有些软件需要安装python2.7，但centos6默认安装的是2.6版本。但yum依赖2.6，所以不能覆盖安装。需要保留两者

编译安装python2.7

wget https://www.python.org/ftp/python/2.7.14/Python-2.7.14.tgz
tar xvf Python-2.7.14.tgz

sudo mkdir /usr/local/python2.7

cd Python-2.7.14
./configure --prefix=/usr/local/python2.7 --enable-shared
make
sudo make install

验证

cd /usr/local/python2.7/bin
./python

报错：

./python: error while loading shared libraries: libpython2.7.so.1.0: cannot open shared object file: No such file or directory

将python2.7的动态链接库加入到系统会读取的配置中

sudo vim /etc/ld.so.conf  # 在该配置文件追加一行：/usr/local/python2.7/lib
sudo ldconfig

备份原有的python

which python
# /usr/bin/python

[myhost tmp]$ md5sum /usr/bin/python /usr/bin/python2.6
8505ca7b24f60f8dca8d6d2622ed0563  /usr/bin/python
8505ca7b24f60f8dca8d6d2622ed0563  /usr/bin/python2.6

# 发现已经有python2.6，且与python的md5一致，那就不用备份直接删除了
sudo rm /usr/bin/python

编辑yum的执行程序

sudo vim /usr/bin/yum
# 将#!/usr/bin/python 中的python改为python2.6
# 即 #!/usr/bin/python2.6

执行yum验证下，没有报错就ok了

配置python2.7

sudo ln -s /usr/local/python2.7/bin/python /usr/bin/python

# 执行python
[foam@host tmp]$ python
Python 2.7.14 (default, Apr  9 2019, 17:06:25)
[GCC 4.4.7 20120313 (Red Hat 4.4.7-23)] on linux2

# ok 正常运行

# 安装pip
wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py

# 软链
sudo ln -s /usr/local/python2.7/bin/pip2.7 /usr/bin/pip

# 验证
[foam@host tmp]$ pip -V
pip 19.0.3 from /usr/local/python2.7/lib/python2.7/site-packages/pip (python 2.7)
# ok 没问题

# 为了能够愉快地在全局运行python安装的软件，将bin加入到环境变量
sudo vim /etc/profile
追加一行：export PATH=/usr/local/python2.7/bin:$PATH