151     def __is_path_below(self, file, root):  argument
152         return (file + os.path.sep).startswith(root)
178     def __realpath(self, file, root, loop_cnt, assume_dir):  argument
179         while self.islink(file) and len(file) >= len(root):
181                 raise OSError(errno.ELOOP, file)
184             target = os.path.normpath(os.readlink(file))
187                 tdir = os.path.dirname(file)
192             file = self.__realpath_rel(tdir, target, root, loop_cnt, assume_dir)
195             is_dir = self.isdir(file)
199         return (file, is_dir)
201     def realpath(self, file, root, use_physdir = True, loop_cnt = 100, assume_dir = False):  argument
210         file = os.path.normpath(file)
216         if not self.__is_path_below(file, root):
217             raise OSError(errno.EINVAL, "file '%s' is not below root" % file)
221                 file = self.__realpath_rel(root, file[(len(root) - 1):], root, loop_cnt, assume_dir)
223                 file = self.__realpath(file, root, loop_cnt, assume_dir)[0]
231                               (file, e.strerror))
235         return file