human
I wrote the below code

    if (not id):
        return current.messages['NONE']
    s3db = current.s3db
    table = s3db.project_theme_percentage
    ttable = s3db.project_theme
    def represent_row(row):
        return ('%s    (%s%s)' % (row.project_theme.name, row.project_theme_percentage.percentage, '%'))
    if isinstance(id, (list, tuple)):
        query = (table.id.belongs(id) & (ttable.id == table.theme_id))
        rows = current.db(query).select(table.percentage, ttable.name)
        repr = ',    '.join((represent_row(row) for row in rows))
        return repr
    else:
        query = ((table.id == id) & (ttable.id == table.theme_id))
        row = current.db(query).select(table.percentage, ttable.name).first()
        try:
            return represent_row(row)
        except:
            return current.messages.UNKNOWN_OPT

What's a good function header?

=====
Here's a good function header?
assistant
#Here's a good function header.

def multi_theme_percentage_represent(id):