无法获取 URL https://pypi.python.org/simple/xlrd/ [重复]答案

【问题标题】：Could not fetch URL https://pypi.python.org/simple/xlrd/ [duplicate]无法获取 URL https://pypi.python.org/simple/xlrd/ [重复]
【发布时间】：2019-03-22 19:51:37
【问题描述】：

当我尝试在我的 cmd 中运行此命令 pip install xlrd 时出现此错误。我使用了具有提升权限的 cmd 但仍然无济于事。请帮忙。非常感谢。

整个错误：

C:\Users\Rodne>pip install xlrd
Collecting xlrd
  Could not fetch URL https://pypi.python.org/simple/xlrd/: There was a problem confirming the ssl certificate: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) - skipping
  Could not find a version that satisfies the requirement xlrd (from versions: )
No matching distribution found for xlrd
You are using pip version 9.0.1, however version 18.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

我有 python 3.6

我尝试升级，结果出来了：

C:\WINDOWS\system32>pip install pip setuptools --upgrade
Could not fetch URL https://pypi.python.org/simple/pip/: There was a problem confirming the ssl certificate: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) - skipping
Requirement already up-to-date: pip in c:\users\rodne\appdata\local\programs\python\python36\lib\site-packages
Could not fetch URL https://pypi.python.org/simple/setuptools/: There was a problem confirming the ssl certificate: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) - skipping
Requirement already up-to-date: setuptools in c:\users\rodne\appdata\local\programs\python\python36\lib\site-packages
You are using pip version 9.0.1, however version 18.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

使用受信任的安装给了我这个：

C:\WINDOWS\system32>pip install --trusted-host pypi.python.org xlrd
Collecting xlrd
  Could not fetch URL https://pypi.python.org/simple/xlrd/: There was a problem confirming the ssl certificate: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) - skipping
  Could not find a version that satisfies the requirement xlrd (from versions: )
No matching distribution found for xlrd
You are using pip version 9.0.1, however version 18.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

【问题讨论】：

标签： python

【解决方案1】：

您可以设置pypi.python.org、pypi.org 和files.pythonhosted.org 受信任的主机来绕过 SSL 证书验证问题：

pip install --trusted-host=pypi.python.org --trusted-host=pypi.org --trusted-host=files.pythonhosted.org xlrd

【讨论】：

对install --upgrade也使用上述命令pip：所有三个受信任主机条目。