安装numpy失败：Could not find a version that satisfies the requirement numpy (from versions: none)

1、背景

错误信息：Could not find a version that satisfies the requirement numpy (from versions: none)

2、方法

找到pip.ini 文件， 一般再c:\users\用户名\AppData\Roaming\pip

把pip.ini 改成如下：（这个是加了多个镜像的源）

[global]
timeout=60
index-url=https://pypi.tuna.tsinghua.edu.cn/simple/
extra-index-url=
        https://mirrors.aliyun.com/pypi/simple/
        https://pypi.douban.com/simple
        https://pypi.mirrors.ustc.edu.cn/simple/
 
[install]
trusted-host=
        pypi.tuna.tsinghua.edu.cn
        mirrors.aliyun.com
        pypi.douban.com
        pypi.mirrors.ustc.edu.cn