python3.7安装，解决pip is configured with locations that require TLS/SSL问题

python3.7安装，解决pip is configured with locations that require TLS/SSL问题
1.安装相关依赖

yum install gcc libffi-devel zlib* openssl-devel
# libffi-devel zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make

2.下载并解压
wget https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tar.xz
# 下载
wget https://www.python.org/ftp/python/3.7.1/Python-3.7.1.tar.xz
# 解压并编译：
tar -xvJf Python-3.7.1.tar.xz
cd Python-3.7.1

3.编译安装
./configure prefix=/usr/local/python3
make && make install
# 编译完成后，创建软链接文件到执行文件路径：
ln -s /usr/local/python3/bin/python3 /usr/bin/python3
ln -s /usr/local/python3/bin/pip3 /usr/bin/pip3
# 我们可以清除之前编译的可执行文件及配置文件 && 清除所有生成的文件：
make clean && make distclean

bug: 使用pip 命令失败
2.1 错误信息
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Collecting virtualenv
Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/virtualenv/
Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/virtualenv/
Retrying (Retry(total=2, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/virtualenv/
Retrying (Retry(total=1, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/virtualenv/
Retrying (Retry(total=0, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/virtualenv/
Could not fetch URL https://pypi.org/simple/virtualenv/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/virtualenv/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping
Could not find a version that satisfies the requirement virtualenv (from versions: )
No matching distribution found for virtualenv
pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
Could not fetch URL https://pypi.org/simple/pip/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/pip/ (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.")) - skipping

2.2 原因
系统版本centos6.5，其中openssl的版本为OpenSSL 1.0.1e-fips 11 Feb 2013,而python3.7需要的openssl的版本为1.0.2或者1.1.x,需要对openssl进行升级，并重新编译python3.7.0。yum 安装的openssl 版本都比较低。

2.3 升级openssl
# 1.下载openssl
wget https://www.openssl.org/source/openssl-1.1.1a.tar.gz
tar -zxvf openssl-1.1.1a.tar.gz
cd openssl-1.1.1a
# 2.编译安装
./config --prefix=/usr/local/openssl no-zlib #不需要zlib
make
make install
# 3.备份原配置
mv /usr/bin/openssl /usr/bin/openssl.bak
mv /usr/include/openssl/ /usr/include/openssl.bak
# 4.新版配置
ln -s /usr/local/openssl/include/openssl /usr/include/openssl
ln -s /usr/local/openssl/lib/libssl.so.1.1 /usr/local/lib64/libssl.so
ln -s /usr/local/openssl/bin/openssl /usr/bin/openssl
# 5.修改系统配置
## 写入openssl库文件的搜索路径
echo "/usr/local/openssl/lib" >> /etc/ld.so.conf
## 使修改后的/etc/ld.so.conf生效
ldconfig -v
# 6.查看openssl版本
openssl version