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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def print_saveframe(self, sf, f=sys.stdout, file_format="nmrstar", tw=3):
 """Print saveframe into a file or stdout. We need to keep track of how far over everything is tabbed. The "tab width" variable tw does this for us. :param str sf: Saveframe name. :param io.StringIO f: writable file-like stream. :param str file_format: Format to use: `nmrstar` or `json`. :param int tw: Tab width. :return: None :rtype: :py:obj:`None` """

        if file_format == "nmrstar":
            for sftag in self[sf].keys():
                # handle loops
                if sftag[:5] == "loop_":
                    print(u"\n{}loop_".format(tw * u" "), file=f)
                    self.print_loop(sf, sftag, f, file_format, tw * 2)
                    print(u"\n{}stop_".format(tw * u" "), file=f)

                # handle the NMR-Star "multiline string"
                elif self[sf][sftag].endswith(u"\n"):
                    print(u"{}_{}".format(tw * u" ", sftag), file=f)
                    print(u";\n{};".format(self[sf][sftag]), file=f)

                elif len(self[sf][sftag].split()) > 1:
                    # need to escape value with quotes (i.e. u"'{}'".format()) if value consists of two or more words
                    print(u"{}_{}\t {}".format(tw * u" ", sftag, u"'{}'".format(self[sf][sftag])), file=f)

                else:
                    print(u"{}_{}\t {}".format(tw * u" ", sftag, self[sf][sftag]), file=f)

        elif file_format == "json":
            print(json.dumps(self[sf], sort_keys=False, indent=4), file=f)