Coexistence of Python2 and Python3 under Ubuntu

  • 2021-01-19 22:18:54
  • OfStack

Linux system 1 usually comes with Python, and sometimes it downloads Python itself, so it is possible for Python2 and Python3 to exist simultaneously. So when we type python in Terminal, which Python is called up? This article is to solve this problem.

Version to view

Type at the terminal

python --version1

See python version information

I found that my version of python is 2.7.15rc1. However, I have installed python3, so how do I use python3? python3 can be opened directly with python3, and python2 can also be opened with python2.

But python is now the default python2, because it has a higher priority. How to change python to python3?

Modify python

Method 1: Modify the alias

python can be set to python3 by changing the alias alias

alias python='/usr/bin/python3'1

And put it in.bashrc

Approach 2: Modify the configuration


sudo update-alternatives --install /usr/bin/python python /usr/bin/python2.7 2 
#  add Python2 Optional, priority is 2
sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.6 1 
#  add Python3 Optional, priority is 1
sudo update-alternatives --config python12345

Select python2. To set it to python3, just select 2 and enter ~

supplement

Load python2 and python3 with pip, be careful not to use each other's pip


sudo apt-get install python2-pip
sudo apt-get install python3-pip
--------------------- 

conclusion


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