我对Python非常陌生,并试图在Windows 7上安装链接检查器。一些注意事项:

pip install is failing no matter the package. For example, > pip install scrapy also results in the SSL error. Vanilla install of Python 3.4.1 included pip 1.5.6. The first thing I tried to do was install linkchecker. Python 2.7 was already installed, it came with ArcGIS. python and pip were not available from the command line until I installed 3.4.1. > pip search linkchecker works. Perhaps that is because pip search does not verify the site's SSL certificate. I am in a company network but we do not go through a proxy to reach the Internet. Each company computer (including mine) has a Trusted Root Certificate Authority that is used for various reasons including enabling monitoring TLS traffic to https://google.com. Not sure if that has anything to do with it.

下面是运行pip install linkchecker后我的pip.log的内容:

Downloading/unpacking linkchecker
  Getting page https://pypi.python.org/simple/linkchecker/
  Could not fetch URL https://pypi.python.org/simple/linkchecker/: connection error: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:598)
  Will skip URL https://pypi.python.org/simple/linkchecker/ when looking for download links for linkchecker
  Getting page https://pypi.python.org/simple/
  Could not fetch URL https://pypi.python.org/simple/: connection error: HTTPSConnectionPool(host='pypi.python.org', port=443): Max retries exceeded with url: /simple/ (Caused by <class 'http.client.CannotSendRequest'>: Request-sent)
  Will skip URL https://pypi.python.org/simple/ when looking for download links for linkchecker
  Cannot fetch index base URL https://pypi.python.org/simple/
  URLs to search for versions for linkchecker:
  * https://pypi.python.org/simple/linkchecker/
  Getting page https://pypi.python.org/simple/linkchecker/
  Could not fetch URL https://pypi.python.org/simple/linkchecker/: connection error: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:598)
  Will skip URL https://pypi.python.org/simple/linkchecker/ when looking for download links for linkchecker
  Could not find any downloads that satisfy the requirement linkchecker
Cleaning up...
  Removing temporary dir C:\Users\jcook\AppData\Local\Temp\pip_build_jcook...
No distributions at all found for linkchecker
Exception information:
Traceback (most recent call last):
  File "C:\Python34\lib\site-packages\pip\basecommand.py", line 122, in main
    status = self.run(options, args)
  File "C:\Python34\lib\site-packages\pip\commands\install.py", line 278, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
  File "C:\Python34\lib\site-packages\pip\req.py", line 1177, in prepare_files
    url = finder.find_requirement(req_to_install, upgrade=self.upgrade)
  File "C:\Python34\lib\site-packages\pip\index.py", line 277, in find_requirement
    raise DistributionNotFound('No distributions at all found for %s' % req)
pip.exceptions.DistributionNotFound: No distributions at all found for linkchecker

当前回答

尽管有40个答案,但我认为没有一个完全解决了我的问题。

我在macOS Catalina 10.15.5上,在公司代理的后面。

在尝试安装或升级包时,提示以下错误

>>> pip install <package name>                                                                                                                           

Looking in indexes: https://pypi.org/simple, https://data:****@pypi.<company>.com/simple/
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1108)'))': <package name>
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1108)'))': <package name>

@Steve_Tauber的回答pip——cert /etc/ssl/certs/FOO_Root_CA。Pem安装链接检查器让我的方式有一部分。

我能够使用现有的cert文件成功安装包,如下所示:

pip install --cert /Users/me/opt/anaconda3/ssl/cert.pem --upgrade pip

但是我不想每次使用pip时都使用cert标志…

答案是更新环境变量:

CERT_PATH=/Users/me/opt/anaconda3/ssl/cert.pem
export SSL_CERT_FILE=${CERT_PATH}
export REQUESTS_CA_BUNDLE=${CERT_PATH}

现在我可以安装了。

其他回答

您可以通过以下方法解决CERTIFICATE_VERIFY_FAILED问题:

Use HTTP instead of HTTPS (e.g. --index-url=http://pypi.python.org/simple/). Use --cert <trusted.pem> or CA_BUNDLE variable to specify alternative CA bundle. E.g. you can go to failing URL from web-browser and import root certificate into your system. Run python -c "import ssl; print(ssl.get_default_verify_paths())" to check the current one (validate if exists). OpenSSL has a pair of environments (SSL_CERT_DIR, SSL_CERT_FILE) which can be used to specify different certificate databasePEP-476. Use --trusted-host <hostname> to mark the host as trusted. In Python use verify=False for requests.get (see: SSL Cert Verification). Use --proxy <proxy> to avoid certificate checks.

阅读更多:TLS/SSL包装套接字对象-验证证书。

在64位Windows 7企业版上尝试使用ActivePython 2.7.8、ActivePython 3.4.1和“库存”Python 3.4.2安装pip ftputil时遇到同样的问题。所有尝试都失败了,错误与OP相同。

通过降级到pip 1.2.1来解决Python 3.4.2的问题:easy_install pip==1.2.1(参见https://stackoverflow.com/a/16370731/234235)。同样的修复也适用于ActivePython 2.7.8。

2013年3月报告的这个漏洞仍然存在:https://github.com/pypa/pip/issues/829。

Kenorb的回答非常有用(而且很棒!) 在他的解决方案中,这可能是最简单的一个: ——可信主机

例如,在这种情况下你可以这样做

pip install --trusted-host pypi.python.org linkchecker

pem文件(或任何其他文件)是不必要的。

我也遇到过类似的问题。对我有效的解决方法 1)卸载python 2.7 2)删除python27文件夹 3)重新安装最新的python

如果您的系统中缺少某些证书,则可能会遇到此问题。在opensuse上安装ca-certificates-mozilla