Rewritten PyImport_Cleanup() and its helper, clear_carefully(). They now implement the following finalization strategy. 1. Whenever this code deletes a module, its directory is cleared carefully, as follows: - set all names to None that begin with exactly one underscore - set all names to None that don't begin with two underscores - clear the directory 2. Modules are deleted in the following order: - modules with a reference count of 1, except __builtin__ or __sys__ - repeat until no more are found with a reference count of 1 - __main__ if it's still there - all remaining modules except __builtin__ or sys - sys _ __builtin__