Python 爬虫初学，urlopen 出错？

Question

代码如下： import urllib.request response = urllib.request.urlopen('https://www.python.org') print(type(response)) print(response.read().decode('utf-8'))错误信息如下：Traceback (most recent call last):  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1317, in do_open    encode_chunked=req.has_header('Transfer-encoding'))  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1229, in request    self._send_request(method, url, body, headers, encode_chunked)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1275, in _send_request    self.endheaders(body, encode_chunked=encode_chunked)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1224, in endheaders    self._send_output(message_body, encode_chunked=encode_chunked)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1016, in _send_output    self.send(msg)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 956, in send    self.connect()  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1392, in connect    server_hostname=server_hostname)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 412, in wrap_socket    session=session  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 853, in _create    self.do_handshake()  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 1117, in do_handshake    self._sslobj.do_handshake()ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1056)During handling of the above exception, another exception occurred:Traceback (most recent call last):  File "<input>", line 1, in <module>  File "/Applications/PyCharm.app/Contents/helpers/pydev/_pydev_bundle/pydev_umd.py", line 197, in runfile    pydev_imports.execfile(filename, global_vars, local_vars)  # execute the script  File "/Applications/PyCharm.app/Contents/helpers/pydev/_pydev_imps/_pydev_execfile.py", line 18, in execfile    exec(compile(contents+"\n", file, 'exec'), glob, loc)  File "/Users/awake/PycharmProjects/untitled/venv/Hello.py", line 4, in <module>    response = urllib.request.urlopen('https://www.python.org')  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 222, in urlopen    return opener.open(url, data, timeout)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 525, in open    response = self._open(req, data)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 543, in _open    '_open', req)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 503, in _call_chain    result = func(*args)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1360, in https_open    context=self._context, check_hostname=self._check_hostname)  File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1319, in do_open    raise URLError(err)urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1056)>