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

答案非常相似,而且有点令人困惑。在我的案例中,我公司网络中的证书是问题所在。我能够使用以下方法来解决这个问题:

pip install --trusted-host files.pythonhosted.org --trusted-host pypi.org --trusted-host pypi.python.org oauthlib -vvv

如图所示。如果不需要详细输出,-vvv参数可以省略

其他回答

您可以尝试使用http而不是https来绕过SSL错误。当然,这在安全性方面并不是最优的,但如果你赶时间,它应该可以做到:

pip install --index-url=http://pypi.python.org/simple/ linkchecker

在我的例子中,我在最小的alpine docker映像中运行Python。缺少根CA证书。解决办法:

Apk更新& Apk添加ca-certificates

不要跳过!找到Linux的安全解决方案

所有使用——trusted-host将pypi.org添加到可信站点的解决方案都是不安全的,基本上跳过了https,并没有真正解决问题。 每个使用这种方法的人,请尝试以这种方式更新您的证书,并删除——trusted-host标志:

sudo yum -y update ca-certificates
export PIP_CERT=/etc/ssl/certs/ca-bundle.crt 

安全很重要!

我对pip 21.0.1有这个问题,没有一个答案对我有效。一些人通过降低pip版本来解决这个问题。

如果在2021年你仍然有这个问题,我确实降级到pip 20.2.4,现在它起作用了。

对我来说,所有建议的方法都不起作用——使用cert、HTTP、trusted-host。

在我的例子中,切换到不同版本的包是可行的(在本例中是paho-mqtt 1.3.1,而不是paho-mqtt 1.3.0)。

看来问题只针对那个版本。