linux下安装python3与python2共存

获取资源

wget https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz

wget未安装：yum install wget -y

安装依赖

yum install zlib-devel bzip2-devel openssl-devel ncurses-devel sqlite-devel readline-devel tk-devel gcc make -y

解压安装

[root@CentOS7 ~]# cd /usr/local/src/

[root@CentOS7 ~]# wget https://www.python.org/ftp/python/3.6.2/Python-3.6.2.tar.xz

[root@CentOS7 src]# tar -Jxvf Python-3.6.2.tar.xz

[root@CentOS7 src]# cd Python-3.6.2

[root@CentOS7 Python-3.6.2]# ./configure prefix=/usr/local/python3 && make && make install

链接

[root@CentOS7 Python-3.6.2]# ln -s /usr/local/python3/bin/python3 /usr/bin/python3

[root@CentOS7 Python-3.6.2]# ll /usr/bin/py*

-rwxr-xr-x. 1 root root  78 Apr 11  2018 /usr/bin/pydoc

lrwxrwxrwx. 1 root root    7 Jul  5 11:00 /usr/bin/python -> python2

lrwxrwxrwx. 1 root root    9 Jul  5 11:00 /usr/bin/python2 -> python2.7

-rwxr-xr-x. 1 root root 7216 Apr 11  2018 /usr/bin/python2.7

lrwxrwxrwx. 1 root root  30 Nov 16 15:04 /usr/bin/python3 -> /usr/local/python3/bin/python3

或者设置默认为3版本，但是得修改yum配置

[root@CentOS7 Python-3.6.2]# vim /usr/bin/yum

#!/usr/bin/python  修改为 #!/usr/bin/python2

[root@CentOS7 Python-3.6.2]# vim /usr/libexec/urlgrabber-ext-down

#! /usr/bin/python 也要修改为 #! /usr/bin/python2

配置pip

Python3装完后，默认已经安装了pip，此时只要配置下软链接即可使用pip工具：

[root@CentOS7 Python-3.6.2]# ln -s /usr/local/python3/bin/pip3 /usr/bin/pip3