,
    502         server_side=server_side,
    503         do_handshake_on_connect=do_handshake_on_connect,
    504         suppress_ragged_eofs=suppress_ragged_eofs,
    505         server_hostname=server_hostname,
    506         context=self,
    507         session=session
    508     )

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py:1040, in SSLSocket._create(cls, sock, server_side, do_handshake_on_connect, suppress_ragged_eofs, server_hostname, context, session)
   1039             raise ValueError("do_handshake_on_connect should not be specified for non-blocking sockets")
-> 1040         self.do_handshake()
   1041 except (OSError, ValueError):

File /Library/Frameworks/Python.framework/Versions/3.8/lib/python3.8/ssl.py:1309, in SSLSocket.do_handshake(self, block)
   1308         self.settimeout(None)
-> 1309     self._sslobj.do_handshake()
   1310 finally:

SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1108)

A fix that worked for me (OSX Monterey 12.3.1, M1 pro chip) is to run the following command in the terminal:

/Applications/Python\ 3.8/Install\ Certificates.command (replace 3.8 with the specific version of Python you are using)

More info here: https://stackoverflow.com/questions/27835619/urllib-and-ssl-certificate-verify-failed-error