install ipython in Cloudera VM using pip

I am practicing pyspark in Cloudera VM, and pyspack need be launched by ipython. In all the old Cloudera VM guide, it use easy_install to install ipython, but it does not work in Virtualbox 5.2.0 r118431 and later. And will get the error :

$sudo easy_install ipython==1.2.1
...
error: Could not find suitable distribution for Requirement.parse('ipython==1.2.1')

The solution for this is to use pip to install ipython. But by default, pip is not installed in cloudera VM, and pip can not be installed by eacy_install as well. And after some search, I  noticed cloudera has yum installed, and yum can install pip:

$sudo yum install python-pip
...
$which pip
/usr/bin/pip

Now ipython can be installed b pip:

$sudo pip install ipython=1.2.1
...

Succesfully installled ipython-1.2.1

After that, launch spack by ipython:

$PYSPARK_DRIVER_PYTHON=ipython pyspark
...

Welcome to
      ____                       __
     / __ /__  ___ _____/  /__
    _\ \/ _   \/  _  ` /  __/    '_ /
   /__ / .__ /\_ ,  /_/  /_ /\_\   version 1.6.0
       /_/

Using Python version 2.6.6 (r266:84292, Jul 23 2015 15:22:56)
SparkContext available as sc, HiveContext available as sqlContext.

In [1]: sc.version
Out[1]: u'1.6.0'