linux环境python3出现pip is configured with locations that require TLS/SSL, however the..不可用的解决方法

首先明确问题出现原因，是因为openssl版本过低或者不存在 so：

1. 查看openssl安装包，发现缺少openssl-devel包 
   [root@localhost ~]# rpm -aq|grep openssl 
   openssl-0.9.8e-20.el5 
   openssl-0.9.8e-20.el5 
   [root@localhost ~]#

2. yum安装openssl-devel 
   [root@localhost ~]# yum install openssl-devel -y 
   查看安装结果 
   [root@localhost ~]# rpm -aq|grep openssl 
   openssl-0.9.8e-26.el5_9.1 
   openssl-0.9.8e-26.el5_9.1 
   openssl-devel-0.9.8e-26.el5_9.1 
   openssl-devel-0.9.8e-26.el5_9.1

3. 重新对python3.6进行编译安装，用一下过程来实现编译安装:

cd Python-3.6.4
./configure --with-ssl
make
sudo make install

pip install pip -U

pip config set global.index-url https://pypi.tuna.tsinghua.edu.cn/simple