Linux设置Python的默认版本

1. 查看

# 查看系统中的Python版本
ls /usr/bin/python*


/usr/bin/python            /usr/bin/python3.5m
/usr/bin/python2           /usr/bin/python3.6
/usr/bin/python2.7         /usr/bin/python3.6-config
/usr/bin/python2.7-config  /usr/bin/python3.6m
/usr/bin/python2-config    /usr/bin/python3.6m-config
/usr/bin/python3           /usr/bin/python3m
/usr/bin/python3.5         /usr/bin/python-config

# 查看系统默认的Python版本
python


Python 2.7.12 (default, Oct  8 2019, 14:14:10) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.

2. 更改

方法一：别名Alisa

• 进入用户配置文件

vim ~/.bashrc

• 添加别名

alias python='/usr/bin/python3.6'

• 使得更改即时生效

source ~/.bashrc

• 检验

python

Python 3.6.8 (default, Oct  9 2019, 14:04:01) 
[GCC 5.4.0 20160609] on linux
Type "help", "copyright", "credits" or "license" for more information.

该方法成功

方法二：设置系统变量

• 进入用户配置文件

vim ~/.bahsrc

• 添加环境变量

export PYTHONPATH=/usr/bin/python3.6

• 使得更改即时生效

source ~/.bashrc

• 检验

python

Python 2.7.12 (default, Oct  8 2019, 14:14:10) 
[GCC 5.4.0 20160609] on linux2
Type "help", "copyright", "credits" or "license" for more information.

该方法暂时无效！（待深究~）