基于如下Linux系统版本:
1、默认情况下,Linux会自带安装Python,可以运行python --version命令查看。
[root@centos7 ~]# python --version
Python 2.7.5
我们看到Linux中已经自带了Python2.7.5。再次运行python命令后就可以使用python命令窗口了(Ctrl+D退出python命令窗口)。
2、查看Linux默认安装的Python位置
看到/usr/bin/python和/usr/bin/python2都是软链接,/usr/bin/python指向/usr/bin/python2,而/usr/bin/python2最终又指向/usr/bin/python2.7。所以运行python/python2/python2.7是一样的,如图:
3、安装python3
(1)登录https://www.python.org/downloads/source/,找到对应版本(我们以Python 3.7.6为例)如图:
执行tar -zxvf Python-3.6.5.tgz命令,将文件解压到当前目录
[root@centos7 src]# tar -zxvf Python-3.7.6.tgz
[root@centos7 src]# ls
Python-3.7.6 Python-3.7.6.tgz
(4)准备编译环境
执行如下命令:
[root@centos7 src]# yum -y install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make libffi-devel
如果python是3.7版本,还需要安装libffi-devel。
(5)编译安装
执行cd Python-3.7.6进入解压后的Python-3.7.6目录下,依次执行如下三个命令:
./configure
[root@centos7 Python-3.7.6]# ./configure prefix=/usr/local/python3.7.6
[root@centos7 Python-3.7.6]# ls
aclocal.m4 config.log configure Grammar Lib Mac Makefile.pre.in Objects PCbuild pyconfig.h.in setup.py
CODE_OF_CONDUCT.rst config.status configure.ac Include LICENSE Makefile Misc Parser Programs Python Tools
config.guess config.sub Doc install-sh m4 Makefile.pre Modules PC pyconfig.h README.rst
make
[root@centos7 Python-3.7.6]# make
[root@centos7 Python-3.7.6]# make install
我们看到,同时安装了setuptools和pip工具。
进入到/usr/local/python3.7.6安装目录。
[root@centos7 yum.repos.d]# cd /usr/local/python3.7.6/
[root@centos7 python3.7.6]# ls
bin include lib share
(6)创建软链接
Linux已经安装了python2.7.5,这里我们不能将它删除,如果删除,系统可能会出现问题。我们只需要按照与Python2.7.5相同的方式为Python3.7.6创建一个软链接即可,我们把软链接放到/usr/bin目录下。
[root@centos7 yum.repos.d]# ll /usr/bin/python
lrwxrwxrwx. 1 root root 7 Apr 19 2019 /usr/bin/python -> python2
[root@centos7 yum.repos.d]# ll /usr/bin/python2
lrwxrwxrwx. 1 root root 9 Apr 19 2019 /usr/bin/python2 -> python2.7
[root@centos7 python3.7.6]# ll /usr/bin/python2.7
-rwxr-xr-x. 1 root root 7136 Aug 4 2017 /usr/bin/python2.7
[root@centos7 python3.7.6]# ln -s /usr/local/python3.7.6/ /usr/local/python3
[root@centos7 python3.7.6]# ll /usr/local/python3
lrwxrwxrwx 1 root root 23 Jun 28 16:55 /usr/local/python3 -> /usr/local/python3.7.6/
(7)配置环境变量
[root@centos7 python3.7.6]# vim /etc/profile.d/python3_env.sh
#/bin/bash
export PYTHON_HOME=/usr/local/python3
export PATH=$PYTHON_HOME/bin:$PATH
[root@centos7 python3.7.6]# source /etc/profile.d/python3_env.sh
##验证
[root@centos7 python3.7.6]# echo $PYTHON_HOME
/usr/local/python3
此时,我们在命令窗口运行python3
[root@centos7 python3.7.6]# python3
Python 3.7.6 (default, Jun 28 2020, 16:22:55)
[GCC 4.8.5 20150623 (Red Hat 4.8.5-16)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>