IPython是python的一个第三方库，本来使用pip(类似于linux的yum)工具是很容易安装的，但是因为版本原因有时会出些问题，比如2.7.x版本的不能安装IPython的最新版本，会报错：
报错如下：
[root@iZ2ze7qh6q0di3qkvef1dzZ ~]# pip install ipython
Looking in indexes: http://mirrors.aliyun.com/pypi/simple/
Collecting ipython
Downloading http://mirrors.aliyun.com/pypi/packages/f3/c3/6c0af5b99d9551fa7b33c674d8f1232033678dcc817098e7a4ac8cd0baf1/ipython-7.1.1.tar.gz (5.1MB)
100% |████████████████████████████████| 5.1MB 97.5MB/s
Complete output from command python setup.py egg_info:
IPython 7.0+ supports Python 3.5 and above.
When using Python 2.7, please install IPython 5.x LTS Long Term Support version.
Python 3.3 and 3.4 were supported up to IPython 6.x.
See IPython `README.rst` file for more information:
https://github.com/ipython/ipython/blob/master/README.rst
Python sys.version_info(major=2, minor=7, micro=5, releaselevel="final", serial=0) detected.
----------------------------------------
Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-MKVcGm/ipython/
这时候就需要一种方法来测试下当前都有什么版本，用如下命令 pip install ipython==0000,0000是胡乱写的，这样就会提示所有的版本，我们找一个中间的，别太新就行，本例是用5.3.0
(helloworld) [root@iZ2ze7qh6q0di3qkvef1dzZ bin]# pip install ipython==0000
Looking in indexes: http://mirrors.aliyun.com/pypi/simple/
Collecting ipython==0000
Could not find a version that satisfies the requirement ipython==0000
(from versions: 0.10, 0.10.1, 0.10.2, 0.11, 0.12, 0.12.1, 0.13, 0.13.1,
0.13.2, 1.0.0, 1.1.0, 1.2.0, 1.2.1, 2.0.0, 2.1.0, 2.2.0, 2.3.0, 2.3.1,
2.4.0, 2.4.1, 3.0.0, 3.1.0, 3.2.0, 3.2.1, 3.2.2, 3.2.3, 4.0.0b1, 4.0.0,
4.0.1, 4.0.2, 4.0.3, 4.1.0rc1, 4.1.0rc2, 4.1.0, 4.1.1, 4.1.2, 4.2.0, 4.2.1,
5.0.0b1, 5.0.0b2, 5.0.0b3, 5.0.0b4, 5.0.0rc1, 5.0.0, 5.1.0, 5.2.0, 5.2.1, 5.2.2,
5.3.0, 5.4.0, 5.4.1, 5.5.0, 5.6.0, 5.7.0, 5.8.0, 6.0.0rc1, 6.0.0, 6.1.0, 6.2.0,
6.2.1, 6.3.0, 6.3.1, 6.4.0, 6.5.0, 7.0.0b1, 7.0.0rc1, 7.0.0, 7.0.1, 7.1.0, 7.1.1)
No matching distribution found for ipython==0000
(helloworld) [root@iZ2ze7qh6q0di3qkvef1dzZ bin]#
(helloworld) [root@iZ2ze7qh6q0di3qkvef1dzZ bin]#
(helloworld) [root@iZ2ze7qh6q0di3qkvef1dzZ bin]# pip install ipython==5.3.0
安装之后查下都安装了那些组件用pip list
(helloworld) [root@iZ2ze7qh6q0di3qkvef1dzZ bin]# pip list
Package Version
---------------------------------- -------
backports.shutil-get-terminal-size 1.0.0
decorator 4.3.0
enum34 1.1.6
ipython 5.3.0
ipython-genutils 0.2.0
pathlib2 2.3.2
pexpect 4.6.0
pickleshare 0.7.5
pip 18.1
prompt-toolkit 1.0.15
ptyprocess 0.6.0
Pygments 2.2.0
redis 2.10.6
scandir 1.9.0
setuptools 40.5.0
simplegeneric 0.8.1
six 1.11.0
traitlets 4.3.2
wcwidth 0.1.7
wheel 0.32.2
现在ipython就可以用了
(helloworld) [root@iZ2ze7qh6q0di3qkvef1dzZ bin]# ipython
Python 2.7.5 (default, Aug 4 2017, 00:39:18)
Type "copyright", "credits" or "license" for more information.
IPython 5.3.0 -- 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.
In [1]: print " hello world"
hello world
