Python allows adding user defined paths to the module search path by setting PYTHONPATH environment variable. It also allows to alter the location of standard python libraries using PYTHONHOME. But there is no way to "only" have user defined paths to python's search paths (sys.path)
This is useful for embedding applications where it might be desired that only user-defined paths are searched for modules. But python creates some default paths and adds it to sys.path. Most of the times it does not matter since PYTHONPATH paths are appended at the beginning but this may sometimes result in unwanted behavior. I think it would be a good idea to be able to say that you don't need any default search paths. In this case if Python gives error if PYTHONPATH is not set- I think that would be reasonable. Since otherwise sys.path would be empty!! Please provide feedback for this feature request. -- http://mail.python.org/mailman/listinfo/python-list
