Can't find SymPy with iPython / iPython Notebook on Mac 10.8.2 (Mountain Lion)

SymPy allows you to see mathematical formulas in their hand written representation. It is just not easy to install on the Mac, at least on the Mountain Lion. It has to do with the package location for SymPy. Python finds the package, but not iPython and of course the notebook. So after installing SymPy, trying to import the module will fail like this:

ImportError: No module named sympy

However, inside the python prompt, I could import SymPy. And checking on the package path, showed where python was looking for, to find SymPy:

>>> import sympy
>>> print sympy.__file__
/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy/__init__.pyc

When I checked the module search path inside iPython, the list was shorter and the /opt/local path was not there :

In [7]: IPython.utils.module_paths.find_module("sympy")

In [8]:

In [10]: sys.path
Out[10]: 
['',
 '/usr/local/bin',
 '/Library/Python/2.7/site-packages/ipython-1.1.0-py2.7.egg',
 '/Library/Python/2.7/site-packages/readline-6.2.4.1-py2.7-macosx-10.7-intel.egg',
 '/Library/Python/2.7/site-packages/pyzmq-14.0.0-py2.7-macosx-10.6-intel.egg',
 '/Library/Python/2.7/site-packages/Jinja2-2.7.1-py2.7.egg',
 '/Library/Python/2.7/site-packages/MarkupSafe-0.18-py2.7-macosx-10.8-intel.egg',
 '/Library/Python/2.7/site-packages/tornado-3.1.1-py2.7.egg',
 '/Library/Python/2.7/site-packages/matplotlib-1.3.1-py2.7-macosx-10.8-intel.egg',
 '/Library/Python/2.7/site-packages/nose-1.3.0-py2.7.egg',
 '/Library/Python/2.7/site-packages/pyparsing-2.0.1-py2.7.egg',
 '/Library/Python/2.7/site-packages/scikit_learn-0.14.1-py2.7-macosx-10.8-intel.egg',
 '/Library/Python/2.7/site-packages/scipy-0.13.0-py2.7-macosx-10.8-intel.egg',
 '/Library/Python/2.7/site-packages/demjson-1.6-py2.7.egg',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python27.zip',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-darwin',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/plat-mac/lib-scriptpackages',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-tk',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-old',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/lib-dynload',
 '/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python/PyObjC',
 '/Library/Python/2.7/site-packages',
 '/Library/Python/2.7/site-packages/ipython-1.1.0-py2.7.egg/IPython/extensions']

In [11]:

So I copied the package over to /Library/Python/2.7/site-packages/sympy so that iPython could find it:

sudo cp -R /opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/sympy /Library/Python/2.7/site-packages/

In [13]: IPython.utils.module_paths.find_module("sympy")
Out[13]: '/Library/Python/2.7/site-packages/sympy'

In [14]: from IPython.display import display

In [15]: from sympy.interactive import printing

In [16]: printing.init_printing()

In [18]: from __future__ import division

In [19]: import sympy as sym

In [20]: from sympy import *

In [22]: x, y, z = symbols("x y z")

In [23]: Rational(3,2)*pi + exp(I*x) / (x**2 + y)
Out[23]: 
        ⅈ⋅x 
3⋅π    ℯ    
─── + ──────
 2     2    
      x  + y