UbuntuでIPythonがcommand not found

環境

• Ubuntu 15.10
• Python 2.7
• Pip 1.5.6
• IPython 5.1.0

問題

$ pip install ipython

でIPythonをインストールしたが、

$ ipython
zsh: command not found: ipython

解決策

python起動時に-mでオプションをつけると動いた。

$ python -m IPython
Python 2.7.10 (default, Oct 14 2015, 16:09:02)
Type "copyright", "credits" or "license" for more information.

IPython 5.1.0 -- 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]:

なので.zshrcにaliasを書いて解決

.zshrc

alias ipython='python -m IPython'