The same module in different libraries

One thing that I found nice in Python compared to IDL, is the amount of very complete and complex libraries that have been developed and are accessible so easily... And one thing I quickly found horrible is the amount os libraries!...

Just an example: I installed the Mayavi package (it means that I have to also install the vtk package, but hopefully all is already in the macport repositories...). and began to try playing with it.
And I found that sometimes some tutorial are talking about functions I don't have... For example, the points3d() function is not available. Well, I realized that it is in the mlab module and that actually I have... 6 mlab.py files in the directory where Python is looking for!!!
Just asking from a command line shell:

find /opt/local/Library/Frameworks/Python.framework/Versions/2.6/lib/python2.6/site-packages mlab.py

give me:
./enthought/mayavi/mlab.py
./enthought/mayavi/tools/mlab.py
./enthought/tvtk/tools/mlab.py
./matplotlib/mlab.py
./numpy/numarray/mlab.py
./numpy/oldnumeric/mlab.py
So I have to be very careful with which module I download and in which order, to be sure that I have the mlab module I want.
Or the best is to call it explicitely and to check what is in each:

from enthought.mayavi import mlab as mlab_mayavi 

from enthought.tvtk.tools import mlab as mlab_tvtk
To obtain the list of the functions available from one module, just type for example mlab_mayavi.  and use the TAB to obtain the possible completions.
We can very quickly realize that the needed points3d() function is absent in all mlab modules except the mayavi one.
So be very careful with the modules, mlab is not always mlab...