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

如果您正在使用Anaconda,并且只有在环境中运行pip时才会遇到此问题,则可能需要重新安装python。

在需要的环境中运行conda install python。

其他回答

我发现最直接的方法是下载和使用“DigiCert高保证EV根CA”从DigiCert https://www.digicert.com/digicert-root-certificates.htm#roots

您可以访问https://pypi.python.org/,通过点击地址栏中的锁图标来验证证书颁发者,或者通过使用openssl来增加您的极客信用:

$ openssl s_client -connect pypi.python.org:443
CONNECTED(00000003)
depth=1 /C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
verify error:num=20:unable to get local issuer certificate
verify return:0
---
Certificate chain
 0 s:/businessCategory=Private Organization/1.3.6.1.4.1.311.60.2.1.3=US/1.3.6.1.4.1.311.60.2.1.2=Delaware/serialNumber=3359300/street=16 Allen Rd/postalCode=03894-4801/C=US/ST=NH/L=Wolfeboro,/O=Python Software Foundation/CN=www.python.org
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
 1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 Extended Validation Server CA
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA

证书链中的最后一个CN值为需要下载的CA的名称。

为了一次性的努力,请执行以下操作:

从DigiCert下载对照表 将CRT转换为PEM格式 2 .将PIP_CERT环境变量导出到PEM文件所在路径下

(最后一行假设您正在使用bash shell),然后运行pip。

curl -sO http://cacerts.digicert.com/DigiCertHighAssuranceEVRootCA.crt 
openssl x509 -inform DES -in DigiCertHighAssuranceEVRootCA.crt -out DigiCertHighAssuranceEVRootCA.pem -text
export PIP_CERT=`pwd`/DigiCertHighAssuranceEVRootCA.pem

要使其可重用,请放入digicerthighassurance anceevrootca。然后在~/.bashrc中导出相应的PIP_CERT。

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。

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

你有4个选择:

使用证书作为参数

$ pip install --cert /path/to/mycertificate.crt linkchecker

使用pip.conf中的证书

创建这个文件:

$HOME/.pip/pip.conf (Linux)

%HOME%\pip\pip.ini (Windows)

然后加上这几行:

[global]
cert = /path/to/mycertificate.crt

忽略证书并使用HTTP

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

忽略证书,在pip.conf中使用HTTP

创建这个文件:

$HOME/.pip/pip.conf (Linux)

%HOME%\pip\pip.ini (Windows)

然后加上这几行:

[global]
trusted-host = pypi.python.org

https://pip.pypa.io/en/latest/user_guide/#configuration

时间和日期设置正确!

对我来说,树莓派上的日期和时间配置错误。结果是使用https://files.pythonhosted.org/服务器的所有SSL和HTTPS连接都失败了。

像这样更新:

sudo date -s "Wed Thu  23 11:12:00 GMT+1 2018"
sudo dpkg-reconfigure tzdata

或者直接与谷歌的时间连用:

Ref。https://superuser.com/a/635024/935136

sudo date -s "$(curl -s --head http://google.com | grep ^Date: | sed 's/Date: //g')"
sudo dpkg-reconfigure tzdata