centos7.2上安装python3和pip19.0.3

安装libressl

下载地址： https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-2.7.4.tar.gz

或者 ：https://pan.baidu.com/s/1zZSPmERAvkEU4-ggj-wpgA 

提取码：zusy

cd libressl-2.7.4
./configure --prefix=/usr/local
make
make install

 libressl代替openssl

vim /etc/ld.so.conf.d/local.conf  #新建local.conf文件，添加下面一行
     /usr/local/lib   # 将 /usr/local/lib 目录加入到模块加载目录。

ldconfig -v   #重新加载共享模块：
openssl version #查看版本

　　

安装python3.7 

下载链接：https://pan.baidu.com/s/1zZSPmERAvkEU4-ggj-wpgA 

提取码：zusy

 让python使用libressl ，修改如下源码包中Setup.dist文件，取消如下注释：

cd /usr/src/Python-3.7.3
./configure --prefix=/usr/local/python
make
make install

　　

vim /usr/src/Python-3.7.3/Modules/Setup.dist 
#_socket socketmodule.c
 
#SSL=/usr/local #libressl的安装目录
#_ssl _ssl.c 
#-DUSE_SSL -I$(SSL)/include -I$(SSL)/include/openssl 
#-L$(SSL)/lib -lssl -lcrypto

　　

 修改默认的python版本

rm -rf /usr/bin/python  #删除/usr/bin下面python2的超链接
ln -s /usr/local/python/bin/* /usr/bin/
ln -s /usr/bin/python3.7 /usr/bin/python

修改下面内容，否则无法使用yum

vim /usr/bin/yum
#!/usr/bin/python  ==>   #!/usr/bin/python2.7 

vi /usr/libexec/urlgrabber-ext-down
#!/usr/bin/python  ==>   #!/usr/bin/python2.7 

如果不修改urlgrabber-ext-down文件，用yum安装软件时会出现下面的情况：

Error downloading packages:
  net-tools-2.0-0.24.20131004git.el7.x86_64: [Errno 5] [Errno 2] No such file or directory

检测libressl和python3.7

[root@localhost pip-19.0.3]# ldd /usr/local/python/bin/python3 | fgrep ssl
	libssl.so.45 => /usr/local/lib/libssl.so.45 (0x00007f0636fe3000)
[root@localhost pip-19.0.3]# python
Python 3.7.3 (default, Apr 5 2019, 02:28:57) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-4)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ssl
>>>

安装pip-19.0.3

[root@localhost src]# cd pip-19.0.3/
[root@localhost pip-19.0.3]# python -V
Python 3.7.3
[root@localhost pip-19.0.3]# python setup.py install
[root@localhost ~]# ln -s /usr/local/python/bin/pip* /usr/bin/
[root@localhost ~]# ls /usr/bin/pip* -l
lrwxrwxrwx 1 root root 25 Apr 5 03:08 /usr/bin/pip -> /usr/local/python/bin/pip
lrwxrwxrwx 1 root root 26 Apr 5 03:08 /usr/bin/pip3 -> /usr/local/python/bin/pip3
lrwxrwxrwx 1 root root 28 Apr 5 03:08 /usr/bin/pip3.7 -> /usr/local/python/bin/pip3.7

重启电脑后才能使用pip install xx：