Something

    def create(self, file=None, startpoint=0, mode="w"):
        if file is not None:
            self.file = file
        f = open(self.file, mode)
            
        try:
            for x in self.list[startpoint:]:
                if os.path.isfile(x):
                    f.write("%s\n" % (os.path.abspath(x)))
        finally:
            f.close()