Centos7安装Python2.7

目前Linux 默认自带安装python 2, 后续由于多种原因配置安装了python3 (3.6 or 3.7) 后，发现误操作 python2 不可用，且安装文件已丢失。需要重新安装，在此仅仅记录个人在已安装python高版本情况下，重装低版本过程。过程入错错误，请留言指正！仅为随笔。

1. 官网下载相应的Python 安装包（python2.7 ）此处

官网下载路径：

https://www.python.org/downloads/release/python-2716/

Note： 

 

2. 安装

1）将下载好的压缩包，上传到服务器的某个目录下
      # cd /usr/local/

[root@bogon bin]# cd /usr/local/
[root@bogon local]# ls
bin  games    lib    libexec  postgresql  Python-2.7.16      python3    sbin   src
etc  include  lib64  man      python27    Python-2.7.16.tgz  python3.7  share

2）# 解压

      tar -xvzf Python-2.7.16.tgz

3) # 创建安装文件夹

      mkdir /usr/local/python27

       

4）# 编译安装

     cd Python-2.7.16

      ./configure --prefix=/usr/local/python27 --with-threads --enable-shared

       make && make altinstall

 5)  #替换以前的python默认版本（创建新的软连接）

        # cd /usr/bin/

        # rm -rf python

        # ln -s /usr/local/python27/bin/python2.7 ./python

        # ls -l  # 查询 /usr/bin/  软连接

 

 6) # 验证 python version

     python --version

[root@bogon local]# python --version
Python 2.7.5
[root@bogon local]#

7) 执行python 报错

      python

[root@bogon lib]# python
Could not find platform independent libraries 
Could not find platform dependent libraries 
Consider setting $PYTHONHOME to [:]
ImportError: No module named site
[root@bogon lib]#
[root@bogon lib]#

解决方法：

1. 查询GCC version

[root@bogon bin]#
[root@bogon bin]# gcc --version
gcc (GCC) 7.3.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[root@bogon bin]# 

2. 配置环境变量

   export PYTHONHOME=/usr/local/python27

    

   export PYTHONPATH=$PYTHONPATH:/usr/local/python27/lib/python2.7

到此 执行python 没问题了

此时验证GCC:

[root@bogon local]# gcc --version
gcc (GCC) 7.3.0
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

[root@bogon local]# python
Python 2.7.5 (default, Oct 14 2020, 14:45:30)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-44)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>>