Ubuntu安装Python3与Python2共存

1.在家目录新建目录python3

cd ~
mkdir python3
cd python3/

2.安装依赖包,不然编译会报:Failed to build these modules: _ctypes

sudo apt-get install libffi-dev

3.下载python版本

wget https://www.python.org/ftp/python/3.9.0/Python-3.9.0.tar.xz
tar -zxvf Python-3.9.0.tar.xz
cd Python-3.9.0/

这里也可以从官网下载自己需要的版本:https://www.python.org/downloads/

可以选择第二个xz压缩格式的

https://www.python.org/downloads/release/python-390/

 

 4.编译安装

# 注意以下命令不使用sudo
./configure --prefix=/home/brian/python3
make && make install

5.创建软连接

sudo ln -s /home/test/python3/bin/python3 /usr/bin/python39
sudo ln -s /home/test/python3/bin/pip3 /usr/bin/pip3

6.测试

  ~ python39
Python 3.9.0 (default, Dec 17 2020, 20:45:58) 
[GCC 9.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> ^Z
[2]  + 734415 suspended  python39
➜  ~ ll /usr/bin/python39
lrwxrwxrwx 1 root root 31 12月 18 22:01 /usr/bin/python39 -> /home/brian/python3/bin/python3
➜  ~ ls ~/python3/lib/python3.9/site-packages 
dateutil         numpy-1.19.4.dist-info  pandas-1.1.5.dist-info  pkg_resources                    pytz                   setuptools                   six.py
easy_install.py  numpy.libs              pip                     __pycache__                      pytz-2020.4.dist-info  setuptools-49.2.1.dist-info
numpy            pandas                  pip-20.2.3.dist-info    python_dateutil-2.8.1.dist-info  README.txt             six-1.15.0.dist-info
➜  ~ 

pip3安装的包的位置:
/home/test/python3/lib/python3.9/site-packages

题外:上面创建的软连接没有用/usr/bin/python3而是用的python39是防止和系统原来已有python3相冲突

否则会导致像lsb_release -a命令不能用,因为它用的是旧版本python3,可能你新安装的版本python3.9.0上不能用

sudo vi  /usr/bin/lsb_release 命令可以看到它使用的python路径:#!/usr/bin/python3 -Es