Ubuntu将默认python版本改为python3

具体流程

• 查看当前系统默认python版本
  python --version

• 查看/安装python

  • 安装python3
    apt install python3
  • 查看python3
    whereis python3

• 删除原有python2的软连接
  sudo rm /usr/bin/python

• 新建python3的软连接
  sudo ln -s /usr/bin/python3.5 /usr/bin/python

• 现在重新查看默认的python版本
  python --version

bash操作记录

cds@cds-virtual-machine:~$ python --version
Python 2.7.12
cds@cds-virtual-machine:~$ whereis python3.5
python3: /usr/bin/python3.5-config /usr/bin/python3.5m /usr/bin/python3 /usr/bin/python3.5m-config /usr/bin/python3.5 /usr/lib/python3 /usr/lib/python3.5 /etc/python3 /etc/python3.5 /usr/local/lib/python3.5 /usr/include/python3.5m /usr/include/python3.5 /usr/share/python3 /usr/share/man/man1/python3.1.gz
cds@cds-virtual-machine:~$ rm /usr/bin/python
rm: cannot remove '/usr/bin/python': Permission denied
cds@cds-virtual-machine:~$ sudo rm /usr/bin/python

cds@cds-virtual-machine:~$ ln -s /usr/bin/python
python2            python3            python3.5m-config  python-config
python2.7          python3.5          python3-config     
python2.7-config   python3.5-config   python3m           
python2-config     python3.5m         python3m-config    
cds@cds-virtual-machine:~$ sudo ln -s /usr/bin/python3.5 /usr/bin/python
cds@cds-virtual-machine:~$ python --version
Python 3.5.2