centos7安装python3和ipython

CentOS7下默认系统自带python2.X的版本，这个版本被系统很多程序所依赖，所以不建议删除，如果使用最新的Python3那么我们知道编译安装源码包和系统默认包之间是没有任何影响的，所以可以安装python3和python2共存。

查看centos7自带python版本

[root@localhost ~]# python -V
Python 2.7.5
[root@localhost ~]# pip -V
pip 19.0.3 from /usr/lib/python2.7/site-packages/pip (python 2.7)

如果原来的python2版本下没有pip工具，可以先安装Python2版本下的pip工具：

wget https://bootstrap.pypa.io/get-pip.py
python get-pip.py
pip -V

安装python 2.7版本对应的ipython,此处用pip工具安装：

[root@localhost ~]# pip install ipython

报错，安装对应的包

yum install python-devel libxslt-devel libffi-devel

安装完成，查看ipython

[root@localhost ~]# ipython -V
5.8.0
[root@localhost ~]# ipython
Python 2.7.5 (default, Oct 30 2018, 23:45:53) 
Type "copyright", "credits" or "license" for more information.

IPython 5.8.0 -- An enhanced Interactive Python.
?         -> Introduction and overview of IPython's features.
%quickref -> Quick reference.
help      -> Python's own help system.
object?   -> Details about 'object', use 'object??' for extra details.

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安装python3

[root@localhost src]# wget https://www.python.org/ftp/python/3.6.4/Python-3.6.4.tgz
[root@localhost src]# tar xf Python-3.6.4.tgz 
[root@localhost src]# cd Python-3.6.4
[root@localhost Python-3.6.4]# ./configure --prefix=/usr/local/python3
[root@localhost Python-3.6.4]# make && make install

创建软连接

ln -sv /usr/local/python3/bin/python3 /usr/bin/python3
ln -sv /usr/local/python3/bin/pip3 /usr/bin/pip3

查看

[root@localhost ~]# pip3 -V
pip 9.0.1 from /usr/local/python3/lib/python3.6/site-packages (python 3.6)
[root@localhost ~]# python3 -V
Python 3.6.4

python3安装ipython

[root@localhost ~]# pip3 install ipython

创建软链接

ln -sv /usr/local/python3/bin/ipython3 /usr/bin/ipython3

查看

[root@localhost ~]# ipython -V
5.8.0
[root@localhost ~]# ipython3 -V
7.4.0

因为yum使用python2，因此替换为python3后可能无法正常工作，继续使用这个python2.7.5

因此修改yum配置文件(vi /usr/bin/yum)。

把文件头部的#!/usr/bin/python改成#!/usr/bin/python2.7保存退出即可。