idatetime.py 文件源码

def fromordinal(ordinal):
        """Return the date corresponding to the proleptic Gregorian ordinal.

         January 1 of year 1 has ordinal 1. ValueError is raised unless
         1 <= ordinal <= date.max.toordinal().
         For any date d, date.fromordinal(d.toordinal()) == d.
         """