CentOS7系统默认安装了python2.7

$ python --versionPython 2.7.5

怎么安装python3？

下载python3安装包

$ wget https://www.python.org/ftp/python/3.6.3/Python-3.6.3.tgz--2018-11-27 15:16:23--  https://www.python.org/ftp/python/3.6.3/Python-3.6.3.tgz正在解析主机 www.python.org (www.python.org)... 151.101.108.223, 2a04:4e42:1a::223正在连接 www.python.org (www.python.org)|151.101.108.223|:443... 已连接。已发出 HTTP 请求，正在等待回应... 200 OK长度：22673115 (22M) [application/octet-stream]正在保存至: “Python-3.6.3.tgz”100%[====================================================================================================================================>] 22,673,115  3.94MB/s 用时 21s2018-11-27 15:16:45 (1.02 MB/s) - 已保存 “Python-3.6.3.tgz” [22673115/22673115])

$ lsPython-3.6.3.tgz$ tar -xvf Python-3.6.3.tgz$ lsPython-3.6.3  Python-3.6.3.tgz$ cd Python-3.6.3$ lsaclocal.m4    config.sub  configure.ac  Grammar  install-sh  LICENSE  Makefile.pre.in  Modules  Parser  PCbuild   pyconfig.h.in  README.rst  Toolsconfig.guess  configure   Doc           Include  Lib         Mac      Misc             Objects  PC      Programs  Python         setup.py

执行配置

$ ./configure

执行编译

make

执行安装

make install

如果需要安装失败的提示：

Traceback (most recent call last):  File "/root/downloads/Python-3.6.3/Lib/runpy.py", line 193, in _run_module_as_main    "__main__", mod_spec)  File "/root/downloads/Python-3.6.3/Lib/runpy.py", line 85, in _run_code    exec(code, run_globals)  File "/root/downloads/Python-3.6.3/Lib/ensurepip/__main__.py", line 4, in 
    
         ensurepip._main()  File "/root/downloads/Python-3.6.3/Lib/ensurepip/__init__.py", line 189, in _main    default_pip=args.default_pip,  File "/root/downloads/Python-3.6.3/Lib/ensurepip/__init__.py", line 102, in bootstrap    _run_pip(args + [p[0] for p in _PROJECTS], additional_paths)  File "/root/downloads/Python-3.6.3/Lib/ensurepip/__init__.py", line 27, in _run_pip    import pipzipimport.ZipImportError: can't decompress data; zlib not available
    

需要安装Development tools和zlib相关工具

$ yum groupinstall "Development tools"$ yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-develtk-devel gdbm-devel db4-devel libpcap-devel xz-devel

执行完后再执行安装make install

至此，安装完成。查看python3版本

$ python3 --versionPython 3.6.3

参考