def _make_tree_defs(mod_files_list):
tree_defs = {}<EOL>for mod, files in mod_files_list:<EOL><INDENT>node = (tree_defs, ())<EOL>for prefix in mod.split("<STR_LIT:.>"):<EOL><INDENT>node = node[<NUM_LIT:0>].setdefault(prefix, [{}, []])<EOL><DEDENT>node[<NUM_LIT:1>] += files<EOL><DEDENT>return tree_defs<EOL>
get a list of 2-uple (module, list_of_files_which_import_this_module),
    it will return a dictionary to represent this as a tree