Return a single section object for the given section. All arguments
        should be strings. Throws a `ValueError` if the section is not found.

        >>> lgst101_bfs = r.course('lgst', '101', '301')

def section(self, dept, course_number, sect_number):
        """Return a single section object for the given section. All arguments
        should be strings. Throws a `ValueError` if the section is not found.

        >>> lgst101_bfs = r.course('lgst', '101', '301')
        """
        section_id = dept + course_number + sect_number
        sections = self.search({'course_id': section_id})
        try:
            return next(sections)
        except StopIteration:
            raise ValueError('Section %s not found' % section_id)