一键安装python3脚本，脚本如下，

yum install -y wget epel-release xz gcc zlib zlib-devel openssl-devel bzip2-devel expat-devel gdbm-devel readline-devel sqlite-devel
if [[ ! -s /usr/bin/python3 ]]; then
        wget http://file.aionlife.xyz/source/download?id=5b9e7227dc72d90ebb47023a -O Python-3.6.4.tar.xz  #https://www.python.org/ftp/python/3.6.4/Python-3.6.4.tar.xz(这个地址国内下载比较慢，所以这里换成另一个地址)
        tar -Jxvf Python-3.6.4.tar.xz
        cd Python-3.6.4
        ./configure --prefix=/usr/python3.6
        make&&make install
        ln -s /usr/python3.6/bin/python3 /usr/bin/python3
        mkdir ~/.pip
        echo -e "[global]\nindex-url = http://mirrors.aliyun.com/pypi/simple/\n[install]\ntrusted-host = mirrors.aliyun.com" > ~/.pip/pip.conf
        ln -s /usr/python3.6/bin/pip3 /usr/bin/pip3  
fi

上面脚本可以用vi保存成installpy3.sh 或者也可以执行如下命令来下载脚本

wget http://file.aionlife.xyz/source/download?id=5bac8dacdc72d91ff8d539fd -O installpy3.sh

执行安装脚本

bash installpy3.sh

执行下python3和pip3,如下提示就是安装成功了,原来的python版本还可以正常使用。

[root@kvm4 ~]# python3
Python 3.6.4 (default, Jul 13 2018, 19:40:36) 
[GCC 4.8.5 20150623 (Red Hat 4.8.5-28)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> 
[root@kvm4 ~]# pip3
Usage:   
  pip  [options]
Commands:
  install                     Install packages.
  download                    Download packages.
  uninstall                   Uninstall packages.
  freeze                      Output installed packages in requirements format.
  list                        List installed packages.
  show                        Show information about installed packages.
  check                       Verify installed packages have compatible dependencies.
  search                      Search PyPI for packages.
  wheel                       Build wheels from your requirements.
  hash                        Compute hashes of package archives.
  completion                  A helper command used for command completion.
  help                        Show help for commands.
General Options:
  -h, --help                  Show help.
  --isolated                  Run pip in an isolated mode, ignoring
                              environment variables and user configuration.
  -v, --verbose               Give more output. Option is additive, and can be
                              used up to 3 times.
  -V, --version               Show version and exit.
  -q, --quiet                 Give less output. Option is additive, and can be
                              used up to 3 times (corresponding to WARNING,
                              ERROR, and CRITICAL logging levels).
  --log                 Path to a verbose appending log.
  --proxy              Specify a proxy in the form
                              [user:passwd@]proxy.server:port.
  --retries          Maximum number of retries each connection should
                              attempt (default 5 times).
  --timeout              Set the socket timeout (default 15 seconds).
  --exists-action     Default action when a path already exists:
                              (s)witch, (i)gnore, (w)ipe, (b)ackup, (a)bort.
  --trusted-host    Mark this host as trusted, even though it does
                              not have valid or any HTTPS.
  --cert                Path to alternate CA bundle.
  --client-cert         Path to SSL client certificate, a single file
                              containing the private key and the certificate
                              in PEM format.
  --cache-dir 
           Store the cache data in 
.
  --no-cache-dir              Disable the cache.
  --disable-pip-version-check
                              Don't periodically check PyPI to determine
                              whether a new version of pip is available for
                              download. Implied with --no-index.