def get_period_strs(self, now=None):
if now is None:<EOL><INDENT>now = self.dt.utcnow()<EOL><DEDENT>year_str = "<STR_LIT>" % now.year<EOL>month_str = "<STR_LIT>" % (now.year, now.month)<EOL>day_str = "<STR_LIT>" % (now.year, now.month, now.day)<EOL>hour_str = "<STR_LIT>" % (<EOL>now.year, now.month, now.day, now.hour)<EOL>isocal = now.isocalendar()<EOL>week_str = "<STR_LIT>" % (isocal[<NUM_LIT:0>], isocal[<NUM_LIT:1>])<EOL>return {<EOL>"<STR_LIT>": year_str,<EOL>"<STR_LIT>": month_str,<EOL>"<STR_LIT>": day_str,<EOL>"<STR_LIT>": hour_str,<EOL>"<STR_LIT>": week_str,<EOL>}<EOL>
meterer.get_period_strings()

Return the period strings for the specified time (defaulting to the
current time if not specified).