def __repr__(self):
a_per = self.header.analysis_period<EOL>return "<STR_LIT>".format(<EOL>a_per.MONTHNAMES[a_per.st_month], a_per.MONTHNAMES[a_per.end_month],<EOL>self.header.data_type, self.header.unit, len(self._values))<EOL>
Monthly Collection representation.