今天是我第一次使用python的urllib.request.openurl 功能获取网页信息，代码如下
# 获取网络文件
from urllib.request import urlopen
with urlopen(url='https://book.douban.com/subject/1005022/') as f:
for line in f.readlines():
print(line, end='')
一个4行的代码，完成了java中几十行的功能，但是。。。。
别人运行一点问题都没有，为什么我的运行起来报错了？
错误代码基本如下(解决以后才写的，所以错误代码也不是我的，错误代码运行的机器是)：
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1318, 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 1239, 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 1285, 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 1234, 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 1026, in _send_output
self.send(msg)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 964, in send
self.connect()
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/http/client.py", line 1400, in connect
server_hostname=server_hostname)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 407, in wrap_socket
_context=self, _session=session)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 814, in __init__
self.do_handshake()
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/ssl.py", line 1068, in do_handshake
self._sslobj.do_handshake()
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/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/a-nguyen/Downloads/EzSorses/APAsauce.py", line 3, in <module>
u1 = urllib.request.urlopen(url)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 223, in urlopen
return opener.open(url, data, timeout)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 526, in open
response = self._open(req, data)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 544, in _open
'_open', req)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 504, in _call_chain
result = func(*args)
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/urllib/request.py", line 1361, 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 1320, in do_open
raise URLError(err)
urllib.error.URLError: <urlopen error [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:777)>
解决方案是：通过控制台运行/Application/Python 3.x(版本号)/install certificates.command
指令为： /Applications/Python\ 3.7/Install\ Certificates.command在/Application/python 3.7/ReadMe.rtf 中提到了这个问题，原文为：Certificate verification and OpenSSL
This variant of Python 3.7 includes its own private copy of OpenSSL 1.1.0. The deprecated Apple-supplied OpenSSL libraries are no longer used. This means that the trust certificates in system and user keychains managed by the Keychain Access application and the security command line utility are no longer used as defaults by the Python ssl module. A sample command script is included in /Applications/Python 3.7 to install a curated bundle of default root certificates from the third-party certifi package (https://pypi.org/project/certifi/). If you choose to use certifi, you should consider subscribing to the project's email update service to be notified when the certificate bundle is updated.
python 3.7 的该版本包括了他自己私有的OpenSSL 1.1.0 副本。被弃用的苹果支持的 OpenSSL 库已经不再使用。这意味着系统认证和用户通过密钥访问应用或控制台进行密钥管理已经不再用于默认的python ssl 模版。一个简单的命令行文件已经包括在/Applications/python3.7下，用于为默认的root认证从第三部分的certifi包中安装辅助包，如果你选择适用certifi，你应该思考订阅项目的email升级服务，关注捆绑包的升级。
官方网站对此问题的描述和解决：https://bugs.python.org/issue28150
