calendar.py 文件源码

def itermonthdates(self, year, month):
        """
        Return an iterator for one month. The iterator will yield datetime.date
        values and will always iterate through complete weeks, so it will yield
        dates outside the specified month.
        """
        date = datetime.date(year, month, 1)
        # Go back to the beginning of the week
        days = (date.weekday() - self.firstweekday) % 7
        date -= datetime.timedelta(days=days)
        oneday = datetime.timedelta(days=1)
        while True:
            yield date
            try:
                date += oneday
            except OverflowError:
                # Adding one day could fail after datetime.MAXYEAR
                break
            if date.month != month and date.weekday() == self.firstweekday:
                break