Here I assume that you've installed Babel in directories rooted at $PREFIX. You need to have $PREFIX/python in your PYTHONPATH environment variable in addition to the directory where you are doing your work.
On many systems, you will need $PREFIX/lib in your LD_LIBRARY_PATH (or whatever system setting controls which directories are searched for shared libraries/dynamic link libraries).
You will likely need to use SIDL_DLL_PATH (a semicolon separated path) to provide the path to the directory that holds the shared library/dynamic link library containing the implementation of the SIDL objects.