python脚本使用源码安装不同版本的python

# coding=utf-8

import os
import sys

# 判断是否是root用户
if os.getuid() == 0:
    pass
else:
    print('当前用户不是root用户，请以root用户执行脚本')
    sys.exit(1)

version = raw_input('请输入您想安装的python版本(2.7/3.5)')
if version == '2.7':
    url = "https://www.python.org/ftp/python/2.7.15/Python-2.7.15.tar.xz"
elif version == '3.5':
    url = "https://www.python.org/ftp/python/3.5.7/Python-3.5.7.tar.xz"
else:
    print "您输入的版本号有误，请输入2.7或者3.5"
    sys.exit(1)

cmd = 'wget ' + url
res = os.system(cmd)
if res != 0:
    print '下载源码包失败，请检查网络'
    sys.exit(1)

if version == '2.7':
    package_name = 'Python-2.7.15'
else:
    package_name = 'Python-3.5.7'
cmd = 'tar xf ' + package_name + '.tar.xz'

res = os.system(cmd)
if res != 0:
    os.system('rm -f ' + package_name + '.tar.xz')
    print '解压源码包失败，请重新运行这个脚本下载源码包'
    sys.exit(1)

cmd = 'cd ' + package_name + '&& ./configure -- prefix=/usr/local/python'+ version + ' && make && make install'
res = os.system(cmd)
if res != 0:
    print '编译python源码包失败，请检查是否缺少依赖库'
    sys.exit(1)